Topic: Question for you guys with either 4.56 or 4.88 gearing

[cromwell]

OK,

 I am looking to upgrade my gearing and was looking at either 4.56 of 4.88s.   Now one of my concerns is of course my D35c rear.  Will 4.88 and a lockrite be too much for it to handle?

My current plan is to lift my 97 TJ 3" and run either 32" or 33"s MT type tire.  My Jeep will over course see pavement and muddy wooded trails, not much rock crawling.

Any suggestions or comments will be accepted.

Thanks,

Tony

[Jeffy]

You'll be more prone to breaking the axle shafts then the gears so I wouldn't worry about the gears.  Might want to get some spare shafts, too.  Lunch box lockers aren't very smooth and the sudden locking action is enough to twist the splines right off the axle shaft.

Here's what I'd recommend for gearing.

http://www.4bangerjp.com/forums/viewtopic.php?t=173

[cromwell]

Man, I must have been blind not to see that.  

Oh, and the trail rated badge post no longer applies.  I tried to get them and was told the only way to get the badges is thru a dealer.

Thanks,

Tony

[SMC4WD]

I'm running 4.88's, and I agree with Jeffy...  It's not the R&P to worry about, it's the axle.

My rear is a 9", so with a 4cyl, I should never have to worry (fingers crossed).  The front is a D30 that's 30 spline, so the weak link there is the smaller pinion gear.  I'm running the small bolt pattern hubs, so I hope that the hub breaks (I carry spares) before the pinion breaks.

Another aspect to consider is...  Stock, almost all 4 cyl. engines came with 4.10's...  the next step up is 4.56.  But in percentages, that's a .899, or 10% difference. (Side note that 4.88's are a .84 or 16% difference).
Now do that with tires...  a 33" tire from a 28" (althought stock may be closer to 27"), but that is a  .848, or a 15% difference.  

With that said, to chose the best ratio ask, how close to stock (or better) do you wanna get?

[Tappie]

My jeep is geared with 4.88's and running on 34" with a Lockright in rear for a couple of years now. Still haven't broken anything yet, but we don't do any rock crawling here. It's all mud. I think it's knowing your rig and it's weakest link(s). Found out that the engine stops first before breaking anything.

Charon

[Cooncan]

I had 4.88s in mine before the axle swap with 35" MTRs.  I was always easy on the throttle and carefull what I went over, though.  I didn't dare lock the rear but I did have the front welded.  Didn't have any problems but I may just be somewhat conservative with the way I drove it.  The 4.88s really helped it crawl with the 35" tires but you can almost kiss 5th gear away in any head wind or slight incline.

[Kmfdm24]

I have a question for the folks running 35's w/4.88's. Does it 'feel' similar to 31's w/4.10's...or better/worse?

I'm undecided between 33's & 35's.

[Jeffy]

Looking at your specs, I would not recommend going with 35's.  Going from 31's to 35's is a big jump.  You'll really want more lift and lower gears.  Lower then 4.88's.

If you're undecided and with stock axles, I'd stick with 33's.

[Kmfdm24]

Thanks for the reply.

Perhaps I should've went into a little more detail. I do plan on picking up an 8.8 (which I plan on leaving open for the time being) when Uncle Sam sends me my money back. Also, I plan on picking up a 1"BL if 35's are in the cards. I have a jigsaw on standby for the fender flares if need be. Perhaps a super 30 kit as well, or at minimum, Chrome-moly shafts up front, which also will be left open. I'm currently waiting on my 1"MM spacers from Goferit offroad.

With all that said, would you still recommend 33's?

As of right now, my main concern is the gears. Will it really be that much worse than the feel of my current setup? (31's, 4.10's)? sidenote: I don't mind the way my current setup feels as far as acceleration is concerned. I kinda like it :wink: .

I apologize for pushing the issue but I really would rather spend the cash on a set of 35's. However, I still would like to hold say 60-65, dare I say70 mph on flat hwy in fifth.

Thanks again for the input!

-Eric

[Bounty Hunter]

Go with the 4.88, as 4.10 to 4.56 isn't enough of a change to warrant the time and $$.  

Go with the 33", if you want 35" I would suggest swapping in a pair of D44's so you can go with 5.38 gears to be geared properly.