4.10 gears in an axle

[project88mj]

okay i really have wanted these for a long time

so i going to the pick and pull this week and need to know

what to look for so i know that there is 4.10 in side the axle and not something like 3.07 or even a rat nest

 

any tips

 

also pm me if you have one so i don't have to look all over ... i meen under every jeep in all oklahoma city/ stillwater

[XJGPER]

Look at the axle tag on the axle.. Will say 4.10 or 41 10. Or pull the cover off the front and look for the numbers on the pinion, will say 41 10. Most 4 bangers had 4.10's..

 

Dave

[project88mj]

Look at the axle tag on the axle.. Will say 4.10 or 41 10. Or pull the cover off the front and look for the numbers on the pinion, will say 41 10. Most 4 bangers had 4.10's..

 

Dave

 

realy? i thought the lowest they came with was 3.55 like mine

i could use some pics of what he is talking about :roll:

 

axle tag?

[XJGPER]

Its a steel stamped tag that is bolted between two cover bolts. Hard to miss if its still got it, sometimes if a rearend gets redone, the tag isn't put back...

 

Dave

 

Also, 2.8L jeeps typically have 3.73's in em.

[Pete M]

There is a small metal tag attached to the axle's differential cover with one of the differential bolts. It'll have a bunch of numbers on it.

 

Also, a 2.5L with the 4-speed manual generally came with 3.55 gears while the 2.5L with the 5-speed manual generally came with 4.10 gears (a benefit of having the overdrive).

 

Don't forget that Cherokee and Wrangler rear axles will also fit with a minimum of effort. Explorer rear axles will fit with a bit more work.

[XJGPER]

This gives you an idea.. of where its at, its the bump between the two bolts there on the left.

 

 

This is the pic of the front axle of the jeep i just picked up, usually that tag is burried under a 1/4" of grease, take a screw driver and scrape it real well to reveal what it says.

 

dave

[project88mj]

i don't see any numbers?

[Pete M]

They are there. Stamped into the tag. You might need to use a wire brush to clean off any accumulated gunk or rust.

[project88mj]

oh my rear axle didnt have one my local jeep shop told me that is antidisestablishmentarianism it had

[reson46]

This will tell you exactly where to go to find the axles. It will ask you for the gear ratio you are looking for. Most places will usually already have the axles removed for you so all you have to do is pick them up.

 

Willy

[xj_dummy]

the 2.5L with the 5-speed manual generally came with 4.10 gears (a benefit of having the overdrive).

 

Um why is it a benefit to have 4.10 gears? :dunno:

[Pete M]

The 4.10 gears give the engine more leverage over the tires than 3.55 gears. To the driver this is felt as if you had more power from the engine. 5th gear would be worthless with 3.55s and the 2.5L because the rpms would be too low at freeway speeds (they'd be below the optimal torque).

[xj_dummy]

So what would be better for fuel economy? 4.10 or 3.55?

[Pete M]

That depends on factors like tire size and the particular type of roads and speeds the truck sees. But any fuel mileage gains either way would be minimal (and I personally prefer driveability to fuel mileage). I'll take 4.10 over 3.55 any day.

[89mjpioneer]

What would a 2.5 with the 4 speed manual tranny be?

[JeepcoMJ]

What would a 2.5 with the 4 speed manual tranny be?

 

likely 3.55's but maybe 3.73

[BLHTAZ]

What would a 2.5 with the 4 speed manual tranny be?

 

likely 3.55's but maybe 3.73

I thought those were geared lower than that...and weren't there some in that configuration with 4.56's?

[Pete M]

Rules of thumb for MJs:

 

2.5L + 4speed manual = 3.55

 

2.5L + 5 speed manual = 4.10

 

2.5L + 4 speed auto = 4.56

[BLHTAZ]

AHHHH... it was the AT that got the 4.56. Thanks Pete... :cheers: I know a lot about the mechanical workings of Jeeps, but I am still a bit rusty on the configurations on that type of stuff for the MJ. I know Wranglers much better though as I have owned them 10 times longer than the MJ ;)