[Jekyll-N-Hyde]

I dont have the pics uploaded yet however I changed my Differential fluid today on a buddies lift since GM says to do so in the service manual @ 1500 miles and WOW boy am I glad I did.

of course it is supposed to look milky grey after use of the rearend heating up breaking down the fluid. The Drain plug is a magnet on these cars I had not a lot but I guess a normal amount of shavings stuck to the drain plug.
I put my finger's inside of the fluid after it came out and it felt a litttle gritty.

I did this at a friends gear and axle shop so I had someone around to tell me if thats good or not he told me it was normal and will be good to get that trash out of the rearend :thumbsup:

I put NEW fluid in the rearend along with the GM additive that GM calls for to be installed with the fluid and she now runs much smoother.

Belevie it or not it does run smoother and you can feel it.


Total cost of this cost me about $26 thats for 1 quart of fluid and the addative. it actually takes 1.1 quarts but after the 1 quart of fluid the addative makes it 1.1 :thumbsup:

This is a simple task you could do in your driveway with simple house hold tools , jack and jackstands :thumbsup:

just 2 bolts ( drain plug and Fill plug ) I would recommend getting a piece of vaccum hose to stick over the nipple on the fluid bottle so you can reach over the exhaust and squirt it inside the rearend :thumbsup:

Also get some cardboard and stick infront of your exhaust pipe because when it comes out it will hit the pipe directly if that cardboard isnt there.

this task is so easy even Shunt could jump out of the trunk and do it :thumbsup: :lol:

took me 15 minutes tops :thumbsup:

 

[RedJewel2SS]

yea i felt a difference as well.

makes me wonder if it is necessary to do the transmission also. :hmm:

 

[WRAITHSS]

yea i felt a difference as well.

makes me wonder if it is necessary to do the transmission also. :hmm:

Well, Like we have all commented in the past it cant hurt. I would have upgraded to Royal Purple if I were you. No additive needed and I noticed a difference over standard/ stock stuff..

 

[RedJewel2SS]

i used the Mobil 1 75w-90 LS differential fluid. it already had the limited slip additive included. and was cheaper than the royal purple

 

[WRAITHSS]

i used the Mobil 1 75w-90 LS differential fluid. it already had the limited slip additive included. and was cheaper than the royal purple

Well, I dont know about the price. I was a Mobil 1 oil only guy for many years.. Then over like 3 or 4 years alot of my friends were trying and loving the royal purple stuff. And after some testing of my own it is the only stuff i use in my diffs and transfer case and transmission. Still think Mobil one 15,000 is the best in the engine. But the rest is royal purple. Great stuff. Price I think is a little higher but you get what you pay for. IMO. :thumbsup:

 

[Michael_Js]

It's worth doing the tranny too! Same level of difficulty (low). A pump is a good idea though, or running a tube from the engine bay as you really can't fit a bottle in there.

 

[OverAnxious]

Wow, I'm surprised they recommend changing it at 1500 miles. Sounds like a good idea...

 

[RedJewel2SS]

Wow, I'm surprised they recommend changing it at 1500 miles. Sounds like a good idea...

the book says if vehicle is intended for racing use, change the fluid at 1500 miles. :thumbsup:

racing recommendations in a vehicle owner's manual... that is AWESOME!

 

[OverAnxious]

the book says if vehicle is intended for racing use, change the fluid at 1500 miles. :thumbsup:

racing recommendations in a vehicle owner's manual... that is AWESOME!

Change it to another type/version or change it in general?
Wonder what the rational is. People drive hard on the street as well

 

[RedJewel2SS]

Change it to another type/version or change it in general?
Wonder what the rational is. People drive hard on the street as well

just change it in general.

a lot of people change it anyways and everyone has said that fine metal shaving have come out with the fluid.

 

[POWERFREAK]

I was kinda shocked to see that it only holds a quart.

Just an FYI, I spoke to John Richmond (of Richmond Gear)...for their gears, they recommend sticking with the GM Fluid and NOT Royal Purple.

 

[demonspeed]

I was kinda shocked to see that it only holds a quart.

Just an FYI, I spoke to John Richmond (of Richmond Gear)...for their gears, they recommend sticking with the GM Fluid and NOT Royal Purple.

IIRC, it was once recommended (years ago) to run the Ford Trac-Lok fluid.

 

[el ess X]

What's the GM part number for the additive if you know it by chance?

 

[Michael_Js]

What's the GM part number for the additive if you know it by chance?

