Rear end noise

[1stjeep.ro]

Hey everybody. My xj has been making these horrible noises while driving around especially when coasting from the rear end. I'm no mechanic but I believe my diff is on its way out. Who do you recommend in calgary for a rebuild/regear solution?

[vantagetes]

If it's stock, the junkyard. Unless you want to regear to something a little more large tire friendly anyway.

[1stjeep.ro]

The most I ever plan on running is 33s on a 4.5" lift. So I believe I'd like to regear as well and add lockers. Having a manual, which gear ratio would you recommend for a DD setup? Also where should I have it done

[vantagetes]

Between 4.10 and 4.56 depending on how healthy your 4.0L is, how much weight you plan on hauling around and if you lean more towards road friendly or rock friendly. If you're going to regear and install lockers then dropping the cash makes more sense.

There are lots of places that can do gears, shop around and see what kind of prices you get for the gears lockers and install and work around your schedule. I use a couple different places depending on who can get what I need or has the time to do it when I want it done. Sometimes large projects come up, or they can't get a particular item. I always go back to places that treat me well, and never go back to places who don't. There will always be a hiccup from time to time it's the ones that make sure it gets corrected after the fact that are worth your money.

[tubby]

There are lots of places that can do gears, shop around and see what kind of prices you get for the gears lockers and install and work around your schedule. I use a couple different places depending on who can get what I need or has the time to do it when I want it done. Sometimes large projects come up, or they can't get a particular item. I always go back to places that treat me well, and never go back to places who don't. There will always be a hiccup from time to time it's the ones that make sure it gets corrected after the fact that are worth your money.

The best answer to this question I've ever come across on here besides the same nut-hugging  responses .

Back to the OP's question regarding gear choices, I went from 3:55 to 4:56 to 1 on my XJ when I had 33" tires and loved them in town from stoplight to stoplight. The highway at 1oo-plus km speeds was having my engine rev a little to high for the 4.0. I wish I had 4:10's.

What do you have for a rear diff? I hope you don't have a Dana35C . I'd hate to waste money on that rear if I was doing gears and lockers. Go find a Ford 8.8 with discs out of an Explorer.

[vantagetes]

He's got a 8.25 which is hateful to regear but a fairly decent axle strength wise. 29 spline not 27.

[1stjeep.ro]

Thank you very much for the fast replies and good advice.  I'm just afraid of those shops with shoddy workmanship. My jeep oriented more towards driving in tough winter conditions and perhaps a couple of wheeling weekends in the summer. That being said, do you think I would need lockers from the start or should I just throw in a new set of gears and be done with it. The 4l runs really strong for its current kilometers ( 286000kms) I've done all the maintenance on it: plugs, wires, caps, thermostat, all the fluids, new waterpump timing belt etc... I currently have the chrysler 8.25 29 spline in the back amd dana30 in the front fyi. Thanks a lot for the advice gentlemen!

[TL-Iguana]

I suffer from rear end noise too.. Usually its just Gas.. 

[emortal]

The most I ever plan on running is 33s on a 4.5" lift. So I believe I'd like to regear as well and add lockers. Having a manual, which gear ratio would you recommend for a DD setup? Also where should I have it done

We would be glad to help you out at E-mortal customs 403-265-6669 give us a call if you would like and I can quote you on what you need and go over some options 

[BlackYJ]

I run 4.10s with my 33s on my YJ and it is decent on the highway.  I can usually hold between 110-115 comfortably.  I would not go any lower than 4.56s with 33s

[Jrama]

I have 4.88's and 35's and while it does rev quite high on the highway (very similar to what 4.56 and 33" would be) I would not want any less power, it already bogs down on inclines and hills. Sure turning about 3k at 110 kph is high for the 4.0 but you really need the power.

[Bnine]

Those 8.25's are typical for growling. Is your fluid good? Have you checked the axle bearings at the wheel? I wouldnt be in a panic. I had one of those growl on me for 4 years before I swapped a 44 in its place. The growly 8.25 was still rolling when I pulled it.

If you are looking to modify, you would be way ahead to be patient and pick up an XJ 44 for 300-400$. They are a better axle then the 8.25, and you will recoup some of the cost to purchase the diff by dropping the bare housing off at a shop for gears and lockers. Most shops will knock a 100$ off gearing and locker install labor if you drop them a nice bare and clean 44 housing that is ready to be worked on.

[1stjeep.ro]

First thing I did was to swap my fluids. The fluids didn't look good at all.  As for going the xj 44 route, which model do you recommend to get them from? And what type of modification would be needed to make them work?

[Bnine]

XJ 44's are pretty much all the same. MJ 44's spring perches vary but thats a small issue to overcome when swapping.  A resident XJ nut would be able to help more with the specifics.

[cLAY]

MJs are sprung under. Pretty easy to swap the perches to the top if you have access to a grinder and welder.