Bevel box gear oil: What do you use?

ZoneIII

Supercharged
Joined
Mar 7, 2016
Messages
284
Location
Northern Illinois
Ride
2015 Triumph Rocket III Touring
My 2015 R3T owner's manual calls for Mobilube 75w-90 SHC synthetic hypoid gear oil for the bevel box. I say "my manual" because later manuals may recommend and different gear lube since Mobil tells me that Mobilube SHC oil was discontinued. I've been using Mobil 1 Synthetic 75w90 LS gear lube with no apparent problems. I change my bevel box oil with every oil change because it's so fast and easy. Since I change fluids at the beginning of each riding season, which will be in about two months, I was just thinking about whether or not Mobil 1 LS oil is the best choice, so I contacted Mobil. Mobil informed me that Mobil1 LS may not be the best choice of gear lube (although they didn't say it was bad). They didn't know for sure what would be the best substitute for the Rocket but they said perhaps Mobil Delvac 1 Gear Oil would be a good choice.

This is no big deal at all and I suppose any brand name 75W-90 gear oil will work fine (although no products I have looked at specify "hyphoid" gear oil), I'm just curious what you folks are using.
 
I used Valvoline Full Synthetic 75w90 but would happily use Mobil 1. The Valvoline I had on hand. I don't know what the LS stands for but would think any full synthetic 75w90 would work fine.
 
My 2015 R3T owner's manual calls for Mobilube 75w-90 SHC synthetic hypoid gear oil for the bevel box. I say "my manual" because later manuals may recommend and different gear lube since Mobil tells me that Mobilube SHC oil was discontinued. I've been using Mobil 1 Synthetic 75w90 LS gear lube with no apparent problems. I change my bevel box oil with every oil change because it's so fast and easy. Since I change fluids at the beginning of each riding season, which will be in about two months, I was just thinking about whether or not Mobil 1 LS oil is the best choice, so I contacted Mobil. Mobil informed me that Mobil1 LS may not be the best choice of gear lube (although they didn't say it was bad). They didn't know for sure what would be the best substitute for the Rocket but they said perhaps Mobil Delvac 1 Gear Oil would be a good choice.

This is no big deal at all and I suppose any brand name 75W-90 gear oil will work fine (although no products I have looked at specify "hyphoid" gear oil), I'm just curious what you folks are using.
I use Motul Gear 300 75w90. It exceeds GL-4 and GL-5 requirements, is ester based, and more than meets all the requirements from Triumph.
 
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I used Valvoline Full Synthetic 75w90 but would happily use Mobil 1. The Valvoline I had on hand. I don't know what the LS stands for but would think any full synthetic 75w90 would work fine.
Seems to me the, " LS", which I have been using, stands for, "Limited Slip". Just checked my Mobil 1 synthetic gear oil bottle. Small print on label says, "Limited slip friction modifiers added."
 
Seems to me the, " LS", which I have been using, stands for, "Limited Slip". Just checked my Mobil 1 synthetic gear oil bottle. Small print on label says, "Limited slip friction modifiers added."
In that case you definitely don't need it LS a simple bevel gear box.
but I wouldn't think it hurts.
 
Seems to me the, " LS", which I have been using, stands for, "Limited Slip". Just checked my Mobil 1 synthetic gear oil bottle. Small print on label says, "Limited slip friction modifiers added."
Yeah. I didn't think of it until recently but it recently dawned on me that the LS does mean limited slip. I'm not sure if that is detrimental to a R3 bevel box but I doubt that it is. I have an F150 with an electronic locking rear differential and I change all my fluids. If I had a limited slip differential, I would have to add a friction modifier. It probably adds some kind of friction material to avoid slippage in a limited slip differential and I'm guessing it serves a similar purpose to the friction modifiers added to motorcycle 4T racing oil for bikes with wet clutches that share oil with the engine (like a R3). But I'm going to switch to a gear oil that doesn't have an added friction modifier just in case. Thanks for your response!
 
it allows the clutches to slide smoothly
for example if u r going in a circle and u dont have the ls then your outside wheel will slide grab.
personally i dont think its a prob
but its going to take professional to say which one is better.
 
Yeah. I didn't think of it until recently but it recently dawned on me that the LS does mean limited slip. I'm not sure if that is detrimental to a R3 bevel box but I doubt that it is. I have an F150 with an electronic locking rear differential and I change all my fluids. If I had a limited slip differential, I would have to add a friction modifier. It probably adds some kind of friction material to avoid slippage in a limited slip differential and I'm guessing it serves a similar purpose to the friction modifiers added to motorcycle 4T racing oil for bikes with wet clutches that share oil with the engine (like a R3). But I'm going to switch to a gear oil that doesn't have an added friction modifier just in case. Thanks for your response!
Here's a picture of the fine print on the backside of my Mobil 1. Says it is for conventional as well as limited slip differentials or at least that is my interpretation of what it means.
 

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