MotorTrike Adventure Driveshaft Evaluation

[Gold Rush]

OK folks. Here is the down and dirty. I've just passed this exact information on to Richard Purdy at MotorTrike so everyone has the same information and can use it as you will... I'd like to really thank those who helped me and those willing to allow me the time to heal and develope this information. I hope we all will benefit. If anyone wants more indepth information shoot me a PM. I'll tell you what I know....


Here are my initial measurements and observations regarding the complete new drive shaft assembly Motor Trike sent me to exchange for the one previously installed in my 2006 Honda GL1800 with Motor Trike Adventure conversion.

1. Rear universal joints are exactly the same.

2. Drive shaft and rear universal length is identical (16 9/16 inches).

3. Spline length on both drive shafts is identical.

4. Front universal joint has been redesigned but over all dimensions remains identical.

a. Front yoke over all length 4.8570 inches with 2.5430 inches over the engine output shaft.

b. Rear yoke over all length 3.4950 inches with 1.2465 inches available to go over the drive shaft spline area. NOTE: Only about 1 ¼ inch of internal spline area in both the old and new universal joint yoke.

c. Instead of tap in “C” clip to retain the end caps the new joint uses full “C” clips. Richard Purdy told me this was done to improve security of caps when installed.

d. The area around the universal joint journal has been opened up slightly. I still don’t think it would be possible to lube the front joint without removing the drive shaft assembly.


3-19-12 Installed new drive shaft assembly into my ’06 GL1800 with Motor Trike Adventure conversion kit. Will test drive tomorrow after work.

3-20-12 Sad to say the vibration has returned even worse then before!! As soon as highway speed is reached (60 to 65) vibration begins and gets worse the faster I got. At 70 mph it was so bad the center line was at least three or four times it’s actual width.

Came home and removed the complete shaft assembly to inspect and take photos. Reinstalled shaft assembly along with ½ inch spacer (just enough to fill the output yoke spline) and test rode trike. Much to my surprise the vibration is still there. It was less then without the spacer but still more then I believe it should be. My initial feeling is that the new drive shaft may not be true. Tomorrow I will reinstall the original drive shaft assembly and one half inch spacer to see if the vibration is still gone. If so that will be the answer.

Previously I had installed two half inch spacers with the original drive shaft assembly but that pushed the drive shaft through the front U-Joint output yoke which was over-kill and increased the force applied to shaft components by compression spring.

3-21-12 Replaced new drive shaft assembly with original assembly along with one half inch spacer. Was surprised the vibration did not go away. It was about the same as the new drive shaft assembly with spacer in place. I now suspect the minimal reduced vibration (on both drive shafts) to be my homemade spacer. When I removed the original drive shaft assembly and two half inch spacer I had installed two weeks ago I notice the rear spacer had several places it came in contact with the differential housing. I remove material in these areas and now think I might have caused the spacer to become unbalanced to the point it is inducing some vibration. Next step is to have a spacer professionally produced so it will be perfectly balanced and symmetrical. No idea how long this is going to take.

3-22-12 While discussing this issue with a friend over lunch the light came on…. I realized the boss on the front of the differential and the recess on the rear U-Joint output yoke were there to center the two units when mated. I had asked one of the TrikeTalk.com guys who had success ridding his Motor Trike Adventure of it’s vibration to send me photos of his spacer. When I got home from lunch the photos were in my e-mail and confirmed the boss/recess idea. Although his spacer is round because he did not have to contend with the ABS ring mounts the concept of space and centering was identical to my thoughts. With the mating in mind I modified my spacer to include a boss and recess so the differential and rear U-Joint output would be in alignment. Installed newly modified spacer and new drive shaft assembly and test rode. There was only very minimal improvement if any over no boss/recess.

3-23-12 Today I am a VERY HAPPY CAMPER!! First thing this morning I removed the new drive shaft and spacer then installed my old drive shaft along with the new modified spacer with boss/recess configuration. My test ride proved this trike could go down the road without buzzing the mirrors. Will contact Motor Trike and report my findings and then post on bulletin boards as promised. For my part I consider the case closed.

[RRSCOTT]

What did you use to center it up? And do you have pictures? Mine was too thick and not balanced right. I have to start over. I did have a piece of 2" exhaust pipe cut about 1/2" long and installed for that reason.

[roscoe 07]

you can take driveshaft to local machine shop and they cabuild one like mine or i will try to get accurate price this week

[RRSCOTT]

The Machine shops here are only welding shops. Most don't have the stuff to go that tailed for something that small and only a one time thing. Do you remember what diameter the round piece is? I know the center is 2". And if you could check that would be great. How long ago did you do yours?

