Unbalanced driveshaft
 

We've gone through pretty much every other option as to the vibration on take off and other high torque situations and have pretty much settled on the the driveshaft as the issue. I added traction bars recently thinking that the old leaf springs just aren't up to the job anymore. That seems to have helped some but it's still there. We've gone through the rear diff also and that's good. I'm looking at options for replacement of the shaft. What are the current thoughts on one piece shafts? Is aluminum the better option? Who to buy from, etc.? Any suggestions?

How does your carrier bearing look? I recently replaced mmine that was shot and first gear clunk is now gone. I also went with spicer u-joints at the same time. Was $260 OTD for that stuff, balancing would have been a little more.

as we enter into the heat of summer...seems like there are more and more case of shudder, vibrations, and funny drive train noises happening......hmmm...my personal opinion is that the thin LV fluid we all were told was OK to put into the torque shift cant live up to the task.....at least not on older worn out trannies. my shudder problems reduced substantially when I did a drain and refill using Mercon SP, and the shudder was eliminated when I added 16 onuces of "RED" container Lubeguard. The Lubeguard bottle says its the only additive "OK'ed" by OEM's. Lubeguard helps restore the plate slip that is needed to have smooth shift power transfers. I am not a tranny expert but before you start replacing drive shaft componets and adding sway and traction bars...invest in the 13 bucks and give it a shot. you can get it on amazon. lubeguard comes in 4 types, depending on the tranny type. RED, BLACK, GREEN and SILVER. the SILVER is supposed to be good for all trannies BUT it does not work as well as the specifc target product like using RED for our trannies.


and sure...this cure may be masking a problem like seloniods that arent functioning correctly or sensors and such that are not working correctly....you decide how you want to proceed based on cost and return on investment.

Is the carrier bearing the center support bearing? If so, we just replaced it and it made it worse.

Well, that sure sounds cheaper than a new driveshaft. I just looked out in the garage to be sure and, yep, I always use LV just like they say. I had an engine swap done about 2 months ago and noticed this issue was markedly worse right after I pulled away from the repair shop. That's when all the "fixes" started. I can't imagine what might have changed, as there's no reason (that I'm aware of) to mess with the driveshaft on a engine swap.

Also, I wouldn't call mine a "first gear clunk". It's really like I'm driving on tractor tires as I start off and will stay that way for several seconds if I accelerate hard. Hince my thought that it was "wheel hop" and might be cured by the traction bars.

Is the red the one listed as part number 50902? If so, they have it at the O'Reiley's auto parts close to my house. I'll have it shortly, if that's the right stuff.

Correct.

Hmm, mine was a noticeable takeoff clunk, especially noticeable when changing from park to reverse or drive.

I think your problem used to be called "crew cab clunk". Back in the day, it was blamed on the long drive shaft required by the long cab. We all just got used to it as it was just thought to be "nature of the beast". That may have been updated by another idea.

Just a couple of questions........Are all of your angles good; i.e. Driveshaft and pinion shaft aligned?
Are your ujoints "in phase"?

What Every Shop Must Know about Drivelines

Proper U-Joint Installation TipsBehling Racing Equipment

A couple of links for some reading

My mechanic said that the angles were off, so he got some angled blocks to correct then. Unfortunately, he felt it made the problem worse, so he took them back out. A little background: I first noticed the shudder on take off was worse immediately after getting the truck back after the engine swap. He and I talked on the phone about it and decided that maybe a wheel weight had come off. I went back to my tire place and they thought it was in the driveshaft. The changed all the u-joints, the center support bushing, and put it all back together 180 degrees off of balance! That REALLY made it worse. Back to the mechanic. He corrected the 180 off and checked all the u-joints for correct installation. He thinks it's all dive shaft related, and is advocating the one piece shaft. That's where we are today.

At O'Reiley's autoparts, I found the synthetic red version. I put 16 oz in, drove about 50 miles, and noticed no difference. I'll reassess tomorrow, but I'm thinking this isn't going to fix it.

Doesn't sound like a tranny issue. Did your mechanic lube the spline shaft generously when re-attaching? If dry, you'll get some of the same charateristics you're complaining about.
Check your rear tranny mount to ensure its secure.
Last, I bet one of your tires could be delaminating. Sometimes very hard to see but easy to feel. Rotate the tires and see if there's any difference?
I wouldn't waste the money, chasing after a new driveshaft if the u joints and carrier bearing were just replaced.
They don't bend by themselves...unless you did some off-roading and got hung up on the driveshafts?

Let's narrow this down a bit. Is the shutter just on initial take off? Does it happen while driving at pretty much all speeds?

If the shudder is the same as mine on take off its the rear axle limited slip binding up. Mine was the worse when pulling a load from a stop and turning a slight turn. I replaced my whole carrier and problem fixed..