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Topic: Belt tensioner issues Re: What did you do to your coach today II (Read 668 times) previous topic - next topic

Belt tensioner issues Re: What did you do to your coach today II

Just a follow-up on the new tensioners. Started out trip to Wisconsin and got 3 1/2 miles before the belt to the hydraulic pump vanished. Narrow country road so stopped right there and called the towing service (Good Sam). They sent out the truck who hooked everything up in the rain, undid the drive shaft, and got us towed to Crosspoint Cummins in Normal, IL. They normally do our work. Next morning we all stood around and "wondered what could be wrong". Decided to put on a new belt since I'd just re-used the one I'd taken off with the tensioner install. Of course it's not a standard so we killed a day to get it in. Ran it and all looked god. Of course I was now out $320.15 for the standing around wondering deal @ $110/hour. Got 51 miles down the road and this belt went the way of the other one!!! :-X OK, Managed to put an old take-off belt from a couple of years ago on and limped back to Normal, IL. Parked at son's and ordered another new belt. A friend and I put the old tensioner back on and the new belt and we made it to Wisconsin. Now the process of replacing the bad tensioners that was new and trying to get some of the dollars for the "wondering" back from somebody. ::) I've noticed that the pulley on the main shaft is narrower than on the Hyd. pump. Both the same number of grooves but different total widths. I'm wondering if the narrower one allows the belt to walk up the side and fly off. I suppose it's all part of the adventure. ($320.15 :'(  grrr)
Larry
1996 U295 36'
Build # 4805
Actually we sold it but just like to lurk

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #1 –
Larry,

Have you verified the alignment of the two pulleys. If they aren't aligned and square to each other it would force the belt to wear on the pulley edge and probably shred itself into destruction is a very short period of time.

Larry
Larry Warren
1996  U320 36' SBID "Lola" sold 2020
Build #4970
Motorcade #18318

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #2 –
As Larry says, it's in the alignment. Not only do they have to be in perfect alignment, the new tensioner pulley must be exactly the same angle as the other two pulleys. I did a couple of posts several years ago on how to do it with photos.

Once you get the correct belt on, buy a couple more exactly the same. Gates Green Stripe Fleet belts are good. Quite a few engines have been lost due to overheating because of this out of alignment issue. Once the belt breaks, it's a mile back down the road so unless you have a matching replacement, you are just guessing.

With a couple of simple tools, an operator with good access to the engine, can install a new belt in less than 30 seconds if there is not another belt on the outside. For fun, I got it down to 7 seconds on our 6V-92TA

Suggest you buy axle covers for the next time you use a tow truck. Axles come out fast and minimize time by the side of the road. Pulling the driveshaft leaves open the possibility of incorrect re-installation. Were the driveshaft fasteners properly torqued or just guessed at? Was the driveshaft marked before removal as there is a small possibility of a out of balance condition if not assembled exactly as it came off? Some tow guys get it right, others don't take the time, don't know better or don't care.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #3 –
Start here;
C8.3 Cummins 325 Belt Tensioners
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #4 –
Quote from: lgshoup –
Just a follow-up on the new tensioners. Started out trip to Wisconsin and got 3 1/2 miles before the belt to the hydraulic pump vanished. Narrow country road so stopped right there and called the towing service (Good Sam). They sent out the truck who hooked everything up in the rain, undid the drive shaft, and got us towed to Crosspoint Cummins in Normal, IL. They normally do our work. Next morning we all stood around and "wondered what could be wrong". Decided to put on a new belt since I'd just re-used the one I'd taken off with the tensioner install. Of course it's not a standard so we killed a day to get it in. Ran it and all looked god. Of course I was now out $320.15 for the standing around wondering deal @ $110/hour. Got 51 miles down the road and this belt went the way of the other one!!! :-X OK, Managed to put an old take-off belt from a couple of years ago on and limped back to Normal, IL. Parked at son's and ordered another new belt. A friend and I put the old tensioner back on and the new belt and we made it to Wisconsin. Now the process of replacing the bad tensioners that was new and trying to get some of the dollars for the "wondering" back from somebody. ::) I've noticed that the pulley on the main shaft is narrower than on the Hyd. pump. Both the same number of grooves but different total widths. I'm wondering if the narrower one allows the belt to walk up the side and fly off. I suppose it's all part of the adventure. ($320.15 :'(  grrr)

I had a number of problems with the Gates hydraulic belt tensioner I installed on my Cummins 8.3 similar to what you are describing.  Belts flying off and the outer back edge wearing down.

After watching it closely over a length of time, I figured out that it needed a couple of washers put behind the tensioner and the motor bracket that it mounts to.  While everything seemed to line up when the engine wasn't running, the hydraulic belt would move towards the outer edge of the tensioner and sometimes fly loose, other times just fray the edge to the belt. 

It took two or three washers for it to line up correctly while the engine was running to keep the belt lined up correctly with the tensioner.
Robert
Build # 5304
1998 34' U270 Cummins 6CTA8.3

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #5 –
Could you be missing an original tensioner spacer that was originally in place?

Check this out:
Replacing Hydraulic Pump Tensioner

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #6 –
The original tensioner spacer is on and in place. I'm thinking now that the drive and driven pulleys are different one seems to have 6 grooves and the other seven. The tensioners were replaced four years ago and have been fine until this past May. The old tensioner is on now and except for the "jiggle" the belt seems to be fine. Gates said they would refund the cost of the installation and second broken belt although I've yet to see the money. I'm going to put a DAYCO on next week and see how that works out. Thanks for all the suggestions. ^.^d
Larry
1996 U295 36'
Build # 4805
Actually we sold it but just like to lurk

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #7 –
Did you compare vertical angles not just aligned with each other?

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #8 –
Larry, I don't believe that different width pulleys are all that uncommon.  My 95 8.3 was that way, never a problem, did replace both tensioners.
Gary B

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #9 –
An excellent 30 second video by Gates Corp on belt tensioners: Failed versus a good belt tensioner.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #10 –
Gates decided that the tensioner must be defective. Unfortunately, I'd all ready sent the unit back to Amazon and could not retrieve it. Gates can't (won't) do anything without the defective unit so that's that. They said they were sorry but apparently not sorry enough to refund the labor to install and replace. Oh, well, another part of the adventure. Put the old Dayco back on and all is well until I can get a new Dayco. ::)
Larry
1996 U295 36'
Build # 4805
Actually we sold it but just like to lurk
 

Re: Belt tensioner issues Re: What did you do to your coach today II

Reply #11 –
Quote from: wolfe10 –
An excellent 30 second video by Gates Corp on belt tensioners: Failed versus a good belt tensioner.

Brett,
 
That is an amazing and vivid comparison between good and bad belt tensioners!
 
Thanks,
 
Trent
Trent and Jean Eyler
2000  U295  4003  WTFE  ISC  350
Build#5603 MC#17385