2003 Roadking works fine, but the shifting like all Harleys is loud. Im using RP 75/90 gear oil. If I go thicker is it detrimental ?

And fellas please, im not asking for what brand is better just would a thicker gear oil quiet the shifts down any?

randy

 

a thicker lube will not flow as easily into the bearings or bushings when it is cold.

like putting sawdust into a car tranny, it may make quiet for awhile- but after the sale it'll reveal itself.

mechanical problems are not fixed by fluids (even the "magic" fluids)

I really suggest using the types of lubes suggested in the manual- the engineers spec fluids which work best with the materials and design of the tranny ( or motor)


so i use modern lubes in my modern bikes- the '53 ( foot shift) uses straight gear oil- but the clearances in that tranny are wider and the mere starting of the bike requires kicking ( through the tranny) which moves the lube around before the motor starts...on that bike the lifters won;t even work until oil is pumped into the motor...by kicking


I'm used to noisy shifting- the gear selector is moving a bunch of gearsets back and forth, with a linkage which may have some slop- alot of my bikes have been noisy- bmw, norton, flathead, guzzi...I think my old tank shift '53 was maybe the quietest of the bunch

 

I agree with Mike, use the correct spec oils. As for noisy gear changes, how long have you owned your bike? It takes a while to master, but decent and reasonably quiet changes can be done with a little practice, asuming the clutch is well adjusted.

 

adjust your clutch pack via the manuals procedure. Is it hard to find neutral? If so, its a good indicator that your clutch pack needs adjustment. Im talking about the adjuster in the clutch itself, not the cable/lever.

 

and the correct spec would be....?

if you look in the manual, it tells you, syn3 or formula +. but if you use gear oil, there are a bunch of different weights, you've got your 75w-90, 85w-140, 75w-140, 80w-90, and so on.....

 

I'm using thicker synthetic but it still Clunks some times. I wouldn't use deno it brakes down almost instantly.

 

redline ,spectro, belray, mobil 1 all are good, just use a gear oil. harley specs their own lubes for profits, just like everything else.

 

That is one time the dealers excuse dor they all do that would be correct.

 

Do not go thicker. That clunk is just the spinning gears stopping when the drive dogs drop in. That heavy oil is required in the huge bearings and gears in auto differentials. Your transmission has some very small needle bearings in the input shaft inside the main drive gear. They need flushed.
Actually, the 75 gear oil is way too thick. Straight weight 50 gear oil has been proven best. If it wasn't, The MotherShip would be selling something else.

 

I know you said not to say which brand is best, but... I used to use Mobil 1 gear oil. After an input bearing and seal failure, I switched to redline transmission fluid with shockproof at the recommendation of the HD tech that rebuilt the tranny. It shifts a lot smoother now.

Also, if your just talking about the clunk and lurch forward when you first start up and shift to first, that has nothing to do with the transmission fluid. That's the wet clutch plates sticking together in the primary. Work the clutch a few times and get the oil flowing between the plates and it will help.....a little.