Transfer Case Vibration Issue

[loveofjazz]

My rig has developed a shimmy/vibration in second gear. It starts as soon as I shift into 2nd and accelerate. It goes away once the RPM's go up a bit (no tach on board, so I have to guess at 1500-2000 RPM's). I don't have any vibration issues in 1st, 3rd, 4th or 5th gear...just 2nd gear.

Thought it might be a u-joint on the intermediate shaft. Further inspection showed the rear u-joint on the intermediate shaft had a little movement, though not much. Had a friend look it over. He said the same thing. Slight movement detected at the rear u-joint.

Went wheeling -before- I swapped the u-joints and part of the shimmy went by the wayside. Swapped intermediate shaft u-joints before my most recent wheeling trip and the problem still exists. Seems like the first wheeling trip did more to alleviate the vibration than the actual repair.

While changing the oil on Saturday, I crawled around underneath and noticed the long arm on my transfer case was twisted at the rear mount. I can't tell if I parked it on a rock to do that, but I don't believe so. I'm going to look through my spare parts bin and see if I have another transfer case arm in better condition. I'd like to swap it out to see if it helps at all.

I know asking 10 guys will get 12 different answers, but I'm a bit stumped. Am I missing anything?

[fart box]

mine does the same thing and i haven't been able to pin it down either,

i'll post up what i find thats causing mine if i find it before you find yours, its probably the same thing, my u-joints are tight though and neither of my t-case arms appear bent or distorted, and mounts are good if not a little squishy

[loveofjazz]

I poked, prodded & pried at the t-case bushings. No issues there. No separation. All bolts tight. I'll probably throw some pics up here in a little bit. That twisted long arm had me a bit confused, though I don't believe it's the issue.

Mine used to shimmy so bad that heavy acceleration in 2nd created enough vibration once to knock the t-case shifter out of gear. Has yours done that too, fart box?

[beekiller]

Jim, a bent arm, however slight, can produce some pretty nasty vibes.  Replace it, then if ya still got vibes replace the ujoints.  They can give you vibes too, and you most def want good ujoints in there since failure will ruin the shaft.   


Or it could be your rig is telling you she wants to wheel more.   

[loveofjazz]

Jim, a bent arm, however slight, can produce some pretty nasty vibes.  Replace it, then if ya still got vibes replace the ujoints.  They can give you vibes too, and you most def want good ujoints in there since failure will ruin the shaft.   

Intermediate u-joints have been replaced. Did that the night before our last trip to Uwharrie. I'll post those pics of my set up in a little bit.

I'll be rummaging through what I have. Hopefully I've got a replacement part.

Or it could be your rig is telling you she wants to wheel more.   

She tells me that all the time. Look a good wife, she never hesitates to let me know that she should be on the trails climbing rocks, not on asphalt running errands. 

[fart box]

mine has only knocked it out of 4lo when i've been into the skinny pedal...HARD

[Surly]

I gave away two or three sets of stock t-case arms when I cleaned out my garage. I'm not sure if you or Ben got them, but one of you has spares laying around in a box.     Also, check the driver's side motor mount and the rear transmission mount. They're both prone to tearing, and will cause intermittent vibration issues when they do.  HTH

[Freebird01]

jim i would be very suspect of the t-case arms....both long and short. pull the case and compare those arms to some known good ones. i chased a similar vibe forever due to bent arms.

the short arm could be bent and you just cant visually see it right away from underneath. i actually bent my short arm about 1/2" and it didnt look much different.

also look at your transmission mount. it will cause vibes and is often overlooked.

but i would say tcase arms if you didnt have it before....make sure you check out the frame mounts as well.

what gears are you running in the diffs and tcase?

[loveofjazz]

mine has only knocked it out of 4lo when i've been into the skinny pedal...HARD

Yeah...the time it knocked the t-case out of gear, I was accelerating hard and turning to the left. I was on pavement, though.

I gave away two or three sets of stock t-case arms when I cleaned out my garage. I'm not sure if you or Ben got them, but one of you has spares laying around in a box. 

