Rear end clunking (I know, I know)

[Firpo]

Semi newbie on here.
Don't post a whole lot, but I lurk pretty often.
Anyhow, with that out of the way..

I get a loud "clunking" sound out of the rear end whenever i accelerate or decelerate. It doesn't matter if it's in a parking lot or on the highway. Foot hits the gas and "clunk!" if I take my foot quickly off the gas I get another "clunk!".

I know there has been a lot of discussion on this topic, I searched quite a bit.
I read a lot of posts, but didn't really find any clear diagnosis/fix.
So is this a tell tail sign of worn ujoint at the axle, or is it likely a pinion gear, or I've even heard a loose Ubolt could be the culprit.

I guess what I'm asking is if anyone has found this problem to be more likely one of these things discussed than another?

Any info is greatly appreciated!
Cheers,
aa.

91 cruiser btw.

 

[Braknstuf]

Sounds like you have the right ideas, your just going to have to get under the cruiser and take a look.
You should probably do it sooner rather than later, could get harder to fix if you keep driving it.

See if thiers any play in the axels, ujoints, pinion gear. Check to see if anything is broken.
Also dont forget to take a look at the bushings on the rear suspension, wheel bearings, brake calipers, spring and struts, the spare tire mount and winch, and sway bar. Start by just tugging and pulling on everything you can see down there - once you find something that moves and shouldnt you have a likely canidate and we can be of more help.

Very hard to diagnose these things as their are so many possibilites from simple/cheap to complex/expensive.

 

[4x4CPOSEADOG]

Grease up all your u-joints first on the rear drive shaft then go from there. The needle bearings may be dry or possibly broken.

 

[masterfab23]

Check and grease your u's , you may just need some grease in your rear shaft

Sent from my HTC EVO4G using IH8MUD

 

[Manuelsv]

Maybe?

Don't automatically assume it's drive line related..
I had the same sound and symptoms as you did.. Went crazy tightening everything, checking every bold UNDER the car.. nothing the noise was still there.. had a friend walk next to the car and tried to hunt it down could not find it.. Drove me absolutely for a couple of months!!
Then one day while doing a routine fluid check I discovered my front DS shock wass loose on the top mount! 2 min later problem solved by tightening the suker down..
Moral of the story With a cruiser always look for the simplest thing first... don't automatically assume the worst! These vehicles are beasts built like tanks.. It's usually something simple!

 

[FloydtheDog]

I had a noise similar to what you describe, though I also noticed it when going over bumps whether I was on the gas or not. Turned out that the exhaust mount bracket behind the 2nd cat had rusted out & the exhaust pipe was banging on the rear axle. Reach under your truck when the exhaust is cool & give it a good shake to be sure that it's not flopping around back there.

 

[Firpo]

Thanks for all the input!
I'll be under that thing for likely the whole day tomorrow.
I'll post pictures, and hopefully a summary of what went wrong.

Cheers!
aa.

 

[Firpo]

Alright, rear diff is hosed. Now what?

I just posted a thread about how I was getting a lot of rear end clunking in the cruiser. I had high hopes of it possibly being something simple via stories of other people solving this by replacing ujoints and loose suspension parts.

I put it in neutral, cranked up the ebrake and got under the thing.
I grabbed onto the axle and gave her a twist, and got a good amount of play accompanied with a good ol' "ping!" once the teeth met up and the play stopped.
This is the SAME noise I have been getting all along, but at a lower volume.

So the setup needs replaced obviously.
Is this something I can do myself? I'm fairly inclined, just never done a diff before.
Can I take out the ring and pinion gears all out as one unit?
Or is this something I sort of have to take to a diff guy?


All the info is appreciated!
Cheers,
aa.

 

[Pin_Head]

I grabbed onto the axle and gave her a twist, and got a good amount of play accompanied with a good ol' "ping!" once the teeth met up and the play stopped.
This is the SAME noise I have been getting all along, but at a lower volume.

.

If the "play" is only rotational, chances are that this is normal and unremarkable. What were you expecting?

 

[Firpo]

From what I understood, with the wheels firmly on the ground there should only be about an 1/8th inch of play. I'm getting quite a bit more than an 1/8th inch. What's more concerning is the "PING" that I'm getting at the end of the play. It's the noise that i've been hearing whenever I put my foot on or off of the gas.

 

[Pin_Head]

If the play is only in rotation (and not sideways, up/down or in and out), you could have 45 degrees of rotation with noise when it reaches the limit and it would be totally normal. How many other axles have you compared it to?

 

[CJF]

91-92's are pretty clunky.

Check your u-joints and drive it.

 

[Dave 2000]

Also note, if your UJ's have NOT been greased and then you grease them, you may find you introduca another clonk and even vibes a short time later. This is caused by the needle bearings drying and getting rusted/frozen in one place, you add grease and they move about and then the problems start. Clonks on these motors are very common at the high mileage they can reach, Mr T reputedly fitted a VC in the centre diff to help iron out some of these noises on thelater models.

I have minor clonks on mine here and there however none dictate a rebuild of a diff ect, are you sure the end flanges are tight and not worn, again a very common problem, in particular on the older 'MK1' versions.

Unless you have spent a lot of time under one of these machines get someone who knows them very well, if not you may start to dig the bottomless pit to throw your wallet in.

regards

Dave

 

[Jigsaw100]

My sound was the rear brakes. Hope that helps someone

 

[rolliges]

Tighten up the spare tire (and give it some air when you're down there).