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Discussion Starter #1
Now before I get reemed for making another rear end clunk post in the ocean of others, I have read through many of them and I feel like I have a good idea what it is, I'm just looking for some advice as to how to go about things.

I have replaced:

  • Engine mounts
  • Trans mount with revshift insert
  • Whiteline differential insert
  • DSS 1pc driveshaft
  • Both axles
  • Torco fluid/modifier

All this leaves is just rebuilding the differential itself. The clunk hasn't improved. If I don't slip the shit out of the clutch, it sounds like a bowling ball is rolling around in the trunk. If I occasionally make the noob mistake of not giving enough gas when letting out the clutch, and the car lurches a little bit, it sounds like that bowling ball is going to bust through the trunk or the gas tank. It's getting to the point where I don't even enjoy driving the car anymore. I've left it parked for weeks at a time just because I feel like I can't drive it how I'd like to without the risk of something breaking. And that "factory drivetrain slop" BS is clearly irrelevant as the sound didn't improve even with new axles and 1pc DS and full drivetrain bushing refresh.

While replacing the DS and axles, I checked the play of the stubs and pinion and everything felt pretty tight. Both stubs had no noticeable axial play, and very slight rotational play, and no axial play or rotational play in the pinion that I could notice, everything rotated smoothly. So I can't really tell where in the diff the clunk would be coming from?

Obviously my checks are nowhere near the stress test as the hundreds of hp and tq going through it, but at that point, do I just buy a full rebuild kit? And axle stubs?

This is the only kit that I can find that looks like it will do the job:


Also, is it really necessary to drop $500+ on just axle stubs? Why are they so expensive? I can't seem to find stock replacements and my car is mildly built, only putting down 373whp/356wtq, so these super expensive stubs that are rated 500+ hp seem overkill, but might be the only option?

Sorry for bugging you guys so much recently with my drivetrain issues, I really do try to do as much research as I can before making a post.
 

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Never have i had axle stubs causing a clunk.

Stock lsd? Stubs not twisted? No spline wear? Not the stubs.

Stock rear crossmember bushings? No witness marks back there? Sway bushings and links ok? What about shock mounts? I had that issue. Shock mounts wore through and the shaft was smacking the body.

It is also possible your spider gears said f u. Then yeah, rebuild time.
 

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Discussion Starter #5
Never have i had axle stubs causing a clunk.

Stock lsd? Stubs not twisted? No spline wear? Not the stubs.

Stock rear crossmember bushings? No witness marks back there? Sway bushings and links ok? What about shock mounts? I had that issue. Shock mounts wore through and the shaft was smacking the body.

It is also possible your spider gears said f u. Then yeah, rebuild time.
Oh yeah, I forgot to mention that, poly subframe bushings, everything aligned where it was previously, no witness marks.

Axle stubs splines looked fine, all straight.

New pedders absorbers and springs.

New gforce toe Rods.

The diff is stock as far as I know.

Haven't replaced sway bar bushings, but when I checked them, it looks like the PO replaced the end link and mount bushings with poly, and they're still in good condition.
 

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I would drain the rear end and pop the rear cover. Carefully examine the gears. Doesn't sound like you have broken gears, but if the gears look 100% AYEOHKAY and you have little chunks in the gear oil, it came from somewhere... like... the spider gears.
 

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Discussion Starter #7
I would drain the rear end and pop the rear cover. Carefully examine the gears. Doesn't sound like you have broken gears, but if the gears look 100% AYEOHKAY and you have little chunks in the gear oil, it came from somewhere... like... the spider gears.
I hate that I didn't even think of cracking the case open to look inside haha. I'll be sure to do that and hopefully find some answers. One way or the other.
 

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Discussion Starter #8
I would drain the rear end and pop the rear cover. Carefully examine the gears. Doesn't sound like you have broken gears, but if the gears look 100% AYEOHKAY and you have little chunks in the gear oil, it came from somewhere... like... the spider gears.
In the event of needing new spider gears or something similar, what would my options be? I haven't found any stock rebuild kits, at least not for the gears, just the bearings and whatnot. Any of the lsd kits I've seen are for gear ratios of like 4.11 or higher than what I have, and I'd like to keep the ratio I have since I daily the car and like cruising 75mph around 2k rpm.
 

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My rear end clunk went away when I installed the rear diff insert and these subframe bushings. It has extra spacer that wasn't there like the stock ones. This stops the subframe from hitting the actual frame IMO on hard launches. Basically have to pry the subframe arm down to insert the top polyurethane washer.

20180915_153350.jpg
 

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Discussion Starter #12
My rear end clunk went away when I installed the rear diff insert and these subframe bushings. It has extra spacer that wasn't there like the stock ones. This stops the subframe from hitting the actual frame IMO on hard launches. Basically have to pry the subframe arm down to insert the top polyurethane washer.

View attachment 504552
Yeah, I forgot to mention in my post that I did replace the subframe bushings with those same poly ones as well, with no change in the sound. It's seeming like the diff internals are my last resort.
 

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Is that FWD?
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Yeah, I forgot to mention in my post that I did replace the subframe bushings with those same poly ones as well, with no change in the sound. It's seeming like the diff internals are my last resort.
I have Gforce axle stubs and inner stubs as well and 1 piece CF driveshaft. Good luck, hope it is not diff internals.
 
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Is that FWD?
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Yeah, I forgot to mention in my post that I did replace the subframe bushings with those same poly ones as well, with no change in the sound. It's seeming like the diff internals are my last resort.
I might of missed it, but have you replaced rear springs and shocks too?
 

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Discussion Starter #15
I might of missed it, but have you replaced rear springs and shocks too?
Yep, with pedders absorbers and springs. Gforce toe Rods, PO installed poly sway bar bushings and end links. Everything suspension wise, front and back has been refreshed.
 
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