I have a friend who has been in the rx7 scene for decades and he uses GM brand synchromesh in his first gen and claims it's like shifting through butter versus other gear oils he has used. I saw Penzoil Synchromesh in autozone today for $6.99 a quart. I read the bottle and it says nothing about being a gl-4 or gl-5 rating oil but it claims it is made to be compatible with yellow metals such as bronze and brass that are used in manual transaxles or transmissions. I have read up about redline products and we want a 75w90 from redline (gl-4) but I don't want to have to order redline products right now things are tight but I think I can swing 3-4 quarts of this synchromesh (don't know exact capacity). Only God knows how long the fluid in the trans has been in there. The previous owner of this car said he never changed the engine's oil.........(the car doesn't smoke at all at any rpms thank God).

Can I use the Penzoil Synchromesh in my 87 with 5 speed manual trans? Anyways sorry if the answer is already in a thread somewhere I couldn't find it.

 

I see some other people are using a synchromesh in their transmissions however they don't specify if it is GM brand or Penzoil. I imagine Penzoil is just as good. I assume I only need 2 quarts of it if I do use it?

 

No, get 3 quarts...I think the FSM claims capacity is around 2.6 quarts but as long as the car is level, just fill till it comes out the fill port and you're done.

 

When I bought my car ('87 TII), it would occasionally grind going into 3rd gear. I switched to a mixture of roughly 2qts. Pennzoil Synchromesh and 1qt. ATF and it has not ground since. I also used Synchromesh in two of my DSMs with great results.