I have a 2000 F250 powerstroke with auto trans. i have noticed a trans shutter in 1st thru 2nd gear, it shudders worse when towing 5th wheel. It's not the limited slip rear axle, already had that fixed. The tires are in good shape. Was wondering if anyone had experienced this problem and what the fix was.

 

sounds like dreaded axle wrap to me

where the axle is rotating back and changing your driveshaft angles, if you have someone else drive the truck, from a stop. watch the axle the top of the houseing will rotate backwards, couple things to fix are addaleaf, ladder bars, track bars. or a little easier on the power through there. sometimes putting ladder bars track bars on it can cause another problem called pinon gear climbing, and wear out pinon gear bearings or worse break a pinon gear. its where all that tourque causes the pinon to climb up the ring gear as its trying to rotate it. i dont know how tough the rear ends on the newer trucks are i have a 97 with a dana 60 under it. thats a pretty tough axle. I put the a ladder bar on mine that i slightly modified so it could rotate and added a shock absorber with very hard compression dampening on it to reduce the axle wrap. i will get some pics for you when i can borrow a camera

 

I experienced similar things with a previous non-Ford truck and my u-joints were toast. Not sure what the recommended replacement is on our u-joints but maybe take a look to see if you have any play.

 

You said they fixed the limited slip. However I have seen many times that they put non-limited slip oil back in the housing. This is known to cause shudder, and premature wear of the clutches. Adding the stuff can be only a few bucks.

 

Thanks for the input. I'll check on these conditions and let you know if they were a help.
Thanks alot!

 

I had to lower my driveline center support bushing (the rubber one) down about a 1/4" for each inch of (suspension) lift kit on the truck. I figured that my truck was lifted about four inches, so I tried an inch worth of drop and all my vibrations went away. You can buy shim kits for this, but I used 1/2" by 1 and 1/4" steel pieces and had to drill two holes in each of them. Install them with a couple of new bolts (longer) and I believe that I used new nuts and threw the original one away. You can kneel down and eyeball your current set-up, but it didn't seem that this fix would work at first. After, I could see the difference that I created, much straighter from the front u-joint to the rear one. I don't know why moving the angle change from the center u-joint to the front one does the trick, but it works.
Dan...

 

This would reduce the amount of stress on the shaft and u-joints that was imposed by the lift you put on the truck. Which I would assume would be why much of the driveline vibration went away. Cool fix!