Gear oil for the rear diff
- Status
1 - 15 of 15 Posts
imported post
While I always use 20w50 engine oil, I won't use 80/85/90w140 gear oil even in AZ. I destroyed a car differential 30+ years ago by using that stuff. It was fine for the gears, but did not lubricate bearings very well. It fried the pinion bearing for 2 reasons. One, because it was so heavy, when the gears threw it around inside the housing, it took longer to run back down, causing the same effect as a low oil level. Two, it was simply too thick to fit into the bearing clearances well, and they did not get enough oil. I don't know if this is the case with the Goldwing or not.
While I always use 20w50 engine oil, I won't use 80/85/90w140 gear oil even in AZ. I destroyed a car differential 30+ years ago by using that stuff. It was fine for the gears, but did not lubricate bearings very well. It fried the pinion bearing for 2 reasons. One, because it was so heavy, when the gears threw it around inside the housing, it took longer to run back down, causing the same effect as a low oil level. Two, it was simply too thick to fit into the bearing clearances well, and they did not get enough oil. I don't know if this is the case with the Goldwing or not.
Joined
·
2,711 Posts
imported post
I love these kinds of discussions.
To confirm what Jerry is posting -- the labeled viscosity values for gear oils and motor oils are not calculated the same way (mostly since gear oils are focused more at shock-loaded pressure uses and motor oils at hydraulic properties).
Thankfully, Bob's The Oil Guy has posted some comparison data for us all to enjoy (the chart below was stolen from http://www.bobistheoilguy.com/viscosity-charts/ ).
Essentially, Jerry's 20W50 motor oil is right inline with 80/90W gear oil from a pure viscosity standpoint - of couse, there's a substantial difference in additives and behaviors (heat, load, shear, environmental, organics, etc)
![]()
I love these kinds of discussions.
To confirm what Jerry is posting -- the labeled viscosity values for gear oils and motor oils are not calculated the same way (mostly since gear oils are focused more at shock-loaded pressure uses and motor oils at hydraulic properties).
Thankfully, Bob's The Oil Guy has posted some comparison data for us all to enjoy (the chart below was stolen from http://www.bobistheoilguy.com/viscosity-charts/ ).
Essentially, Jerry's 20W50 motor oil is right inline with 80/90W gear oil from a pure viscosity standpoint - of couse, there's a substantial difference in additives and behaviors (heat, load, shear, environmental, organics, etc)
Joined
·
2,824 Posts
imported post
As a test example with using the 85/140 hypoid gear oil in the rear end of an 1100 Goldwing:
Putting it in was usual.
The amount was usual.
The biggest noticeable difference was that it came out the vent breather, filled up the hollow around the vent and began migrating to the hub, the circumference of the wheel and in very short order was all over the rear of the bike.
At 85/140 wt it did a good jib of lubricating outside of the rear end. With a cleaning and removal of that heavy weighted oil and a replacement of 80/90 wt the process was easy and it stays put, that is I see no evidence of hypoid oil outside the rear end.
It like all fluids is changed regularly, I would rather see used hypoid oil coming out instead of a black substance that was originally removed upon receipt of this 1100.
At time when buying products only a weird number as 85/140 was in stock and this experience tells me the correct viscosity is crucial, similar to motor oil, transmission fluids, coolant...every fluid.
As a test example with using the 85/140 hypoid gear oil in the rear end of an 1100 Goldwing:
Putting it in was usual.
The amount was usual.
The biggest noticeable difference was that it came out the vent breather, filled up the hollow around the vent and began migrating to the hub, the circumference of the wheel and in very short order was all over the rear of the bike.
At 85/140 wt it did a good jib of lubricating outside of the rear end. With a cleaning and removal of that heavy weighted oil and a replacement of 80/90 wt the process was easy and it stays put, that is I see no evidence of hypoid oil outside the rear end.
It like all fluids is changed regularly, I would rather see used hypoid oil coming out instead of a black substance that was originally removed upon receipt of this 1100.
At time when buying products only a weird number as 85/140 was in stock and this experience tells me the correct viscosity is crucial, similar to motor oil, transmission fluids, coolant...every fluid.
imported post
"At time when buying products only a weird number as 85/140 was in stock and this experience tells me the correct viscosity is crucial, similar to motor oil, transmission fluids, coolant...every fluid."
I agree. Fortunately 20w50 is listed in the manual as being correct for my temperature. If not though, I would probably use it anyway.
I don't know what the recommended viscosity is for the newer 1800s, but back in '85 when mine was built, vehicle manufacturers had not yet jumped on this super thin oil bandwagon like they are now. Most new American cars recommend 5w30 "energy conserving" oil, but I know a city government fleet manager who uses nothing but 15w40 in all of them, without problems. Shell Rotella, he buys it by the 55 gallon drum.
"At time when buying products only a weird number as 85/140 was in stock and this experience tells me the correct viscosity is crucial, similar to motor oil, transmission fluids, coolant...every fluid."
I agree. Fortunately 20w50 is listed in the manual as being correct for my temperature. If not though, I would probably use it anyway.
I don't know what the recommended viscosity is for the newer 1800s, but back in '85 when mine was built, vehicle manufacturers had not yet jumped on this super thin oil bandwagon like they are now. Most new American cars recommend 5w30 "energy conserving" oil, but I know a city government fleet manager who uses nothing but 15w40 in all of them, without problems. Shell Rotella, he buys it by the 55 gallon drum.
Joined
·
742 Posts
imported post
Hmmm. Very interesting. I have used 75w140 Super Tech Synthetic in my 1500 for almost 6yrs and over 35k miles. It only came out the vent when i overfilled it. I thought a little extra would come out the hole a ittle more at the drive shaft that is supposed to help lube that end. I drained some out so it waa at the proper level and no problems. I change the lube only when i change tires and it is time for that now.
Hmmm. Very interesting. I have used 75w140 Super Tech Synthetic in my 1500 for almost 6yrs and over 35k miles. It only came out the vent when i overfilled it. I thought a little extra would come out the hole a ittle more at the drive shaft that is supposed to help lube that end. I drained some out so it waa at the proper level and no problems. I change the lube only when i change tires and it is time for that now.
Joined
·
3,258 Posts
imported post
I just do it once a year and use synthetic 75/90. Correct weight for bike and a bottle lasts 5 years.
I just do it once a year and use synthetic 75/90. Correct weight for bike and a bottle lasts 5 years.
1 - 15 of 15 Posts
- Status
Join the discussion
Join now to ask and comment!