Topic: Severe clunk/rattle when in 4wd

[calvinh]

Whenever I'm in 4wd and the system is under load (accelerating, letting the clutch out) there is a severe banging/clunking noise from the front end.

Could it be the front driveshaft u joint? It only does it in 4wd, and does it while going in a straight line as well as turning.

I know its not bad gears in the differential, as I had the cover off last week and they are in perfect condition.

If it is the driveshaft, is it an easy DIY job? How much could I expect to pay a shop to do it?


Thanks!

[chardrc]

u-joints for the drive shaft or axle shafts would fit the description.

[FourbangerYJ]

Grab hold of the front drive shaft and give it a good push pull from side to side and up and down. There should be very little if any play. If you have a bunch then it's time for new joints. They are pretty easy to swap. I would bet if you youtubed changing drive shaft U joints there is a lot of video on how to do it.

[calvinh]

Ok, I think it might be the transfer case chain slipping. The noise I'm experiencing is like this, just not as bad. http://www.youtube.com/watch?v=xIKq-ihpzQI

Is the chain replacement on a np231 pretty easy?

[sharpxmen]

Ok, I think it might be the transfer case chain slipping. The noise I'm experiencing is like this, just not as bad. http://www.youtube.com/watch?v=xIKq-ihpzQI

Is the chain replacement on a np231 pretty easy?

i doubt it but if that's it you'd need to take it apart, not hard but keep track of all the parts.

[Bounty Hunter]

A stretched chain will cause a banging noise when in 4wd and under load, it's the chain skipping on the sprockets.

The chain runs about $70 and is relatively easy to replace.  Shoot me an email if you run into any problems and I can walk you through them. bountyhunter AT sija.org .

[jfrabat]

A stretched chain will cause a banging noise when in 4wd and under load, it's the chain skipping on the sprockets.

The chain runs about $70 and is relatively easy to replace.  Shoot me an email if you run into any problems and I can walk you through them. bountyhunter AT sija.org .

If it was the chain, you could also consider going to the larger (thicker, not longer) one.  I dont remember the specs, but I am sure others can chime in here and let you know what you need...

[neale_rs]

I'll vote for axle u-joints.  Mine was like that when I bought it.

[calvinh]

Im 99% sure its the chain as it isn't just a single clunk, it definitely feels like a slipping chain on a bike.

I'm headed to the junkyard tomorrow to try to get a chain off a cherokee, because they don't have any wranglers.

If they have any 2.5 cherokees there I might try to get a tps sensor, iac, and whatever else I can think of

[FourbangerYJ]

Im 99% sure its the chain as it isn't just a single clunk, it definitely feels like a slipping chain on a bike.

I'm headed to the junkyard tomorrow to try to get a chain off a cherokee, because they don't have any wranglers.

If they have any 2.5 cherokees there I might try to get a tps sensor, iac, and whatever else I can think of

Did you check any of your U joints?

[Jeffy]

Did you check any of your U joints?

A loose U-joint strap or a bad joint will also make repeated clunks.

[FourbangerYJ]

A loose U-joint strap or a bad joint will also make repeated clunks.

That's where I would have started to look.

[sharpxmen]

is the noise coming from between/under the seats or from the front? that could tell where the problem is (with 1 remaining u-joint at the front output of the t-case which can be easily ruled out if there is still a doubt).

[Bounty Hunter]

I would recommend against using a used transfer case chain, it's a roll of the dice for all the work involved, and new ones are inexpensive.

[calvinh]

Checked the u joints today, no slack in the driveshafts, the slack was coming from the transfer case... so I think its confirmed as being the chain.

I probably won't even end up doing the repair this year, because I've only had to use 4wd once so far and it still works well unless its under a lot of load.