Is it true you can use the same synthetic oil for all your engine fluids instead of one for the primary,tranny, engine?

ORIGINAL: fatboy1729

Is it true you can use the same synthetic oil for all your engine fluids instead of one for the primary,tranny, engine?

Yes, but it isn't the wisest choice.

Good question. I'm about to do my 15k service & the bike (bought it used last year) has always been run on Syn 3 in all 3 holes.
Giving some serious thought to at least beefing up the tranny oil weight for the summer. Any suggestions would be appreciated (at least on my part) - there are lots of suggestions in prior posts and it's a bit confusing sorting all through it.

just because you Can does not make it a good idea.
HD is NOT a Honda the transmission is a true gear box.
Question would you put gear lube in your engine NO
Then why would you put oil in your gear box.
Read up on the lube thread lot of good ways to go there are a lot of good 100% true sny out there to meet your needs
SNY3 is at best an ok oil not a true sny

Thanks for the info. I'm surprised that HD doesn't sell a heavier grade syn for the tranny.

ORIGINAL: itileman

Thanks for the info. I'm surprised that HD doesn't sell a heavier grade syn for the tranny.


Me too. But many dealers have carried BelRay 85w140 gear saver for years. Any 75w90 or 85w140 GL5 gear oil will work fine.

guys,
Puttin Amsoil svg75w/90 in the tranny, and Amsoil 20w/50 in the other two, Feedin My girl the BEST !
Tj

Thank you for all of the replies. I never really thought about the different weights and grades. Thanks again. Ray

Redline synthetic in the engine, MTL for primary and Heavyshock for the tranny.