TTagz

it doesn't make sense that the "correct" fluid makes your tranny work like ****. I've seen huge improvement from using MT-90.

joe@vwvortex

Thanks - never even heard of the stuff.

GeTT da NeTT

tranny noise since the switch. I spoke to a project engineer at Redline and he explained all that stuff that crew219 did, explaining to me that the GL-4 vs GL-5 for us is not really a problem. I talked to a NASA buddy that does lubricant R&D and he researched all of this stuff for me and came backwith a OK on the MT-90

ablankS4

Smoother shifting, though user reports vary from dramatic improvement to minimal.

crew219

MT-90.

By reading their white papers it seems that MTL definetely doesn't meet the GL4/5 requirements and the MT-90 may or may not depending on how you read it.

<i>MTL®can be used in most manual transmissions and transaxles for both street and racing use <b>unless the manufacturer requires the additional protection of an SAE 90 or the extreme-pressure protection of a GL-5<b>. In those situations the MT90 (GL-4) or 75W90NS (GL-5) will provide good shiftability and synchro compatibility and extra gear protection.<i>

From reading that statement I am assuming that they're referring to MT-90 "if you want the additional protection of an SAE 90" and the 75w90NS "if you need the extreme-pressure protection of a GL-5"

my .02

Dave<ul><li><a href="http://www.redlineoil.com/pdf/6.pdf">http://www.redlineoil.com/pdf/6.pdf</a</li></ul>

crew219

All the gear lubes will shear down, including redline. When comparing to a gear lube that shears down to an 85 or 85 wt to fresh 90wt gear lube, one will notice a marked improvement.

Also, the amount of friction modifier will deplete and cause slower syncro engagement as the gear oil gets older.

Personally, I think the reason why most people shy away from OE fluid (even though it is excellent) is because of the $$$.

Dave

ablankS4

notchiness is one of the few disappointments I've found in the car. I thought it was all in my sloppy shifting at first, but several MT-90 threads suggest there's at least a bit of a chemical cure

crew219

and the fluid just feels to be a little bit thin when warmed up. First to 2nd and 2nd to 3rd are a bit notchy when warmed up but smooth and solid when the fluid is cold.

After searching on here and BITOG regarding good alternatives to the OE stuff . . . I settled on SF MTL-R which is made by one of the long-standing members on BITOG.

Searching through tons of threads, I read about enough VW/Audi owners with 02J and 02M trannies switching from MT-90/MTL mix to MTL-R with positive results.

Anyways . . . . if you're interested in researching this more, check out www.bobistheoilguy.com

Dave

ablankS4

Thanks. Doesn't help that I also have muscle memory of shifts in a Honda CRX...

msauve

I was thinking that MTL/MT-90 were GL-5/MT-1 oils. Redline shows them at GL-4.

Reality is they they're probably not even that. Redline, like amsoil, doesn't do the full testing required by the API on their motor oils, but uses ambiguous and deliberately misleading labelling such as "for API service xx."

I suspect they do the same with thier gear oils.

Regardless, both MT-90 and MTL have been widely used in VW/Audi manual trannies for years, without any problems. The OEM is very good stuff, so I see no reason to switch unless you're trying to address a shifting problem. MTL seems thinner than OEM, and MT-90 thicker, so either would provide a slight difference compared to the OEM.