That's exactly where I was checking next. I re-organized my shelves recently. I looked on the shelves just to be sure when I got back in a few minutes ago but had nothing there.

Also, check the driver's side motor mount and the rear transmission mount. They're both prone to tearing, and will cause intermittent vibration issues when they do.  HTH

This does help, Ken. More than you realize. I hadn't even thought of either of those locations.

jim i would be very suspect of the t-case arms....both long and short. pull the case and compare those arms to some known good ones. i chased a similar vibe forever due to bent arms.

the short arm could be bent and you just cant visually see it right away from underneath. i actually bent my short arm about 1/2" and it didnt look much different.

also look at your transmission mount. it will cause vibes and is often overlooked.

but i would say tcase arms if you didnt have it before....make sure you check out the frame mounts as well.

what gears are you running in the diffs and tcase?

I'm running stock diff gears currently and 4.16's in the transfer case, Jason.
What "frame mounts" are you talking about? Do you mean where each transfer case arm mounts to the frame?  (I get confused easy, man...you know this. )

[Freebird01]

What "frame mounts" are you talking about? Do you mean where each transfer case arm mounts to the frame?  (I get confused easy, man...you know this. )

that's exactly where in talking about. the tower for the short arm can bend pretty easy. so can the rear most mount on the long arm. it doesn't sound like you got enough gearing going there to bend the frame mounts but you could very well have bent the long arm with just beating on it. you don't really have to park it on a rock to bend those.

[loveofjazz]

That long arm is bent. I'll post a pic a little later. It's kind of twisted.

[Freebird01]

That long arm is bent. I'll post a pic a little later. It's kind of twisted.

thats probably your culprit then

[fart box]

ill have to recheck my arms tonite, good thing i have a set of strengthened arms waiting to go in, if they are bent

[loveofjazz]

ill have to recheck my arms tonite, good thing i have a set of strengthened arms waiting to go in, if they are bent

Ain't it funny how we don't replace stuff until we absolutely need to?
When customers leave me alone for the day, I'll post a pic or two.

[Lizooki]

I think it's a loose screw behind the steering wheel. 

 

*Check the bolts on the tcase arms themselves.( arms to case)
*Tranny ( hee hee, I said tranny ) mount.
*Drivers side engine mount.
Uneven tire pressure.
Fat dude driving ... skinny chick ridin'.
Long floppy Fang-O-Death shackles.
Bad shocks.

Confused yet?

U-joints. PULL THE SHAFTS TO CHECK! I have tight ones explode the next day.

The ones with trhe asterisks are the 1st choices.

[catfishblues]

Come by the house with a 12mm wrench and steal the one of the t-case in my driveway. Replace it, maybe, someday. Hopefully it'll fix your problem.

[loveofjazz]

UPDATE:
Since the last post in this thread...

* I did the CJ/RUF on my rig. The shudder remained.

* I -finally- swapped the bent transfer case arm for a straight one. The shudder remained, but now seems more harsh. For the record, all 3 transfer case mounts were intact and still look brand new.

* Tonight, I'll be checking the following...

- Rear drive shaft spacers...I have a 1 1/2 inch on the top and no spacer on the bottom of the rear drive shaft. I'll be splitting the difference by placing a 3/4 inch drive shaft spacer at each end of the rear drive shaft. This may or may not help.

- Motor mounts

- Transmission mount

- Rear pinion angle...but I have to get an angle finder first.

Any thoughts?

[Surly]

Any thoughts?

When exactly does it shudder? Only under acceleration? Only in one gear or all gears? Have you tried putting the t-case in neutral, starting the engine and running it through the gears?

[loveofjazz]

When exactly does it shudder? Only under acceleration? Only in one gear or all gears? Have you tried putting the t-case in neutral, starting the engine and running it through the gears?

I like the transfer case idea. I'll add that to the list.
I made sure to drive it this afternoon for a few minutes. It hasn't been starting easy, so I waited until it was warm outside. As I accelerated from a dead stop, I could see the transfer case shifter move slightly to the left and right...almost like it was wallowing slowly...the faster I went in first, the faster the movement...shift into second gear, and there's the shudder.

