webekd

Is any one with 37" tires running a automatic? If so what is the gearing you are running? I came across a chart on another thread that show auto gearing ratio is different then standard. I have never heard of this before. The chart is below.

funtimes

I have auto with 35's and have 5.13's and wish I would of went 5.38's so I can't imagine you would go anything less than 5.38's.

Rubidonn

I've got 35's w/an auto and 5.13s... Like the setup, and wouldn't hesitate to go to 37's w/the 5.13s. However, if I were starting fresh and planning on putting 37s on, I'd go with 5.38s from the get go...

wayoflife

the pinion on a 5.13 in a 30 is way small already and can only imagine a what a 5.38 would look like. even if one were available, i think it would be bad news to use. while 5.38 would be the right ratio to go with, i think 5.13 is the better option even if you have a dana 44 front and rear.

jkrubi09

I've got 5.38's with 37's that actually barely measure 36". You don't want anything higher with an Auto if you have the Dana 44's. I mean come on its a 3.8 liter engine. You need all the help you can get!!!!

BillionDollarDan

sorry no 37"s here but i have 35"s with 5.38 and i really like it. rpm gets a bit high at highway speeds, but i would never ever ever go less than 5.38. with 37"s you can imagine that 5.38 gearing would be even more important

Rubidozer

I run 37s with the stock 4.11s in my Rubi 44s with my 3.8 and it's fine on flat ground. It sucks when driving up hills at higher speeds. I think the 37s feel
better than the 35s with the stock gearing, but maybe that's just because they look better!
Anyway, I haven't changed gears because I'm waiting to do my Hemi swap before any regearing. Just looking at different options, before taking the plunge.

1dirtracer

i have 5.13 with 35s auto wish i had 5.38 but got talk out of it by the installer,he said the pinion gets to thin with 5.38 on a dana 44

wayoflife

as mentioned, 5.38 is the right ratio to go with but, if you wheel your jeep really hard, the pinion will be a weak link. trust me, i've run 5.38's in a dana 44 and blew it up in a little over a months time. granted, i am running 40's and did run 9 hard trails in about 6 weeks but, i am easy on the skinny pedal and still was able to trash it.

wytmike

I jest re-geared with 5.13's. Was looking at 5.38's but as has been stated the pinion is pretty small even in a 44. Between the Flashpaq and the gears it does pretty well. Dropping down into 3rd at 70 will put you at +/- 3200 rpms.

Would the 5.38's be better? Yes. Is it worth the extra risk? I didn't think so.

Mike