The rachet top 4 speeds, do they have the yellow metals that some gear oils are not good for? Is the GL4 the only safe one?

Thanks guys

 

Yes they have brass bushings, (yellow metal). I just use Valvoline VR1 SAE 50 at present.

 

Ok thanks.

Looks like Redline makes a yellow metal safe GL4 type synthetic gear oil called MT90 , I thought about trying it.

 

I asked Baker engineering if the Spectro Heavy trans oil they sell is compatible with the older 4 speeds trans (I have some for my 6 speeds) because of bronze bushings and they said it would not harm them. It's a GL5 oil but they said no problem. Some manufacturers say that oil companies claim their oils have buffered sulfur and are not corrosive to yellow metals. Note the "some", so I'd be careful and check with the manufacturer for other trans oils.

A wise man on this forum told me to use 60 weight valvoline syn and 25 percent of Lucas oil stabilizer. Other than the stabilizer, that's about what I've run in the 4 speeds for more than 40 years, straight weight non sythentic trans oil.

Paul

 

When the 4 speed was invented the motor company used the same oil that was in the engine we have used this type oil since it came along and 25 thousand miles is the life of a Harley 4 speed - this oil has been my go to for many many years valvoline vr synthetic 60 weight

its 10 bucks a quart - you need to spend 20 or 25 a quart hey go for it but we do 75 some years others 100 4 speeds and they dont come back with issues

now the magic oil is in the ones leaking like a lumber truck - but what do i know

 

I use 50/50 60W mineral oil and Lucas Oil Stabiliser, clunks going into first when it is cold but loving it all the same.

 

i use straight 50wt morris gold film motor oil as the factory recomended, never had a problem

 

Straight 50 or 60 Valvaline dino in my 4's, never had an oil related problem out the usual leak with age or abuse. What they want for f**king oil today the Road King may end up on this diet too.

 

Thanks guys. I'll try some VR1 60 weight.

 

Aren't all the bushings bronze?

The "yellow metal" that scares people about gear oil is the synchronizer rings used in older cars. Never saw a sync ring in a motorcycle transmission.