Lexus IS Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter #1

This video demonstrates me rotating a wheel/axle back and forth. It almost bounces when changing direction by hand.

I have recently swapped over to an m98 t2 differential in my 2004 is300. Along with this, I replaced the stock diff bushings with superpro polyurethane. The issue at hand is that upon changing from acceleration to coasting there is a thud coming from the rear end and can be felt dependent on how smooth I transition between coast and drive. I believe this is caused by an excessive amount of backlash. I have checked the U joints and drive shaft, the pinion gear seems fine as well, with little to no play there.

Any suggestions or resources on how to solve an issue like this would be greatly appreciated.
 

·
Registered
2002 Lexus IS300
Joined
·
1,227 Posts
Could be backlash or possibly the pinion gear and the ring gear are just worn out. Any idea how many miles were on the M98 when you put it in? Did you take the cover off and inspect it before slapping it in?

If not, I would pop it open and have a look at the ring gear wear pattern and the pinion gear if you can see it. Also check the worm gears for any abnormalities.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #6
Could be backlash or possibly the pinion gear and the ring gear are just worn out. Any idea how many miles were on the M98 when you put it in? Did you take the cover off and inspect it before slapping it in?

If not, I would pop it open and have a look at the ring gear wear pattern and the pinion gear if you can see it. Also check the worm gears for any abnormalities.
The was no information that came with the differential when I got it this guy had like 4 of them. I did take the cover off and cleaned the gears seemed to be perfect on visual inspection. However I did not check wear pattern or backlash. Also I do have polyurethane bushings on all 4 mounting points but I’m not sure if that’s contributing to this issue.

I can physically feel and hear the differential changing between coast and power. The more aggressive and snappy I get on and off the throttle makes this effect more severe.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #8
I changed all of the bushings to super pro polyurethane. There are no more rubber bushings on this car
 

·
Registered
Joined
·
15 Posts
Discussion Starter #9
Here is a further inspection of my torsion T2 lsd. Upon inspection the backlash seems to be in spec, the pinion depth or preload could be off I feel. However I think most of the noise and issues are the hubs. They are definitely not supposed to move in and out, I’m not sure how to address this.

Video
 

·
Registered
Joined
·
15 Posts
Discussion Starter #11
I took out the axles shafts and I noticed that the piece they butt up against in the middle of the core can move. This creates a gap on one side which in turn causes the axle shaft to move in and out. I consulted some professionals and I decided to say screw it and put it back in, and axle shaft is 100% in there and will not come out when driving.
 

·
Registered
Joined
·
629 Posts
I watched the video and it seems like the axle stubs aren't pushed in far enough, as there's way to much in and out play. I used a mallet to get my stub axles back in the housing when I did my MK3 Supra LSD swap on my stock open diff. I'm sure you're aware there's snap rings (I think that's what they're called) that you need to push past a certain point to stay in place.
 
1 - 12 of 12 Posts
Top