Currently I drive a 99 manual cherokee with stock gears, since I swapped from my 31's to 33's, I have had a significant loss of power and bogging of the engine in 5th gear. That alone makes me believe that a regear is in order. That is not the only issue however, my true reason for worry is the sound I hear when I hammer down at a full stop in 1st gear. It feels like the gears are slipping or something like that, I get 2-3 small pops (like something is hitting the tailgate in the trunk) and then it is gone. This is alarming, going into winter, I don't want to have any issues. I have a Chrysler axel in the rear and I believe a Dana thirty in the front. Please any help is appreciated, along with where to find a reliable place to receive the parts. Thank you.

 

Try to find some axles out of an auto. They'll have 3.55s and will be cheaper and easier than regearing your current axles.

As far as your vague pops, your guess is as good as ours without some solid information.

 

I thought the manuals came with 3.73 gears? The clunking might be bad u joints.

 

Clunking could be a bad motor mount since you hear it from a stop to throttle. But that's hard to diagnosis with out being there or have more info.

As for a regear, I had 3.55s in my stock auto axles with 33s. The power loss was real. With 33s, you'll want 4.10s to be roughly close to stock. You could do an 8.8 swap, and regear the front 30, or try to find the stock XJs with the towing package and the rear 44 and front 30. If my memory serves me right, they had 4.10s. I think YJs did as well. I could be wrong on the models, but there are stock keeps with 4.10s, just stupid rare.

 

33's and a manual = 4.10's
http://www.grimmjeeper.com/gears.html

 

So I was spot on. I just go by tire size from experience and what has worked for me and rigs I've built. Thank you for confirming!

 

I am going to purchase 4:10 gears, however, how in depth are we talking for an install?

 

I was in the same boat as the O.P. When I bought my XJ it had 33" tires on it. With the 5 spd. (3.07 gears) I couldn't stand the lack of low end especially on the trail. So I went ahead and traded my 33"s for 31"s and it was better. Then I ended up parting out my son's XJ. and swapped in his axles. with 3.55 gears I now can enjoy my XJ the way it was intended to be. I think I could get away with 33" now but I want to save for gears and a front E-Locker while I wear out my 31"s. Since you never know If 33" is as tall a tire I will go with. I plan on 4.56 gearing. Plus I plan on towing a small camping trailer and think the lower gearing will help on the mountain passes.

I agree with others. Check all your u-joint in the front end. I found the right u-joint in my front axle was bad before I bought my rig and fixed it first thing when I got it home. Mine made some popping noises at times before I fixed it.

 

"I am going to purchase 4:10 gears, however, how in depth are we talking for an install? "
^
Attention to detail is important if you don't want to trash the new gears, find a pro.

 

https://www.google.com/search?q=Ring...utf-8&oe=utf-8

 

If you've never done gears, do not do them yourself. It's a tedious task that if you do one thing wrong, you could be buying a new ring and pinion. Get them done by a shop.

 

Yeah installing gears is not something a rookie should try at home.You need a few special tools and understand how you shim everything.But before you buy the gears you might want to think do you want to stay 33s or go bigger later.And while the axles are apart you can add lockers real easy then.

 

If it's a 4 cylinder, then your axles would have 4.10's

If it's a 6 cylinder, the axles would have 3.07

Those with towing packages with the Dana 44 are still 3.55 if it's auto and 3.07 if it's a manual.

Sure swapping in a set of automatic axles would help but only so little especially on 33's.

Regearing would be better.

Im gonna assume that your jeep is a 4.0, since yours is a manual, going 4.10 is ideal for 33"s unless it's a 4 cylinder then u might would need to go a bit deeper.

 

I agree have it done by a shop who is knowledge about gear installs I did as all I had done in the past were Ford 9" ones. A 4x4 shop in my area charged me $200 per differential for labor to install gears and lockers in mine (I bought the gears/lockers elsewhere). The also installed an SYE and a new chain for me another $200 for it, like they were stuck on $200 a lot of the time but it was a fair I thought.

 

I have done my own gears a couple of times and had great pride that I did them myself, if its not a daily driver and you can take your time (because you will need a LOT of patience) it is possible, YOU CAN NOT JUST SAY GOOD ENOUGH. If you only plan on doing it once, it is not all that cost effective.... you might as well have a pro do it.

You will need a;

$140 for 12 ton press @ Harbor Freight
$ 30 for a bearing puller @ Harbor Freight
$ 23 for a mechanical micrometer @ Harbor Freight
$ 35 for a clamping dial indicator @ Harbor Freight
$ 25 for a INCH (not pound) Swing Arm Torque Wrench

Plus a way to hone out the old bearing to make into setup bearings.

Regarding what gears for 33's with a manual I would say 4.10, with Auto 4.56. If you have more time than money and want to do your own gears, maybe buy a set of axles with 3.55 ($250ish), install them, then take your old ones and upgrade them to the gears you want, swap them back in, then sell or keep for spares the other axles.

And regarding the noise, try putting your foot on the brake and tap the gas few times, if you hear the banging it is probably a bad motor or trans mount..... doubtful it is coming from the axle, maybe exhaust banging around or ujoints, as someone else said hard to diagnose with out being there.

Also figure out if you have a Dana 35 or 8.25 in back, in my opinion (others will vary) it is not worth putting money in a Dana 35 installing gears.

Bryan