Rear differential bearing out: How should I proceed from here?

[TJ Todd]

The bearing in the rear differential of my 04 X has gone out. Looking for suggestions on how to proceed from here. I could just replace the whole rear end with a rebuilt one but wanted to find out if there is a better option. My TJ is a 5 speed and currently has 30x9.5 tires. Ideally I would like to set it up with a lift and a little bigger tires. I have read that these are things to consider when deciding what to d about the gearing.. Any input would be appreciated.

 

[Chris]

I would just replace the bearing. However, while I was in there, I would definitely re-gear it and add a locker as well.

If it's a Dana 35, I would add the Revolution "Super 35" kit also.

With that setup on a Dana 35 you can run up to 35" tires without issue.

 

[Xposure]

I would just replace the bearing. However, while I was in there, I would definitely re-gear it and add a locker as well.

If it's a Dana 35, I would add the Revolution "Super 35" kit also.

With that setup on a Dana 35 you can run up to 35" tires without issue.

But if he does all that he may as well go ahead and get the 35” tires, which then should rework the front axle and install a lift for the 35’s.

Basically it’s like this....you could just replace the bearing...but while your there with it on jack stands you may as well replace everything possible on the underside of your Jeep



I can’t believe how similar Jeep folks are to rx7 folks....I suppose it’s just ‘car guy genes’ in general.

 

[Chris]

But if he does all that he may as well go ahead and get the 35” tires, which then should rework the front axle and install a lift for the 35’s.

Basically it’s like this....you could just replace the bearing...but while your there with it on jack stands you may as well replace everything possible on the underside of the Jeep



I can’t believe how similar Jeep folks are to rx7 folks....I suppose it’s just ‘car guy genes’ in general.

Very true. I guess what it ultimately comes down to is how much money you've got, and whether or not you want to do things twice (or even three times).

If you have the money, it makes sense to do it all at once while you're in there. The front axle could get by with nothing more than new gears and some alloy axle shafts (a locker for the front could wait), but again... it's all about money.

I think it's probably similar amongst most car people. If you've got the money, might as well do it all at once!

 

[Xposure]

Very true. I guess what it ultimately comes down to is how much money you've got, and whether or not you want to do things twice (or even three times).

If you have the money, it makes sense to do it all at once while you're in there. The front axle could get by with nothing more than new gears and some alloy axle shafts (a locker for the front could wait), but again... it's all about money.

I think it's probably similar amongst most car people. If you've got the money, might as well do it all at once!

That’s what I’m thinking!....if he’s going to take the time to jack it up and remove the wheel he may as well do a Currie lift, gears, lockers, axles, larger wheels and tires, shocks, get the black magic brake pads, change out all fluids, spot repair any rust spots, make sure all the drivetrain vents are in good order......anything else you can think of?

Oh yea, get the stuff to do an alignment yourself, it’s like $30 worth of stuff.

Oh yea, after all that, don’t forget the bearing! Maybe just change to a Ford 8.8 that has new bearings.

I think that would make great efficiency and really make pulling out the jack worthwhile.

It’s like everything else....people used to ask me how much for a new computer, or stereo, or theater system, car mods.....I’d say it’s not about how much they cost, it’s about how much can you afford to spend and finding what good within your budget. My daughter wanted a record player....well they have them from $150-$40,000 lol

 

[Chris]

That’s what I’m thinking!....if he’s going to take the time to jack it up and remove the wheel he may as well do a Currie lift, gears, lockers, axles, larger wheels and tires, shocks, get the black magic brake pads, change out all fluids, spot repair any rust spots, make sure all the drivetrain vents are in good order......anything else you can think of?

Oh yea, get the stuff to do an alignment yourself, it’s like $30 worth of stuff.

Oh yea, after all that, don’t forget the bearing!

I think that would make great efficiency and really make pulling out the jack worthwhile.

It’s like everything else....people used to ask me how much for a new computer, or stereo, or theater system, car mods.....I’d say it’s not about how much they cost, it’s about how much can you afford to spend and finding what good within your budget. My daughter wanted a record player....well they have them from $150-$40,000 lol

It's very easy to see now how I've spend 17k and going on my build... Because once I take apart something, I figure I may as well replace everything while I'm in there... with better parts of course.

 

[Xposure]

The bearing in the rear differential of my 04 X has gone out. Looking for suggestions on how to proceed from here. I could just replace the whole rear end with a rebuilt one but wanted to find out if there is a better option. My TJ is a 5 speed and currently has 30x9.5 tires. Ideally I would like to set it up with a lift and a little bigger tires. I have read that these are things to consider when deciding what to d about the gearing.. Any input would be appreciated.

I see this is your first post....you have stumbled onto the black abyss of modified Jeeps.....I can tell by your wording and the use of the phrases “I have read” and “I could do” and “ideally I would like” that you have in fact already fallen into the hole....but there is still probably time to claw your way back out, forget you ever saw this place and just change what is actually necessary.....and get out alive and with a bank account still in tact! It’s probably not too late if you run now!!! They sucked me in several months ago....it’s not too late to turn around! Save yourself!!!

