i have a 91 ford explorer with 79 bronco dana 44 and 9 inch. it has 3.50 gears abd stock 4.0 with 5 speed and stock t case. i blew the rear end up in it and looking to gear it down and put a spool in the rear. what gears should i run? i have 35.s on it right now but soon to be 37's in a couple of months. thanks for the input guys


brandon

If its mainly just a road warrior...4.56s
If it will see some good offroad use...4.88s
just my 2 cents

get the 5.43's for the 9 and 5.38's for the 44... it was too low when I ran 35's but was awesome when I ran 38's. I forget the rpm's I ran at but I drove the truck to rubicon quite a few times when I had 35's and those gears... yeah it revved out, but it was driveable ;) That was with a 4.0L and a 5 speed too. The 4.0's like to be revved... you will like it :D

- go with 4.88 if you drive on the road alot with 37s - otherwise go with 5.13 - my bro has a 89 f150 with a 4.9 and 5 spd ( had 37 boggers) - 5.13 and a spool - its like diving a sports car - much more acc. and highway was good to - helps offset heavy tires ( now it has 38.5 x15.5 boggers and he wants 5.38s ) :smokin:

Here are some numbers I posted to a similar question over at RRORC.

Stock:
28s - 3.55 - 1:1 trans - 65 mph - 2769 rpm
28s - 3.73 - 1:1 trans - 65 mph - 2909 rpm

35s - 4.56 - 1:1 trans - 65 mph - 2845 rpm
35s - 4.88 - 1:1 trans - 65 mph - 3045 rpm
35s - 5.13 - 1:1 trans - 65 mph - 3201 rpm

35s - 3.55 - 1:1 trans - 65 mph - 2215 rpm
35s - 3.73 - 1:1 trans - 65 mph - 2328 rpm

37s - 4.88 - 1:1 trans - 65 mph - 2881 rpm
37s - 5.13 - 1:1 trans - 65 mph - 3028 rpm

This is what I'm running...
38s - 5.13 - 1:1 trans - 65 mph - 2948 rpm

Actual package in my Ranger SAS project:

C4 - Transmission -- 1 - 2.46, 2 - 1.46, 3 - 1.0
1354 T-case -- low - 2.48, high - 1.0
1354 doubler -- low - 2.48, high - 1.0
Gears - 5.13 - tires 38s

Crawl ratio 1st gear: low -- 31:1, low-low -- 85:1
2nd gear: low -- 18:1, low-low -- 52:1
3rd gear: low -- 13:1, low-low -- 34:1

Stock: A4LD -- 1354 -- 3.73 -- 28s - 1st gear - low: 22:1, high 9:1

Here are some numbers I posted to a similar question over at RRORC.
Crawl ratio 1st gear: low -- 31:1, low-low -- 85:1
2nd gear: low -- 18:1, low-low -- 52:1
3rd gear: low -- 13:1, low-low -- 34:1

Stock: A4LD -- 1354 -- 3.73 -- 28s - 1st gear - low: 22:1, high 9:1

you forgot that the A4LD (and Im not sure if the C4 is the same) has a 2.56:1 reduction at the torque converter..

Im runnin 35's with stock 3.73's and an auto..
a4ld 1st gear 2.47:1
1354 low is 2.48:1
doubler low (its a 1350/54 planetary) 2.48:1
axle ratio is 3.73:1

so its 2.48x2.48 to get the ratio of the doubler and the low in the t-case..=6.15:1

..and the converter ratio is 2.56...


2.47x6.15x3.73x2.56=145:1

stock is 23:1

Wanderer,

I got the figures from an on-line calculator. You plug in your transmission, t-case, rear axle, tire size, etc., and it spits out data. It may not factor in the torque converter advantage that you suggest.

Here is the link -- best ratio converter I've found!

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

I would also say 5.13 gears. That's about perfect on the 4.0L V6 with 37" tires.

Keep in mind. This set of tires may be 37's, but tires "wants" keep growing. Go 5.13 and you may be ok for that next size up.

ok thanks guys! well any of ya have any parts? in need of a whole 3rd member and dana 44 stuff