Focus on Engine Oil - what about Tranny?

[Sugz]

We pay so much attention to putting the best oil in our TDI, and I am wondering if I should be paying the same attention to the transmission oil?

Should I change out the stock for something superior? If so, what?

 

[Turbo Steve]

See What Manual Transmission Fluid Should I Use? 101.

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2000 Jetta GLS 5-speed: Silver & Gray / Luxury & CWP, Monsoon & CD. Engine Mods

 

[TDI Believer]

The tranny fluid that VW puts in is really good stuff. I have read several reports of folks using the Amsoil 75W-90 oil (also really good stuff) having problems shifting when the car is cold. My personal choice is to stick with the lube that VW sells for the tranny. My car has always shifted smoothly and I intend to keep it that way.

- Rich

 

[mickey]

The VW stuff is synthetic, top quality, and never needs to be changed...according to VW. I don't buy that "no change" crap, though. Change it every 100,000 miles or 5 years. More often if you race or otherwise abuse the transmission.

-mickey

 

[GoFaster]

I know of one forum member (tdimeister) who had very good success using Redline MTL 75w80. I plan to do the same, come summertime.

Brian P.
'96 Passat TDI mit UPsolute

 

[ralphwood]

I've had shockingly good results from using Amsoil gear oil in some old Beetles and a couple of Subarus. I don't know about other synthetic gear oils but compared to conventional gear oils I could see a big difference. When you are dealing with a lot of gears and a small engine it is easy to feel the difference in power. I'm not familiar with what is factory fill by VW. I changed to Amsoil when I bought my 84 Subaru new. I never changed the gear oil in 230,000 miles. I'm sure the fuel economy paid for the gear oil many times. I don't say you should go 230,000 miles without a gear oil change like I did but it worked well for me.

Ralph

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84 F-350 stretch cab dually 6.9 with submicronic Gulf Coast bypass filters
on lube oil, fuel, ATF and coolant
Click here for Photos

 

[ralphwood]

Sorry for double post

Ralph

[This message has been edited by ralphwood (edited February 03, 2001).]

 

[GANZGUT]

Brian:

I've had really good luck with Red Line MT-90 in my '96 Passat TDI's transmission. I was under the impression that MTL was for VW's made before 1985, but that could be bunk. I've heard that it's a little thinner than MT-90 and you get a bit more whine from the transmission, but thin viscosity may not be a bad choice for Canada. Then again, I use the MT-90 here in cold Bemidji MN (-25F here today) and have had no appreciable problems shifting. I replaced mine at 64K miles when I got the car and will probably not change it until 100K miles or so at the earliest.



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Jim

 

[TDIMeister]

Actually, Redline MTL is 70W-80... even thinner still. I was a little hesitant about installing it at first when I compared the viscosity with Amsoil 75W90. And when and I poured it in, it looked and smelled like ATF! But I couldn't be happier with the results. And anyone is welcome to see for themselves of there's any transmission whine. I notice NONE.

 

[Turbo Steve]

FYI:

Redline MTL is a 75W-80 weight Gear Lube (GL) that is much closer to a 70 weight oil and MT-90 is a pure 75W-90 GL.

Many people are surprised to learn that the majority of 7W-90 synthetic GL's have similar viscosities to a 10W-30 motor oil, which is why they appear to be so thin when you pour them in.

Yes, GL classifications are different than those of motor oils.

 

[TooSlick]

For shifting in really cold weather, the Redline MTL is going to be the best, simply because it's considerable thinner than their MT-90 product, or the Amsoil 75w-90.

The gear whine we're talking about is only something you'd notice in high heat, high load conditions ....You may be trading off some wear protection to get the best cold weather, but you'd have to do comparative oil analysis to know for sure ....

TooSlick

 

[GANZGUT]

TooSLick:

You're probably right re the MTL and cold weather/whining issues. I guess I didn't notice much difference from the factory fill with the MT-90 in my transmission.

My experience is that most of these synthetic products really quiet things down over their dino counterparts in trannys and differentials. And Red Line, like Amsoil, makes some pretty good stuff for our TDI's.

MTL or MT-90, you're probably going to be happy with the results.



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Jim

 

[Turbo Steve]

Ted:

I agree about the Redline's MTL 75W-80 Gear Lube (GL). Redline indicates that their MTL is more like a 70W viscosity.

FYI - a 75W-90 GL has a similar viscosity to a 10W-30 motor oil

For hot and warm climates, I recommend the following Gear Lubes:

AMSOIL Series 2000 Race-Proven Gear Lube: 75W-90
Redline MT-90 Gear Lube: 75W-90

For extremely cold climates, I still recommend Redline MTL Gear Lube: 75W-80 (70W-80)

 

[Boundless]

What about Mobil 1 Synthetic Gear Oil 75W-90? I hear this is good stuff.

What about Mobilube SHC 75w-90? This is the commercial full synthetic gear oil. It is allowed to go 500K to 750K miles by the manufacturers of OTR axles & gearboxes. Anybody use either one of these oils?