Engine Oil vs Gear Oil

[SCUD]

would you use gear oil in a sportster tranny since the clutch, gear train and the primary are lubed together what is gear lube going to do to the clutch operation

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[garyhendley]

= 1 ON WHAT HD DON SAID

[italfatboy]

Gear oil 75W140 all the way!

[Ozoneman]

20W-50 Amsoil MCV in all 3 holes.&nbsp\\; It's made to be used in the motor, trans, and the primary.&nbsp\\; It is what Amsoil recommends for all three.

[HSMaxim]

ORIGINAL: Big Hog

Just go to the dealer and ask what's best for your bike and then go with that from then on. That's what I did.

I witnessed a salesman at a stealership rev a sporty up to the redline to show&nbsp\\;the&nbsp\\;potential sucker, er, buyer,"how great the pipes sound".
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Think I'll stick to my own common sense.

[roadking1893]

Sometimes you just have to go with what you know and the result from your own research.&nbsp\\; Take amsoil pioneer in synthetic oil.&nbsp\\; Now they even make a special blend just for the V-twin.&nbsp\\; Transmission needs gear oil that's there is in there gears.&nbsp\\; Hence that's why I went the 75W/140 in the tranny,&nbsp\\; WOW 5th gear is quite and able find "N" fast.&nbsp\\;

[Snakeoil]

I hope this reply&nbsp\\;works this time. 3 tries with FAST REPLY failed.
I put Amsoil 20W-50 MCV in my 2001 Fatboy tranny after doing a reduced effort clutch kit. Prior to that, I was running Amsoil 75W90 Gear Oil which was what they recommended a few years ago. With the new oil, the bike developed a tranny whine/howl once warmed up. At first I thought it was a tire howl, but the roads were common roads for me with no previous howl.
I found this thread and decided to contact Amsoil. to summarize, here's what I learned.
1. They no longer recommended the 75W-90 Gear oil. They said it is on the low end of the viscosity range and the 20W-50 is actually a little heavier (hard to believe given my experience last week).
2. They always follow OEM recommendations. So since HD recommends Syn3 or F+ in the tranny, they recommend their equivalent.
3. They said MCV is only preferred by them over their Severe Gear Oil SVT 75W-110 because of ease of maintenance.
4. One rep said that discussions with HD riders show a preference for the SVT or SVO gear oils over MCV motor oils because of reduced noise and smoother shifting.
5. Their website shows SVT 75W-110 or SVO 75W140 as replacements for the old HD tranny fluid 99892-84.
I picked up some SVO 75W-140 for the cold starting wt of a 75 wt oil and the high temp protection of a 140 wt oil. I'll let you know what differences I notice when it goes in this weekend, weather permitting.
Rob

[Strike1]

I just went down the same road as Snakeoil.&nbsp\\; I bought an '03 Deuce in '05 (love it).&nbsp\\; The previous owner ran Redline oil in the tranny and I don't remeber in the engine and primary but he thought it was "special oil".&nbsp\\; &nbsp\\; I never had a Harely before (used a Honda to train on) but I thought shifting could be smoother.&nbsp\\; I'm a big synthetic fan.&nbsp\\; I read that Mobile 1 was developed/specified by NASA for the Shuttle.&nbsp\\; I switched to Mobile 1 20W 50 in all three holes.&nbsp\\; The engine ran cooler by ~10F.&nbsp\\; The primary&nbsp\\;was clean after changing but I don't know how to measure any difference there.&nbsp\\; I did think that the tranny was still loader and rougher than what I liked.&nbsp\\; I switched to Mobile 1 Gear Oil 75W 145 in the tranny after reading what posts said on the forum. &nbsp\\; I have noticed a distinct improvement in shifting smoothness, less&nbsp\\;noise when shifting and it is easier to find neutral with Mobile 1 synthetic gear oil 75W 145.&nbsp\\;&nbsp\\;I would be OK with other full synthetics as well.&nbsp\\; I have not yet changed the tranny gear oil or looked for shavings on the plug but&nbsp\\;I don 't expect to see any with a full synthetic. I have only used the gear oil in the summer so temps above 60F (cold weather has not been tested yet).

[02flh]

Spectro gear lub 75w90 i think is the number. well anyhow I put that in my chain case about to weeks ago and now my clutch enguages right at the end on the lever travel. I bought the 02 Flht damaged and from Slicks salvage near Lansing Mi. About 26000 m,i and now 28300 mi. I wounder if the gear lub was not raited for wet clutches? I sure acts contaminated. I guess I will just drain it and put in Mobile 1 V-twin oil, befor it starts slipping. Just remembered The Spectro was formulated for chain cases and was not synthedic,
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&nbsp\\;&nbsp\\; If one thing doesn't work try something else.

[Frankster69]

I had the syn 3 in all three holes now but went back to HD 20w50 for engine and HD Formula + for tranny and Primary. I had no problems with the syn 3 but the tech at HD said the other would work just fine and save some money. He said he thought the formula + was even better than the syn 3 for the trans.