Coog

Looks like both my axles on my '99 4.0 ZJ are shot

I'm thinking that I might just swap them for standard junk yard like for like items (upgrades hard to come by over here).

Looking some assurances on how difficult/easy a job this is using axle stands and basic tools. Is it DIY-able in a basic workshop, or should I be going to a mechanic?

I'm pretty handy with a spanner but have never replaced a full axle before and to be honest replacing both seems a little daunting to me. The most I've done before is lifting an XJ, replacing a few leaf springs and replacing some D35 axle seals lol.

Any tips/advice?

Thanks

00jeepXJ

why did your mech say that your whole axle's are shot? More likely you need bearings in both axles.

Coog

Yes they both need bearings. My understanding was that it is easier & cheaper to swap axles than pull existing ones and have them rebuilt. I could do a swap myself but a rebuild would require specialist and lots of money.

troy fritz

Your 99 is a WJ not a ZJ. If you can do what you listed then replacement will be no problem. You have kinda already done it. You should be able to do both axles in less then a day. It's easier to replace bearings front and rear then the entire axle. Also, if it only needs bearings then you don't need special tools or a degree to replace them. All you need is a 36mm, 13mm and a 12mm sockets to do the front. For the rear you need to remove the diff cover and pull the c-clips and pull axle shafts. Then get a blind hole slide hammer to remove the old and use a big socket slightly smaller then the new bearings to tap them in and reassemble.

Coog

It's definately a ZJ and not a WJ. We got them here in the UK/Ireland till late 2001! It's more than just the wheel bearings that have gone. Those I would do in situ. To support my diagnosis:

Front pinion bearing has about 1mm play left/right/up/down/in/out (not rotational slop) it also has considerable metal shavings in the diff oil. Severe grumble from front axle, I suspect wheel bearings.

Rear diff is whining under load at 50-70mph, not much slop in pinion, oil is like tar but no shavings.

Full rebuild of front almost certainly required, upper and lower pinion bearing for rear required. I thought an axle swap to be easiest repair. I would then try and rebuild old axles over winter as a bit of a project.

xjboy14

If someone could tell what axles he has I could say how easy they are, with me I had my chrysler 8.25 apart in 20 minutes. Same with my dana 30, but I dont have a ZJ

Coog

D30 front, D35 rear

xjboy14

Thats like the tj, they are c clips, it helps to have 2 people at some points like putting the axles back in and lining them up right, still doable with 1 person,
By the way im talking about replaceing the axle shafts, I hope that is what he means

Coog

No, I'm talking about entire axles. Swapping the whole assembly (instead of doing an axle rebuild). Have done half shafts before on a XJ no probs.

I'll see about recruiting a buddy for hauling duties. Apart from that straight forward enough then?

troy fritz

If you can do what you listed then replacement will be no problem. You have kinda already done it. You should be able to do both axles in less then a day.

ShredSled7

my last rear end swap was a blazer but fundamentally the same.
first time removal, 3 hours, wrong rear end...4 wd is wider.
second time, hour and a half out, return for exchange.
2nd install, bout an hour. used a small jack, jackstands and a few blocks of scrap wood. not rocket science, you can handle it

Coog

Thanks mate!

Is there anything in particular I should watch out for? I'm thinking especially about things like bolts that commonly break, etc.

ShredSled7

pb blaster anything rusty and let it soak. way better than liquid wrench or wd-40. re-torque! always re-torque, just to be sure you didn't miss any bolts.
when you disconnect the brake lines, they will siphon fluid from the master cylinder. be prepared to cap the line. doing so will minimize the amount of air you will have to bleed out when the swap is done.

torque specs can be vague. i've gotten in the habit of using the torque wrench to take a torque value while loosening. is'nt precise but will give a not to exceed value. may prevent snapping bolts from overtightening.

Coog

Thanks all. Think I'm going to start this job this coming weekend. Wish me luck!

dave1123

Hey Coog! If you are buying junkyard axles, pull the covers and check for gear galling and bearing particles BEFORE you yank out your old ones. Also, make sure the ratios match. Doesn't matter which ratios you get, but make sure they are both the same. Swapping them shouldn't be much of a problem.

Have fun! OH, YEAH! Make sure your front caster settings are the same when you're done.