Castrol BOT 338 Fluid Replacement

[Cary]

Trying to figure out what oil to use for my 2006 Cayenne 6 speed manual transmission (uses some obscure Castrol/Porsche Oil called Burhma BOT 338 75W). Looking at ZF's list of approved lubricants (TE-ML11) they cross reference BP Castrol BOT 338 to BMW MTF-LT2, VW Oil No. N 05279800, and Castrol Syntrans B 75w.

I researched the [censored] out of it and there is very little information out there. Castrol's MSDS for the BOT 338 and Syntrans B 75w fluids show they have a thickness of 7.3 cSt @100c. The Fuchs MTF-LT2 apprpved oil is their Titan Sintofluid 75w-80 GL-5 which is thicker 9.4 cSt @ 100c, while Pentosin's MTF-LT2 oil is speced at 7.7 cSt @100c. Finally, Penrite specs their Progear 70w-75 as meeting the ZF TE-ML11 and MTF BOT 338 specs with a thin 6.9 cSt @100c.

I am debating between trying Redline (which I have had great luck with) and Fuchs. Looking at Redline, the D4 ATF has a thickness of 7.5 cSt @ 100c. MTL 75w-80 steps it up to 10.4 cSt @ 100c. For replacing MTF-LT2 oils Redline recommends either D4 ATF or MTL 75w-80. Dave Granquist at Redline has said that the MTL works well except in cold climates where the transmissions can get really stiff and suggests mixing D4 and MTL 50/50.

I am pretty sure the transmission in the Cayenne is an off the shelf ZF 6 speed, but so few have been made it has been impossible to determine what variant it is. I am guessing it is virtually identical to the version used by BMW (it is actually stamped VW on the side).

What do the BITOG members think for the oil choices? Fuchs or Redline? If Redline, which one or mix?

Thanks,

Cary

 

[tommygunn]

Mag 1 Synthetic Low-Vis ATF meets ZF TE-ML11A

Is ML11A the same as ML11?

Mag 1 is available on Amazon at a great price, or in Pep Boys for a still-not-too-bad price. Part number 64092

 

[dparm]

I believe BOT338 is a 75w80 GL4, actually.

 

[Cary]

Originally Posted By: dparm
I believe BOT338 is a 75w80 GL4, actually.


Except that is not what Porsche, the ZF Cross-reference say. The Porsche oil is Burmah BOT 338 SAE 75w, Porsche Part Number 000.043.300.38.

 

[dailydriver]

Straight RL MTL should not be much of a problem where you are located (unless you are at a cold, high altitude).

I am currently looking for a THIN (< 7.7 cSt @100*C), fully synthetic, MTF-2, since the 'thick' RL MTL currently in my T56 DOES grind into second and third in the now usual 0*F to 15*F mornings we have here.

I may have convinced Blauparts (their ONLY U.S. importer) to persuade Ravenol to let them bring in a few cases (vs. the usually required full pallet lot or more) of their 7.5 cSt, mostly PAO, MTF-2.

 

[antiqueshell]

Either Pentosil MTF 2 or Castrol Syntrans B75w.
Of equal importance is the GL-4 ONLY rating.

DO NOT EVER use any fluid rated in any other way. That includes
GL-5, GL4-5, & GL-4+.

Only use a product that states it is "GL-4"

The question is where in the heck within the USA can you get
ANY Castrol branded Syntrans Transaxle products?

These products are available in most of the rest of the world, except for the US and Canada. That is ridiculous!

 

[Cary]

Originally Posted By: antiqueshell
Either Pentosil MTF 2 or Castrol Syntrans B75w.
Of equal importance is the GL-4 ONLY rating.

DO NOT EVER use any fluid rated in any other way. That includes
GL-5, GL4-5, & GL-4+.

Only use a product that states it is "GL-4"

The question is where in the heck within the USA can you get
ANY Castrol branded Syntrans Transaxle products?

These products are available in most of the rest of the world, except for the US and Canada. That is ridiculous!


