Grinding SM420 with 80w90 when warm. Heavier oil needed?
 

As stated in the title my 1967 C50 4speed shifts amazing right now when it's about 50ºF outside with the 80w90 oil, brand new.

But when the weather was warm and/or the trans starts to get warm, it'll start to want to grind unless I take an eon to shift and slide it in like a feather--even when double clutching which I always do.


Am I a perfect candidate for a heavier oil? I was also thinking about adding some Lucas oil "stabilizer"(it's just a thickener).

Any advice appreciated, thank you.

Re: Grinding SM420 with 80w90 when warm. Heavier oil needed?
 

I am no help on this. Here is a bump for you.

Re: Grinding SM420 with 80w90 when warm. Heavier oil needed?
 

I used common sense with this one, and also just talked with an acquaintance and at this point I'll probably switch to heavier oil and lucas, that's all I can do for now. Rebuild is out of the question unless I have a catastrophic failure.

Thank you for the bump.