Bonedoc

Okay everyone, here is my dilemma. I have an '08 Sahara unlimited. Putting a trailmaster 4.5" kit in it with 37's. My jeep is a manual 6sp. trans.
I asked a while ago before I ordered my stuff what gear ratio everyone thought would be best. I looked at the chart, etc, was debating on 4.88 or 5.13. I do mostly road driving, some highway, so 4.88 looked like the best for a daily driver with some offroad use.
The opinions came in from everyone saying to go with 5.13, that the chart doesn't take into account the weight, etc. So I ordered the 5.13's, I haven't installed anything yet but would like to hear from everyone/anyone who has gone with 5.13's. Any regrets? Anyone go with 4.88 and regret it. Just looking for somemore confirmation before I send to the shop for install.
Please let me know what you think, what benefits you saw, etc. Again my jeep is a manual 6sp., not the automatic trans.

Thanks everyone for your time

JDScott10

went 5.13s on an auto with 35s. Seems a bit much. Chart doesn't seem to account for "squish factor"

jlarso

From recent posts on this forum it seems that the 4.88 are the preferred gear ratio for a manual transmission with the added benefit that the 4.88 gears are stronger and more durable than the 5.13 gears.

Bonedoc

Thanks so far guys, anyone else have any suggestions/comments? I can easily ship the 5.13's back and have them exchanged for 4.88's. Just want to hear as many opinions as possible before my JK goes under the knife. LOL

Joisey

200 rpm diffrent between the two.
4:88 are stronger.

wayoflife

pushing a set of 37's, 5.13's would definitely be the ratio i would recommend but, being that you only have a dana 30 up front, i can potentially be a weak point. so long as you're easy on the gas, don't install a locker up front and don't do any hard wheeling, you should be okay.

08RedRecon

I have exactly the same setup you have, and went 5.13s. Love it.

Torrin

I would stick with the 4.88's. I am running them with 35's and I am still a bit too low geared. I would think they would be ideal with 37's. Also, on a D30, the pinion is tiny on a 5.13.

PS. I would recommend you sleeve and gusset your D30 when you put those 37's on, I will also start saving for a D44 up front.

Joisey

watch out
(incomming pro rock nazis)

j/k love the pr

Bonedoc

Thanks for the input guys, I understand what is being said about the pinion, I also considered the 4.88 as it would slow my driveshaft speed down, hopefully minimizing the chance of blowing a transfer case.
I'm not going to be doing any rockcrawling so my main concern is if 4.88 are low enough to get decent acceleration and hold highway speeds? By some of the replies it sounds as it would be, I'm just don't want to go with the 5.13 and have it be too low and have the engine screaming everytime I'm on the highway. I also don't want to go with 4.88 and not be driveable.
I don't plan on going bigger than 37's.... at this time and if I did I'd definately be doing axle upgrades first so I would have to readdress the ring and pinion options then.
Anyway, please keep filling me in, I already have the 5.13, like I said I can still exchange then for 4.88.
Anyone with a 6sp, 37's and those ratios, how is it on the highway? What RPM's are you running? How is your gas mileage?

thanks again guys