Sealed Primary Fluid; Dextron?

[John Guntner]

I'm doing the top end on my 47 Chief. I'm changing all fluids at the same time. Red Line in the tranny, but I'm not sure if the red transmission like fluid I drained fron the primary case is a dextron fluid or not. What do you think?

[pisten-bully]

How about is it synthetic gear oil? I don't think transmission fluid for a chain drive would be a good idea at all.

[John Guntner]

Primary oil

Hi Harry,
OK, I'm confused now. I put red line in the tranny. I assumed because I see a sealed bearing between the primary and the transmission that it was a sealed unit. I tilted the motor and tranny to do something and the red line from the tranny started to leak out of the primary drain hole. So I assume I'm running the same oil in the tranny as the primary. So I guess my next question is, can I run red line synthetic gear oil in the tranny and the primary?

[pisten-bully]

I think it's done all the time, I mean synthetic gear oil in the gearbox and primary. I'm sorry, I hadn't considered the sealed option... but then it sounds like yours isn't sealed anyway. I was more commenting on the use of an oil (ATF) designed for a different purpose, e.g. hydraulics, being used where a chain and clutch discs are constantly doing their thing, and with the chain tension shoe constantly dragging on the chain my cautious nature would be to follow manufacturers recommendations and use 30W (+/- depending on ambient temperature).... but then I bet there's lots out there using ATF in their primaries... but maybe not in an antique application? Anyway, sounds like you answered your own question! Gearbox oil and primary oil are the same on your bike, and if it worked fine for you then great!

[tfburke3]

I'm doing the top end on my 47 Chief. I'm changing all fluids at the same time. Red Line in the tranny, but I'm not sure if the red transmission like fluid I drained fron the primary case is a dextron fluid or not. What do you think?

I use an oil designed for trans with wet clutch,HD Sport Trans Fuid.Little more cost but works for me.
Tom

[upsrod]

Although I don't have an Indian, I use ATF type F with no problems.

[phillie]

I have seperated mine but I use Valvoline Synthetic 75w 90 in my primary and have had no issues, we run the same oil in our racing transmissions so I think that would work fine also. I am running Redline shockproof "blue" gear oil in my transmission now works great.

[John Guntner]

Hi Phillie,
Sounds like you know your oils. I'm going to use Redline in my trans and primary and see what happens. What could go wrong.

[prjmongo@yahoo.com]

The tranny and primarily typically share oil through a passage where they mate. With the bike level the check plug under the clutch worm is the level to fill to. I use HD primary oil because it is what I have on hand- no particular preference. The concern with ATF is that it may prove too slippery for the wetclutch. With thin oils like synthetics there may also be more chain/gear noise. If you don't like your oil you can always just try another one.

[tomfiii]

I know some clutch manufacturers say not to run synthetic in clutch ,but don't say why. Clutch should always use an oil made for clutches like ATF,sport trans-primary oil ,non-detergent, if separated you can use almost anything in trans except 4 wheel vehicle hypoid gear oil as that is detrimental to brass do to sulfur compounds.