2.73 stock rear end to 3.73 gears ?
12-18-2016, 04:19 PM
#3
https://www.summitracing.com/parts/MGR-G875373X
https://www.summitracing.com/parts/MGR-R7-5GRLMKT
What I bought to do mine
https://www.summitracing.com/parts/MGR-R7-5GRLMKT
What I bought to do mine
12-19-2016, 02:10 AM
#4
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As your username suggests you have a '98, be sure that you refill the diff with 80w90 conventional lube (NOT synthetic) and 4oz of GM LSD additive. This is very important for proper operation of the Auburn LSD.
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12-21-2016, 02:06 PM
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Traction is more difficult with this setup. I'd honestly rather have a 3.23 + SS3600 combo myself, easier launch and better highway cruising rpms; perfect combo IMO, and leaves no more than ~0.10 seconds of ET on the table over 3.73s
12-21-2016, 02:41 PM
#11
Since you have a factory 2.73 geared car you have a 2-series carrier so make sure the gears you buy are for a 2-series carrier. The factory 3.23 geared cars have a 3-series carrier and gears for a 3-series carrier will not work in your case.
FWIW...I've been out of the gear world for a while but I believe the GM gears are known to be the most quiet. I've ran both AAM and Motive and both made a little noise. Not sure your car usage/intentions but I have 3.73's in my auto car and dislike it on the highway with the 4l60e trans, too much rpm. I like the 3.73's for driving around town, raising hell and racing but if I daily drove the car or drove it on the highway a lot I'd probably switch to a 3.42. Just some food for thought.
FWIW...I've been out of the gear world for a while but I believe the GM gears are known to be the most quiet. I've ran both AAM and Motive and both made a little noise. Not sure your car usage/intentions but I have 3.73's in my auto car and dislike it on the highway with the 4l60e trans, too much rpm. I like the 3.73's for driving around town, raising hell and racing but if I daily drove the car or drove it on the highway a lot I'd probably switch to a 3.42. Just some food for thought.
12-27-2016, 10:50 AM
#13
I have 3.42's in my A4 car. I picked up my rear from a totaled 02 15k car and swapped the entire rear end. No messing or fussing with gears. The 3.42's pull hard out of the hole and run about 2000rpm at 70mph.
12-27-2016, 11:05 AM
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Not an option for this rear end.
G875373x is a thick gearset, or you can run a standard thickness GM75373 or G875373 and buy a spacer to correct the thickness issue.
Dont let these guys scare you away from the gear. Ive ridden, driven, and installed them all. 3.73 is fine.
G875373x is a thick gearset, or you can run a standard thickness GM75373 or G875373 and buy a spacer to correct the thickness issue.
Dont let these guys scare you away from the gear. Ive ridden, driven, and installed them all. 3.73 is fine.
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12-27-2016, 02:02 PM
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As said above, 3.55s are not an option for this rear. Next closest would be 3.42...
This is a nice option as used 7.5" rears can often be had for less than the total cost of gears + labor to install a set in your existing rear, plus you eliminate the concerns of aftermarket gear whine and break-in procedure. Still need tuning for the speedometer and shift points though. Only risk then is making sure that the rear is solid before you purchase. But cruising rpms would actually be more like 2200 @70mph with stock height tires and a 4L60E - not bad, but only worth the hassle if coming from a 2.73 (wouldn't be worth the cost/time from 3.23 IMO.)
This is a nice option as used 7.5" rears can often be had for less than the total cost of gears + labor to install a set in your existing rear, plus you eliminate the concerns of aftermarket gear whine and break-in procedure. Still need tuning for the speedometer and shift points though. Only risk then is making sure that the rear is solid before you purchase. But cruising rpms would actually be more like 2200 @70mph with stock height tires and a 4L60E - not bad, but only worth the hassle if coming from a 2.73 (wouldn't be worth the cost/time from 3.23 IMO.)
12-27-2016, 02:27 PM
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Driver carrier bearing race is ALWAYS fucked in m6 cars, even low mileage ones. Suggesting he buy a 3.42 complete rear is walking him into that problem. Just a heads up for those who may not really see the insides of these things.
12-28-2016, 12:20 AM
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Of course, I agree that some of them are junk and wouldn't be worth the cost or hassle of the swap.
10-09-2019, 07:06 PM
#18
What did you do when it started making that noice bc i just switch mine on my car and its making that noice
10-10-2019, 12:45 AM
#19
Wow - this just got spit out from the wayback machine. It was a friend's car and the noise was there immediately from installation. It is said that it's because Richmonds have straight-cut gear teeth which are stronger but tend to be noisier. It's not indicative of a problem, just annoying. Perhaps there are guys out there who can get them setup to be quiet, but they have a reputation for being noisy.
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