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Old 06-05-2008, 05:27 AM   #2956
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I thought about that, so I did what I thought was a sufficient test to determine if that was a possibility: I took the two eccentrics out and held them up to each other, then flipped one around and held them up to each other again. I could see no difference in the location of the bearing, and concluded that the parts are the same, left to right, and the 'direction of eccentricity' (if you will) is in line with the alignment nub.

Are you sure there is a left and right? It's an easy enough thing to check, so I will check when I get back home, but I have a feeling that can't possibly be the problem.
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Old 06-05-2008, 06:08 AM   #2957
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If the eccenter lip is facing the wrong direction (inside) it can allow the pulley to slide and push the bearing almost out of the eccenter, which can cause other issues, but I don't believe anything related to belt tension.

Not sure what could be causing the issue, I've never had a rear belt as loose as you're explaining it.. Just a quick thought, how are you moving the eccenters to "tighten" the belt? Are the eccenters "nubs" pointed toward the front or back of the car (straight up and down is the default position).
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Old 06-05-2008, 06:10 AM   #2958
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Also, are you using the "Fast" rear pulley, I did notice with mine that the height of the teeth on the "fast" pulley was a bit shorter than the stock pulley, which I felt could contribute to a skipping belt.
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Old 06-05-2008, 06:20 AM   #2959
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The eccentrics are definitely not turned around, as, like you said, there would be nothing to keep the bearings from falling outward otherwise.

I am pushing the nub forward to get more tension, which I'm sure is correct.

In fact, even if I push the nub beyond the 'tight' location before putting back on the 'suspension bracket', which is the 'top cover' for the rear bearings and has the indents for the nubs, the belt still seems too loose.

I'm not sure what the 'Fast' rear pulley is. I think I've got the stock part in there.

I'm starting to think that there is nothing I'm missing here... there just isn't that much to the rear belt tensioning system. I'm going to try a brand new belt and see if that's it.

So, back to the second part of my question: what's the easiest way to get the belt off of the 2-speed shaft? Is it possible to slide that shaft out without taking the entire rear end of the car off of the chassis so that the two halves (bearing blocks) can be separated?
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Old 06-05-2008, 06:33 AM   #2960
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Sounds like you have it correct. As for an easier way, not that I've found.

I don't bother with the upper half of the bulkheads, when I replace a rear belt I take off the left bulkhead which after removing the pulley, carbon side stiffner, sway bar holder, rear carbon shock moount and the upper carbon brace will allow you to slide the bulkhead off the layshaft and give you access to the layshaft and rear pulley at the same time.

I've never found an easy way to change front or rear belts.
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Old 06-05-2008, 08:05 AM   #2961
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the alloy brake pulley makes life better, it is one piece and has a single grub screw that is easily accesible
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Old 06-05-2008, 09:21 AM   #2962
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the alloy brake pulley makes life better, it is one piece and has a single grub screw that is easily accesible
I think that's the only pulley on my car that's not the alloy version... yet.
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Old 06-05-2008, 09:35 AM   #2963
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I think that's the only pulley on my car that's not the alloy version... yet.
Now I remember why I didn't convert that pulley. 909257 = $40.

But I'm wondering now if I can instead use 903280 = $20. It's the 'V2 Brake Pulley adapter'. Seems like it would have the same easier maintenance (set screw not covered by the cog itself). Can anyone confirm if this would be the case?
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Old 06-05-2008, 11:05 AM   #2964
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Walt, I change the belt the way Darrin described. No need to remove the layshaft that way. Either way it's a bit of a pain. Can't believe you don't have the alum brake pulley, with all the other 'bling' on your car.
On the subject of belt tension, I have the same loosness. Even with brand new belts, I run the eccentrics on the tight setting. If yours has been skipping much, you will need to replace the pulleys at same time as belt.
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Old 06-05-2008, 12:19 PM   #2965
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I don't necessarily see any evidence that the belt has been skipping, but I can't imagine that it hasn't been skipping with as easy as it is for me to make it skip.