[Surly]

Sounds like either a pinion angle problem or a rear driveshaft problem.

[Freebird01]

didnt i mention checking the rear pinnion angle on the phone? 

[durnzuki]

I am betting on axle wrap.  I have had many problems with this over the years with mine dong exactly the same thing.

[Nemesis]

SHAKE ALL 3 OF YOUR PROPELLER SHAFTS THE UNIVERSAL JOINTS MAY NEED CHANGING

[loveofjazz]

Cool! I got responses!   

When exactly does it shudder? Only under acceleration? Only in one gear or all gears? Have you tried putting the t-case in neutral, starting the engine and running it through the gears?

It shudders when accelerating in second gear just as you release the clutch in second and press down on the accelerator. I -did- try all 5 gears with the transfer case in neutral...I had no vibration whatsoever.
Also, I pulled the rear drive shaft and went for a short drive down my street. Most of the vibration went away. In fact, any vibes I got with no rear drive shaft were completely different. It was easy to determine the source. Not the problem.

Per our earlier phone conversation...the motor mounts both seemed fine, but the transmission mount appears to have separated almost completely. It turns out the local Advance Auto Parts had the part listed, but we won't know for sure until it arrives tomorrow morning whether it's the correct part or not.

I'm starting to believe this to be a rear pinion issue, but resolving other smaller issues along the way is okay with me. I feel more confident about my rig's capabilities when I work out the smaller problems.

I didn't get to replace the 1 1/2 inch spacer on the rear drive shaft with two 3/4 inch spacers as I hoped. The bolts I got from the store were half an inch too short.    Guess I'll go by the store & swap for longer bolts tomorrow afternoon.

Sounds like either a pinion angle problem or a rear driveshaft problem. 

Freebird01 said as much last week, but there were other variables needing to be defined before I could agree entirely.

didnt i mention checking the rear pinnion angle on the phone?   

Yes sir, and I appreciate the insight. Believe me...your good advice won't go wasted. As I mentioned four posts back I've got to get an angle finder (inclinometer). It won't be tonight, though. I might get a chance tomorrow. I'm heading out of town for a couple of days, so that may wait until I return.

I am betting on axle wrap.  I have had many problems with this over the years with mine dong exactly the same thing.

I can't dispute it. This is my first SPOA rig, and I've been suffering this vibration issue for six months. You've been doing this a lot longer than I have. Still, I'm having the same exact vibration issue but I've moved the rears-up-front. That leads me to believe this is more of a drive line issue, not a suspension issue. Of course, I could very well end up exhausting all my potential drive line issues and be back here asking for potential suspension issues.   Let's see how this plays out. I've been wrong before. Ask my first wife. 

SHAKE ALL 3 OF YOUR PROPELLER SHAFTS THE UNIVERSAL JOINTS MAY NEED CHANGING

I recently replaced my intermediate shaft universal joints. I checked both front and rear propeller shaft universal joints Friday night before I went to the Zu -and- tonight. All of the front shaft and rear shaft u-joints are in fine shape.

Thanks to everyone for the useful input. Y'all keep 'em comin'. I'd hate to think I might have missed something simple.

[Bama Zuk]

4  Jack stands in a wide open area.(to be safe)
Lift all 4 tires off the ground and have someone go threw the gears as you stand to the side and do a visual inspection.
Pay attention during the normal vibe area.

[loveofjazz]

4  Jack stands in a wide open area.(to be safe)
Lift all 4 tires off the ground and have someone go threw the gears as you stand to the side and do a visual inspection.
Pay attention during the normal vibe area.

Thanks, Bama.
Think I'll give that a shot.
Jack stands under the axles or the frame? I don't know that I could safely lift the frame high enough for adequate tire clearance to do what you're suggesting. I'd have to jack the axles up with jack stands.

[Bama Zuk]

Under the axles, just enough to get the tires off the ground.

