Re: The Best Possible Transmission Oil

[m in sc]

ive used it all, to be honest, i get the best bearing life using 75 wt gear oil. Ive had 2 gears go out mid ride on bellray. I know, not the norm and im not nec blaming the oil, but ive never had an issue using plain gear oil. Just valvoline stuff.

I never had an issue using type f to be honest, but the cling properties arent that good. Keep in mind, type F is used in a system with a PUMP pushing it around. 

[Alain2]

I use cheap motorcycle 10w40, Castrol Grand-Prix or Motomaster on the bikes I use less.
I use Maxima MTL 80 in the bike I use more often.

The red stuff stinks, I don't want it near my garage.

[2strokesforever]

my RD like to mark it's territory

PTFE tape on drain plug threads

Atctually thumbs down.

Those are straight threads. YAMAHA put a fiber washer on it for  reason. your just asking to strip the case out by over torquing it.

I seconf Belray Gear saver. Good stuff.

To be honest ATF isnt really ideal for this application. Furthermore, if you know anyone that does any serious drag racing with more than 7-800 hp atf even type F is not used.....

[Jessup]

Atctually thumbs down.

Those are straight threads. YAMAHA put a fiber washer on it for  reason. your just asking to strip the case out by over torquing it.

Never stripped sump threads. Never relied on torque numbers. Always nipped up with a plain ring spanner. To each their own

[Robert58]

Ive been using Bel Ray 80-90 wt Gearsaver on advise of Gary from Spec II with no problems

[thatguy]

After trying just about everything I returned to 10W30 recommended by the manufacturer. I've never had a transmission failure on any bike I've owned. Worn parts out but no breakage regardless of oil used. Clean oil is best.

[motodreams]

My question would be, has anyone personally had a transmission failure due to using an oil in a motorcycle transmission?  I'm not talking 800hp drag cars, real life failure in normal conditions.  Also excluding clutch slippage due to long life additives as that would be simply incorrect application IMO.

I have never and have ridden hard for decades.  Run all sorts of oils from manufacturer recommended to dino motor oil (often actually recommended by manufacturer) and not had issues.

Many of the dirt bikes I have purchase have potentially never had the transmission oil changed and the gears are fine.

I have read the literature and although i'm sure the shear qualities are better but I think you are looking at the margin and talking microsheers that would take a million miles to accumulate.

Personally I feel the expensive oils are money down the drain unless you feel you are getting better shifting. 

[Banshee Hp]

Mobil 1 5w30 full synthetic

[Redbird]

my RD like to mark it's territory

...YAMAHA put a fiber washer on it for  reason...

Thank you for this ;)
I had completely overlooked that reason as to why mine was "marking her territory" too.
Couple of bucks to Economy Cycle later, and no more drips on the shop floor  ;D

[daniel4616]

I run only Bel-Ray Gearsaver

Following the advice of a very wise man who told me back in 2010, "Bel-Ray Gearsaver 80w for street (75w for race bike)"  8)

I'm with you Russ, I only use Bel-Ray 80w in all my streetbike builds...except in the race bikes I use 75w for the most HP I can get.
I have best R&D Motorsports race prepped trannys and when you spend $600 on this, the most expensive oil is cheap!
Ed, if you want the tranny to last, just use the belray 75W. I changed my transmission oil every 2 race weekends. (200-250 miles)
I put 3 years of hard road racing on my transmission without any failure's.
Chuck

Hi Chuck, I think you know the "very wise man" I referred to in my previous post!  ;D

Chuck helped build my bike years back, probably doesn't remember it has been so long. He told me the same thing, and I have listened and never had an issue either.  ;D

[EE]

My question would be, has anyone personally had a transmission failure due to using an oil in a motorcycle transmission?  I'm not talking 800hp drag cars, real life failure in normal conditions.  Also excluding clutch slippage due to long life additives as that would be simply incorrect application IMO.

I have never and have ridden hard for decades.  Run all sorts of oils from manufacturer recommended to dino motor oil (often actually recommended by manufacturer) and not had issues.

Many of the dirt bikes I have purchase have potentially never had the transmission oil changed and the gears are fine.

I have read the literature and although i'm sure the shear qualities are better but I think you are looking at the margin and talking microsheers that would take a million miles to accumulate.

Personally I feel the expensive oils are money down the drain unless you feel you are getting better shifting.

Here's the reasons I have looked at this issue a number of times over the years and revisit it: 1) As a racer I need any hp advantage available, BUT ALSO 2) as an RD racer I/we don't have the worlds largest racing budgets.. period.. so I/we need our expensively undercut trannies to last.. and 3) as an engine builder I've rebuilt just mountians of THESE engines litteraly.. and had to be the guy to completely disassemble, inspect and try to save peoples RD Trannies with an ever dwindling supply of descent used parts. These trannies had thin gears riding in many areas over splined shafts that's bad enough, not pressure fed, not filtered, not modern designed, add low oil levels or cheap oil, and I have replaced too many gears in these bikes to count anymore.. You wanna run cheap oil? Not me. Ed

[~JM~]

High quality lube, changed often, is cheap insurance.

Parts supplies are dwindling.

[Old Brit]

I'm with Chuck on this one, it's a gearbox so use gear oil 
I've never used anything other than an 80w GL4  in a street bike and have never suffered a failure or excessive wear issues as a consequence in nearly 50yrs.

[Alain2]

I'm with Chuck on this one, it's a gearbox so use gear oil 
I've never used anything other than an 80w GL4  in a street bike and have never suffered a failure or excessive wear issues as a consequence in nearly 50yrs.

Do you use Universal Tractor Transmission Oil (GL-4)? That would be cheap to replace often.

[MRDRcycle]

Can someone tell me how many liters of transmission fluid a 73' RD350 holds? I can't find my manual