20w50 in tranny ?

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leroyd92

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So when I was working for a Harley shop here in town, we would get customers that wanted (synthetic in everything)

I was told Harley says its ok to put synthetic in the transmission? And it comes standard with new bikes?

I put lots of revtech full synthetic inside of transmissions. I put 80/90in mine when new, put 85/140 and didn't change much, thought about trying 20/50 and seeing if it changes anything.
 
I put Red Line Shockproof heavy in the transmissions of BMW R bikes. I'm told that the Harley guys like to use the same stuff. Read up on it and give it a try.
 
Mine is clunky, whines in 5th gear, and I had to change out trans bearing and race couple of years ago. Wish I could find some good lube for the transmission
 
Originally Posted By: toneydoc
Mine is clunky, whines in 5th gear, and I had to change out trans bearing and race couple of years ago. Wish I could find some good lube for the transmission
Originally Posted By: Bandito440
I put Red Line Shockproof heavy in the transmissions of BMW R bikes. I'm told that the Harley guys like to use the same stuff. Read up on it and give it a try.
 
I use 75w-140 in the transmission on my Heritage. I would never use 20-50 in a manual transmission on a 4 wheel vehicle so not in the transmission of my Softail.
 
"thought about trying 20W50 and seeing if it changes anything."

In terms of viscosity alone, 20W50 engine oil is roughly equivalent to a 75/80W90 gear oil.

However, the 20W50 will likely be more shear-prone and has a poor add-pack for a transmission. Friction modifiers might be a problem as well (if the transmission has clutches or synchros).

I'd do it in an emergency ... but there are so many good gear oils out there, I'd opt for one of those instead.
 
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Quote:
So when I was working for a Harley shop here in town, we would get customers that wanted (synthetic in everything)

I was told Harley says its ok to put synthetic in the transmission? And it comes standard with new bikes?

I put lots of revtech full synthetic inside of transmissions. I put 80/90in mine when new, put 85/140 and didn't change much, thought about trying 20/50 and seeing if it changes anything.


You worked at a Harley dealership and don't know the Harley recommended lubricants?
HD has been recommending 20w-50 in all three holes since for 3-4 years now.

With that said Redline Shockproof, Amsoil 75w-110 (SVT), Mobile gear oil or Schaffers 75w-90 all work well in the transmission.
 
Originally Posted By: leroyd92
So when I was working for a Harley shop here in town, we would get customers that wanted (synthetic in everything)

I was told Harley says its ok to put synthetic in the transmission? And it comes standard with new bikes?

I put lots of revtech full synthetic inside of transmissions. I put 80/90in mine when new, put 85/140 and didn't change much, thought about trying 20/50 and seeing if it changes anything.



Don't do it.

I've got shockproof heavy in mine. Nothing better in a Harley transmission. The 6 speed anyways.
 
Originally Posted By: rossn2
Quote:
So when I was working for a Harley shop here in town, we would get customers that wanted (synthetic in everything)

I was told Harley says its ok to put synthetic in the transmission? And it comes standard with new bikes?

I put lots of revtech full synthetic inside of transmissions. I put 80/90in mine when new, put 85/140 and didn't change much, thought about trying 20/50 and seeing if it changes anything.


You worked at a Harley dealership and don't know the Harley recommended lubricants?
HD has been recommending 20w-50 in all three holes since for 3-4 years now.

With that said Redline Shockproof, Amsoil 75w-110 (SVT), Mobile gear oil or Schaffers 75w-90 all work well in the transmission.


I said nothing about a dealership.... I worked at a local shop whom I had been taking my stuff to for years. Good guys, and all of them used gear oil in the gear box...
 
And I will say that just because a manufacturer says something, it does not make it the best advice or even right. My car for instance has a "lifetime fill" of ATF. Every single UOA of the transmission fluid they used to fill mine show it shot to Hades in 40k miles. I also have an owners manual for my older Chevrolet that has a carbed 305 from the factory. Manual says that 5w30 conventional that is SF rated is good for a 7,500 mile OCI. Every UOA from carbed engines show bad fuel dilution well below that.

I am a firm believer in "Trust, but verify"
 
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Harley trans: Use any gear oil. 20w50 will also work but won't last as long as gear oil. Redline shockproof heavy will last 20-25,000 miles.
 
If anyone cares, motorcycle motor oil that is designed to be used in transmissions only carry a GL-1 rating.Even Harley's own Syn III oil. They have been recommending it for transmissions since '03 when it first came out.Some friends use it and haven't had any problems.I use cheap 75/90 wt gear oil that has a GL-5 rating, and haven't had any problems, and I doubt using any brand would cause any. Harley transmissions are pretty much bullet proof.,,,
 
" just because a manufacturer says something, it does not make it the best advice or even right."

+1. Manufacturer's recommendation are usually correct (are at least a good place to start) but they are NOT gospel. Your use may vary greatly from the average/typical use they have in mind.

By the way, does anyone know the viscosity in cSt @ 100C of Red Line Oil Heavy Shockproof gear oil??
 
Originally Posted By: Smoky14
When I was in the business, we had great luck with BelRay gear oil products in transmissions.
YMMV

Smoky
Schaeffer's 707 in the engine, Bel-Ray primary chaincase in the primary, and Bel-Ray 6 speed in the transmission. This combo is sweet, and I will search no longer.
 
Originally Posted By: Bror Jace
By the way, does anyone know the viscosity in cSt @ 100C of Red Line Oil Heavy Shockproof gear oil??

RL says:

Heavy Shockproof Gear Oil, being a non-newtonian fluid, cannot use ASTM D445 to measure the viscosity. The viscosity varies with the size of tube used. There is no common analytical technique which can accurately measure the viscosity. The low temperature properties are not designed for temperatures below -25°C.
 
not a Harley owner, but I can tell you that all shared sump bikes (same batch of engine oil takes care of engine, transmission, clutch/primary) use 'common' motorcycle engine oil/heavy duty engine oil (Shell Rotella T or T6)...the major drawback is that the transmission shears the oil down quicker than bikes with separate lubricant sumps
 
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