[loveofjazz]

Under the axles, just enough to get the tires off the ground.

Cool. I'll give that a try Friday when I get back in town.

[loveofjazz]

UPDATE:
The transmission mount from Advance Auto Parts came in this morning. When I got back in this afternoon, I picked up the 2 inch bolts for the rear drive shaft spacers. I removed the 1 and a half inch spacer at the top of the rear drive shaft, replaced it with a 3/4 inch spacer on each end of the rear drive shaft. I replaced the worn out transmission mount. Took the Zuk for a drive, and part of the shimmy was missing. In fact, I -HAD- been able to duplicate the shudder/vibration if I revved high enough in 1st gear...but that seemed to have went away.

I still have the shudder in 2nd gear. It isn't quite as present as it was, but when the shudder occurs you can still feel how rigid it is.

Funny how numerous problems can combine to become one big symptom.   

When I get back, I'll locate an angle finder (inclinometer) to check the different angles on the transfer case rear output flange and the rear pinion flange. I'm fairly certain after looking at them yesterday that there is a difference there.

I'll update this in a couple of days.

Thanks again, y'all.

I'll also put it up on jack stands (per Bama's suggestion) and look for anything that might not be correct.

[madbob]

Durnzuki may be on to something with axle wrap.  it can cause the u-joints to work at an angle past what they are designed to do, and cause a vibration.  incorrect pinion angle can add to this problem.  Good luck.

[loveofjazz]

Durnzuki may be on to something with axle wrap.  it can cause the u-joints to work at an angle past what they are designed to do, and cause a vibration.  incorrect pinion angle can add to this problem.  Good luck.

Yeah, I'm not ruling ANYthing out, and I know Jeff, Richard, Jason and Ken have all offered good info. I'm doing my best to follow all valid suggestions offered up (as time allows). I've posted this here in hopes that fellow Zukers that have dealt with this will weigh in on the subject. I'm starting to believe that this could be a combination of things.

If it turned out to be an axle wrap issue, I only know of two ways to resolve it currently...
  1. Install a traction bar
  2. Modify my rear springs (CJ fronts) by adding a leaf to each spring pack. Maybe I could add a leaf out of some of the older Samurai front packs in the garage to stiffen the rear springs. Would that work?

[Surly]

Would that work?

Remember, a stiffer spring will give you a harsher ride.

A better solution would be to rotate the pinion flange down 2 degrees from parallel with the t-case flange. Then the angles will be parallel under torque.

[tonkatoy]

I had the same problem. I will tell you what stopped mine was the rubber adapters between the transfer case and the bracket. They where still together but very spongy or loose you might say. I put some new ones on and the vibe stopped. Good Luck I hope this helps you!!

[zuki scott]

you have checked that the u joints are aligned on the rear shaft haven't you. meaning phased correctly

[tonkatoy]

Thats the way I found out that is was the rubber things where bad. I checked the phase and replaced all u-joints. Nothing changed until I replace the rubber things. It fixed mine. It took 6 months to find it. All good now. Shawn

[madbob]

you have checked that the u joints are aligned on the rear shaft haven't you. meaning phased correctly

good call

[loveofjazz]

I am betting on axle wrap.  I have had many problems with this over the years with mine dong exactly the same thing.

Alright, Jeff. You may be right, buddy. If it shakes out that way, I concede defeat.     

UPDATE:

I got as far as pulling the front drive shaft earlier this afternoon (to see if the vibration/shudder remained with the front drive shaft removed). The vibration was still there during the test drive with no front drive shaft.
I had a friend over that was going to help me with the jack stand test (jack stands under axles, run through all gears). Unfortunately, he left his phone in the driveway next to my rear wheel and I rolled over his phone after I pulled the front drive shaft.      Believe it or not, my Zuk only killed his screen. He could still make calls and receive them.

While next to the Zuk, he noticed there was some movement when I put it in gear. He got behind the wheel so I could see, and this could very well be the problem. The pinion moves quite a bit when you release the clutch.     Looks like axle wrap just moved up a few notches on the "Primary Cause" list. Actually, it seems that the axle wrap allows the pinion to move a bit too far upward, so I guess axle wrap AND pinion angle are looking to be strong contenders here.

