41 replies to this topic

[springer]

I brought the GT/SC in to my local Ford dealer yesterday to have one of the rear window regulators replaced.  Today they called, and while doing a "27-point" inspection of the car, the tech noticed that my fan belt, or drive belt as it is referred to now, was shot.  I hadn't noticed it the last time I was in there, which was a week ago.   I drove to the dealership and met the tech and service rider at my car and observed my Gates drive belt, which was completely missing the inside rib - the rib closest to the firewall.  My six-rib Gates belt now contained only five ribs.  It looked like a clean cut, and I didn't notice any fraying.  The missing rib looked as if it had been cut-off with a razor blade.  I also noticed a six to eight inch long, and 1 inch wide,  slice in the hood insulation.  

This is the first Gates belt that I've had a problem with since the installation of my Thump RRR tensioner arm several months back.  Prior to the installation of the new tensioner arm, the supercharger shredded my first Gates belt within 10 miles after I received the car back from the GT/SC conversion by SA.

The Ford dealer is removing the belt and is going to examine all the pulleys and make an attempt to determine what caused one of the ribs to be ripped from the belt.  Those reading this message, especially those with the GT/SC package, know that these Whipples love shredding the Gates drive belt.  I've read in some other threads both here and on other forms about other supercharged cars being fitted with the Goodyear Gatorback belt.  It sounds like the Gatorback belt is a much better quality belt, so my question here is whether anyone reading this thread has had experience with the Gatorback belt after switching from the Gates belt?   From my personal experience, I'm beginning to believe that these Gates belts are not a quality product. at least when it comes to powering our supercharger.

Also, I'm having trouble finding a part number for the Gatorback belt, so if anyone can help out with a part number, I would appreciate any help there also.

Tomorrow I'll try and get a photo of the current belt and get it posted here.

Edit:  After this original post, I found out that the Goodyear Gatorback only comes in a seven-rib design, not a six-rib design as needed for the Whipple supercharged Mustangs.  One rib has to be cut-off the Gatorback belt to make it will work with the Whipple superchargers on the GT/SC Shelby.

Edited by springer, 03 July 2011 - 07:56 PM.

[Doug_GT350]

I had the same problem.... once. It was my second one. of three, that went that way. I believe the only belt you can buy for them at this time is the Gates belt.

[MMcGuirk]

Call the tech line at Whipple.

they will help determine why you belt is wearing funny.

I have over 4oK miles of trouble free operation with mine.

[RogerS]

There is no part number avalible for the Gatorback for our specific application any longer. Due to the size I believe. I am running a Gates, 5K track miles and just changed the original belt in January of last year. And it really didn't need to be changed.

Roger

[Doug_GT350]

When mine was diagnosed it was a bad bearing in the 100mm idler that was causing the belt to walk off. Check that one first since it was the only pulley that was replaced during the install.

[springer]

Today, I talked with a Whipple tech named Mike, who stated that he has heard of a similar problem like that which occurred on my Gates belt where a single rib was rippled from the belt.  He stated that in one particular case, something was interfering with the belt causing a rib to be ripped from the belt.   He said another cause could be the Whipple supplied adjustable steel smooth idler pulley which must be set very tight after a belt is replaced.  (This is the small idler pulley that is located directly to the right of the alternator pulley.)  He also noted that the instances where this occurred to these other belts where one rib ripped off always seemed to be the outer rib on the engine block side of the belt - just like what occurred to my belt.  After some discussion and all was said and done, he agreed to send me a new Gates belt.  

Later today, I talked to the Ford service writer and the tech working on my car.  The tech said they couldn't find any issues with pulleys, debris etc. except that the belt flexes or moves some under load.  The service writer stated that this should have been a twin belt design for this Whipple application, and that he has seen the single belt shredding problems many times with a single belt application as found on my supercharger.  He said that a few years ago, guys were adding the Whipple to their F-150 trucks to mimic the power found on the the supercharged Lightnings.  He said that he saw problem after problem with the single belt set-up on these supercharged "Lightning wannabees."  He was rather dumbfounded that Whipple never corrected or addressed this problem since then and still retains the single belt system.  The service writer has escalated  my belt problem to Ford and hopefully there is something somewhere in Ford's database that can help us out.  Personally, I believe it is a very poor engineering and design flaw that Whipple should have corrected many years ago.  There are hundreds of posts on it to be found all over the internet.  

I also talked with Goodyear today and as Roger noted, there is no Gatorback belt produced in a 6-rib version that is 124.7 inches (the closest length is 120.5 inches).  But, there is a 7-rib Gatorback available in that size.  I'm in the process of obtaining several 7-rib Goodyear Gatorback belts.   They will be custom cut to to 6-rib width and will work with the Whipple on our GT/SC's. Based on my past experience with the Goodyear belts on my Harleys, and other cars, these Gatorback belts  just might be the ticket for the Whipple GT/SC's.  Hopefully I'll find out.

