I am wanting to change my transmission fluid and rear differential fluid this weekend but this is something i've never done before nor do i know if the previous owner ever changed it. Its a 1999 Camaro SS with 70k miles and has the T-56 6-Speed.

What Fluid should i use for both? From the research it looks like Dextron III for the tranny fluid? Is there a tranny filter that needs to be changed out as well? how hard are these changes? and where can i find the tool to put the fluid back in? i have no idea what its called or even looks like....Thanks for all the help guys, i really appreciate it!

 

Use what your owners manual recommends as far as fluid in both. No filter for manual transmissions and i usually use the quart bottle with a piece of 3/8 hose to refill

 

whatever you get youll need a posi additive unless fluids have improved and its in there now.

 

i would use the additive regardless

 

fluid change is pretty easy, for the t-56 yes dextron III AT fluid i use MOBIL 1 synthetic. you need to look up the specific amount of oil for the transmission since their is no dip stick and you don't want to add to much or to little. drain plug is at the bottom of transmission, when you fill it, fill it from up top you'll have to take your shifter assembly apart and the plate add the fluid and re install.

the differential cant remember what weight it takes but you need to add the special additive for the slip. to drain you have to crack open the face pan let it drain wipe it down re-seal and bolt up, then fill with gear oil till it over flows the fill port. personally i would take it to a jiffy lube its alot easier to let them do it they can suck the gear oil from the top and re fill

 

I wouldn't trust Jiffy lube. No thanks.

 

Do not go to jiffy lube!!

 

id take it to a gm EFI specialist instead if an oil change place.

 

Royal Purple 75W-90 Synthetic for the Rear End. You won't need an additive for it. I know its expensive. I just got 2 Quarts for my 2000 WS6 for $18 a piece online. That was the cheapest I could find it. It wasn't from a sponsor, so PM me if you'd like to know where. You'll also need a new Rear End Cover Gasket. They're $4 at Autozone.

As for the Tranny Fluid, pretty much any type of DEXRON III will due. I believe I used Castrol when I upgraded the Clutch on my 99 Formula last year. A friend and I finished swapping the Clutch on his 98 Trans Am about a month ago and he used STP ATF that he bought at Dollar General. Wouldn't have been my choice, but the car runs and drives great, so I'm sure its fine.

As for the procedures, both are pretty straight forward. I recommend making sure you can get the fill hole plugs on both the Rear End and the Transmission loose prior to draining the fluid on either. Its just a matter of using a 3/8" Ratchet and Extension to break them loose. Once you've done that, remove the drain plug on the Transmission (Its on the Passenger Side Rear of the Tranny) and let it drain. Reinstall the Drain Plug and remove the Fill Plug (which is on the Driver Side). I refilled my Tranny thru the Fill Hole when I completed my Clutch Swap. I got the job done, but it made a ******' mess doing it. For my buddy's Trans Am, we had the shifter removed and filled it slowly thru the Shifter Opening. No mess at all this way, but this will require you to remove your console and shifter. Its not tough, just a little more work. Whichever method you choose, fill until you start to get fluid coming back out of the Fill Hole. Reinstall the Plug and you're done.

For the Rear End, remove the 10 Bolts (I believe they're 1/2") that hold the Rear End Cover and remove it, allowing the Rear End Oil to drain. Scrape the old Gasket from the Cover and Rear End. Reinstall the cover with a new gasket and a little Blue Glue to hold it in place and help it seal. Remove the Fill Hole Plug and add fluid until it starts to come back out the hole. I used a Bulb Syringe to suck up fluid from the oil container, then squirt it into the hole. It takes a while, but gets the job done. Good luck, man.

 

Yeah if you go to Jiffy Lube your next post will be asking how to unfuck your car after taking it to Jiffy Lube.

 

Prepare for stink when you pop the cover off that diff..

 

"Say no to jiffy lube"

 

For my Transmission, i used the reccomended Weight royal Purple. Theres a Plug at the bottom of your tranny, you will undo this and let it drain, once its finished Draining, Tighten plug, and you will see another just like it at the top. Fill it with your trann fluid until it begins to overfill. Will be exactly 4Quarts. Make sure to tighten your fill plug and recheck yourdrain plug.

Same for your Rear end, Use royal purple. Recomended weight. You dont need your special Additive with this stuff. Drainging it will be a little tricky. you can pop the rear diff cover of and let it pour out, or just run down to your local mom and pop shop and let them use their Rear Diff machine. So much easier because you can just put the tube in and let it suck it out, and reverse it to fill with new fluid. Good Luck

 

These are the actual pages from the 1998 camaro user manual, rear axle differential oil change is not required unless you are towing something with the car.
As for the oil these are the required types.

 

I don't care if it says "not required" - oil breaks down over time with age and use. For how little the oil costs compared to a rear axle I'd rather replace the gear oil on occasion.

Unless of course you blow up the 10 bolt then it's a moot point

 

this!

 

So you're saying you know better than the General?
Plenty of people around me hitting 180k miles without changing the diff oil. If its not broken don't fix it !

 

Replacing the Dif Fluid and/or Tranny Fluid (or any other fluid) is cheap insurance against failure. And is also a great way to get familiar with maintaining your vehicle. **** the manual.

 

If you got to either trans or rear specific forum you will get a broader range of opinions.

FOR ME:

Trans: Pennzoil Synchromesh; GM sells it but they make it, OTC and easy to use. Thicker but for some T-56 actually run better, some run regular ATF your choice, if you don't like it swap it out. I want to try Redline DTF next time I decide to do it.

Rear: IF you were to do it I always used conventional diff fluid spec'ed to factory weight and added GM Diff Lube. IF you diff has clutches. Up keep is Up keep and I myself will over service a car vs under service. My 2007 HHR has a crazy transmission & coolant service interval, I can tell you I will be doing MUCH sooner then Recommended

 

THANKS!!! This is exactly what i was looking for!! Much appreciated!!