Any guesses as to why my truck is "shuddering" on acceleration?

[King$nake]

Ok, first - I had my transmission rebuilt a few months ago - like $1900 or so in repairs & labor. Fortunately there is an extended warranty coverage for it at my Ford dealer.

But when I got it back, the 'shudder' was still there, but it was hardly noticeable. However it is getting worse. It seems to shudder worse when I am accelerating AND turning. It's often very quick, maybe 2-3 seconds and it goes away as I accelerate. There are no problems shifting or anything, only when accelerating from a stop.

It feels like it's coming from the rear end, and Im wondering if it has to do with my axles.

Any guesses?

Thanks!

 

[ViperPliskin]

Shuddering

Is it RPM specific?

Do the obvious first. Check fluid level and shifter cable adjustment. I had a similar problem that went away after I readjusted the cable.

 

[iwannabamedic]

check all the u joints also

 

[my pos mounty]

Lets see if this is right:
When the truck is cold, you feel the shutter mostly when starting from a stop and turning at the same time (not as much when rolling slowly, but a little). As the truck heats up, it shutters accelerating from a stop (or a slow roll) and does not matter as much if you are turning or not.

Pretty close to whats going on? If that describes it, your clutch packs in the limited slip differential need to be replaced.
Might I suggest that if you are prepared to dive into this and replace them, replace the spider and side gears as well. They wear on each other and are near impossible to get back in the way they came out and will whine.
Theres an excellent thread I found on the Mustang forum about rebuilding/regearing the whole Limited Slip differential, posted below. Post #6 gives an excellent narrative and in post #1 theres a link to an article that was written for a Magazine (with tons of pics.) You will not need to do all the steps because you won't be changing the gear ratio.
http://www.allfordmustangs.com/forums/5-0l-tech/118464-how-rebuild-your-8-8-rear-end.html

 

[96eb96]

Lets see if this is right:
When the truck is cold, you feel the shutter mostly when starting from a stop and turning at the same time (not as much when rolling slowly, but a little). As the truck heats up, it shutters accelerating from a stop (or a slow roll) and does not matter as much if you are turning or not.

Pretty close to whats going on? If that describes it, your clutch packs in the limited slip differential need to be replaced.
Might I suggest that if you are prepared to dive into this and replace them, replace the spider and side gears as well. They wear on each other and are near impossible to get back in the way they came out and will whine.
Theres an excellent thread I found on the Mustang forum about rebuilding/regearing the whole Limited Slip differential, posted below. Post #6 gives an excellent narrative and in post #1 theres a link to an article that was written for a Magazine (with tons of pics.) You will not need to do all the steps because you won't be changing the gear ratio.
http://www.allfordmustangs.com/forums/5-0l-tech/118464-how-rebuild-your-8-8-rear-end.html

Thank you sir!
That is a great how - to..I bookmarked it. I need to do this for a Thunderbird.

 

[King$nake]

Lets see if this is right:
When the truck is cold, you feel the shutter mostly when starting from a stop and turning at the same time (not as much when rolling slowly, but a little). As the truck heats up, it shutters accelerating from a stop (or a slow roll) and does not matter as much if you are turning or not.

Pretty close to whats going on? If that describes it, your clutch packs in the limited slip differential need to be replaced.
Might I suggest that if you are prepared to dive into this and replace them, replace the spider and side gears as well. They wear on each other and are near impossible to get back in the way they came out and will whine.
Theres an excellent thread I found on the Mustang forum about rebuilding/regearing the whole Limited Slip differential, posted below. Post #6 gives an excellent narrative and in post #1 theres a link to an article that was written for a Magazine (with tons of pics.) You will not need to do all the steps because you won't be changing the gear ratio.
http://www.allfordmustangs.com/forums/5-0l-tech/118464-how-rebuild-your-8-8-rear-end.html

Well, It does seem to do it more when the truck is warmed up and I've been driving for awhile. The best way to describe it is it feels like axle teeth are slipping.

So, assuming it's the rear end, how much $$ can I expect to spend if I do this myself? How long do you guess it would take if there were 2 people working on it?

 

[my pos mounty]

Well, It does seem to do it more when the truck is warmed up and I've been driving for awhile. The best way to describe it is it feels like axle teeth are slipping.

So, assuming it's the rear end, how much $$ can I expect to spend if I do this myself? How long do you guess it would take if there were 2 people working on it?

That depends on what you find when you open up the differential, your skill level and the tools available at the time. You may find other parts that are best replaced at this time, such as carrier bearings, side and spider gears, axle bearings and axle seals.
I would replace the axle seals, the clutch pack and the side/spider gears as a minimum anyway. (seals are very easy now and inexpensive, a true pain in the butt later) When checking the axle, If you find anything that you can feel with your fingernail on the surface of the axle where the bearing rides, you may want to consider buying a different kind of axle bearing, it rides further outboard on the axle shaft and has an integrated seal. If it looks good, check the axle bearings for excessive wear/slop. Replace as necessary. Give the carrier bearings a serious check, even the slightest doubt, replace them now.
I would hazard a guess at a good afternoon anyway. Mark everything so you can put it back together EXACTLY as it came apart! To the extent of the same bolts go back in the same hole. Follow tourqe values to the letter and double check everything.