bfons

Thx for reading guys,

I just recently purchased a project ZJ. I mainly bought it due to low miles and what seemed like a killer deal.

So I have it a week and it starts making this Whirring noise somewhere in the front end. I take it to my mechanic who reported my TC was shot. Bummed but not defeated, I sourced a rebuilt 249 and slapped that baby in there yesterday

So today, I get out on the road and the whirring is still there! Sigh....

It is not constant and It comes and goes, and is most pronounced when I let off the gas. The volume of the noise is also relative to speed. As I slow down, the noise gets slower and stops when stopped.

So I was thinking the Diff or something to do with the front shaft. But here's the kicker. When I'm driving, and I hear the noise, I moved the shifter to Neutral and the noise goes away. I did this a few times and each time, the noise would disappear while rolling and I'm in neutral.

So that points to the tranny right?

Your assistance is greatly appreciated.

B

dave1123

Welcome to CF!

It's probably the front diff. Pull the cover and check the gears and bearings. Most likely the pinion bearings are toast.

bfons

Thanks

I'll focus on that.

cypher

Toasted pinion bearing in diff. My rear axle does the same thing. It kind of roars a bit at higher speeds but when you let off the gas, it is much more pronounced. Almost sounds like a siren or an air raid siren...kind of....when you take your foot off the gas.

dave1123

I suggest you get to it BEFORE it blows. My ZJ did!

bfons

Thx guys,

I was out hunting this weekend so didn't get to look at it.

I think I'll take the front drive shaft off and drive her to see how it does.

I did get a quote from a shop as it looks like it's outside my skill/tolerance level. They quoted $600 to rebuild her.

I was also thinking of just swapping the whole axle if I can find a decent donor.

chilly

I agree with everyone else. My rear end does the same and will be gone through shortly. Best of luck.

bfons

Curious...

Is $600 the going rate to rebuild that bad boy?

Thx

chilly

$500 is about average labor cost for a gear setup/rebuild not including parts IMO. But depends on where you live I suppose.

bfons

Sorry for so many questions but if I take the front drive shaft off, will it be ok to drive that way just scooting around town?

dave1123

Not if you have the AWD 249 t-case. It will toast your viscous coupling. If you've got the 242, no problem. I just re-read your post. Don't do it!

bfons

It was my understanding that only the earlier 249s had a problem running without the front drive shaft.

Although, even if shaft removed, I'm still going to work that bearing right? Just not under load.

Thx

dave1123

What year is your project jeep? the 93 to 96 has one type coupling and the 97 and 98 have another type. In 99 they started using the 247 (WJ).

bfons

1997

dave1123

Duh! Senior moment. I should have seen that. I still wouldn't risk it myself. That coupling costs about $400.