4.56 gears, now what?

So, I cam across a deal for an '88 2-door with 4.10 gears and and ARB in the rear: $1000. I jumped on it, expecting to possibly swap out some parts into my '89 2-door. However, it turns out that it's in overall better condition than mine, 60k fewer miles, so I'm keeping it. The other surprise is that the gears are actually 4.56.

But now what? It has stock wheels with 235/75R15 tires, a suspension in good condition but no substantial lift. It also has some kind of aftermarket fender flares (they're pretty rigid compared to my other two XJs, and wider) which were riveted on with about 20 rivets for each one: they're cracking around most of the rivets and I'm pretty such they wouldn't survive removal.

Drivability definitely suffers from the combination of 29" tires and the gears. Funds are tight as a result of needing the wife's approval...

I could just buy some 33" tires, but it looks like new wheels will also be required. Would 10" be enough width? Should I get less than 3.5" backspacing? The tire options seem to increase substantially with 16" wheels, but are there consequences from making that transition?

Plus, in the long run I probably won't even be keeping these axles (D30/35), so maybe the bolt pattern will end up changing as well.

I'm definitely feeling overwhelmed.

well, new wheels are not a must, I just put 33x12.5" tires on my stock 7" wide wheels and they fit fine, look good too. and for backspacing i just put 1.25" wheel spacers. worked out good, i got 4.56 gears too and with the 33" tires its still got a little more torque than stock. but you would probably be happier with 32" tires if there isn't much of a lift, then you could go with 10.5" wide tires and not have to worry as much about the backspacing, also, 4.56 gears and 32" tires would haul ass.... even 31's would work good.

33's and a turdy five are not gonna end well, unless you add a Super 35 kit your going to have problems. Especially since it has a locker.

Sell the turdy five and buy a stronger axle and gear it to match, 8.25's are going to be the easiest way to go (bolt in and pretty available).

Oh and you probably have rustys offroad fender flares if they are rivited.

-Alex

Yeah, the 35 is a weak sister. That being said, its already there, and its got an ARB, Id run it till it broke. I would most likely go to a 31 instead of a 33. The gears will be fine with 31s....

You can NEVER be too low geared...

ah, didn't catch that.... yeah the 35 is no good, i would run it until it breaks if you can afford to have it out of commission for a while.

I've read about the weaknesses of the D35, but I also plan to do absolutely zero rockcrawling or recreational driving with this Jeep: it's strictly for hunting and other backcountry transport, so I expect that I won't be stressing it very hard.

Plus, as I mentioned with basically needing wife approval for projects, breaking an axle is good evidence that I should spend some time putting in a stronger axle to avoid it in the future.

Jonathan said:

I've read about the weaknesses of the D35, but I also plan to do absolutely zero rockcrawling or recreational driving with this Jeep: it's strictly for hunting and other backcountry transport, so I expect that I won't be stressing it very hard.

Plus, as I mentioned with basically needing wife approval for projects, breaking an axle is good evidence that I should spend some time putting in a stronger axle to avoid it in the future.

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I broke my dana 35 making a u-turn on a gravel road.

They are just that weak.

I have wheeled my 35 in the rocks pretty hard held up for me for about 2 years then I snapped it fliping a bitch. I stepped on the throtle a little too hard an when the jeep went from gravel to pavement I snaped the drivers side. no big deal though I bought a good used axel shaft for 40 bucks put her in and Im up and running again, just got back from a 13 mile rock crawl, no issues yet, Im running 33's and 4.10's

Not gonna comment on the 35

You want 33's with 4:56 gears. If you run 31's and 4:56's your RPM's will be outragous on the highway. YOu also want either 7" or 8" rims with anywhere from 4.25" to 3.75" os backspacing. There are LOTS of folks who sell stock rims or after markets on Craigslist for cheap.

You will need a minimum of 3.5" of lift and minor trimming for 33's. If you aren't going to do any rock crawling you can go with a cheaper lift, but I always recomend the RE Super Flex

I'm pretty surprised to hear that 7" or 8" rims would work: I expected that tires 12.5" wide would require a larger rim.

Since right now all I have are a few sets of 15x7 stock rims (5" backspacing?) I assume I'll need new rims just for the backspacing. Although I could just use spacers, I'm not fond of that idea. So if I get new wheels, what's the best way to go? Is it really a good idea to use a 7" or 8" width?

if your getting new wheels anyways go with at least an 8" wheel. but honestly, stock 7" wheels and spacers(spydertrax is the best) wrok just fine for alot of guys on here. however, you can get aftermarket steelies for about the same cost as spacers.

Jonathan said:

So, I cam across a deal for an '88 2-door with 4.10 gears and and ARB in the rear: $1000. I jumped on it, expecting to possibly swap out some parts into my '89 2-door. However, it turns out that it's in overall better condition than mine, 60k fewer miles, so I'm keeping it. The other surprise is that the gears are actually 4.56.

But now what? It has stock wheels with 235/75R15 tires, a suspension in good condition but no substantial lift. It also has some kind of aftermarket fender flares (they're pretty rigid compared to my other two XJs, and wider) which were riveted on with about 20 rivets for each one: they're cracking around most of the rivets and I'm pretty such they wouldn't survive removal.

Drivability definitely suffers from the combination of 29" tires and the gears. Funds are tight as a result of needing the wife's approval...

I could just buy some 33" tires, but it looks like new wheels will also be required. Would 10" be enough width? Should I get less than 3.5" backspacing? The tire options seem to increase substantially with 16" wheels, but are there consequences from making that transition?

Plus, in the long run I probably won't even be keeping these axles (D30/35), so maybe the bolt pattern will end up changing as well.

I'm definitely feeling overwhelmed.

Click to expand...

BFG makes their AT KO in 33x9.5 i believe... solves your tire fitment problem

wow.... 33x9.5 would look rediculously skinny and tall, even the 33x10.5 looks pretty tall and skinny.

Jonathan said:

I've read about the weaknesses of the D35, but I also plan to do absolutely zero rockcrawling or recreational driving with this Jeep: it's strictly for hunting and other backcountry transport, so I expect that I won't be stressing it very hard.

Plus, as I mentioned with basically needing wife approval for projects, breaking an axle is good evidence that I should spend some time putting in a stronger axle to avoid it in the future.

Click to expand...

I'm real happy with 4:56 and BFG 32 x 12.5 tires. A bit torquierer (is that a word) than stock, but I like it!. I'll probably bump to 33s next time I buy tires. I have a RE 4.5 lift.

You might be able to squeak 32s in there with a bit of fender trimming.

I wouldn't worry about the weak 35 unless you plan on rock crawling or mud bogging.

mitsumotors said:

wow.... 33x9.5 would look rediculously skinny and tall, even the 33x10.5 looks pretty tall and skinny.

Click to expand...

I don't think 33x10.5s look funny at all. I don't think 9.5s would, either. The wheels are 15x8 with stock 5.25" backspace.

FWIW, I ran with 235x75s for several thousand miles with the 4.56 gears and it was OK. As long as you have OD, they are fine on the highway at any reasonable speed. IIRC, RPMs were around 2,600 at 65 (per GPS)--right in the power band.