ATF in the Primary>

[Bud White]

Went to the dealer today and was talking with a service writer about changing the primary to Formula+ oil and get rid of the Syn3. Boy what a bunch of static he said he wouldn't do that and stay with the Syn3 in all three holes. Why are these guys so dead set against change? Well tomorrow morning Mobile 1 v-twin goes in the motor, mobil 1 75w90 in the trans, and Formmula + in the primary.
Thanks for all the input.

good stuff there i run lucas in trans is 75-140 which is close to the spectro 6 speed everyone seems to liek you might want to look for mobile one in 75-140 instead if ya want m1

 

[propflux01]

Went to the dealer today and was talking with a service writer about changing the primary to Formula+ oil and get rid of the Syn3. Boy what a bunch of static he said he wouldn't do that and stay with the Syn3 in all three holes. Why are these guys so dead set against change? Well tomorrow morning Mobile 1 v-twin goes in the motor, mobil 1 75w90 in the trans, and Formmula + in the primary.
Thanks for all the input.

Engineers, my friend...Engineers...

 

[propflux01]

One important fact about automatic transmissions that was not mentioned was clutch packs in auto transmissions are not designed to purposely slip like HD clutch packs. If the clutch packs in automatic transmissions were slipped like HD packs, the oil would be burnt in no time. The clutch packs and its oil on a bike will withstand hard slippage without burning up. In my opinion, the fact a HD clutch can do that is not by clutch design alone. It is a function of both clutch pack disc design and it's corresponding oil. I don't feel ATF fluid was designed to be used in clutch packs designed for excessive slippage.

But PropFlux, I do admire your open mind to try/experiment with new ideas and improvements.

Actually, there is slippage built in to clutch bands and pack design. This is why type 'F' and 'trickshift' is different from 'dextron 3' and such. It is the design of the fluid that prevents it from smoking up, and allows a certain type of shift 'feel'. Motor oil was designed to lube parts, not monitor how much slippage a clutch makes. This is why some brand oils make a clutch slip, and some do not. IMHO, I beleive HD went with Syn in all holes ONLY as a marketing tool, nothing more. It is easier to specify and handle one fluid, than it is 3. Many bikes use a share sump system, so using motor oil in a gear area will work, but is it optimal? Just look at some UOA's in BITOG or other sources and you can answer that for yourself.

And while you may or may not agree with my analogy of using ATF, I am glad you at least see where I am coming from and why, and I do thank you for the compliment. !:cheers

 

[Hoople]

Actually, there is slippage built in to clutch bands and pack design. This is why type 'F' and 'trickshift' is different from 'dextron 3' and such. It is the design of the fluid that prevents it from smoking up, and allows a certain type of shift 'feel'. !:cheers

Yes, that is true. The "accumulators" and flow rate orifices in an automatic transmission do allow for soft compression of the clutch pack, but the entire process takes only a second. That's a big difference from holding a bike from rolling backward while waiting for a stop light to turn green. I am sure you would agree that if the torque converter in a cage was removed and in its place, the transmission clutch packs were used to hold a car still while at a stop light, smoke would be pouring out the transmission. But I do understand why you made that point.

I may be wrong but the real reason I feel Dextron is a poor choice for this application is because of it's inability to climb. I would like to see the oil in action using a clear primary cover. It sure would be interesting.

 

[glider]

While propflux01 feels he has a better idea and continues to try to proove it without any success and furthermore has posted NO proof of his statements other than his own views, this thread is being closed because there are no gains being made when a member continues to argue their own point without posting any proof.