If I just apply the brakes very lightly (much more lightly than I know I apply them while racing) and push the car along the top of my workbench, the belt skips.

I'll take a closer look at the pulleys, but the rear one is brand new (not even run with it yet) because there was damage where the cross pin goes through my old one.

And most of the 'bling' on my car was from the previous owner... it was an e-bay purchase (and a damn good one at that). But I remember noticing that the rear pulley was not the alloy version, and then seeing that it cost $40, I decided to just leave it the way it was.

I did recently break the 2-speed shaft on my car though... I suppose that could be evidence of a skipping belt.
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Old 06-05-2008, 12:54 PM   #2966
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Walt, what does it do when you apply the break that makes you think the belt is skipping?
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Old 06-05-2008, 01:04 PM   #2967
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Quote:
Originally Posted by Walt View Post
I don't necessarily see any evidence that the belt has been skipping, but I can't imagine that it hasn't been skipping with as easy as it is for me to make it skip.

If I just apply the brakes very lightly (much more lightly than I know I apply them while racing) and push the car along the top of my workbench, the belt skips.

I'll take a closer look at the pulleys, but the rear one is brand new (not even run with it yet) because there was damage where the cross pin goes through my old one.

And most of the 'bling' on my car was from the previous owner... it was an e-bay purchase (and a damn good one at that). But I remember noticing that the rear pulley was not the alloy version, and then seeing that it cost $40, I decided to just leave it the way it was.

I did recently break the 2-speed shaft on my car though... I suppose that could be evidence of a skipping belt.
I hope I am wrong....but since this is a used car, can you check the number of TOOTH on both pulleys (brake pulley and your rear diff pulley)....are they the same as the original one (#) supplied for 960? If one of the pulley is 1 tooth LESS.......the belt will get loose.

Again, I don't think that is possible, but I don't think your belt should SKIP even you are on the tight setting with only a little of brake apply. Imagine when you are running BYRON race, 60 mphs and apply brake and your belt is skipping and rubbing against both pulleys...how long does those pulleys or belt last...? Not long...you should address that.
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Old 06-05-2008, 01:13 PM   #2968
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Originally Posted by Solara View Post
I hope I am wrong....but since this is a used car, can you check the number of TOOTH on both pulleys (brake pulley and your rear diff pulley)....are they the same as the original one (#) supplied for 960? If one of the pulley is 1 tooth LESS.......the belt will get loose.

Again, I don't think that is possible, but I don't think your belt should SKIP even you are on the tight setting with only a little of brake apply. Imagine when you are running BYRON race, 60 mphs and apply brake and your belt is skipping and rubbing against both pulleys...how long does those pulleys or belt last...? Not long...you should address that.
Maybe I can just drop the car off at your house and you can figure it out for me?

Just kidding... I'm planning on getting to the bottom of this tonight (and racing it on Sunday... I'm looking forward to trying out Paolo's latest clutch setup suggestion). I'll let everyone know what it ended up being once I've got it figured out, in case anyone is curious.
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Old 06-05-2008, 01:23 PM   #2969
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Maybe I can just drop the car off at your house and you can figure it out for me?

Just kidding... I'm planning on getting to the bottom of this tonight (and racing it on Sunday... I'm looking forward to trying out Paolo's latest clutch setup suggestion). I'll let everyone know what it ended up being once I've got it figured out, in case anyone is curious.
I too also found out Paolos's artcile is from 2006....I just installed that flyweigh at the Chicago MWS but I was not aware that this flyweigh is suppose to install it on the poles (leading)....I placed them in between post....hope I didn't screwed up those weight since they are on back order along with the brown shoe...

I won't be able to hit LHR...but will do that on Father's day.
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Old 06-05-2008, 01:27 PM   #2970
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I'm talking about Paolo's post from just a week and a half ago, at the top of this page.

And didn't you have a clutch problem at the MWS race over the weekend, final qualifier? Before you clipped a board on lap one of the main and took yourself out...
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