Dana 30 questions

[Toivo]

any info on why I am gettin grinding noise when in 4wd. Itll work at low engine rpm, but ne rpm over about 1500 and it pops and grinds. Axle joints and u-joints are OK too. I havent ruled out a stretched t-case chain (NP 231) but I think its highly unlikely, seeing as how Ive put over 1000 miles on it since the problem happend. More concentrated on vacuum axle disconnect. Any ideas?

[ned]

did you open your diff up and look
maybe worn gears??
or broken teeth

[Toivo]

not yet...but doesnt the one side of the axle shaft spin all the time. regardless of wheter the 4wd is engaged or not?...i thought so..I could be wrong but I kinda figured that if that was the case..then wouldnt just driving it daily make tons of noise and cause serious other problems?

[Haggar]

Thats your best bet..

First, pull the cover off the vacuum disconnect and inspect it. If it looks ok there, then maybe drain the t-case into something like a gallon size glass jar. Look at the fluid... any metal?

Gotta figure if there's grinding and popping, there's wear.


You can't tell the general location of the sound? Axle or T-case area are a few feet apart..

If the t-case fluid is clean (probably needed to be flushed/refilled anyway, right ;) ), then pull the diff cover.

Also, check the driveshaft CV centering yoke. That makes some nasty noises when it goes, also quite common on any jeep..


Do those things, and report back!

[Toivo]

it sounds like the axle to me..as well as a few of my friends think so too..im gonna check the vacuum disconnect here soon. as for the t case drainin..i changed the fluid prolly 1500 miles ago...i will check everything twice again tho..I do not have any lifts my disposal, all I have is a parking lot..and its damn cold n crappy out

[silverxj]

It's not unlikely to stretch the chain on a standard np231. It's actually more common than you think, especially if you're in 4wd often.

Just changing the t/case fluid will have no adverse affect on a stretched chain. It's not like it's a rubber band and going to collapse back to it's original shape ... I wish mine had.

If you find that it ends up being the chain, replace it with a wide chain kit...

[Toivo]

eh ok sounds good.....btw doing 4wd drifts for a long time one icy day COULDNT have had anything to do with that