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MG MGB Technical - Red Line tranny oil?

Has anyone tried the Redline tranny oil? I believe it may be synthetic. I am interested in trying some in my 67' GT with 3 syncro tansmission. Moss appears to be offering it for sale now.
Steve
Steve Brooks

id be very careful in choosing redline for an mg...it's great stuff for a modern manual transmission but i believe the synchros in the mg box need a lube that isnt so "slick"...unless the redline tranny fluid has some additive that gives it the same properties as regular motor oil.

im currently running sythetic brake fluid and a synthetic blend for my motor oil , but id dont have plans to use synthetic in the trans mission
bruce

Steve,
I don't necessarily think that everything Moss sells is correct, in spite of the fact that I work for them.
While the Red Line fluid may be the hot ticket for modern transmissions, I've heard that it tends to seep past the seals on older types of gearboxes. Ours are a design that really harks back to the '50's. I have used Castrol 20w50 in my "B" gearboxes for years, and have never had a bit of difficulty with them. So I have no intention of changing to something for which I see no real advantage. For a while in the late '70's, the factory specified 90w for "B" boxes. I don't have much comment on that, but I do know that they changed the spec back. If you have an O/D, you should NEVER use any kind of additive, just plain oil. My TD uses 90w, and I put some Power Punch in it...Mr. Moly is another of the same sort of moly additives. It makes the box shift really nicely, I also use it in the rear ends of all of my cars.
Craig Cody

Using RedLine in the tranny is pretty common among midget owners. I run it in my 1500. No problems with seals. The factory calls for 90w.
Chris

I plan to run a 50/50 mix of Redline and Castrol 20W50W this spring in my 72 MGB. I have had problems on occassion getting it into reverse easily, I am hoping that this mix will clear that little problem up. Redline claims that its MT90 product is better for syncros than plain motor oil, which they say may be too slippery. In any event, I have heard good things about the Redline, heard from some happy users on this site. I talked to Redline directly and feel this won't hurt my high mileage (97,000 miles) transmission. I am just not sure it will cure my minor problem. The Redline should lube the old parts better, with a greater resistance to shear from gears lashing than regular motor oil.
Joe

I run castrol syntax synthetic gear box oil, all the oil in mg B is synthetic...
Ross

I put Redline synthetic motor oil in the gearbox , immediate improvement in shifting .

_any_ synthetic oil will seep more than dino oil , just remember to check it monthly and top up as needed .
NSH


Chris, ( sorry that I digress from the thread ) But can you tell me more about 90W oil in the 1500 Transmissions?? I have a 75 Midget and I am using 20/50 engine oils. I have to shift at a snails pace to make a clean shift. ( The tranny is totally rebuilt)
David
David

David,

The 1500 tranny used a heavy gear oil when new, never motor oil. Check out a Haynes manual or the owners manual. The Midget BBS archive was a good bit of info on the subject. I would think that using a "thin" 20w50 will damage the gearbox over time.

-Chris
Chris

This thread was discussed between 22/02/2002 and 25/02/2002

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.