to gear or not to gear

[bugler30]

I am currently running a 89 Cherokee on 3" lift with 31s with a 4.0 and 3.55 gears. I have a set of axles out of an 86 Cherokee with 4.10s. Rear will be easy enough to just swap the axles, Front, not as easy. I was lucky enough to get the non vacuum disco front end in mine and it has the better u-joints, etc. Whereas the 86 front end has the vacuum disco. My plan was to take the gears out of the 86 front end and install them into my 89 front end (my dad has the shop and tools and ability to do it).

My delima now being I've gotten used to the slightly better mileage the bigger tires provide with stock gearing. Also I'm being told that it is not worth trying to pull and reinstall used gears. The XJ is my only rig at the moment and cannot afford to have it down for more than my days off... so should I do it or should I sell the axles with the 4.10s? its a 30/35 in both cases.

 

[WB9YZU]

If you have the desire, as both axles are D35s, just swap the axles. The disco is no problem, just take a clamp and lock the vacuum motor engaged.

The only thing I would caution is if you have the 297 shafts on the 93. If you do, then do the carrier and gear swap into your D30 because the 86 D30 had 260 joints.

Ron

 

[bugler30]

The only thing I would caution is if you have the 297 shafts on the 93. If you do, then do the carrier and gear swap into your D30 because the 86 D30 had 260 joints.

Ron

that is what I'm talking about. My 89 has the ABS axle (without the ABS) so it has the 297 u-joints.

I also just replaced the ball joints and such in it, so I'd really hate to throw my current housing away essentially.

Otherwise I'd make a plate to block off the disco and put my better shafts/u-joints into the housing with the 4.10s. Swap over my hub/bearing assembly, etc. would be a lot of work but would be safer than re-gearing.

it might be worth it still to put new ball joints into the 4.10 axle housing would probably cost about the same buy time I buy the pinion bearing/seal kit.

 

[Johnnie Walker]

Check the gears and make sure they are in good shape, and get a master install kit and swap them!

 

[FoMoCo]

I say do it, you should get better mileage with 4:10s

 

[bugler30]

I say do it, you should get better mileage with 4:10s

maybe in town, but I do alot of highway driving 55+ so I'll be loosing mileage on the top end.

 

[jeeperjohn]

maybe in town, but I do alot of highway driving 55+ so I'll be loosing mileage on the top end.

If you're running 30 or bigger tires you should see better mileage with 4:10's.

 

[FoMoCo]

yup, unless you are routinely doing 85+ you will get better mileage with the 4.10s on the highway, the 4.0 is most efficient between about 2500 and 2800 rpm

 

[NW-ZJ-SCOTT]

Use the 86' Dana 30, do the vacuum delete. and install your 297' shafts into it, so simple a caveman can do it. you wont need your pops'