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View Full Version : Anyone running 37s with 4:56 gearing?



Cornflake
December 26th, 2013, 09:48 PM
My YJ is currently sitting on 35s and I'm running 4:56s. I'm going to stretch and step up to 37s and I'd love to not have to re gear.. Anyone getting away with this on the trail? I should prob include that I'm installing a D300 with a LoMax 4:1 at the same time. Thanks guys!

willys dave
December 26th, 2013, 09:57 PM
I have been looking at lomax for my d 300 also . Cheaper then Teralow , and according to lomax , stronger . Are they still having a sale ? Have you bought yet ? Maybe if we bought 2 sets , they would be cheaper.

Cornflake
December 26th, 2013, 10:05 PM
I have been looking at lomax for my d 300 also . Cheaper then Teralow , and according to lomax , stronger . Are they still having a sale ? Have you bought yet ? Maybe if we bought 2 sets , they would be cheaper.

I've already purchased mine but I was looking at them for quite some time and they always seem to be "on sale" according to the website lol

69cj5
December 27th, 2013, 05:40 AM
I am running 35's with 4:10 gearing. Have a sm465 with a Dana 18 behind it though that help out with this setup. The sm465 is the only way I get away with this with its 6.something granny 1st. I would probably drop gears in the axles and put a overdrive in it if I ever did it again.

But it works pretty well in all but the most serious crawling situations. Been through the rubicon several times with this setup.

Dirty Harry
December 27th, 2013, 05:52 AM
What is the rest of the drivetrain? Gearing that works for a four cylinder with an automatic won't necessarily be the same as a V8 with an SM465 behind it.

Assuming you have a 4.0L and a thee speed auto, I think that 4.56 should work OK with 37s on the road and not be a problem on the trail. With 4:1 gears in the transfer case (assuming you had a stock NP231 before) you crawl ratio will be 25% lower in low range (40.7 vs 30.4) so you should be fine. If you decide it isn't enough gearing you can always regear the diffs down the road.

69cj5
December 27th, 2013, 06:00 AM
What is the rest of the drivetrain? Gearing that works for a four cylinder with an automatic won't necessarily be the same as a V8 with an SM465 behind it.

Assuming you have a 4.0L and a thee speed auto, I think that 4.56 should work OK with 37s on the road and not be a problem on the trail. With 4:1 gears in the transfer case (assuming you had a stock NP231 before) you crawl ratio will be 25% lower in low range (40.7 vs 30.4) so you should be fine. If you decide it isn't enough gearing you can always regear the diffs down the road.

This ^^

I am running a Buick v6 gruntmaster with this setup. May not like it if you are running something that can't chug down low

Dennis
December 27th, 2013, 06:12 AM
I have a 4.0 with 3-speed 999 and 4:1 t-case. 4.88 gears and 40s. Works great.

Cornflake
December 27th, 2013, 06:54 AM
What is the rest of the drivetrain? Gearing that works for a four cylinder with an automatic won't necessarily be the same as a V8 with an SM465 behind it.

Assuming you have a 4.0L and a thee speed auto, I think that 4.56 should work OK with 37s on the road and not be a problem on the trail. With 4:1 gears in the transfer case (assuming you had a stock NP231 before) you crawl ratio will be 25% lower in low range (40.7 vs 30.4) so you should be fine. If you decide it isn't enough gearing you can always regear the diffs down the road.

Ya sorry guys I left that out.. 4.0 with a 5speed and yes it's currently the stock t-case. D44 with molys and a Detroit and ford 8.8 in the rear.

Cornflake
December 27th, 2013, 06:55 AM
I appreciate the input fellas thank you!

Cornflake
December 28th, 2013, 09:56 AM
I'd love to take a ride in someone's rig that has a similar set up if they're willing. Fuel on me

White7
January 5th, 2014, 06:50 AM
I ran 258/sm465/d300 with 4:56 and 37's no prob

Cornflake
January 5th, 2014, 08:34 AM
I ran 258/sm465/d300 with 4:56 and 37's no prob
just off road or did you drive it on the street as well? And thank you!

XRATEDXJ
January 5th, 2014, 10:14 AM
I run a YJ with a 4.0L, 5-speed, and 231 with a 4:1 and 37's. 4.88's in the axles. It is alright for both street and trail, but it really isnt low enough for my liking. Off road it seems to stall a lot and I wish I had a little more power down low. On the street it will do 70 without revving it to the moon, but I rarely drive it that fast so once again a little more gearing would be better. I can rarely drive around in 5th. 4Hi with this setup is just about useless. You can barely get out of first gear with all four spinning. My guess is that you wont be very happy with 4.56's. When I swap my axles I will be going with 5.38's. Your welcome to take a ride in mine if you want to check it out.

Cornflake
January 5th, 2014, 01:54 PM
I run a YJ with a 4.0L, 5-speed, and 231 with a 4:1 and 37's. 4.88's in the axles. It is alright for both street and trail, but it really isnt low enough for my liking. Off road it seems to stall a lot and I wish I had a little more power down low. On the street it will do 70 without revving it to the moon, but I rarely drive it that fast so once again a little more gearing would be better. I can rarely drive around in 5th. 4Hi with this setup is just about useless. You can barely get out of first gear with all four spinning. My guess is that you wont be very happy with 4.56's. When I swap my axles I will be going with 5.38's. Your welcome to take a ride in mine if you want to check it out.

That's awesome of you to offer that thank you! I'd greatly appreciate that opportunity.