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What gearing for 32’s???

7roy1117

NAXJA Forum User
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I’m putting 32 inch tires on my xj and don’t know much about gears in the front or rear and what ratio would be best for this tire size?
 
That's a nice looking xj I'll let the experts chime in on gearing choices.
 
I'm running 4:10's on my XJ with 31" tires, and 4:56's on my XJ with 33" tires.

Is it an automatic or manual?

What is your primary use of the Jeep? Daily driver with occasional wheeling, or mostly a trail rig?

You can go to this website and calculate your ratios:

http://www.grimmjeeper.com/gears.html

For me as a daily driver, I would probably do 4:10. For mainly a trail rig, 4:56. JMO.
 
Another vote for 4.10's on a street/trail rig, and 4.56's for dedicated hard core rig!
 
I'm happy with 4.10/4.11 on my MJ running 32s and around 5" of lift. Some mild offroading, no rock climbing, but lately mostly intermittent commuting and when I take my mountain bike with.

I swapped in 4-cyl junkyard axles a long time ago.
 
Forgot to mention, I'm running an 98 AW4 automatic so my OD ratio is 0.75:1, versus the 0.705 ratio and 21-spline prior to mid 1990. Also ran this with the AX-15 5-speed.

As I recall, my speedo gear was pulled from a 4.0 that had 3.73 axles and it spot on. 36 tooth?
 
I'm running 4.10s with 32s (metric) on a 98 XJ auto with 4.5 lift. It does OK. Does feel a bit sluggish at times. Mine does have a bore TB and 2.5 cat back, and an aftermarket header. I did plan to regear to 4.30s. Yes, an odd choice. Build plans have changed.
Also, I do use the gear calculator posted above. It seems fairly accurate. I do like to run about 2,200 RPMs at 70 mph. Also, if DD, it depends on what location. Basically, mountains or such. I have another build 2" Auto 3.73's and 31's. Gets a bit slugish on mountains in WV. I do have a header on it, 2.5 CAT back, and bored TB. I did thin the throttle shaft on the TB. It did make a difference. Nothing you would notice. Still, my tranny is not searching between 3rd and OD on some inclines.
 
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I run 4.56 on 31s with an AW4 in Colorado; it's used for both daily driving and rock crawling. I would not go lower (numerically) for my uses. It runs just fine up to 70mph (and a bit faster, but I generally have no desire to drive it any faster than 65 in most cases...the XJ is not exactly safe or can handle quick maneuvers well).

It searches between gear 3 & 4 on long/sustained climbs in Interstate-70 (mountainous) cruising around 60-65 mph. It wants to go faster to stay in 4th, but I don't like going that fast, so it's beyond frustrating. I tend to keep it in 3rd and let it scream a bit.
 
I run 4.56 on 31s with an AW4 in Colorado; it's used for both daily driving and rock crawling. I would not go lower (numerically) for my uses. It runs just fine up to 70mph (and a bit faster, but I generally have no desire to drive it any faster than 65 in most cases...the XJ is not exactly safe or can handle quick maneuvers well).

It searches between gear 3 & 4 on long/sustained climbs in Interstate-70 (mountainous) cruising around 60-65 mph. It wants to go faster to stay in 4th, but I don't like going that fast, so it's beyond frustrating. I tend to keep it in 3rd and let it scream a bit.
Hell yes... finally someone else that has run 4.56s and 31s and loves it!! That was probably the best combo my old xj ever had......

Sent from my SM-S901U using Tapatalk
 
4.56 is my vote. I had 33's on 4.10s and it was meh, on 31's it was fine but any bigger you're going to want deeper gears. Don't get me wrong 4.10s are way better than stock but if you're going to the trouble of regearing get some pep in there. Not like the 4slow is a power house.
 
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