Why is the Gl-4 only rating important? According to what I have read, including Molekule's postings, GL-4 is basically a dead spec. In the old days, we had concerns regarding sulfur in GL-5 fluids eating the syncros, but virtually all GL-5 oils now use neutralized sulfur so it is not an issue. Is there something I a missing?

 

[dparm]

There are plenty of dual-rated GL-4/GL-5 fluids. Been using those for many years in GL-4 applications without issues.

 

[antiqueshell]

Originally Posted By: Cary
Originally Posted By: antiqueshell
Either Pentosil MTF 2 or Castrol Syntrans B75w.
Of equal importance is the GL-4 ONLY rating.

DO NOT EVER use any fluid rated in any other way. That includes
GL-5, GL4-5, & GL-4+.

Only use a product that states it is "GL-4"

The question is where in the heck within the USA can you get
ANY Castrol branded Syntrans Transaxle products?

These products are available in most of the rest of the world, except for the US and Canada. That is ridiculous!


Why is the Gl-4 only rating important? According to what I have read, including Molekule's postings, GL-4 is basically a dead spec. In the old days, we had concerns regarding sulfur in GL-5 fluids eating the syncros, but virtually all GL-5 oils now use neutralized sulfur so it is not an issue. Is there something I a missing?


While this spec is not very active in the US and Canada if you look around the rest of the world, there are plenty of applications using it and companies offering it.

Also it is not just about sulfur corrosion, but the specific friction modifiers used in GL-4 spec vs GL-5 spec.

There are STILL new cars being made that specifically state that GL-4 only fluid should be used.

 

[MolaKule]

Quote:
Why is the Gl-4 only rating important? According to what I have read, including Molekule's postings, GL-4 is basically a dead spec.


Because a GL-4 spec infers a minimum level of Anti-wear and fluid film protection for the gearing and bearings.

Quote:
Gearing: Most gear types in manual transmissions are of the helical type, which because of the cut, reduce noise and vibration. Due to their angular cut, thrust loads are transmitted to the shafts on which they reside. The gears on the input and output shafts are usually produced in one integrated piece, called “gear clusters, “ or the cluster gear assembly. You will notice the only gear that is actually moved is the reverse idler gear. This is moved into position to mesh with the small reverse gear on the input shaft so you can “back up” or reverse direction. At higher reverse speeds, this gear will usually give off the familiar “reverse” whine. Lubricant effects: Being in constant mesh, they are dipping in the oil bath and slinging the oil up to the shifter assembly. Since they transmit torque, they must have an anti-wear/Extreme Pressure additive in the lubricant in order to reduce wear. The slipping and rolling action of the gear teeth causes localized high pressures and heating. The anti-wear/Extreme Pressure additive forms a protective but complex ferrous film at the contact surface to protect from galling and other wear mechanisms. Other components such as thrust washers, flat thrust bearings of the roller type, and shims may also need cooling, lubricant film, and anti-wear additives as well.

 

[Cary]

Just to follow up on this. I ended up trying the Redline MTL which worked great when warm, but was very notchy and caused an occasional first to second grind when below 40F on the first shift of the day. While several on the porsche groups have reported good luck with MT-90 or 75w-90NS, I believe those to be way to heavy of oil. I have ended up running a 50/50 mix of Redline MTL and D4, as is recommended by Redline for the BMW ZF transmissions and the shifts are much better. I may ultimately try straight D4 on my next change, as it is very close to the viscosity of the factory Bot 338.

 

[supercity]

You could try this maybe
Syntrans FE 75w

 

[seanf]

I tried a mix of 2:1 2quarts Redline MT90 and 1 quart MTL in my Audi 01a and found it very notchy when cold,at -30 2nd gear was almost un useable for 2 blocks. When the time came for my other 01a to be serviced I used the Fuchs Titan Sintofluid 75w80. Even though its speced as a GL5 it meets the requirements for the VW fluid requirement of my trans. I find the cold shifting of the Fuchs to be better than the MT90/MTL cocktail in my other 01a box.

 

[dailydriver]

Originally Posted By: supercity
You could try this maybe
Syntrans FE 75w



I'm not so sure that is available in NA.