DIY SPL front/rear differential bushings
DIY SPL front/rear differential bushings
This took about 5 hours total but not because it's hard but because we didn't have the tools so we had to improvise. This would have been a 2 hour job or less if we had the right tools. I want to thank Kenny@K&D Auto for the help.
The key to getting this done was a 3.5" 12 gauge aluminum pipe I used as an intake for my car. I had a spare pipe and we cut a piece off a little longer than the bushing itself. The bolt we used is a cylinder head stud from a motor and was very strong and did not break.
For the ears of the bushings we simply used a socket with a hammer to take them out and a wood block to drive them in and finish off with a press.
We torqued everything to factory spec with a SnapOn digital torque wrench except the new bushings and went slightly higher.
The problem is that SPL only tapered one end of the rear bushing and because of that it was intended to go in only one way, from the back of the car towards the front. The OEM bushing is tapered at both ends so it goes in from both sides easy. Since the SPL one was not, we had had to center it constantly with a wood block and a hammer because it wasn't tapered and did not want to go in straight until the half way point.
I would strongly recommend that SPL revise the bushing so that it's tapered at both ends because no one is going to drop down the entire cradle for the install.
The car feel much better than before, going straight at 80-85mph or making slow or hard turns and wheel hop is all but gone. It's much easier to corner hard now and feel the car. There is some hardly noticeable gear noise now but only on deceleration and very light acceleration and only at certain speeds. Does not bother me since it's hardly audible and I like the noise. Sounds like a very faint whistle. I cant wait to drive her again.
The axles were lubricated with Teflon to prevent them from clicking in the future. Red Locktite was used on all the bolts.























































































The key to getting this done was a 3.5" 12 gauge aluminum pipe I used as an intake for my car. I had a spare pipe and we cut a piece off a little longer than the bushing itself. The bolt we used is a cylinder head stud from a motor and was very strong and did not break.
For the ears of the bushings we simply used a socket with a hammer to take them out and a wood block to drive them in and finish off with a press.
We torqued everything to factory spec with a SnapOn digital torque wrench except the new bushings and went slightly higher.
The problem is that SPL only tapered one end of the rear bushing and because of that it was intended to go in only one way, from the back of the car towards the front. The OEM bushing is tapered at both ends so it goes in from both sides easy. Since the SPL one was not, we had had to center it constantly with a wood block and a hammer because it wasn't tapered and did not want to go in straight until the half way point.
I would strongly recommend that SPL revise the bushing so that it's tapered at both ends because no one is going to drop down the entire cradle for the install.
The car feel much better than before, going straight at 80-85mph or making slow or hard turns and wheel hop is all but gone. It's much easier to corner hard now and feel the car. There is some hardly noticeable gear noise now but only on deceleration and very light acceleration and only at certain speeds. Does not bother me since it's hardly audible and I like the noise. Sounds like a very faint whistle. I cant wait to drive her again.

The axles were lubricated with Teflon to prevent them from clicking in the future. Red Locktite was used on all the bolts.























































































Last edited by Andrei; Nov 27, 2010 at 11:42 PM.
Really nice write up.
I would be a bit worried though if after installing these, you're getting gear whine. That seems very odd to me. I'd expect some drivetrain vibration, buit that's about it. By looking at the pics, it sure looks like the SPL ear bushing seem to be thicker, possibly tilting the differential down fractionally and possibly putting load on the pinion. Did you do any measuring?
I would be a bit worried though if after installing these, you're getting gear whine. That seems very odd to me. I'd expect some drivetrain vibration, buit that's about it. By looking at the pics, it sure looks like the SPL ear bushing seem to be thicker, possibly tilting the differential down fractionally and possibly putting load on the pinion. Did you do any measuring?
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