Redline MT90 correct spec?

[andyasj]

I was considering putting Redline MT90 in my 5-speed manual gearbox (1986) but am getting no advice from sellers. MT90 is 75W90 but original spec for my box is SP80 but sometimes I have seen 80W90 recommended. What difference will it make. Is 75W90 safe in my box. Sellers will make no comment and just want me to buy it or not and will only say that it is my risk.
Can anybody help?
Cheers.[/b]

[andysimpson]

I run redline MTL in 2 of mine, thats a replacement for 75/80. Big improvement in gear changes.

[Aidan]

MT90 is the one for the gearbox, check with the importer and he'll look it up in the book. I use it in some of mine, but I'm trying Millers 75/90 instead after it was recommended by a gearbox manufacturer I know, and it's half the price of redline and british rather than yank and comes in proper 5 litres container instead of us quarts.

[andyasj]

Redline have replied to my email. Here is there advice:
<<Thank you for contacting Red Line Oil, originally in the Vanagon VW
called for either an 80W or a 80W-90 GL4 fluid according to my guide.
The MTL is an 70W80, a suitable replacement for the original 80W, the
MT-90 is a 75W90 viscosity a suitable replacement for the 80W90. You
could use either and I would base my recommendation on the operating
conditions and/or transaxle condition.
I would recommend the MTL if most operation was at relatively low
temperatures and cold shiftability was of prime importance. If it is
typically used in higher operating conditions, elevated temperatures
and/or there is some noise in the transaxle, I would recommend the
MT-90.
I hope that helped clear some of the confusion.>>
So I have a choice. But what are low/high temperatures?
Has anyone used both and can tell me if there is any difference.
I'll check out Millers, thanks.

[toomanytoys]

Several of us have been using Comma SX 75w90 GL5 oil in ours.. I have been running it for 7 years.. the gearbox has taken a lot of abuse and prob about 200k km in that time, thes change is still good (apart from worn linkages) and is showing signs of leakage (but to be expected as its 24 years old and 350k km+ on it) when I changed theoil it made such a difference..

Any good (ie branded) GL4 or GL 4+ you can find in a local motor parts store should be more than good enough... its been running on "cheap" stuff all this time so expensive stuff wont "repair" the wear... but its your money..

[Pootle]

Redline have replied to my email. Here is there advice:
<<Thank you for contacting Red Line Oil, originally in the Vanagon VW
called for either an 80W or a 80W-90 GL4 fluid according to my guide.
The MTL is an 70W80, a suitable replacement for the original 80W, the
MT-90 is a 75W90 viscosity a suitable replacement for the 80W90. You
could use either and I would base my recommendation on the operating
conditions and/or transaxle condition.
I would recommend the MTL if most operation was at relatively low
temperatures and cold shiftability was of prime importance. If it is
typically used in higher operating conditions, elevated temperatures
and/or there is some noise in the transaxle, I would recommend the
MT-90.
I hope that helped clear some of the confusion.>>

Here's the Redline page for manual transmissions:

http://www.redlineoil.com/products_gear ... tegoryID=7

Which should I use, MTL-90, MT-90 or 75W90? I'm still confused.

Thanks

[toomanytoys]

Which ever one you like... Have you seen how much it is???

Personally I wuld use a GL4+ rated 75w80 that you can get easily..

As I said.. the redline will not repair any worn components in your box, so any good fresh oil will work as well and be a massive improvement over the 20 year old gunge in there already..

I know of one member that went to the trouble of filling his box with redline and withing 3000 miles his box had broke... prob more a coincidence than cause, but he was peed off that he had spent a lot of money and didnt get any benefit...