I could use some help. When I accelerate from a stop, I get this bang/bump sound out of my rear end/driveshaft area then it drives fine until I stop and accelerate again. I heard this was a common problem in Broncos. Can anyone tell me what this might be and how I can fix this issue. THANKS ALOT!!!!
Bronco Problem
- Thread starter ckarvala
- Start date
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How can you adjust these if there is play? Am mechanically inclined but am unfamiliar with u joints.
Miss Kitten
New member
if there's play replace them
Do you have a two piece drive shaft? It could be your slip joint on the rear drive shaft. Sometimes the grease within the slip joint will dry up and the joint will stick. When your rear end goes up or down as you accelerate/brake that sticky joint is going to cause a bang/thump/clunk (and the longer you drive it, the more it'll clunk). Its a real easy fix, just take the driveshaft out, pull the joint apart and grease the crap out of the splined shaft and shove grease inside the other end of the shaft. While you're at it, check the u-joints as well. They very well could also be the problem.
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does this happen only in a straight line, or in a turn as well(like turning in a parking lot). new clutches in a limited slip rear end can make some noise if they werent soaked for awhile before install. They grab and slip. Play in your ring/pinion, play in your ujoints. Ive also had rear shackle bolts wear out enough that the hanger was moving when the leafs loaded up.
you need to put your truck in park, parking brake on, wheels blocked just in case it rolls. then crawl under the truck and grab your drive shaft(DID I MENTION TRUCK OFF!!!) move your drive shaft around and look for play in the joints at either end of the shaft.
you need to put your truck in park, parking brake on, wheels blocked just in case it rolls. then crawl under the truck and grab your drive shaft(DID I MENTION TRUCK OFF!!!) move your drive shaft around and look for play in the joints at either end of the shaft.
Roadkill
New member
I think Walnuts hit it right on the head. That clunk on acceleration is almost always caused by this. It could also be a problem with the radius arm bushings or the the radius arm brackets but my money is on the driveshaft. It costs practically nothing (only the cost of a little bit of grease) to pull it out, grease the slip joint, and put it back in so I would start with that first.
Edit:
When you remove it, make sure to mark the parts (white out works great) so you can reasemble everything exactly as it was before. Skipping this step can cause you to get vibrations in the driveshaft after you get rid of the "clunk".
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black beauty
New member
suer sounds like a bad rear u-joint. just spend a little money and get some good ones AND MAKE SURE THEY STAY GREASED!!!
michibronc
New member
One shortcut that may work with lubing the slip joint is to just press the end of your grease gun on the slip joint while its assembled and try to shoot as much grease as you can in it. Sometimes yes, sometimes no.
If that doesn't work and you end up dropping the driveshaft to separate it, you'll need to use an end wrench / pipe for leverage / and lots of blaster on the bolts that hold the driveshaft to the differential in back. I'd soak the bolts with PB for a few days leading up to the project for best results.
Either way, you'll have to get some beefy zip ties to hold the boot back around the joint.
If that doesn't work and you end up dropping the driveshaft to separate it, you'll need to use an end wrench / pipe for leverage / and lots of blaster on the bolts that hold the driveshaft to the differential in back. I'd soak the bolts with PB for a few days leading up to the project for best results.
Either way, you'll have to get some beefy zip ties to hold the boot back around the joint.