Anyway, I got this friend that turned loose of a bunch of stock Zuk axle stuff when he moved on to bigger, better axles. (Thanks, my friend)
I went searching for the stuff in the garage. I had stashed it for such an occasion, if the occasion ever occurred. In the box o'booty I'd received were had two sets of shims (3 degree shims and 5 degree shims). I also borrowed an angle finder from a friend earlier this evening. I'll be checking the rear pinion angle and the rear output flange angle for the difference when things calm down in a little bit. (Our kids have friends over.)

In addition, I believe I'll be adding a lower Samurai front spring leaf to each front CJ (in the rear) to stiffen these springs a bit. I know the ride will be stiffer, but I'm hoping this will be adequate.

[loveofjazz]

UPDATE:
Found a lull in the kid storm. Rolled around underneath the Zuk with a flashlight and the borrowed angle finder. Seems like the transfer case angle is at 2 degrees, and the rear pinion angle sits at 5 or 6 degrees.

I'm thinking that I should try the 5 degree shims on this. Any thoughts?

[Freebird01]

use the 3 deg shims jim... if you got wrap like you say you will want that pinnion a hair low

[loveofjazz]

use the 3 deg shims jim... if you got wrap like you say you will want that pinnion a hair low

The rear pinion angle is 5 or 6 degrees and it's higher than the 2 degrees on the transfer case rear output flange.

[Freebird01]

ok i was misunderstanding him. after a phone call i recommend going with the 5 deg shim.

[Bama Zuk]

YEP The jack stand trick is a good one to see what is going on while keeping the rig still.

[loveofjazz]

YEP The jack stand trick is a good one to see what is going on while keeping the rig still.

Never got to the jack stand test. We caught the axle wrap issue with all 4 tires flat on the ground.
I'll give that a shot soon enough.

[viking]

My T-case was wobbling in first and second gear, I pulled the driveshafts and the U-joints were good.  Could be spring wrap because I changed out the springs for newer ones with Teflon hockey pucks  isolating the ends of each spring leaf under the main leafs.  Could also be too soft of T-case mounts so I went to some local tire dealers and got heavy duty shock end rubber and poly mounts, drilled out the frame mount holes to 5/8" to clear the end sleeve  and bought three 3/8" X 2 1/2" #8 hard bolts and double nutted them so they wouldn't come loose.  I had to use two poly mounts to get the spacing of the OEM mounts.  There is a little more noise, probably because the poly mounts are a lot stiffer than rubber and I may change the top one with a rubber mount just to see if it makes it quieter.

[viking]

P.S. T-case doesn't wobble anymore.

[jr4x]

I had a real bad vibration under acceloration with the rear in rear /RUF combo because it was axle wrapping so bad. Normal driving it was fine but the spring wrap was unbearable. I couldnt fit an anti wrap bar without cutting the nice 16V swap exhaust out and starting over. So I put the 4 inch lift CJ fronts SUA in the rear to keep the same lift but not have to use an anti wrap. Fixed all my issues except for the bent t-case arms. I have ruined 4 sets of t-case arms and really need a bucket or gorrilla mount to stop that. I now have absolutely no spring wrap and the vibe is gone.

[Freebird01]

I had a real bad vibration under acceloration with the rear in rear /RUF combo because it was axle wrapping so bad. Normal driving it was fine but the spring wrap was unbearable. I couldnt fit an anti wrap bar without cutting the nice 16V swap exhaust out and starting over. So I put the 4 inch lift CJ fronts SUA in the rear to keep the same lift but not have to use an anti wrap. Fixed all my issues except for the bent t-case arms. I have ruined 4 sets of t-case arms and really need a bucket or gorrilla mount to stop that. I now have absolutely no spring wrap and the vibe is gone.

if you bent that many sets of arms id be looking closely at your frame mounts. chances are they are tweaked too...

