Getting ready to buy some gear oil for the transmission. I have narroed it down to two types. Bel Ray or Mobil 1 Able to buy it locally. I am leaning towards mobil 1. I can't find anywhere where it states bel ray being synthetic.

Question is 85 / 90 or 85 / 140

Thanks

 

I just had Mobil 1 75W-90 Gear Oil put in at my 1,000 mile service.
When it gets to 5,000 miles, I'll switch to 80W-140.

 

Im running the Mobil 1 80/140, works well. I like it better than the BelRay.

 

Most run the 75/90 but either will do fine. I run the 75/140 M1 and after this , a refill will be the redline shock proof heavy.

 

I run Mobil 1 75w/90 in my SG cause its easy to get and highly rated...

 

Gear oil weights are rated with higher numbers than motor oils. The heavier gear oils are really equal to (appx) a 20/60 motor oil in weight.

Bottom line, the heavier may run quieter in hot climates and the lighter may be better in cold weather. Kind of like motor oil but definitely NOT as critical and either will probably exceed the protection of using a motor oil instead of a gear oil.

Rough equivalents of weight of motor vs. gear oils.......................

SAE Engine Oil SAE Gear Oil

10w thru mid range of 20w 75w

Mid 20w thru mid 30w 80w

Mid 30w thru low 40w 85w

Low 40w thru 50w 90w

60w up 140w

Lots of this info is available in the forum just above this one in the form of FYI info from fairly expert posters.

EZ

 

Does not matter as long as you have gear lube in there. 85w90 or 85w140.....either one is ok.

 

Mobile 1 75w-90

 

The lower-viscosity is fine, and either brand will work well. I don't think BelRay is synthetic, and although it is considered an excellent product, I would pick Mobil 1 for that reason alone. The 85w140 can quieten 6-speed trannies considerably, but 5-speeds usually have no such issues, so I would use the 75w90. I ran the thinner oil (Royal Purple) in my RK for nine years and had no problems at all.

 

Thanks for all the reply'severyone
Just want to confirm that the mobil 1 gear oil we are talking about is the one typicaly used in cars right. It says nothing about motorcycle's on the bottle.

I have found both at the local auto parts store. Quite a difference in price. 10.00 for 85/90 or 20 for the 85 /140. Only takes 1 quart so I am willing to pay the extra for the 140 if that is the way I go.
Thanks again