Dana 30 autolocker?
 

So I've noticed my front diff D30 making sort of a knocking noise for a while, usually notice it around slower speeds (10-15 mph). There's no strange behavior or movement when engaging 4WD. I took my diff cover off and did a fluid change on it today & I took some pictures. I'm still not 100% sure of what I'm looking at. It doesn't look like an Aussie autolocker but it also doesn't look like a stock ring & pinion setup to me. Can any of you give me an idea of what I'm looking at? Thanks!

https://cimg0.ibsrv.net/gimg/www.che...6631914fa8.jpg
https://cimg1.ibsrv.net/gimg/www.che...a5f5a61005.jpg
https://cimg2.ibsrv.net/gimg/www.che...e337033f9d.jpg
https://cimg3.ibsrv.net/gimg/www.che...9f0d8a0f86.jpg

You have an open diff. You can see the spider gears in the 3rd picture. The ring looks like it has some miles on it so it could be original.

OK, thanks for the response 5-Speed. The reason I was under the impression that I had some sort of locker was because the first time I tested my t-case (in a parking lot) and put it in 4 low, I heard chirps and rubbing from my tires as though the front was locked and the tires were spinning at the same rate. I've noticed a sort of knocking or thunking noise coming from what I believed to be my front differential, a little more so now that I've recently lifted my '01 XJ more than before.

is there any reason for me to be concerned about this noise or is this normal operation? Anything in particular I should inspect/repair?

Thanks guys :thumbup1:

That is normal for it to bind up and chirp the tires when turning on pavement in 4x4. The reason for this is when turning the front and rear axles need to turn at different speeds and since the transfer case is locked it won't allow it to differentiate and you get the tire chirp.

Ok that makes sense. Thanks for the replies guys. I feel like a noob for thinking I had a locker or something now but I guess you have to learn somehow, haha!

On another note I think I found the cause of my "clunking". I took my Jeep on a trip with my friend and we noticed my passenger's side axle u-joint is pretty much shot. This makes sense, because the noise was always at lower speeds, usually while coasting in which case the u-joint would just be bouncing around in the knuckle. I'm gonna pick up some Moog u-joints tomorrow and change them out soon. Hopefully my noise goes away!!

Use the Spicer U joints. They are better reviewed on the forums. I don't have first hand experience using the MOOG, I just installed the Spicers based on internet wisdom.

To clarify the 4WD on pavement issue, DONT DO THAT. :lol: As stated the front and rear axles must rotate at different speeds when cornering. The 231 transfer case is locked front to rear, no slippage. Using 4WD on pavement will cause things to bind and break.

Ok, I won't do that again I suppose haha. I'm guessing if I have the NP242 T-Case the same principles apply?

Also, finished the install on the U-Joint today. Went smooth. No more noise :thumbup1: I threw a MOOG one on for now because I needed it back on the road - my XJ is my daily. Going to buy myself one or two Spicer ones online that I can keep on hand to swap over. The drivers side is beginning to go out but it's nowhere near the catastrophic condition of my passengers side :icon_cheesygrin:

If you have an earlier XJ, you can get the axle shafts from a late model with the larger u joints. Search the forum for the specifics, I can't remember at the moment. On my 90 it was a significant difference in u joint size stepping up to the later shafts. IIRC I pulled them from a 97. Then throw some Spicer u joints with snap rings in those, pull yours out and throw them in the boot as trail spares.

The 242 is a different type of transfer case. It has a differential in it similar to what is in each axle. It will allow the front and rear axles to slip as needed. I'm not sure if it should be operated on dry pavement, I have no experience with one. I know it is labeled as an all-time 4WD though.

I have a 242 in my 88....it is basically the same as a 231, except it has a position that allows it to be used full time on any surface, but mine is labeled on the shifter as full time, not AWD.

I have also not ever heard it called AWD...only full time 4wd.

The 228 has a diff like what's in the axles with spider gears and side gears, and the 229 has a viscous coupling, but the 242 has a diff that is actually a gleason-torsen torque biasing setup, basically a planetary gear.



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