[jr4x]

I agree, My thoughts are cutting it all out and starting over with all home made mounts. My only concern is getting it back in the exact same place its supposed to be. When my arms have been bent as little as 1/2 inch it makes it vibrate bad. So I worry that once I cut the crap out how to hold it where it needs to stay.

I hate the stupid L shaped short arm. That is the stupidest thing about a samy. The engineers could have put that mount any where they wanted and they chose to make it have a step?

[loveofjazz]

UPDATE:
Installed the 5 degree shims between the rear perches and the rear springs just a little while ago. The rear pinion angle now matches the transfer case rear output flange angle. It reduced the shimmy somewhat, maybe 15 - 20 % at best.

I have another set of four leaf-pack front CJ's and a new pack of CJ bushings. I'll add one of the front leaves from some Samurai front springs to make a stiffer 5 pack, install the new bushings, and maybe this could help reduce the shimmy some more.

[zuki scott]

i still have not heard if the rear drive shaft is phased correctly. Do you know what i mean by being phased correctly? A pic of the rear drive shaft in the samurai would help alot

[loveofjazz]

i still have not heard if the rear drive shaft is phased correctly. Do you know what i mean by being phased correctly? A pic of the rear drive shaft in the samurai would help alot

Sorry. I remember you posting that question. The drive shaft is in phase, I believe. I can take some pics later tonight to confirm.

[Biggerhammer]

Out of phase...


In phase...


Check for the alignment dots on the slip yokes also...



The splines could also be worn enough to make it wobble. HTH

[viking]

Even though it has been nice having stiffer T-case mounts I've had another vibration problem, come to find out that I had to install 3/8" spacers to raise the T-case even more because the rear driveshaft slip joint was bottomed out and i couldn't even pop the u-joint flange from the rear end out.  So now that vibration is gone, when it stops raining I go pull the shaft and check the line up dots.  Thanks Biggerhammer!

[Surly]

The rear pinion angle now matches the transfer case rear output flange angle.

That's good, but the ideal angle is one or two degrees down from parallel. LMK if you wanna try a different rear driveshaft and/or use my garage & tools while I'm home from work.

[loveofjazz]

Out of phase...


In phase...


Check for the alignment dots on the slip yokes also...



The splines could also be worn enough to make it wobble. HTH

The shaft is in-phase. I have a cold & feel like crap, otherwise I'd have taken a pic or two of the drive shaft.
There is very slight movement when I hold the slip yoke and shaft and try moving them side to side. All of the splines are still there with no signs of wear.

That's good, but the ideal angle is one or two degrees down from parallel. LMK if you wanna try a different rear driveshaft and/or use my garage & tools while I'm home from work.

Let me get over this cold and I'll come up and take advantage of your offer. I was up all night coughing. I'm missing out on Uwharrie today because of this danged cold.

[viking]

A few weeks back I swapped the driveshaft from my soft top into the tintop to see if that was a vibration problem.  Today I pulled the original TT driveshaft out of the soft top and found that the dots were 180 degrees out, lined them up and reinstalled that shaft in the TT and no more vibs.  One can have the shaft phased right but not have the dots lined up, I didn't even take that into consideration because the first time I heard about this was from Biggerhammer but it certainly makes sense that the factory balanced it that way.

[loveofjazz]

UPDATE: Placed the rear axle on jack stands, chocked the front wheels, started the Zuk and let it idle in first gear. I couldn't see any signs of being warped or bent. I turned off the Zuk and crawled back underneath. The rear end seemed to have a bit of play in it, like it was almost sloppy. Any thoughts?

[viking]

UPDATE: Placed the rear axle on jack stands, chocked the front wheels, started the Zuk and let it idle in first gear. I couldn't see any signs of being warped or bent. I turned off the Zuk and crawled back underneath. The rear end seemed to have a bit of play in it, like it was almost sloppy. Any thoughts?