[Gold Rush]

Randy my situation is a bit different then you and Rosco07 because I have to deal with the ABS sensor ring. What I did was trace the outline of the rear U-Joint output flange onto my piece of stock then cut, grind, and file until they matched. I then used a series of small drilled holes to make the center hole and eventually enlarged it so I could put the alignment boss in place.

To do that I bolted the U-Joint flange and spacer together exactly as they matched up. Then I placed a 1/2 inch long piece of 1 1/4 inch schedule 40 PVC coupler (exactly fit the recess in the driveshaft) into the driveshaft recess and filled the gap between the spacer and guide boss with JB Quick.



by using 1/2 inch of PVC coupler I left the exact amount of recess on the reverse side of the spacer as there was boss on the side you see. Take a look at my tech picture album if you'd like to see the other side....

I think with a good file and some elbow grease you could do the same thing as long as your round spacer is indeed round. It should balance out even better then my spacer did...

Hope all that made sense and helps you...

[RRSCOTT]

Thanks Jerry for your findings and ideas and pictures.
roscoe 07 if it isn't to much trouble please check, if you have to take your trike apart, don't bother.

[roscoe 07]

It is the same diameter as flange on rearend

[ti-rouge]

hi everybodie, i have a suggestion,,,,instead of putting a spacer why not have a shaft made longer in a machineshop,,,,i wonder if it will cost alot!
just an idea,,,,

[Gold Rush]

hi everybodie, i have a suggestion,,,,instead of putting a spacer why not have a shaft made longer in a machineshop,,,,i wonder if it will cost alot!
just an idea,,,,

That is an even better option if you could find someone that can do that for you economically. The spacer in my case only cost me a few hours of work and a little skin .... I'd guess having a shaft made would be big bucks. I'm hoping Motor Trike will step up and add half an inch to their driveshaft then offer a retro-fit. Guess we'll see how that goes...

[roscoe 07]

if you use a spacer and you have to replace driveshaft you can order from motortrike
and not get a custom one built everytime

[RRSCOTT]

Thanks roscoe 07 I'm just going to get a round piece that size and what Gold Rush did.

[ti-rouge]

good morning everybody,,,, i found some interesting thing on the net when i call for driveshaft vibration,,,
ther is a place where they explaine how to aligne the drive shaft etc
(driveshaft harmonics)
maybe it is more then just the driveshaft,the probleme,could aligment, balance etc,,,,

pls look at ( drive shaft harmonics ) and let me know what you think !!

[Gold Rush]

Most of us are now keenly aware that balance and alignment are vital to no vibration. I don't believe I'll get into the slide rule and theory of driveshaft design. There is nothing most of us could ever do with that. The research and testing we have done here pretty much proves the length issue will help cure the majority of vibration and that satisfies me.

During my conversations with Richard Prudy we touched a couple times on the possibility that secondary issues could contribute to the vibration a few of us are seeing. During our last conversation I stated that by lengthening the driveshaft just the half inch needed to fully engage the front U-Joint spline that the ill effect of these "possible secondary issues" would be eliminated or at least vastly reduced.

[Rowdy]

Goldrush. You should be commended on your time and effort to help resolve the vibration issue for yourself and others. I owned a 1500 MT before the trike I now own and had several years of good service with it. They definitely make a good trike and I would not hesitate to buy another. I have ridden the new Adventure and it is a really good conversion. Their customer service is as good as it gets as well. The only problem I have is their reluctance to acknowledge a problem when it has been proven to exist. Hopefully your effort will help others who have some vibration to remedy it.

[Gold Rush]

Thanks Rowdy!!

As I've said before I do hope the driveshaft gets lengthened. If not a retro-fit then at least in new production units. So far it looks like only a few have issues. If future kits don't develop the vibrations then we are ahead of the game.

[roscoe 07]

We wouldn't need longer driveshaft if motortrike would make the part longer that slips over splines on driveshaft

[RRSCOTT]

Yes, that is what it needs.

[roscoe 07]

If motortrike would make the female
Part of the front yoke that slides on the shaft we wouldn't
Need spacer or longer driveshaft

[Gold Rush]

If motortrike would make the female
Part of the front yoke that slides on the shaft we wouldn't
Need spacer or longer driveshaft

No matter how they accomplish the full spline contact it will be the same thing. More front U-Joint output yoke or more drive shaft. Both result in the exact same result.

On second thought, I think the drive shaft would be the better choice. It would keep the spinning mass and weight down and also keep it closer to the U-Joint itself.

[RRSCOTT]

This must one of the reasons they been welding CSC driveshafts.