What Oil for M21?
Burning Brakes
Joined: Mar 2001
Posts: 1,211
Likes: 5
From: Nashville TN
Re: What Oil for M21? (redvetracr)
I run the Redline products in the manual tranny in my BMW. Top notch stuff.
http://www.redlineoil.com/products.htm
http://www.redlineoil.com/products.htm
Melting Slicks
Joined: Oct 2001
Posts: 2,064
Likes: 1,382
From: Halifax, Nova Scotia, Canada
Re: What Oil for M21? (Rob's 73)
For many, many years, GM technicians here do not recommend using gear oil.
The reason I was told was that under cool/cold conditions, heavy Gear oil
does not lubricate properly. For years they recommended 30W engine oil.
Maybe something to do with the Canadian climate.
Now GM recommends "Synchromesh Transmission Fluid", PN 10953465.
This is a GM product.
States on the back of the bottle:
"Designed specially for use on GM manual transmissions. This product has excellent lubrication properties and does not break down. It withstands high temperatures and functions well in low temperatures. It is an amber colored light bodied base product that's a partially synthetic manual transmission fluid."
That's what I'm using in mine.
Thanks
Barry
The reason I was told was that under cool/cold conditions, heavy Gear oil
does not lubricate properly. For years they recommended 30W engine oil.
Maybe something to do with the Canadian climate.
Now GM recommends "Synchromesh Transmission Fluid", PN 10953465.
This is a GM product.
States on the back of the bottle:
"Designed specially for use on GM manual transmissions. This product has excellent lubrication properties and does not break down. It withstands high temperatures and functions well in low temperatures. It is an amber colored light bodied base product that's a partially synthetic manual transmission fluid."
That's what I'm using in mine.
Thanks
Barry
Racer
Joined: May 1999
Posts: 382
Likes: 0
From: Long Beach CA
Re: What Oil for M21? (73 LS-4)
I'm using valvoline synthetic 75w-90. Wanted mobil one but couldn't get my hands on any that day. It made a noticable difference compared to the who know's what/how old stuff that was in there. I am very happy with it.
BTW its an M-20 (t-10)
Jim
BTW its an M-20 (t-10)
Jim
Burning Brakes
Joined: Jul 2001
Posts: 831
Likes: 0
From: Reston VA
Re: What Oil for M21? (Rob's 73)
Pretty hard to beat Redline. Call the tech line and tell them your driving parameters and the mileage on your tranny. They will recomend a specific wieght for your application.
:cheers:
:cheers:
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Le Mans Master
Joined: Oct 2000
Posts: 6,563
Likes: 2
Re: What Oil for M21? (Rob's 73)
Steer clear of rear end gear oil; most contain an additive for limited slip which will damage a manual trans. This was related to me by Richmond Gear when I bought the 6 speed. They recommended RedLine ONLY (no posi additives).
:yesnod: :chevy :chevy :yesnod:
:yesnod: :chevy :chevy :yesnod:
Melting Slicks
Joined: May 1999
Posts: 2,897
Likes: 0
From: Moon Township PA
Re: What Oil for M21? (Rob's 73)
Mobil 1 synthetic gear lube is the standard by which a lot of folks measure their gear lube. It is a great product and virtually all the auto parts stores carry it. I like the stuff enough to put it in all of my rear wheel drive cars. The same thing holds for its use in transmissions.
Gary
Gary