A lot of things combine to make things sloppy, pinion to ring gear backlash, spider gear play, axle spine to spider gear play.  Because of the noise and play in the rear end just after I bought my soft top I pulled the third member out to check on the backlash and see how the bearings were.  There really wasn't excessive play between the ring gear and pinion and the bearings were in great shape.  The gear lube was horrible so I cleaned the inside of the housing put it all back together and don't worry about it anymore.

[loveofjazz]

A lot of things combine to make things sloppy, pinion to ring gear backlash, spider gear play, axle spine to spider gear play.  Because of the noise and play in the rear end just after I bought my soft top I pulled the third member out to check on the backlash and see how the bearings were.  There really wasn't excessive play between the ring gear and pinion and the bearings were in great shape.  The gear lube was horrible so I cleaned the inside of the housing put it all back together and don't worry about it anymore.

Funny you should mention that...

The plot thickened this evening.

As I mentioned earlier, I had the rear axle on jack stands earlier...I couldn't see an issue with the rear drive shaft, but there was a noise I wasn't familiar with. It sounded like the rear end was..I don't know...sloppy...like maybe there was something loose. This has all been a learning experience, y'know.

I drove on to rehearsal, but stopped by and spoke with a mechanic friend on the way home. When I mentioned to him what I saw, he crawled under my rig and started playing with the rear shaft and rear pinion.

He could actually move the rear pinion up and down a little. The rear pinion nut is loose.

As much as I've been under this vehicle, I'm not familiar enough to recognize when there's too much play in the rear end. I'd asked before when I had rear u-joint issues a few years ago, but was assured what was there was normal. This was well before I ever had any vibration issues to speak of.

I'd like to find a stock rear third to swap in for the time being, I think. After looking at the FSM, I realize that
A.) I'm not familiar with setting backlash
    and
B.) I could easily swap the rear third and drive this until my wagon is back on the road. Then I could start worrying with my axle swap. I really don't want to rush that when the time comes.

I imagine I could just try to tighten the nut on the rear pinion, but I believe that alters the backlash somewhat. I'm afraid I could over-tighten that nut and cause a catastrophic failure. I prefer fixing it in my driveway or garage to fixing it on the side of the road.

Either way, let's hope this remedies the issue. I will update as time goes on.

[viking]

I forgot to mention that it's not a bad idea to check the pinion nut. Shortly after we bought our 1989 F-250 SC diesel 4X4 I found that the u-joint flang was loose due to the pinoin nut not being tightened properly.  I fully believe the Dana 70 was assembled on Monday or Friday when all the workers wanted to do go drinking or stop their headache.  One day the sun was setting and as I walked up to the truck I could see air under the bolt heads that retain the brake backing plates, oh yeah the brake shoes got slimed and they replaced them too.  I used every lick of money spent on extended warrenty and they ate plenty of their own time and money on that truck.  Even had a free repaint which is now just about as bad as before.  But not all is lost, even though the truck isn't that pretty anymore, it sure runs great.  I did check the pinion for being loose on my tintop because I thought that might be some of the cause for vibration but that was before Biggerhammer mentioned the dots, it was the dots not being lined up.

[flashboiler]

Mine goes thru a vib/shudder at about 10-13 mph.  It's done it thru several u-joint changes, two drive shaft changes, axle shaft changes spring changes.  I finally put new tires on it and the shudder went away.

I was/am running 33" mud tires.  Old ones were BFG's and the new ones are Cooper SST's.  I'm thinking the cogging of the tread lugs was resonating something in the driveline causing the T/C to vib and shudder.

[madbob]

If you get anywhere near Fayetteville I have a rear 3rd you can have.  Slim chance I might to go Raleigh Friday night.

[loveofjazz]

If you get anywhere near Fayetteville I have a rear 3rd you can have.  Slim chance I might to go Raleigh Friday night.

Bob! Where you been hidin', buddy?

[madbob]

in a bucket?

[loveofjazz]

in a bucket?

Must be some bucket.
I tightened the loose pinion nut.
No, I did -not- do the complete set up.
Yes, I will be seeking a stock rear third member locally to swap out. Something is not right with the rear diff.
Yes, the shudder in second gear is still there. (sigh)