kheltman

I have with regrets now a 96 cherokee, 4.0, 5 speed, 8.25 chrysler, with the dreaded 3.07. The lock nut came off on the rear dif at about 50 mph. pulled over with out a problem. Tow trucked it home, driver busted a couple teeth when unloading. Need to replace R and P. Can't find any for less then $600 for just the R and P. $1200 +- for the whole axle. Can I just change out both the front and rear R and Ps and change the ratio? If so whats best for gas Milage?

Big David

I can tell you have never heard of a JY.

For less than $500 you could have "new" axles, front & rear with 3.55's or 4.10's.

cruiser54

Get both front and rear diffs out of a Cherokee with an auto trans. Get the speedo driven gear from the transfer case, too.

kheltman

OK, so what is a JY?

cruiser54

Junk Yard

Used Parts Emporium

Wrecking Yard

Salvage Yard

Auto Wrecker

Pick A Part

freegdr

Instant 355 ratio upgrade ....410s if ya find 4cyl

kheltman

And what years Automatics?

kheltman

Thanks guys. Still new at this. Glad I have masters like yous guys. Cant believe I thought JY was a jeep model. POM.

cruiser54

I knew that's what you were thinking!! LOL.

Big David

Most all inline 6 motors with auto will have 3.55's. Most all 6's with 5 speeds have 3.07. The 4 cylinder 5 speeds are 4.10 older ones possibly have 4.56.

You need to look for axles out of a 96+ for the non-disconnect front axle bigger U joints & a 8.25 with 29 spline shafts.

The non disc axle has a smooth tube on the passenger side. The 8.25 will have a "lip" built into the pumpkin (below the diff cover).

You are close. Jeep made a YJ, or square headlight Wrangler.

cruiser54

Here's the front axle with the vacuum motor which Big David is suggesting you avoid.

1991Jeep_Man

x2!

That CAD disco sucks. Dumbest thing ever slapped into the XJ. Mine failed during a snow storm while my wife was driving it when I was at work. Her grandpap luckily was following and pulled her up the hill into our old townhome. Had to replace in the freezing **** cold and snow and ice. SUCK. Almost as bad as drums (which I soon will be rid of!).

kheltman

So as I was driving home last night, listen to the clackety clack noise my chero makes now, sounds like a train going down the tracks, I started pondering the ratio principle in my head. My 3.07 means my pinion turns 3.07 times for every 1 turn of the ring? So the larger the ratio such as the 3.55 my motor will "think" its going further than it realy is. I have been getting 20 miles to the gallon. And get this. With the AC on doing 85, I was getting 21 MPG. I figure its a computer thing. Anyway, I guess I will lose that mileage benifit. But in exchange I will get more torque? Your thoughts?

Lowrange2

You're still driving it with a broken ring gear?!


From 3.07 to 3.55 I doubt you'll notice a difference in fuel economy. Not much anyway.

salad

Makes a difference in driving at least on stock tires with a stick, 35 MPH in 4th will go from ~1250 RPM to ~1450 RPM.

Good time to get some larger tires