John
springerjfp@aol.com
972/841-6245 (Dallas/Ft. Worth)

Edited by springer, 21 January 2011 - 07:17 PM.

[Doug_GT350]

I fixed my problem!!!!

Attached Files

•  DSCF2938.JPG   164.81K   105 downloads

[MMcGuirk]

Doug_GT350, on 08 January 2011 - 06:21 AM, said:

I fixed my problem!!!!

Doug

Who's kit is that?

[Doug_GT350]

MMcGuirk, on 08 January 2011 - 07:41 AM, said:

Doug

Who's kit is that?

Whipple's..... see the last line in my sig... ( the one above the Thumper    )

Edited by Doug_GT350, 08 January 2011 - 12:02 PM.

[springer]

Doug_GT350, on 08 January 2011 - 12:01 PM, said:

Whipple's..... see the last line in my sig... ( the one above the Thumper    )

Hopefully your crankshaft holds out Doug.  I've heard mixed reviews on the twin belt set-up.  It sounds like it  puts additional stress on the crank by moving the crank pulley farther outward.  I've already talked to a guy that has seen issues with some crankshafts using that set-up.  I looked into it at one time, but backed away from it for now.

Edited by springer, 08 January 2011 - 05:33 PM.

[springer]

Today (Saturday)  I picked up the car and talked with a couple techs regarding my belt.  According to them, my belt is "walking" back and forth approximately 1/4" on the idler pulley located on the the top right side - or driver's side of the engine.  (See the pic below which identifies this pulley.) They spent some time trying to isolate the problem so my hat is off to them.  With the car running, one of the techs sat in the driver's seat revving the engine while the other tech showed me how the belt was sliding back and forth approximately 1/8" to 1/4" on the idler pulley.  As I watched, and as the engine was revved,  I could see the belt moving inward and actually going off the backside of the pulley - probably 1/8" of the belt was going off the pulley.  The backside of the pulley is hollow, and since the pulley is made of stamped steel,  the edge is about 1/8" thick and it is rather sharp.   The techs said that the edge of the pulley was actually cutting the outer rib off the belt.  As we watched the belt while the engine was placed under a  load, the belt seemed very tight elsewhere.  The techs recommended that I install a pulley that has both the inner and outer pulley lips to keep the belt from slipping off the pulley.  The other thing I noticed was that with the engine off, the belt rests against the inside edge of this idler pulley, while on the other idler pulleys, the belt is almost centered.

So, with my Thump RRR tensioner arm, Gatorback belt, and a new pulley all should be good - I hope.  Well, almost.  I tried to locate a 100mm idler pulley today but wasn't having much luck finding one with the lips.  I ended up calling Peter at Thumper RRR and found to my dismay that he doesn't have a pulley for my application, but he would help me with my problem.  He offered to make me some "lipped" pulleys, and said that he'll probably make some extras to keep in stock.  So, in three to four weeks, I'll have the pulleys, as I ordered five.  Three are spoken for and I have two left if anyone is interested before I post them for sale.

And, my apologies to Gates !!!

One more thing I noticed regarding the idler pulley in the pic below.  This idler pulley fits over a pedestal that protrudes from the timing chain cover.  When installed, the backside of the pulley is about 5/16" from touching the timing chain cover. If the pulley was moved inward, closer to the timing chain cover, by milling some material from the pedestal so that it would place the pulley closer to the timing chain cover  by 1/8 inch,  this might allow  the stock 100mm pulley to work without adding a pulley with lips.  I say it might work because this would move the belt more toward the center of the pulley, and if it walked  an 1/8", the belt would remain on the pulley and not rub the outer edge of the pulley.  I don't know if it is possible to mill this pedestal while the timing chain cover is on the car, but this might be another option for someone exploring this problem.  A pic of the timing chain cover pedestal is attached.

John

Attached Files

•  IDLER PULLEY WALK.jpg   332.5K   105 downloads
•  Dscn1754.small.jpg   111.56K   89 downloads

Edited by springer, 07 April 2012 - 07:24 PM.

[springer]

As promised here is a photo of the Gates belt.  Notice there are only five ribs there now instead of six.  Also for comparison is a photo of the Gatorback belt after it was modified to six ribs.

 Dscn1733.jpg   62.92K   53 downloads  Dscn1735.jpg   86.1K   60 downloads

Edited by springer, 09 January 2011 - 03:29 PM.

[springer]

Doug_GT350, on 07 January 2011 - 05:33 PM, said:

When mine was diagnosed it was a bad bearing in the 100mm idler that was causing the belt to walk off. Check that one first since it was the only pulley that was replaced during the install.

Doug, it definitely sounds like it is the 100mm pulley causing the problem.  As you noted, the belt is "walking" or sliding back and forth on the pulley, ever so slightly.  The problem is that once the belt gets to the inner edge of the pulley, it just keeps on going for about 1/8"over the edge of the pulley which causes the sharp edge of the pulley to cut the belt.  Attached is a photo showing the location of the 100mm idler pulley.

