front and rear drive oil

[buck91]

My Yammy has a shaft drive, so there is a front and a rear diff, both of which are spec'd for 80 or 90 weight gear, ambient temp dependent, or 80w90 for all seasons. Two years ago I put in some cheap 80w90 conventional oil and it seems to have worked well with no leaking and no noises but I'm curious if a synthetic would be worth it in this instance? I'm primarily thinking this because the fluid volume is very low 300 and 375ml so heat build up can be an issue, though she doesn't typically see long highway stretches.

But I have heard of people developing leaks when switching to synthetic- which I did when I went to M1 motor oil in the bike. So I am hesitant to do so. What would some of the better conventional 80w90 gear oils be for a bike like this?

 

[JPP]

Originally Posted By: buck91
My Yammy has a shaft drive, so there is a front and a rear diff, both of which are spec'd for 80 or 90 weight gear, ambient temp dependent, or 80w90 for all seasons. Two years ago I put in some cheap 80w90 conventional oil and it seems to have worked well with no leaking and no noises but I'm curious if a synthetic would be worth it in this instance? I'm primarily thinking this because the fluid volume is very low 300 and 375ml so heat build up can be an issue, though she doesn't typically see long highway stretches.

But I have heard of people developing leaks when switching to synthetic- which I did when I went to M1 motor oil in the bike. So I am hesitant to do so. What would some of the better conventional 80w90 gear oils be for a bike like this?



**** I would think Valvoline 80W90 Semi-Synthetic would be a great choice for ya! I have used it a couple times in my Beemer rear drive.

JP

 

[The_Jeff]

I put whatever syn or syn blend Advance auto sold in my 82 Virago XV750. Still had most of the quart left over.

It was in a yellow bottle if that helps. Maybe pennzoil?

No performance difference, no leaks, no problems.

 

[Chris142]

Syn would be fine but im sold on Valvoline conventional myself

 

[QuietPortage]

Red Line Shockproof Heavy is my go-to for motorcycle transmissions and final drives; I use it in my BMW. The Harley crowd loves it too.

 

[Doog]

I would only use a mineral based 80w90 like Valvoline or Shell. If your bike is a 1980 the sealing material technology of that time is sometimes not too friendly to synthetic oils.