front diff replacement

[tekjlab]

I have a 2002 liberty with 180 000km on it. I sent it to my mechanic this week because I have a really bad noise coming from the front end when rolling.

At first I thought it was the wheel hub bearing and replaced it. Still the same noise.

Then I thought it was the cv axle but before spending money on parts I send it to the garage.

It's not the cv axle but the differential that need to be replaced. I don't want to buy a rebuild kit because it,s cheaper to buy a used one at the scrape yard.

Can someone tell me if all liberty's use the same front diff dana 30a? I surely prefer to put a 2013-12-11-10 than a old 2002 from the yard.

Is there a model that use LSD or they all the same?

Thank you

 

[tjkj2002]

All '02-'07 KJ's used the same front D30a,no LSD offered but you must know your gear ratio and get a replacement D30a with the same gear ratio.Most are 3.73 gears but 2.4 gas KJ's got 4.10 gears and 6 speed manual KJ's got 3.55 gears.You can not use a '08+ KK front D30m,totally different and not a direct bolt in by any means.


I shouldn't have to say this but you can't mix-match gears,both front and rear must be the same.

 

[tekjlab]

Thank you for your fast answer. I will try to find a low mileage 2007.

I have an automatic 3.7 so it should be 3,73 ratio. Is there a way to be sure without opening the diff?



Indeed you don't have to tell that both front and rear had to be the same ratio.

 

[02blue]

Should be a tag on the rear axle and on front diff. You could request a build sheet from DC and it will tell you what the originals were.

 

[dude1116]

Might be worth checking the front driveshaft CV joint first...much cheaper fix, and easy to tell if it's causing the noise. Just remove the driveshaft.

 

[02blue]

Might be worth checking the front driveshaft CV joint first...much cheaper fix, and easy to tell if it's causing the noise. Just remove the driveshaft.

Good point! All that stuff is always moving. Check the recessed boot near the Tcase for cracks. That ones a ******. Mine rumbled when it went especially under acceleration. Worse in 4wd.

 

[tekjlab]

Might be worth checking the front driveshaft CV joint first...much cheaper fix, and easy to tell if it's causing the noise. Just remove the driveshaft.

Good point! All that stuff is always moving. Check the recessed boot near the Tcase for cracks. That ones a ******. Mine rumbled when it went especially under acceleration. Worse in 4wd.

The front driveshaft have less than 20000km

On the road the noise is always there. On the lift only on 4wd

 

[tekjlab]

Another question; While the front diff is off, is this the best time to remove the oil pan and replace-it without having to lift or remove the engine ?

 

[dude1116]

The front driveshaft have less than 20000km

On the road the noise is always there. On the lift only on 4wd

Neither of these two facts prove that it's not the front driveshaft.

Like I said...it's worth a check. It could very well not be it. But hell, it's your money! :manos: :waytogo:

 

[TwoBobsKJ]

Another question; While the front diff is off, is this the best time to remove the oil pan and replace-it without having to lift or remove the engine ?

The engine still needs to be lifted in order to get the pan off. Having the front diff out improves access to the pan bolts but doesn't improve clearance between the pan and the crossmember/cradle. The pan is a pain to remove/replace plus the gasket replacement is a bear because the gasket is also the windage tray and is bolted to the oil pump. It can be done but... :disgust:

P.S. I agree with others here. Double check that CV joint on the T-case end of the front driveshaft. It's unusual for the front diff to go bad (if it hasn't been grenaded while in 4WD) so your noise symptoms could well be that CV joint.

Bob

 

[tekjlab]

I'm taking it back home. I will take your advice and try to take off the front driveshaft at my place. If it doesn't change anything I will wait a few weeks so I can find the right differential at a good price.

As you say , even if the diff is off I still have to pull off the engine.

In that matter of case i will change the engine mount. When i'm rolling over a pothole , over a rock or even a manhole there is something knocking on the passenger side. Last summer I replaced all the suspension with front billstein shock and a 2,5inch strut extension kit. In the back 3inch longer coil springs and longer shocks. But even with new suspension the knock still there. All other components are ok. Checked the upper and lower ball joint , tie-rod , link kit.

It,s starting to be expensive oil pan , engine mounts , differential (hopefully the cv joint) and the labor. Oil pan and engine mount from rockauto for around 200$ with delivery to Montreal and the differential for 400$tx/in. labor 250 to 400.

Thanks a lot for you answers and advice. Sorry if my english is not that good it's not my primary language.

 

[TwoBobsKJ]

In that matter of case i will change the engine mount. When i'm rolling over a pothole , over a rock or even a manhole there is something knocking on the passenger side. Last summer I replaced all the suspension with front billstein shock and a 2,5inch strut extension kit. In the back 3inch longer coil springs and longer shocks. But even with new suspension the knock still there. All other components are ok. Checked the upper and lower ball joint , tie-rod , link kit.

It,s starting to be expensive oil pan , engine mounts , differential (hopefully the cv joint) and the labor. Oil pan and engine mount from rockauto for around 200$ with delivery to Montreal and the differential for 400$tx/in. labor 250 to 400.

Thanks a lot for you answers and advice. Sorry if my english is not that good it's not my primary language.

Your English is no problem - we're not too worried about proper English. Jeepers understand each other just fine

The knock you described does sound like an engine mount. They do go bad - I replaced mine when I swapped out my engine. This is what the original mount looked like - the rubber in the center was basically ripped in two:

You must be registered for see images

Let us know what you end up doing :waytogo:

Bob

 

[tekjlab]

I just finish to remove the front driveshaft. And good news the noise is gone. I didn't make a long road test but tomorrow I'll confirm that everything is OK.

twobobskj before you swap your engine did the engine knock also when you put it on gear or only on bumps? I'm not quite sure but when the engine mounts are finished it's supposed to knock when you put it on gear or give gas. Mine does it only on bumps.

 

[TwoBobsKJ]

I just finish to remove the front driveshaft. And good news the noise is gone. I didn't make a long road test but tomorrow I'll confirm that everything is OK.

twobobskj before you swap your engine did the engine knock also when you put it on gear or only on bumps? I'm not quite sure but when the engine mounts are finished it's supposed to knock when you put it on gear or give gas. Mine does it only on bumps.

Great news! Now you don't have to worry about a diff swap!

Mine knocked on hard acceleration but not on bumps - at least that I remember :boxed:

Bob

 

[tekjlab]

so today I made a real road test and the noise is still there but less than before. I stop in a 4x4 garage and explain the situation and he think that he all ready saw that on liberty. At first he told me it must be the driveshaft cv joint (just like you folks suggested) but like it's no longer installed it must be something else. he's second opinion was just like the picture on this thread:

LINK http://www.jeepkj.com/forum/f196/front-end-noise-anyone-had-replace-differential-bearings-55115/