Dana 30 or 45?

So I've got a 91 Sport XJ with the 4.0L. I'm not sure what a Dana 35 or 40 is, or what I have. I do know I have SelectTrac, but not sure if that's a good thing or bad. I want to swap in rear disk brakes for street performance and wanted to know if I should swap anything else in there while I'm at it. Also, what's a Chrysler 8 1/4?

Wow.

A good place here is to back up and tell us more about your jeep. Is it lifted? Does it have larger tires? Do you plan on doing that? Can you post a picture or your rear axle (that might matter)? What do you intend to do with it in the long run?

There is alot to teach you there, but any -good- advice given should depend on those answers.
-Cal

goodburbon said:

Wow.

Click to expand...

x eleventy billion.

You need to take advantage of this and do a lot of reading.
http://www.naxja.org/forum/search.php

yeah, I know its a weird question. But when you grow up racing karts and move into Porsche Club Racing, you don't know a whole lot about off-roading. I did a search. It's too generic a question, so it didn't help. I thought all 91 Sport models had the same set-up. Am I wrong about that? Whats the difference between these three things? And what are they? Rear Diffs?

I'm pretty sure all '91s have Dana 45s, although some might have 40s, 38s, or 22s.

Could b trolling...
OR could just need some mentoring!

head over to http://www.quadratec.com pretend like you have ton's o money... shop 4 lift, axels, etc. and you will find some answers, go to Amazon.com buy the Cherokee repair manual.. better yet, lookup and join your local 4x4 club, you can find lots'a info there and maybe even go out on a club run with your stocker... then you will learn what needs to be replaced, built up etc.

best I can do...

fizassist said:

I'm pretty sure all '91s have Dana 45s, although some might have 40s, 38s, or 22s.

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Play nice, at least the guy asking isn't being a punk!---Like we have had before with the why won't this work ideas...and the body lift guys.
J

alpinetiburon04 said:

yeah, I know its a weird question. But when you grow up racing karts and move into Porsche Club Racing, you don't know a whole lot about off-roading. I did a search. It's too generic a question, so it didn't help. I thought all 91 Sport models had the same set-up. Am I wrong about that? Whats the difference between these three things? And what are they? Rear Diffs?

Click to expand...

yes, they are rear diffs (and axle assemblies).

You either have a dana 35 or a Chryslier 8.25 27 spline. Neither of them are really something you want to keep, the shafts are on the weak side, and if its a 35, the housing itself is weak. Find a 29 spline Chrylser 8.25 (97+ cherokee without abs) or a dana 44 (on some 87-90s). You can find information on them here, and find them in the local junkyards.

ok

dana 30 refers to front axles on 4wd models

dana 35 refers to the weaker rear axle diffirential option on the xj

chrysler 8.25 is the stronger rear axle diffirential available on xj's

dana 44 was an optional rear axle diffirential in the early xj year models and overseas, and is preferred for strength and aftermarket support.

dana 40 and 45 if they are actual models, have nothing to do with xjs

selectrac refers to the type of transfer case. searching will yeild a plethora of info on this.

91 had 2 available rears, dana 35 and Chrysler 8.25. ABS gurantees you have a d-35 and the other its a 50/50 on which one you have. Searching will yield identification characteristics of each, and how to tell what you have.

It's pretty easy to tell....Dana 35 and 44 along with the Chrysler Corporation 8.25 are the axles in the XJ. It's pretty easy to tell them apart. The Dana 35 and the Chryco 8.25 have oval diff covers, the Dana 44 is an oblong shape. You can tell the difference between the 8.25 and the D35 in that the D35 has a round bottom and the 8.25 has a flat bottom.

The D44 only came in a select few models (some metric version, tow packages, etc.), so chances are you likely have the D35. I only did a disc brake upgrade on a Currie 9" axle, and I've never seen one for the D35 myself, but that certainly doesn't mean that they don't exist.

If you're not going with tires bigger than 33" I really wouldn't sweat beefing up the D35. Disc brakes are nice, but at the price, I'm not sure I'd even consider it worth it to be honest. You could add a limited slip for traction, but again, its a decent amount of money to throw into a street Jeep when you don't really need it.

EDIT: BTW, with a nice e-mail and your VIN, Jeep will happily e-mail you back a build sheet of your vehicle describing exactly what your rig came from the factory with leaving you with no question at all. I had mine inside of 48 hours.

I was trying to help him learn to help himself sandiego.

The guy has 80 posts, and if you continue to spoon feed him answers he will continue to come back for more and just say "gosh I really tried searching but I just can't find anything, wouldn't it just be so much easier if you could just tell me."

Well I checked out my rear diff. The unit has a round rear cover, with a flat edge at the very bottom. So I'm guessing this is the 8.25. Not so bad right? So for only street use there's no need to upgrade it?

I only want to upgrade the rear brakes because I took a cornertoo fast today and almost flipped myself. I'm very very very used to having a car that takes certain corners at 35mph. I'm not used to having to drop down to 15 or 20 to take those same turns. And by the time I realize I'm in a four-door Sport Ute, the brakes can't keep up. But anyway, I'm in good sahpe right? Just do some searching for upgrading rear disks to the 8.25?

Correct.