Section 10-8 in the owner's manual:

Manual Transmission (V8 Engine) Manual Transmission Fluid (GM Part No. U.S. 88861800,
in Canada 88861801).
Rear Axle (V6 Engine with
Automatic Transmission)
Rear Differential Fluid 75W-90 to GM Specification 9986155.
GM Part No. U.S. 89021677, in Canada 89021678.
Rear Axle (V6 Engine with
Manual Transmission)
Rear Differential Fluid 75W-90 Limited Slip to GM Specification 9986226.
GM Part No. U.S. 89021677 and Friction Modifier 1052358,
in Canada 89021678 and Friction Modifier 992694.
Rear Axle (V8 Engine)
Rear Differential Fluid 75W-90 Limited Slip to GM Specification 9986226.
GM Part No. U.S. 89021677 and Friction Modifier 1052358,
in Canada 89021678 and Friction Modifier 992694.
Key Lock Cylinders Multi-Purpose Lubricant, Superlube (GM Part No. U.S. 12346241,
in Canada 10953474).
Hood Latch Assembly, Secondary
Latch, Pivots, Spring Anchor,
and Release Pawl
Lubriplate Lubricant Aerosol (GM Part No. U.S. 12346293,
in Canada 992723) or lubricant meeting requirements of NLGI #2,
Category LB or GC-LB.
Hood, Door, and Folding Seat Hinges Multi-Purpose Lubricant, Superlube (GM Part No. U.S. 12346241,
in Canada 10953474).
Weatherstrip Conditioning
Weatherstrip Lubricant (GM Part No. U.S. 3634770, in Canada 10953518)
or Dielectric Silicone Grease (GM Part No. U.S. 12345579,
in Canada 992887).

 

[el ess X]

Thanks. Ahh, that's what I thought. 1052358, good old "posi lube"....stuff's been the same for years. I just happen to have a few bottles already.

 

[weland]

I dont have the pics uploaded yet however I changed my Differential fluid today on a buddies lift since GM says to do so in the service manual @ 1500 miles and WOW boy am I glad I did.

of course it is supposed to look milky grey after use of the rearend heating up breaking down the fluid. The Drain plug is a magnet on these cars I had not a lot but I guess a normal amount of shavings stuck to the drain plug.
I put my finger's inside of the fluid after it came out and it felt a litttle gritty.

I did this at a friends gear and axle shop so I had someone around to tell me if thats good or not he told me it was normal and will be good to get that trash out of the rearend :thumbsup:

I put NEW fluid in the rearend along with the GM additive that GM calls for to be installed with the fluid and she now runs much smoother.

Belevie it or not it does run smoother and you can feel it.


Total cost of this cost me about $26 thats for 1 quart of fluid and the addative. it actually takes 1.1 quarts but after the 1 quart of fluid the addative makes it 1.1 :thumbsup:

This is a simple task you could do in your driveway with simple house hold tools , jack and jackstands :thumbsup:

just 2 bolts ( drain plug and Fill plug ) I would recommend getting a piece of vaccum hose to stick over the nipple on the fluid bottle so you can reach over the exhaust and squirt it inside the rearend :thumbsup:

Also get some cardboard and stick infront of your exhaust pipe because when it comes out it will hit the pipe directly if that cardboard isnt there.

this task is so easy even Shunt could jump out of the trunk and do it :thumbsup: :lol:

took me 15 minutes tops :thumbsup:

At 1500 miles? I don't think mine's been changed yet!

Will call dealer now.

 

[RedJewel2SS]

At 1500 miles? I don't think mine's been changed yet!

Will call dealer now.

you can easily change it yourself for cheaper than the dealer cost.

just crawl up the rear of the car, unbolt the fill plug, put a oil drain bucket underneath, unbolt the drain plug, put drain plug back in after it stops dripping, use a 3/8" hose and connect it to the new oil bottle and squeeze 1.1 quarts in through the fill plug, put the fill plug back in and done!

 

[POWERFREAK]

you can easily change it yourself for cheaper than the dealer cost.

just crawl up the rear of the car, unbolt the fill plug, put a oil drain bucket underneath, unbolt the drain plug, put drain plug back in after it stops dripping, use a 3/8" hose and connect it to the new oil bottle and squeeze 1.1 quarts in through the fill plug, put the fill plug back in and done!

my exhaust is in the way

 

[Jekyll-N-Hyde]

my exhaust is in the way

Mine was to so thats why I put a piece of hose on the end of the bottle and put it over the pipe and in the hole. I emptied the whole bottle in the car which was 1 quart. Then the Addative which after that is slowly started dribbling out of the rearend.

Thats when I was told its full :thumbsup:


1 quart and 1 bottle of addative :thumbsup:


besure to put a rag or a piece of cardboard between the drain hole and your exhaust pipe or it will shoot out and hit the exhaust.

POWERFREAK besides the mufflers you and I have the same exhaust so this is how i know what you are dealing with lol

 

[RedJewel2SS]

if you can fit a 1/2" ratchet wrench into the plug, you can do it without removing the exhaust.