what weight is GM Synchromesh??

[00 scrub]

I've looked everywhere, and I can't find an conrete answer as to the viscocity of GM Synchromesh transmission fluid. My friend put it in his 5spd mazda transmission and it feels nice, but I'm afraid that it is too light because it shifts VERY smoothly.
thanks

 

[Judd]

Hmmmm, dunno. But my highly calibrated fingers says it's thicker than Dextron.

 

[Michael SR]

what does your mazda call for? i believe synchromesh is pretty close to ATF, or 5w30ish.

-michael

 

[Bror Jace]

I have the same problem when trying to look up a weight for Pennzoil syncromesh fluid. It seems like the companies just want us to use it ... with no questions asked.

--- Bror Jace

 

[unDummy]

Thinner than normal gear oil and thicker than ATF.

http://www.angelfire.com/ms/brianberryhill/pgt/stf.html

http://www.chevron.com/prodserv/neworonite/library/li_viscosity_amt.htm

http://www.pennzoil-quakerstate.com...te/Gear&Transmission/pdf/SynchromeshFluid.PDF

http://216.239.37.100/search?q=cach...d.pdf+#12345349+mtx&hl=en&lr=lang_en&ie=UTF-8

 

[00 scrub]

I'm pretty sure(the car isn't mine, it is a friends) the manual calls for 75w-90 oil. WIll usign this thinner oil harm the tranny and/or the syncros? Should he move to Redline MT-90 (or Redline 75w-90) or another tranny fluid like Motul with the proper wieght?
Thanks for the links.

 

[vettenuts]

The smoothness you have noticed may be the result of better syncro action rather then oil viscosity. Your results seem consistent with other reports on this fluid.

 

[Michael SR]

quote:

---

Originally posted by 00 scrub:
I'm pretty sure(the car isn't mine, it is a friends) the manual calls for 75w-90 oil. WIll usign this thinner oil harm the tranny and/or the syncros? Should he move to Redline MT-90 (or Redline 75w-90) or another tranny fluid like Motul with the proper wieght?
Thanks for the links.

---

right, MT90 is specifically called for to replace a 75w90 GL4 lube.

-michael