*thunk*

[Nekron99]

Hello all,

I have a 94 xlt, 140K mi. Just had the tranny rebuilt, and transfer case too. I still get a loud thunk occasionally when I'm accelerating uphill, and I let off the gas. Sometimes I get it when I go from coasting to accelerating, or vice versa. Im not very mechanically skilled so sorry for the description, but I think I get it when the trans. is engaging and disengaging. Sounds like a bowling ball is loose under the car. A friend says it's a Ford thing, and the mechanic that rebuilt the tranny 'doesnt hear anything'

Ideas?

 

[Albino 94LTD]

Check your radius arm bushings.

 

[Doug]

It could also be your u-joints. With the truck in park see if the is any movement in the driveshaft.

 

[Nekron99]

Thanks! Ill chek it out.

 

[Rhett]

Ideas?

Probably the slip yoke on the rear driveshaft. It just needs some lubing. It's a routine maintenance item.

 

[DeRocha]

I'm going to say all of the above... If the u-joints or RA bushings are new they are candidates for being replaced... The slip yoke is another drive line item that is often overlooked and will benefit from some lube..

 

[ParadoxRacing]

Sorry to revive a REALLY old thread, but I've done some searching and can't seem to figure something out. First, the problem: I am getting a thunk from the center of the vehicle. It usually happens when I'm slowing down, and almost stopped as the tranny shifts into what seems like 1st gear, although it will sometimes happen in the higher gears too. It only does it if I am off the gas and the tranny is shifting without a load, ie: accelerate to speed limit, then let off gas. Vehicle slows down a little and tranny shifts into next gear to drop rpms, "thunk". Now a little background. RA bushings have been replaced, but haven't done the ball joints yet (They need it I just haven't had time). New U-joints on rear drive shaft, and the tranny was rebuilt about 3000 miles ago, and tranny mount was just replaced. I lifted the rear wheels and put the vehicle in gear, and the drivetrain sounds fine, no rattles, clunks, or other noises, and I cannot duplicate the problem. I shut it off, put it in park, and checked for loose stuff using the pull, yank, shake, and twist method. In this condition, I can turn the driveshaft about 1-2 degrees, and if I do it quickly it results in a "clunk" that sounds suspiciously familiar coming from the transfer case. I am assuming it is just a slightly loose chain, but want to make sure before I ignore this noise and focus on other problems. Anyone got any insight?