View Full Version : Those of you with 4.88's in your D30?

February 28th, 2007, 12:46
I have a few questions for those of you who have 4.88 gears in your D30. I am considering going with them but am just a bit concerned with the strength of the ring an pinion when going that low. I have heard that they are weaker then running 4.56's but have also heard that they have held up fine. I would like to hear from those of you who have them.

- How have they held up?
- How hard do you wheel with them?
- What size tires are you running with them?
- Are you happy with the way they drive and wheel?

February 28th, 2007, 12:56
- How have they held up?

I broke one set the first time I went out, but that was because I jumped my XJ off a sand dune and landed on the front axle. Even then I believe the ring and pinion broke because the housing flexed, not because of the strength of the ring and pinion. Since then I have replaced that housing and installed a crane diff cover and have had no further problems.

- How hard do you wheel with them?

Hard, people tell me there is more then one peddle down there, but that other ones no fun so I don't make a habit of using it all that often, and Iíve never taken a by-pass with out at least trying the hard line first.

- What size tires are you running with them?

33" TSL

- Are you happy with the way they drive and wheel?

Extremely, I worry more about my U-joints then my ring and pinion. I think the HP design of the XJ D30 makes the R&P significantly stronger then the R&P in a TJ.

fubar XJ
February 28th, 2007, 12:59
The key seems to be a stiff aftermarket cover to stiffen up the diff and avoid the flex that seems to spit teeth out.

I've talked to a few people that say 4.88"s aren't an issue with a reasonable skinny pedal and a stiff cover.

Starboard M
February 28th, 2007, 13:36
- How have they held up?
Yes, have held up fine. No issues
- How hard do you wheel with them?
No idea on how hard. Im rather easy on the gas, but it has gone through the Rubicon, and a couple other trips with no problems
- What size tires are you running with them?
35'' MTRs
- Are you happy with the way they drive and wheel?
Happy with them, but because my engine is so tired, takes away from the top end speed. Other then that, love them.

February 28th, 2007, 13:57
Thanks for the replies everyone! I think I am going to go with them and just wont get too wild with the skinny pedal lol!

February 28th, 2007, 16:18
A fellow Bako guy, Nice!
I have had my 488's in for about 5 years. Zero Problems. I have went anywhere that I have wanted to. I have 33's and the Disco Housing and stock cover and fresh 4.0.

My Father N Law has 35's, non Disco, stock cover, and a stroker! He has had his in for about 1 year and broke about 3 teeth off while in reverse.

I would say do it. I love mine (untill they break, then I'll piss n moan about it.)

February 28th, 2007, 17:58
I wheeled a D30 with 4.88's and ran 36" sx's locked, I broke a Ujoint and a main leaf in one (on my yj :-P) run but the R&P are still doing good.

February 28th, 2007, 22:25
I wheel 33" tires on my D30 with 4.88's (obviously no, it's not a DD). I don't wheel serisous rocks often (mostly forrest trails and sand/mud) but when I do, I've been known to substitute skinny-pedal for my lack of a rear locker. (it's something I'm trying to fix; but I'll just be honest here... it happens)

I've been OK so far, but I do remember when I was installing the axel that I was looking at the pinion of a D30 4.88 thinking how small it looked... Kinda like what you'd expect to find on one of those BarBie-Jeeps that 3 year-olds cruise around the yard in... :D

I do have the WARN dif skid that probably adds a good bit of stiffness to the whole thing. And, like I said, I don't hit it hard very often.. but I have given it a few good shots, and it's got me home every time... So far.

- Not that I'll be supprised if it blows to bitty bits... but as I mentioned, it's not my daily driver, so I'll still be able to get to work Monday morning. they ARE fun though.