TKX500 Oil or fluid, partnumbers

Joined
Aug 2, 2019
Messages
23
Location
Belgium
Hi All,

After grenading my 200R4 (broke a sprag gear, quite spectacular to be honest), I bought a TKX 500.
It's a bit notchy still after a whopping 60 miles of break-in.
On the internet I read some people having luck with pennzoil Syncromesh and a better shift quality.
On the other hand, Tremec (whilst advertising that pennzoil and GM syncromesh is OK to use in their transmissions, say by mail that I shouldn't use a syncromesh fluid).
Confusion identifies.


Mobil 1 synthetic DIII atf seems one of the safe choices to make.
However, I'm European and when I look for Mobil 1 atf synthetic I get a variety of choices ( LV, SHC, ATF 220).
Amsoil ATF isn't allowed as it's not tested they (tremec) said by mail.

So 2 questions:

- What Fluid can I use sucessfully without messing up the syncros?
- And what's the partnumber of said fluid so I can search a little bit more accurately?

Bonus question: If you're European, what fluid are you using with succes?

As always, I thank you very very much.
 
Gm and other companies like to spec thinner oil in these tremec transmission for EPA reasons but tremec themselves almost always spec something thicker than the oem's that use them.

Tremecs website says this takes tremec hp mtf which is a 12cst 75w-85 gl4. So you can basically use anything you want as long as it's around 12cst kv100 and is yellow metal safe which is all automatic transmission fluids and all manual transmission fluids also labeled as MTF and some but not all gear oils. The gear oils that are safe to use in a manual are the ones that are rated gl4 or dual rated both gl4 and gl5 but not gl5 on its own. Gm likes to use their dexron atf in tremec manuals which is like half the viscosity and something I'd never use unless it had to be used in very cold winters.

And as for the person you emailed 90% of them don't really know much about what they're talking about even though they work there.

https://tremec.com/wp-content/uploads/2023/07/HP-MTF-Condensed-Specs-Product-Info_19Feb2018.pdf
 
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The two fluids that come to mind as replacements would be

HPL's Manual Transmission Life 75W85 and Redline's MT-85 75W85 GL-4 offerings.
 
Gm and other companies like to spec thinner oil in these tremec transmission for EPA reasons but tremec themselves almost always spec something thicker than the oem's that use them.

Tremecs website says this takes tremec hp mtf which is a 12cst 75w-85 gl4. So you can basically use anything you want as long as it's around 12cst kv100 and is yellow metal safe which is all automatic transmission fluids and all manual transmission fluids also labeled as MTF and some but not all gear oils. The gear oils that are safe to use in a manual are the ones that are rated gl4 or dual rated both gl4 and gl5 but not gl5 on its own. Gm likes to use their dexron atf in tremec manuals which is like half the viscosity and something I'd never use unless it had to be used in very cold winters.

And as for the person you emailed 90% of them don't really know much about what they're talking about even though they work there.

https://tremec.com/wp-content/uploads/2023/07/HP-MTF-Condensed-Specs-Product-Info_19Feb2018.pdf

Gm and other companies like to spec thinner oil in these tremec transmission for EPA reasons but tremec themselves almost always spec something thicker than the oem's that use them.

Tremecs website says this takes tremec hp mtf which is a 12cst 75w-85 gl4. So you can basically use anything you want as long as it's around 12cst kv100 and is yellow metal safe which is all automatic transmission fluids and all manual transmission fluids also labeled as MTF and some but not all gear oils. The gear oils that are safe to use in a manual are the ones that are rated gl4 or dual rated both gl4 and gl5 but not gl5 on its own. Gm likes to use their dexron atf in tremec manuals which is like half the viscosity and something I'd never use unless it had to be used in very cold winters.

And as for the person you emailed 90% of them don't really know much about what they're talking about even though they work there.

https://tremec.com/wp-content/uploads/2023/07/HP-MTF-Condensed-Specs-Product-Info_19Feb2018.pdf
I think the motul looks the best?
It doesn't specifically say something about carbon syncros though, don't know how "sensitive" those are.

Screenshot_20250403_221423_Adobe Acrobat.webp


Screenshot_20250403_221905_Adobe Acrobat.webp
 
I think the motul looks the best?
It doesn't specifically say something about carbon syncros though, don't know how "sensitive" those are.

View attachment 271706

View attachment 271707
Viscosity difference isn't big. I'd use 85 unless it's a warm weather only vehicle that is used harder. I'd may use 90 then but 85 is good enough. Besides these mostly lived off of very thin ATF in many vehicles.
 
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