SS M6 transmission and differential fluid change - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

blumaro · 05-13-2015, 06:19 PM

I finally got around to changing the transmission and differential fluids with 20,800 mile on the odometer. I really wish I did it sooner. The transmission shifts way better now and the car seems to roll with noticeably less resistance.

The differential: I used the GM synthetic fluid 88900401 and limited slip additive 88900330 from my local Chevy dealer. The stuff that came out of the diff was rather thick. There was the normal amount of metal on the drain/fill plugs. I noticed that the new fluid was thinner than what came out. I can't be certain that the old fluid was some how causing resistance, but now it just seems like the car is smoother.

The transmission: My transmission has always been notchy since it was brand new. I even suffered the high RPM second gear grind initially, but as the miles added up, it seemed to mostly go away. Based on recommendations on this forum, I went with Redline D4. Wow! What an amazing difference! This thing shifts like butter now. It's like a different car. I can actually shift it like my old Z28's T56, as fast as humanly possible. I used to have to take it easy because fast 1-2 shifts would occasionally result in a grind.

The job: I performed this job in my garage with the car supported on four jack-stands. The differential was just as easy as any other that I have worked on. A little of the old fluid managed to get on the exhaust pipe. I cleaned it up with some brake cleaner. The LSD additive bottle is small enough to be used to directly squirt the stuff into the diff fill hole. I used a cheap Advance Auto fluid pump to suck the gear lube from the bottle into the diff fill hole. The differential took one quart plus the additive. This part of the job was a non-event.

The transmission had a nice surprise for me. Upon removing the drain plug the fluid shot out with enough velocity to completely miss my drain pan and land on the floor just beyond the passenger side door. I don't remember my T56 doing that. Fortunately I had plenty of oil absorbing pads so the cleanup was relatively easy. To refill the transmission, I used a tip gleaned from this site. I used some cheap Lowes clear 5/8" ID vinyl tubing ran from the engine compartment to the fill hole. I simply stuck a small funnel in the tubing and poured in the fluid. The transmission took just about four quarts.

Conclusion: If I had it to do over again I would have performed this job somewhere between 7,500 and 10,000 miles just to insure everything was good and broken in. I waited too long and could have been enjoying the benefits a lot sooner. Finally, if you are on the fence about performing this job on your car, just do it! It was relatively easy and the results were quite surprising.

wally mayfield · 05-13-2015, 06:34 PM

Thanks..Im on it..

blumaro · 05-13-2015, 06:41 PM

One more thing I forgot to mention. I couldn't find the Redline D4 at any local retailers. I ended up ordering it from Jegs. They have free two-day USPS ground shipping.

ZYBORG · 05-13-2015, 06:52 PM

Nice write up.

I already have all the stuff set aside for the same, just been a little lazy about it.

This thread might have been the push I needed.

Dimitrim · 05-14-2015, 08:08 PM

I like to set the dif fluid in a pan of boiled water while I jack up the car and drain the dif. It pumps in a lot easier.

Nighthawk89 · 05-14-2015, 11:44 PM

I used Royal purple synchro mesh and there fluid for the rear. I think i might try amsoil the next go around..

05-13-2015, 06:19 PM	#1
blumaro Drives: 2012 Camaro SS / 1977 Trans AM Join Date: Apr 2012 Location: NJ Posts: 102	SS M6 transmission and differential fluid change I finally got around to changing the transmission and differential fluids with 20,800 mile on the odometer. I really wish I did it sooner. The transmission shifts way better now and the car seems to roll with noticeably less resistance. The differential: I used the GM synthetic fluid 88900401 and limited slip additive 88900330 from my local Chevy dealer. The stuff that came out of the diff was rather thick. There was the normal amount of metal on the drain/fill plugs. I noticed that the new fluid was thinner than what came out. I can't be certain that the old fluid was some how causing resistance, but now it just seems like the car is smoother. The transmission: My transmission has always been notchy since it was brand new. I even suffered the high RPM second gear grind initially, but as the miles added up, it seemed to mostly go away. Based on recommendations on this forum, I went with Redline D4. Wow! What an amazing difference! This thing shifts like butter now. It's like a different car. I can actually shift it like my old Z28's T56, as fast as humanly possible. I used to have to take it easy because fast 1-2 shifts would occasionally result in a grind. The job: I performed this job in my garage with the car supported on four jack-stands. The differential was just as easy as any other that I have worked on. A little of the old fluid managed to get on the exhaust pipe. I cleaned it up with some brake cleaner. The LSD additive bottle is small enough to be used to directly squirt the stuff into the diff fill hole. I used a cheap Advance Auto fluid pump to suck the gear lube from the bottle into the diff fill hole. The differential took one quart plus the additive. This part of the job was a non-event. The transmission had a nice surprise for me. Upon removing the drain plug the fluid shot out with enough velocity to completely miss my drain pan and land on the floor just beyond the passenger side door. I don't remember my T56 doing that. Fortunately I had plenty of oil absorbing pads so the cleanup was relatively easy. To refill the transmission, I used a tip gleaned from this site. I used some cheap Lowes clear 5/8" ID vinyl tubing ran from the engine compartment to the fill hole. I simply stuck a small funnel in the tubing and poured in the fluid. The transmission took just about four quarts. Conclusion: If I had it to do over again I would have performed this job somewhere between 7,500 and 10,000 miles just to insure everything was good and broken in. I waited too long and could have been enjoying the benefits a lot sooner. Finally, if you are on the fence about performing this job on your car, just do it! It was relatively easy and the results were quite surprising. Last edited by blumaro; 05-16-2015 at 10:57 AM. Reason: Added diff fluid & additive part numbers

05-13-2015, 06:34 PM	#2
wally mayfield Drives: 2013 2SS 6M Join Date: May 2013 Location: eastern high sierra Posts: 893	Thanks..Im on it.. __________________ Strut tower brace(GM), CAI, Blade Spoiler, ZL1 wheels and tires, Heritage grill, Dual mode exhaust, and thats it, no more..except for the lowering springs..Ok Hotchkis springs were delivered today, thats it..

05-13-2015, 06:52 PM	#4
ZYBORG Lets roll... Drives: 14' Join Date: Jun 2014 Location: TX/S.FL Posts: 1,495	Nice write up. I already have all the stuff set aside for the same, just been a little lazy about it. This thread might have been the push I needed. __________________

05-13-2015, 06:41 PM	#3
blumaro Drives: 2012 Camaro SS / 1977 Trans AM Join Date: Apr 2012 Location: NJ Posts: 102	One more thing I forgot to mention. I couldn't find the Redline D4 at any local retailers. I ended up ordering it from Jegs. They have free two-day USPS ground shipping.

05-14-2015, 08:08 PM	#5
Dimitrim Dimitri Drives: 68 GTO 455 Ram Air; 2014 Camaro ZL1 Join Date: Jan 2014 Location: Novato, California Posts: 602 View My Garage	I like to set the dif fluid in a pan of boiled water while I jack up the car and drain the dif. It pumps in a lot easier.

05-14-2015, 11:44 PM	#6
Nighthawk89 Drives: 2011 Camaro 2Ss M6 Join Date: Dec 2011 Location: Southern California Posts: 4,013	I used Royal purple synchro mesh and there fluid for the rear. I think i might try amsoil the next go around..