3.73 or 4.88 ?

If you where building a jeep which would you choose?

225 V6, T14 trans, 31 x 10.50 max tire size.
Mostly short trips, maybe 15 miles.
Occasional trips to the lake with a canoe, 50 - 75 miles round-trip.
Maybe plowing a few driveways in the winter.

I've got '70 axles, 4.88, flanged rear, the front diff is blown.
.. or '69 axles, 3.73, working condition.

Oh, and no OD and I don't want to spend the money on one.

 

4.88's. I liked the 3.73's for street driving in my '73, but they were too high in my opinion for off road use with the Dana 20 and t-15 transmission.

 

Sounds to me, that you won't be doing much wheeling with the JEEP, right? I would say the 3.73's with 31s for mostly road/light trail use. I ran 3.73 with 33s for years. Couldn't really go slow enough in rocks but, did OK otherwise. I currently have 4.88s with the 33's and I'm in 3rd gear in no time flat, on the road.

 

i'm running 225, t-14, with 3.73 gears, 31x11.50. Its nice for driving around town and such, but when i'm offroading I wish the gear was a little lower so I don't have to use low range all the time. It still does really good, Just got to know which hills you need to put it in low range and get a little speed. (I like the really steep hills.)

for me I keep going back and forth on switching out the gears and going to 4.27. I will most likely leave the gears alone and swap in a four speed to get extra gearing while maintaining high way speed ability.

 

For the use you list I'd say 3.73 and around a 30" tire. Work well on and off road for what you list.


Sent from my iPhone

 

4.88s i have 3.73s and sure would like to change , jeeps dont go fast, and wernt meant too so i feel the 3.73 s just make my jeep a little anemic on the trail an dont do alot on the street

 

3.73's, but not sure that will be very compatible with much plowing. And I don't really think you want to be in low range for that unless you have very little to plow.

 

I plowed with 3.73's for yearswith no problem

 

3.73 with 30" tires is fine . the weak link is the T14

 

Seems like the 3.73's win out, which is what I was planning on, just second guessing myself. I've had all these combinations in the past but it's been some years since I've had them. The last jeep I had was 5.38's and a T18, great off-road and not to bad on the street with the OD, but I also remember the jeeps with the 3.73's being nice to drive on the street. With this current project that's more what I'm after, the snow plowing will be fine with low range.

 

If you opt for the 3.73 gears, I'd be interested in the 4.88 axle. I'm building a f-134 powered cj with 4.88 gears and it would be nice to have the flanged axle in the rear...

So, if you choose 3.73 -- send me an e-mail at panax@fuse.net

I'm up to PA about 8 - 9 times a year...

thanks

kamel

 

go with the 3.73s for now
4.88s are gonna be hard to locate for a D27

 

I remember when I was asking and researching online about this same question. I opted for the 4:27 gears which was in the middle. I've not run them yet but am almost done with my axle rebuilds and should be going by late spring.
And like jp said 4:88 will be hard to find for a 27 but 4:27 will be a bit easier

 

I'd go 4.88 - you can run 4.88s on the highway with a healthy 225, as long as you aren't expecting to go over the speed limit. I don't doubt that you'll have a tough time finding 4.88s for a 27. However, 4.88s are available for the 30, so I'd likely put the 3.73s in for now, and look for a 30 to build for the front axle. That offset flanged rear axle is a very desirable component, and you could sell it if the 3.73s are to your liking.

 

Might consider 4.27 gears, which would put you midway between the other two.

 

I ran 31's and 32's with V6/T14/3.73's for a few years. For your useage the 3.73's would be fine.

The torque of the V6 makes it very flexible. For what you're doing anything from 3.73 to 4.10 or maybe 4.27 would work well. IMO the 4.88's would be too low for a tire that small unless you're mostly off road or have the OD. Gas isn't getting any cheaper either.

 

Good info Lynn! I was just about to ask what everyone's thoughts were with a t-18 instead of the T-14, but didn't want to threadjack R) I'm building a 225/T-18 combo and have a dana 30 front axle with 3.73, and a set of axles with 5.38's, so the topic is very relevant for me right now!