: Rear Differential Assembly mods



mrmojo95
05-07-13, 04:03 PM
Gentlemen, I am replacing my 2005 grenade'd differential assembly (157k miles, 500hp motor0 with an 06-07 unit from Lindsey Cadillac ($1594 shipped). I am also going to do the front pinion support with the BMR U-shaped support to prevent deflection. I already have CS poly Bushings. Is there anything else i should consider while in there? Thanks for any help!

HAMSTAR
05-07-13, 04:13 PM
the revshift diff bushing is a better design. go with that, along with the CS diff bushing block. there's not much love for the BMR pinion support brace-- some reports of them causing damage.

thebigjimsho
05-07-13, 05:07 PM
Yeah, no positive reviews of that BMR brace. I'd ditch that. I have one I bought used YEARS ago, but don't even want to sell it. Not worth messing up someone else's V...

MotorMounts
05-07-13, 06:09 PM
[QUOTE=HAMSTAR;3306546]the revshift diff bushing is a better design.

Please explain

HAMSTAR
05-07-13, 06:45 PM
[QUOTE=HAMSTAR;3306546]the revshift diff bushing is a better design.

Please explain

First, I'm a fan of yours, Max, and someday hope to wind up with one of your 8.8s under your car. The diff block is also excellent. My problem with the diff bushing is the metal sleeve that it sits in. I believe it shrinks with cold weather. I'm running your diff bushing, and cold weather brings back the clunk. It's not as bad as it was with the stock bushing, but it's there. The revshift design is straight poly, with no outer metal sleeve to shrink or expand with temp fluctuations. I could be wrong about this, of course...

MotorMounts
05-07-13, 07:21 PM
[QUOTE=MotorMounts;3306650]

First, I'm a fan of yours, Max, and someday hope to wind up with one of your 8.8s under your car. The diff block is also excellent. My problem with the diff bushing is the metal sleeve that it sits in. I believe it shrinks with cold weather. I'm running your diff bushing, and cold weather brings back the clunk. It's not as bad as it was with the stock bushing, but it's there. The revshift design is straight poly, with no outer metal sleeve to shrink or expand with temp fluctuations. I could be wrong about this, of course...


No problems here with another mans point of view(as long as it's inline with mine of course, haha) Even in the coldest of weather, the outer steel sleeve of our bushing could not get cold enough to fall out, if it wasn't captured in place by the subframe of course. If, when your current bushing of ours was installed there was even a small amount of force required to push the bushing in to the bore of the diff housing there should be no movement of the bushing in the housing. Now, if the bushing just slid in with no resistance that would be a problem, depending on the amount of clearance, that could cause a clunk. Not saying that you are one of "these guys", but double check the tightness of the bolt that passes through the diff bushing. We have had a few "clunking bushings" that turned out to be the bolt moving up and down in the holes in the subframe ears, due to not being tight enough.
If you are willing to do the work, I am willing to send you a free bushing and tool to determine where the clunk is coming from and fix it.

barrok69
05-08-13, 01:15 PM
[QUOTE=HAMSTAR;3306677]


No problems here with another mans point of view(as long as it's inline with mine of course, haha) Even in the coldest of weather, the outer steel sleeve of our bushing could not get cold enough to fall out, if it wasn't captured in place by the subframe of course. If, when your current bushing of ours was installed there was even a small amount of force required to push the bushing in to the bore of the diff housing there should be no movement of the bushing in the housing. Now, if the bushing just slid in with no resistance that would be a problem, depending on the amount of clearance, that could cause a clunk. Not saying that you are one of "these guys", but double check the tightness of the bolt that passes through the diff bushing. We have had a few "clunking bushings" that turned out to be the bolt moving up and down in the holes in the subframe ears, due to not being tight enough.
If you are willing to do the work, I am willing to send you a free bushing and tool to determine where the clunk is coming from and fix it.


Interesting. . . I wonder if there is a quality issue with the size of the sleeves??

My rear end clunk is back (not as loud as stock failed bushing) and I recall when I did the CS bushing swap last year that the new CS bushing just slid right in by hand. I didn't need the tool to put it in. I did however need the tool to remove the old stock bushing.

MotorMounts
05-08-13, 02:08 PM
The offer is open to you too, call if you would like a replacement bushing.