Attached Files

•  IDLER PULLEY WALK.jpg   332.5K   37 downloads

Edited by springer, 09 January 2011 - 06:05 PM.

[jmn444]

Very interesting....

I had previously had a single bearing 100mm from thump racing, and felt it had tooooo much play in it, so I've gotten a double bearing version now that it's available and the thing is rock solid...  thump pulleys are a bit wider than the stock ones, so it may not have been a problem either way, but it just didn't sit well with me.  I can completely see how this could have been the source of a lot of peoples belt issues with that stock whipple 100mm!

[springer]

jmn444, on 09 January 2011 - 07:28 PM, said:

Very interesting....

I had previously had a single bearing 100mm from thump racing, and felt it had tooooo much play in it, so I've gotten a double bearing version now that it's available and the thing is rock solid...  thump pulleys are a bit wider than the stock ones, so it may not have been a problem either way, but it just didn't sit well with me.  I can completely see how this could have been the source of a lot of peoples belt issues with that stock whipple 100mm!

The inside diameter of the bearings are the same, so it would have to be off substantially to cause the pulley to wobble.  As you noted JMN, it could be a bad bearing from the factory.   If you look at the photos here, you have a 7mm gap from the timing chain cover to the back of the pulley.  If the pulley was 4mm closer to the timing chain cover, the belt would be centered better and probably work properly, even if it wobbled or "walked" a little - which most of them will do.  But, if the pulley was flanged, or had "lips,"  the belt would stay in place on the pulley as the "lip" would keep the belt from slipping off the backside.  You can see in one of the photos below that my belt was riding on the very inner edge of the pulley - which is highlighted by the red arrow in the photo.  This was the only pulley where the belt turned this close to the outside edge of the pulley.  It isn't hard to imagine why the belt slipped off the back of pulley based on the location where it makes contact.  All the belt has to do is slip or walk 1/8" to 1/4" and it's "belt shed time,"  which many of us here have experienced.

If you look at the routing of the belt, which you can see below, the addition of the supercharger makes for a very long path for the belt to travel once it passes under the 100mm idler pulley.  On a N/A engine, the belt doesn't travel as far before it connects with another pulley, therefore it would make the belt more stable as it passes from pulley to pulley negating the chance the belt would wobble or "walk" on a pulley that is not ribbed or flanged.  I believe that if Whipple had used another small pulley above the other small adjustment pulley, all would have been good with our belts.  But, what do I know...LOL.

Glad to see you got yours taken care of JMN.  Hopefully all this talk will help someone in the future from experiencing all our aggravation.

Attached Files

•  Dscn1732.small.aaa.jpg   90.58K   57 downloads
•  IDLER PULLEY WALK.jpg   332.5K   73 downloads
•  Dscn1730.small.jpg   76.85K   58 downloads

Edited by springer, 09 January 2011 - 08:52 PM.

[jmn444]

I will measure the distance to the block, just for kicks, but what I didn't say clearly, was that I believe 100mm diameter may make normal single bearing wobble amplified.  My Tensioner has a single bearing 90mm and it not nearly as noticeable.

[springer]

jmn444, on 10 January 2011 - 03:52 AM, said:

I will measure the distance to the block, just for kicks, but what I didn't say clearly, was that I believe 100mm diameter may make normal single bearing wobble amplified.  My Tensioner has a single bearing 90mm and it not nearly as noticeable.

I get you now.  The flanged, 100mm pulleys Peter is making will be a double bearing pulley.

[zachman]

springer, on 10 January 2011 - 05:53 AM, said:

I get you now.  The flanged, 100mm pulleys Peter is making will be a double bearing pulley.

Thanks for your research. Good job.  Count me in for one pulley.

[NordicShelby]

springer, on 09 January 2011 - 06:03 PM, said:

  Attached is a photo showing the location of the 100mm idler pulley.

Thats the pulley that cracked and ate my belt while I was on the track this summer in Tulsa.

Whipple said they never heard of that happening before. They sent me a new belt and a pulley for free but the rotten dealership charged me $90 for labor to install it even though it was exactly 12 months to the day of of it being installed.

Hey Springer I will take one of those extra pulleys if you still got it.

[springer]

NordicShelby, on 10 January 2011 - 08:27 AM, said:

Thats the pulley that cracked and ate my belt while I was on the track this summer in Tulsa.

Whipple said they never heard of that happening before. They sent me a new belt and a pulley for free but the rotten dealership charged me $90 for labor to install it even though it was exactly 12 months to the day of of it being installed.

Hey Springer I will take one of those extra pulleys if you still got it.

Scotty and Zachman,  I'll save each of you a pulley.  Jim Clark wants one also.  That leaves one left for now.  They haven't been made yet, so if anyone else needs one, I probably need to know within the next week.  Again, I have one left that isn't spoken for.  The cost for the pulley is $100.

I talked with Peter again today and they should be ready in three weeks.

John

Edited by springer, 10 January 2011 - 11:40 AM.