Topic: Gear Ratios

[Sidewinder]

Hey guys,

I have an '88 YJ with 35's and am looking to do a re-gear.  The stock 4.10's just aren't cutting it.  

Was planning on 4.88's but heard they now go as low as 5.38's (D30/35).

Is this the case?
Any problems with using gears that low (i.e. heat)?

Thanks in advance.

[Jeffy]

Check the FAQ for details.

[Sidewinder]

Thanks Jeffy.
But any concerns with running those gears in a D30/35?

[Jeffy]

5.38's?  You can't run them in a D30/D35 combo.

4.88's aren't a problem.

[SMC4WD]

5.13's are available for a D30, but I don't think for a D35...

What a waste of any money into a D35.  I built a D30 fairly massively, and I am currently running 4.88's.  But the D35.  Never!  Save your money.

If you are planning on that tall of a gear, you must be running massive tires (I'm running 35's).  I hate to say it, but your crazy!  

You are obviously spending money on tires and wheels.  Spending money on gears and set-up kits...   Stop spending money and start saving money.  Save up for an axle!

[Jeffy]

Those are CJ D30 gears.  Chrysler-Era D30's stop at 4.56 for Spicer and 4.88 for aftermarket.

[Sidewinder]

Thanks guys.

I thought 4.88's were the lowest for these axles but had someone telling the 5.38's were available.

As far as the D35 is concerned, there's no way I would pay a shop to re-gear it, I agree.  But it had a lcoker in it when I bought it and I may know someone who could help me set up the gears, so I am only looking at a couple hundred bucks.

[SMC4WD]

http://ringpinion.com/content/products/default.asp?vid=1&pid=4&aid=40&rid=

Randy's Ring & Pinion does show that 5.38 gear set.  TJ gears are different than a CJ/YJ...  I don't know where the XJ falls...

But I still think whatever!  any investment at all into a D35 is a waste of money.  The Super 35 kits are a great value, and for a TJ it might be worth it (I'm I a hypocrite to myself?)(I'll explain that theory next*).  But whatever you spend on a D35 could be money put towards something else.

*The TJ theory:  See, a YJ rear axle replacement requires spring perches.  Thats all.  Shock mounts could be put on the Ubolt skid plates.  So it's an easy in inexpensive investment.  The TJ is much more substantial axle upgrade.  Unless you buy one premade, the welding of the coils spring seats, upper & lower control arm mounts and track bar mount is a huge undertaking.  Plus, it requires more that just welding skills, it requires absolute precision.  So with that said...  the TJ theory is...  spend alot of money on a really good great axle, or buy the Super 35 kit, but please...  don't go over a 32" tire.

IMHO

[Jeffy]

Code: [Select]

YG D30-538   D30 5.38 R&P   Dana   D30   5.38

Those are CJ D30 gears.  TJ gears are lsited as SHORT and YJ gears are REV.

[Bounty Hunter]

4.88 isn't really low enough for 35" behind a 4banger, you'll need 5.38 for anything near stock performance.  I wouldn't do anything short of swapping in D44's.

[SMC4WD]

I'm running 4.88's and I'm happy.  

Again, I'm dealing in a YJ/D30, so 4.88 were all that'll fit.  And I'm still pretty convinced that you could built a D30 beefy.  

The 30 doesn't break, the 35 does all the time!

[joe-joe]

I am running my dana 30/35 combo with 4.88's in my 99 TJ 2.5L and I upgraded to Yukon "Hardened 27 spline replacement shafts" as well. I am running Detroit Trutracs in both the D30 and D35 and have had no issues with my 33x12.50 Kuhmo MT's. I don't really play in the rocks here in the midwest but we have 2 great offroad parks within 3 hours of me (The Cliffs insane Terrain and The badlands). I wheel with my brother quite a bit who also has his 4.0 TJ with 4.56 gears and a detroit in the rear and has not broken a stock shaft yet.

I upgraded my axles for $92/shaft and they carry a 5 year warranty so I am not worried. I think that is a little cheaper than paying $800 for a bolt in 44 or more for a junkyard 8.8 and then having to pay someone to weld in all of the brackets.

just my .02