Shaft Spacers

[Darian1m]

So I've been doing the torque converter cleaning per the video that KartFab provided (thanks, great video) and I noticed that there are only (2) 1/8"spacers on the shaft and that the breakdown for this kart below shows 4 spacers on the drawing. How much do you think this could contribute to premature belt failure? it's an 1/8" off with these missing spacers.

 

[OzFab]

That would depend on whether the alignment is off; have you checked it?

That is the factory setup, how do you know previous owners haven't realigned both components?

 

[landuse]

I am not too sure how i missed this thread. I would do as Fabroman suggests and have a look at your setup and compare it to the diagram. Some pics of yours would help us too

 

[Darian1m]

....... how do you know previous owners haven't realigned both components?

I am assuming they are off because the drive sheave has the spacers per the factory documents but the driven is short (2) 1/16" spacers. Not sure how to check the alignment other than eyeballing it. Is there a procedure to ensure they are aligned? Below is a pic, I've pulled both of these off and am servicing them and removing the rust. The picture is at a bad angle so you can't determine alignment off of these, so please don't even try. You can sort of see in the pic that there was a remnant of an old belt wrapped around the driven unit shaft.

I found this in the forums but not much help other than giving me the parameters.

http://www.bmikarts.com/PDF/Comet_40series.pdf


Any pointers on ensuring/getting them aligned would be great, this forum has been very helpful. Thanks guys

 

[itsid]

well the driver should be further out for sure.

also: it MUST NOT float on the drive shaft, so make sure whatever amount of spacers you have, it doesn't move on the PTO.

The driven on the other hand...- as I interpret the manual - could be allowed to float on the jackshaft, to compensate for the belt offset when shifting (3/4" is enough; I'd go for one belt width (7/8") though).

And that's likely what I'd do with an outboard mounted driven, lacking any other option to have a perfectly straight belt at all times *shrugs*

There might be another way that I don't know of;

generally, you align not the sheaves, but the centerline between both sheaves;
with non floating pulleys and inboard driven that keeps the belt always straight,
when moving up and down the angles (and thus 3/8" lateral).

Sorry, I cannot tell you the perfect way to align this, especially not if the js sprocket is firmly attached to the driven, since then you cannot have the driven floating of course

*shrugs*

Let's wait for Grant, I'm sure he did several series 40s and likely at least a handfull outboard mounts too...

'sid

 

[Darian1m]

Well I was able to clean the Comet torque converter and simply eyeballed the alignment. Here is a video of how it's working, I didn't know that the belt bends so much when this things takes off. Also my go kart wants to take off on me when I get it started because the rpms are too fast and engage the drive unit. When I hold the kart in place with the brakes the belt starts smoking some. Time to find a thread on how to fix the idle speed.

https://youtu.be/mlB_zLX8IbQ

 

[Darian1m]

Did anyone get a chance to look at the video above?

 

[Denny]

Drive clutch is still too close to the engine the belt should stay straight all the way through the rpm range. One other thing the axle shaft looks bent, but that is a different problem.

Denny

 

[itsid]

just what I expected actually..

the driver clutch is where it should be.. but in that outboard config, the driven has to float inwards..
which in your case means you must move the sprocket (jackshaft and axle of course) to the other side of the jackshaft to not interfere with the driven.

that's the 3/8" offset (from low to highgear) I mentioned.. since it happens on both driver and driven that adds up to 3/4" as you can see

'sid

 

[Darian1m]

Ill give that a shot, thanks

 

[itsid]

Grant may have missed this thread, so I asked him to drop by if he has a better idea...
Just be patient, he'll be here any minute

'sid

 

[KartFab]

My thoughts on this are, Denny has it right.

...and if you want to get the unit 'close enough' to lined up, take a straight edge and run it over the sheave edge of the driven unit and line it up with the sheave edge of the drive unit.

 

[itsid]

Okay cool...

that still looks weird to me..
so I asked the next source I could come up with:
maxtorque..
simple reason: they sell a series 20- esque (symmetric) TC with an outboard mounted driven...
And here's what they say in their instructions:

Assembly instructions

Your complete unit must be mounted on parallel shafts with a desired center distance no greater than 6 13/16 (6.8125) inches. After it is centered at idle the driven unit must have at least 3/8 of an inch inward float to properly align with the driver unit.DO NOT USE UNIT WITHOUT COVERGUARD IN PLACE. Pieces may not be interchanged with any non Maxtorque components.

that's a smaller belt than a series 40... but it MUST float *shrugs*

And in fact MFGsupply paint an even darker picture in their FAQs
an even darker picture...

....If not parallel, the belt will be pulled to the side of the sheave face, creating uneven and damaging side pressures. This wil not let the belt of the system attain either its proper low end or high speed power range. When not parallel, the system will be erratic in its operation from engagement through the highest speed. Belts will wear very rapidly, and the uneven wear pressures will in many cases cause severe wear and damage to the clutch assembly. The damage caused by this can be likened to that created by a bent crankshaft.....

*shrugs*

I don't know.. I'd trust Grant enough to give it a try for exactly ONE belt..
but while doing so, I'd search for a method to move the sprocket to have a floating driven.
Just in case.

Also, just because I would take that risk....
I'm not sure I could confidently tell anyone to do the same.

Sorry Grant; I know I specifically called for your advice, but I just read those websites, and I'm just unsure now.

'sid

 

[Darian1m]

itsid, thanks I think I understand what you are saying. When you say "float" do you mean it should be able to move back and forth 3/8" on the jack shaft to compensate for the offset caused by the driven unit pushing the belt out?

I need to check if this is even possible given the design of the jack shaft, it may be more than I want to deal with if I have to move sprockets around. I find it strange that this is the factory setup and no float is indicated on the drawings. Maybe it was a bad factory design, oh well.

I think I am going to move the drive unit out to minimize the amount of bend I get in the belt as you and Grant suggest. I know a lot more about torque converters now than I ever had.

BTW my axle is fine, it only looks bent because of the non-centered warped plastic around it.

Thanks

 

[itsid]

it's indeed odd.. odder.. the ODDEST!
3/4" but yes.. lateral to the belt; back and forth on the jackshaft .. (well actually just back [inboard]) but you know LOL.

I cannot imagine why Manco made it the way it was, but there are few things I like to ask, just to be sure I'm overcautious and there is nothing wrong with the setup you have.

So, the stock jackshaft should be 13.7" long.
And the engine bolts should be inline with the bolts that attach the adapter plate to the kartframe.
Anyways.. the earlier model (we talk about 810 dingo's correct??)
had a 12.75" jackshaft, so nearly an inch shorter...
but it also had a series30 TC (on the same 10hp tec engine!!)

I can't tell for sure, but it appears that was changed
since they figured the series30 won't stand the 10hp very well,
while at the same time they didn't want to redo all the transmission..
so they just discarded the series30 in favour of the series 40...and changed nothing but the jackshaft length.
Now, the extra inch in JS length ... either to hold the series40 driven (is it an inch thicker really??)
or to allow the unit to float to compensate for the belt.. I can't tell honestly.
but something's fishy.... *shrugs*


'sid

 

[Darian1m]

I'll check those dimensions. It very well could be an 810, but I've been looking at the 812 plans. I don't see any difference between the two other than the model number.

---------- Post added at 09:34 AM ---------- Previous post was at 09:28 AM ----------

Nope it's an 812, the Chassis of the 810 is different than mine.