Belt question

[Big Sal]

OK...the crossover I traced down was a epic failure....so I'm going to measure the belt I need out myself...these are my questions...with the engine not running when the belt is on the primary how far down does it ride? In other words does it touch the hub in the center of the assembly? If it does is there any play side to side in it? (2nd question) Where does the belt ride on the secondary? does it ride flush with the top or is it ride down inside? I figure I can take measurements and get close....or if someone can measure there belt or give me the part number of a belt that works well with there machine I would be forever greatful...spending $40-$50 per belt to find out there wrong is starting to irk me (not to mention undoing all the stuff to get the belt on and off)...thanks

[LarryW]

Found a site that may help you find your dimesions. If you can measure your center to center distance from crankshaft to trans. shaft. The measure the driven pulley. 40 series clutches use 7 1/2" driven. The 44 use a 8 1/2" driven. What ever one is closer to your driven, I dont know off hand. That will tell you the circimferance and then I think your machine should have a 1" wide belt. With circumferance and width should have no problems



40/44 Series Belts

[jerseybigfoot]

The top of the belt should fit about an eighth to sixteenth of an inch above the driven pulley top edge. The width should allow the belt to lay against the shaft on the drive pulley with about a 1/16" side clearance. The belt should be snug with about an inch slack on one side when pulled tight. Hoffco Comet gave me a formula one time to calculate the approximate belt size. They may give you some advise. The driven pulley width determines the width of the belt. You may get close with the the belt length using the following online calculator. Its for v belts and the principal is the same. Belts are measured from the outside.



V-Belt
Length Calculator

if the clutch has alot of side clearance but fits snug (proper length) The side clearance on the clutch may corrected by shimming.
Photos of the installation may be helpful. Is the engine origional?

[LarryW]

http://www.6x6world.com/gallery/showphoto.php?photo=3032

I think napa sells gates???

[Big Sal]

Thanks guys....I tried the Gates numbers and they ended in a dead end...no crossover to another part number....the old belt I have seems to be close to the width I need but the length is too long (47 inches) I'm gonna try the Comet belts...7/8 I think will work well....just got to get the correct length....I've never messed with a varible type setup before so this is all new to me....the info you guys gave me was a huge help Thanks again!!

[atvrider93]

7/8" may be more prone to snapping and wear quicker or slip more, not sure but worth noting

[6X6]

Big Sal: If the belt is too narrow and sits down in the driven (not sticking out 1/8" like JBF said), you'll loose a LOT of low end, like driving your car stuck in 3rd gear to start off. You'll also loose some top end if you can get to it. Both my machines should have a 30mm or 1 3/16" belt from the best I could track down the #s, but neither uses the 6040 yours originally had.

[atvrider93]

actually, wouldnt that give it more torque, less RPM?
because the RPMs would be higher when it engages so it comes off the line faster but winds out quicker

[6X6]

It revs more before engaging, but since the belt is sitting lower in the driven pulley, it's in a higher gear. And believe me, it's a BIG difference. Feels like it's a weed-eater motor, no power.

[LarryW]

http://www.recreationsupply.ca/pdf/2008-10_Drive_Belts.pdf

Found this. Page 3 has some dimensions.

[jerseybigfoot]

Calculating your cvt belt length

George called and was wondering what the calculation was for determining the belt length. I came a cross this web sit years ago when I was calculating ratios for the Blackbird. The paperwork recently surfaced with the info so here it is. Belt sizing is #4.
Mike you may want to post the link.

What are the steps to select a CVT

[micmac]

I just wanted to add, to use the above calculator: for the small pulley diameter you must include the thickness of the belt x2 for the calculator to work.

[mustangwagz]

Jerseybigfoot: wow...sophisticated calulator ya posted there buddy! i like it! lol

Micmac: hey..you said gotta add belt thickness to the equation for the smaller diameter pulley..now..let me clear a few thigns up so that IM sure i got this all right.. The illustration shows "D1" being the smaller pulley, and in the picture it shows the belt riding on the inner line of the "Clutch". In section 4.2 it shows it in the same manner. by this i mean, its illustration in the figures show the belt riding on the area of the drive clutch when its in the "off" or "not running" manner. So say my inner clutch area measures 1.5 inches, i need to add Thickness of belt to that size? (1/2" thick belt X2 +1.5=2.5) so in my "smaller pulley" box, i'd need to convert 2.5 inches, and then enter that into the box. Correct?

[allwheeldrive]

Rise from the DEAD!

Resurrecting this old thread, While looking for this answer this thread was linked to from a few others however it seems the calculator is no longer available at https://cld.pt/dl/download/d14396fd-...cvt/index.html unless I'm missing something.

I had my Coot out this weekend and was driving around in 18" deep snow with chains. Before I installed the snow chains I didn't have the traction to put significant strain on the CVT belt. However now with so much traction I found in 2nd gear I would always come to a gradual stop while the engine was still revving at the same speed. This wasn't really that big of a deal as I could switch into low. However at a point where I was high centered and all 4 wheels had dug into the earth. I resorted to traction ladders to free myself and I found that in reverse AND amazingly in Low my belt was slipping and I had no wheel rotation. Yet full engine power.

Now my machine only has a 9 hp engine so I know there should be no way I'm operating beyond the clutch capabilities of this machine. That said It is very noticeable that a great deal of slack exist in the belt. It floats many inches on all sides from the drive clutch center and when rolling at low speed it doesn't fallow a smooth course but instead sort of bucks and flops up and down until it's pinched under heavy load.

I have not witnessed the belt slipping with my eyes yet, but I can think of no other place in the drive-train that would allow slippage. It reminds me of when My Scrambler's friction steering plates would slip and the engine would be revving but the wheels would have no power to spin.

Is it reasonable to assume a very lose belt would be the cause of the slippage?
I can post pictures later. Don't have any currently.

Here's a picture of me stuck. Because everyone likes pictures
free image hosting

[Mike]

I think it's reasonable to assume a loose belt could be the culprit. That's probably the best place to start. Check the belt tension and you should be able to quickly rule that out. It could also be that the belt/CVTs were wet from the snow and causing the slippage. You could also have a CVT slipping on the shaft but that's less likely.