 

[Xposure]

It's very easy to see now how I've spend 17k and going on my build... Because once I take apart something, I figure I may as well replace everything while I'm in there... with better parts of course.

I took a already built rx7 and blew up the engine then after I rebuilt it but before I reinstalled it I thought....while the turbos are off I may as well replace them with a giant turbo, which of course means new piping which means I may as well replace the inter cooler with one that lines up better with the new piping, of course a new down pipe means I may as well redo half the exhaust so it’ll line up better too, if I do all this I may as well get bigger injectors so I can turn the boost up...which means new fuel rail...which means new fuel pressure regulator, which means new lines, which then may as well swap the fuel pump for a double pump to make use of all that injector.... all this means another 8 hours of dyno time......it went on and on and on LOL......

The “while I’m here” will get ya every time....it’s always a chain reaction

I think my wife is worried that I got another enthusiast type vehicle.....

 

[Chris]

I took a already built rx7 and blew up the engine then after I rebuilt it but before I reinstalled it I thought....while the turbos are off I may as well replace them with a giant turbo, which of course means new piping which means I may as well replace the inter cooler with one that lines up better with the new piping, of course a new down pipe means I may as well redo half the exhaust so it’ll line up better too, if I do all this I may as well get bigger injectors so I can turn the boost up...which means new fuel rail...which then may as well swap the fuel pump for a double pump to make use of all that injector, which means new fuel lines and a new fuel pressure regulator, all this means another 8 hours of dyno time......it went on and on and on LOL......The “while I’m here” will get ya every time....it’s always a chain reaction

Haha, back when I was younger I did something similar to my Mitsubishi Evo 8 (this was around 15 years ago when they had just come to the U.S.), so I can relate 100%. It's amazing how much money you can spend on a car if you really get into it.

 

[Xposure]

Haha, back when I was younger I did something similar to my Mitsubishi Evo 8 (this was around 15 years ago when they had just come to the U.S.), so I can relate 100%. It's amazing how much money you can spend on a car if you really get into it.

Yea mine was about 15 years ago as well....it’s been a long time since I messed with cars....but my wife is spotting all the signs

At least the Jeep is more family oriented and we can use it to go riding and camping and my wife isn’t scared to ride in it....she was scared to ride in my FD (rx7)....but I drove it like an idiot even when I was trying to drive ‘normal’ so I don’t blame her....the Jeep I drive slow so she feels much safer and enjoys riding in it.

 

[Chris]

Yea mine was about 15 years ago as well....it’s been a long time since I messed with cars....but my wife is spotting all the signs

Yep, I got out of the "tuner" thing in my late twenties. After owning a Wrangler I couldn't own anything else.

We're men... it's in our nature to want to tinker with things!

 

[TJ Todd]

You all make for some good reading. As much as I would love to break the bank on this, a little restraint is in order. The immediate need is to address the rear diff because I can't drive it right now but I don't want to fix it just to have to redo it again done the road. My vision for this project is a modest lift and some 33's still keeping it as a daily driver.

 

[ohiopatriot]

:risas3:. This thread is priceless.

Only on a Jeep forum can a bearing turn into a 10k build.

 

[ac_]

It's a Jeep thing!

 

[Chris]

You all make for some good reading. As much as I would love to break the bank on this, a little restraint is in order. The immediate need is to address the rear diff because I can't drive it right now but I don't want to fix it just to have to redo it again done the road. My vision for this project is a modest lift and some 33's still keeping it as a daily driver.

In that case, I would do the bearing(s), the axle seals, possibly the unit bearings as well, and call it a day.

That's all the maintenance you'd really need, and if you really get into it, it's very easy to start spending money and getting ahead of yourself (ask me how I know).

 

[Rob5589]

What do mean by "bearing is out?" Hard to say what way to go without knowing how bad of shape it's in.

 

[Xposure]

You all make for some good reading. As much as I would love to break the bank on this, a little restraint is in order. The immediate need is to address the rear diff because I can't drive it right now but I don't want to fix it just to have to redo it again done the road. My vision for this project is a modest lift and some 33's still keeping it as a daily driver.

First think is you may want to put it on jack stands so you can turn the gears then pull the cover and get a good look at exactly what’s going on in there. Make sure some trash hasn’t gone through your gears. Are you positive it’s the diff making the noise?

Will you be doing the work or is a shop doing it?

 

[Flib]

the pinion bearing or the carrier bearing??

And watch these guys they will have you broke in no time

Your course of action depends heavily on what you want to do with your jeep, if you wanted bigger tires now would be the time to re-gear, I would not bother with a locker unless you plan on doing some serious off road'n or have cash to burn.

 

[TJ Todd]

Found a local 4X4 specialty shop to take a closer look at the rear end. The plan is to rebuild it and upgrade the gears. So the question becomes 3.73 or 4.11? My jeep is a 4.0L 5 speed. It will be used mostly for city driving. Future tires will be 32" or 33" and a 3"- 4" lift.

 

[Rob5589]

33's and the 5 spd, 4.56.