Diff Clunking/Grinding AFTER Diff seal replacement?

[JimmyS]

G'day to you all.

I've recently purchased a 2003 WK Caprice with 233,000ks on the clock.
Ran like a gem, no odd sounds.
Took it to my local mechanic, good reliable guy, stated that the Diff Pinion Seal was leaking -and to get it sorted "sooner rather than later"
The week after, I made the mistake of taking to a Holden dealership to have the seal replaced, against my mechanics advice.
So, $600 or so later for the diff seal replacement, I got in my car, noticed a slight knocking sound, thought nothing of it initially.
The knocking/grinding sound is ever so slightly audible in Park, but when I shift into Drive or Reverse, stationary or not, it becomes decently louder. It also happens when the trans is about to shift, and at low speeds.
I can't hear it at higher speeds, but maybe the LS1 drains it out.
Also - the Diff is still leaking at the rear, more so than it was originally.
All signs point to a botched job IMO.

Sorry for putting in a lot of info, but the more info you guys have, the better.
Can anyone shed any light on this issue? Pisses me off that you pay someone good money to fix an issue, and appears to have cocked it up.

Any clarification as to why this noise has suddenly appeared would be gold.
Cheers gents.

 

[EYY]

They wouldn’t have got the pinion preload right. Too much or too little destroys the pinion bearings which in turn alters the contact patch and backlash and ends up destroying your gearset.

It’s a full rebuild to fix it unfortunately. They probably had the apprentice doing it with an impact gun and just sent the pinion nut home

 

[JimmyS]

They wouldn’t have got the pinion preload right. Too much or too little destroys the pinion bearings which in turn alters the contact patch and backlash and ends up destroying your gearset.

It’s a full rebuild to fix it unfortunately. They probably had the apprentice doing it with an impact gun and just sent the pinion nut home

Understood, I really hope this isn't the case, but I'm sure your correct.
Would it be reasonable to assume, due to their negligence, that I would not have to pay for the rebuild? Doesn't seem quite right if I did.
And how much would a rebuild set me back, should I have to pay?
Cheers.

 

[Immortality]

They wouldn’t have got the pinion preload right. Too much or too little destroys the pinion bearings which in turn alters the contact patch and backlash and ends up destroying your gearset.

It’s a full rebuild to fix it unfortunately. They probably had the apprentice doing it with an impact gun and just sent the pinion nut home

Spot on. They farked it up.

Take it back and get them to fix it properly at their cost. I wouldn't call it a full rebuild but they will need to reset the pinion pre-load, depending on what the bearings and gears are like that maybe all that is required or just a new set of pinion bearings along with the spacer.

 

[Smashfist]

Unlikely it's a diff bearing/preload issue if it can be heard in park. Take it back, could be a loose heatshield/bracket/exhaust leak/etc.

 

[JimmyS]

I appreciate all the input gents.
I've got it booked in for the 30th of Jan.
I'll keep you guys updated via this thread.

Thanks again.

 

[EYY]

Unlikely it's a diff bearing/preload issue if it can be heard in park. Take it back, could be a loose heatshield/bracket/exhaust leak/etc.

Very likely actually. It messes with the backlash (increases). So will clunk when our into gear - very loud and metallic.

 

[EYY]

Spot on. They farked it up.

Take it back and get them to fix it properly at their cost. I wouldn't call it a full rebuild but they will need to reset the pinion pre-load, depending on what the bearings and gears are like that maybe all that is required or just a new set of pinion bearings along with the spacer.

Close enough to a full rebuild without reconditioning the centre and replacing the gears lol whole thing needs to come apart at any rate

 

[JimmyS]

How long can you drive the car once this issue starts happening? I need to run a few errands, but I'm concerned something is gonna go fkn BANG and then I'll be in a world of ****.

 

[JimmyS]

Very likely actually. It messes with the backlash (increases). So will clunk when our into gear - very loud and metallic.

Apologies, should of pressed reply, not comment.
Final question below:
How long can you drive the car once this issue starts happening? I need to run a few errands, but I'm concerned something is gonna go fkn BANG and then I'll be in a world of ****.