Never done this, wanna do it right but dont know how!

[JeepcoMJ]

to chime in...

 

we just swapped from 3.07 gears to 3.55 gears in my brother's 88 4.0 ax15 5 speed 4x4 MJ with 31x10.50 M/T's...

 

the difference is DRASTIC. his gas mileage went from 18mpg on a long haul to 20.5mpg on a long haul, and he averages around 18mpg city as opposed to the previous 15mpg city.

 

now, tell me that is not "worth it"

 

he can almost out-do the 3800 now :yes:

[mvusse]

Almost? I though any Comanche moving under it's own power could out-do the 3800 for now... :D

[project88mj]

thanks for all the help posting your PRICES :wall:

 

i just want to know what to expect :doh:

 

didnt think think it would be that hard :hmm:

[pingpong]

I wil post up my opinion on this. To me it isnt worth the money to do the swap. Figure install kits are around 100 bucks a piece, and you said you can get the gears done for 100 an axle... you are at 400 bucks :eek: Thats a lot of money for an axle you can get stock. If you were doing 4.10's I would say it is still high.. but at least a drastic enough improvement that I would deem it a reasonable expense.

 

 

AS for used gears. I almost use them exclusively. :huh???: Most of the time they are cheap :yes: and for the most part none of my rigs really see any highway use. I have yet to have a noisy install with used gears, but I have alwayspaid to have my gears installed. I do all my other work but that. [/color]

 

 

On a side note... I have a used set of 4.10's for the d35 I will sell you for 20 bucks plus shipping.

[project88mj]

how used are you talking

 

i need to know how many miles

 

and how hard those miles were

 

pm sent

[Redramman]

You can even buy dvd's on the topic,I took the easy way and bought my Ram with 4:10's everybody thought I was crazy,I sometimes wish I had 4:56 or even 4:88 . Also when figuring RPM most gear charts asume 1:1 trans ratio, overdrive will lower RPM, an Automatic trans will have more RPM depending on stall speed of torque converter,Just thought I'd FUEL the FIRE :fs1: :rant: :grrrr: :mad: Just Kidding :rotfl2:

[aemsee]

I've used second hand gears numerous times. Ran used 4.10's in my ZJ for 40K miles.

If you go from 3.07 to 3.55, you can reuse your carrier. Above that you need a new carrier and it adds to your cost.

 

If you look at the end of the pinion, there will be a variance marking. Either (+) or (-) . There is a chart to put in the original pinion variance and the new pinion variance, and it will tell you how much shim you need to add or subtract to your new pinion. This will give you your pinion depth.

 

If you are reusing the carrier. I would start with the original shims and check backlash and pattern, and adjust accordingly.

 

If it is a new carrier, and you don't have the special tools to determine side clearance, be prepared to pull the carrier numerous times. A case spreader is often necessary for this.

 

If you are still determined to try this yourself, get a good book with illustrations. And some gear marking compound and pattern your old set before you take them out, drive and coast sides, so you have something to compare your new set up to.

[pingpong]

how used are you talking

 

i need to know how many miles

 

and how hard those miles were

 

pm sent

 

 

I replied to your PM.