V-Twin Forum banner

1 - 20 of 66 Posts

·
Registered
Joined
·
1,300 Posts
Discussion Starter #1
Ok, I have a good feeling this has been discussed but I searched for a whole 30 seconds and didn't find it so I apologize if it is a repeat haha

I have a friend with an Ultima 6 speed gear set sitting on his shelf that he might trade me for some stuff Ive had sitting around for awhile. Yes I know the reliability of the Ultima has been questioned but that is not the topic here.

It says it fits 1990 and above and as some of you know I recently converted my '89 to a 1990 only mainshaft and 1990+ RP clutch assembly. Everything else in the primary stayed the same.

I know 1991 and on is a different length mainshaft so will this kit work or will I need to change out primary parts? If so what all would I need to change?
 

·
Registered
Joined
·
5,739 Posts
if you are referring to the 98-902 6 speed OD builders kit the only thing I think you might need to change is the spacer, someone else can chime in.
I just put one in a 2000 Twin Cam and had to trim 1/4" off the shift bushing but that is not required on older models.

the online instructions kinda suck but I used the complete transmission break down to get a better look from the complete 6 speed left side drive model http://www.ultimaproducts.com/6spdLSDmanual.pdf
Don't know WTF they have better information on the fully assembled transmission then the builders kit but the guts are basically the same
 

·
Registered
Joined
·
1,917 Posts
My 89 had tapered shaft it sucked shattered two clutch baskets. If I remember correctly I think the 91 was a bastard year for the main shaft had a finer spline for clutch hub. You might need different clutch basket. They went to to heavier spine in 92 on prior to 91 was tapered. Something to check up on
 

·
Registered
Joined
·
1,300 Posts
Discussion Starter #5
Arc I think you might mean 1990? 90 was the first year splined shaft which is the same length as the tapered. In 91 they changed to a different slimed mainshaft which I believe was longer? Not sure on details and how they affect me here hopefully someone knows but 1990 was the bastard year on the shaft. Not sure on hubs tho
 

·
Registered
Joined
·
601 Posts
Doubt you will have to change primary parts. I have had 3 transmissions in mine. All different... stock 5 speed, back cut Jims 5 speed splined cassette, now a Baker OD6. Personally I would not use Ultima but that’s up to you.
 

·
Registered
Joined
·
480 Posts
Ok, I have a good feeling this has been discussed but I searched for a whole 30 seconds and didn't find it so I apologize if it is a repeat haha

I have a friend with an Ultima 6 speed gear set sitting on his shelf that he might trade me for some stuff Ive had sitting around for awhile. Yes I know the reliability of the Ultima has been questioned but that is not the topic here.

It says it fits 1990 and above and as some of you know I recently converted my '89 to a 1990 only mainshaft and 1990+ RP clutch assembly. Everything else in the primary stayed the same.

I know 1991 and on is a different length mainshaft so will this kit work or will I need to change out primary parts? If so what all would I need to change?
Every response about main shafts is irrelevant as you would be replacing everything inside the trans case. That being said, that Ultima 6-speed gears will bolt right into your case. the case might need some clearancing for the shifter forks.

Good luck with your project.
 

·
Registered
Joined
·
3,531 Posts
Doubt you will have to change primary parts. I have had 3 transmissions in mine. All different... stock 5 speed, back cut Jims 5 speed splined cassette, now a Baker OD6. Personally I would not use Ultima but that’s up to you.
The voice of Reason...

a six speed simply reduces the RPM drop between shifts... nothing more... in fact even the Final ratio is one to one... like any other including the old H-D 3 speed....
Noww... If we're racing... maybe need to stay in a Narrow RPM range.... Maybe.
Yet the old 2 Speed GM trans still Rules the Strip...
 

·
Registered
Joined
·
9,330 Posts
depending on which gear ratio set your 6 speed has,,, determines the differences..

an O.D. 6 speed,, will have a .86 or .80 6th gear,,, 1st gear can be 3:24 or 2:94,, the other 4 gears are the same ratio as the harley gearset.

a plain 6 speed,, depending on the manufacturer,, can have any combination of gear rztioz,,, many having 6th as a 1-1,,, these gearsets,, just add another short, to arrive at the same point in 6th as you had in 5th before..

ultima transmissions are hit or miss as rare as quality is concerned.. as mentioned already clearancing my be necessary,, as the shift forks are thick on the shaft end,,, due to them being cast... on mny ultima trans Baker shift forks and drum may be exchanged for the ultima set,, as well as the shift shaft with stops built in... this fight and up the very long throws of the ultima shift mechanism. some have shifts so long it feels like you went back to a pancake top 4 speed...

I dont use ultima transmissions... they may be ok on a stock engine,, but add some power,, and problems may arise,,,

I've worked on enough ultima transmissions to have formed this opinion,,, I see what looks like casting flash on the flat edges of some if not all of the gears,,, I wondered how they could be made of 8620,, and my conclusion was,, that scrap and machining droppings were re-melted then cast,, to decrease materials costs,,, this would be considerably less expensive than buying bar stock 8620,,,, can't prove it,, but???

Baker gears and shafts are cut from 8620,,(by andrews), and look perfect,,
it would seem ignorant to me to spend more on the shift mechanism than the transmission cost.. I would save up for a Baker kit, and be done with trans issues forever..

i
 

·
Registered
Joined
·
3,531 Posts
^^ Ok ... Most 6 speeds are High gear 1:1
IF [big word] if it is Specifically an O.D. then obviously Not gonna be 1:1

Howzat???
 

·
Registered
Joined
·
5,739 Posts
The voice of Reason...

a six speed simply reduces the RPM drop between shifts... nothing more... in fact even the Final ratio is one to one... like any other including the old H-D 3 speed....
Noww... If we're racing... maybe need to stay in a Narrow RPM range.... Maybe.
Yet the old 2 Speed GM trans still Rules the Strip...
The final ratio is not 1:1 on that tranny it is .86:1 If I recall or I wouldn't have bought it

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
17,482 Posts
The final ratio is not 1:1 on that tranny it is .86:1 If I recall or I wouldn't have bought it

Sent from my SM-G920V using Tapatalk
Speaking of which, how you like yours so far?

Sent from my 2 Tin Cans With A String using Tapatalk
 

·
Registered
Joined
·
5,739 Posts
Speaking of which, how you like yours so far?

Sent from my 2 Tin Cans With A String using Tapatalk
Shifts smooth, a little gear wine on downshift, talked to the manufacturer about that and was told that was normal on break in

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
17,482 Posts
Shifts smooth, a little gear wine on downshift, talked to the manufacturer about that and was told that was normal on break in

Sent from my SM-G920V using Tapatalk
Cool. Keep us updated occasionally.

Sent from my 2 Tin Cans With A String using Tapatalk
 

·
Registered
Joined
·
1,300 Posts
Discussion Starter #18
Not a for sure thing yet but it would go behind that low HP 131 I got haha.

The bulk of the trade would be for a bunch of old Honda trail 70 parts I have that I’ll never use and got as a bulk parts buy for a project 70 I built for a friend a long time ago. So I won’t have anything but time invested into it. Still would love a baker but I know it’s not in the cards anytime soon. This could get me where I wanna be short term I’m thinking. If not could screw me over and I’ll slap the 5 speed back in
 

·
Registered
Joined
·
1,300 Posts
Discussion Starter #19
Or that could be just me rationalizing to convince myself into a deal. I’ve done that plenty of times too.
 
1 - 20 of 66 Posts
Top