Foretravel Owners' Forum

The Gatorback belt with 8000 miles started to shred. See photo. The tensioner, hydraulic and drive pulleys look aligned. The tensioner roller bearing spins freely but the spring mechanism squeeked when torqued with a 1/2 inch socket wrench.
Fortunately I have a non-Gatorback replacement and will be inspecting this belt more regularly.

QUESTIONS::

Did anyone else have issues with Gatorback type belts?

Should I obtain a new tensioner?

Could the dusty dry high-desert take a toll on rubber belts?

That "scrubbed" edge sure tells a story..!

Tim mine was eating belts like that. Changed to gates tensioners and gates green stripe belts. 🤞not a problem for 2 years. Also be sure you have the right belts, the tensioner should be running in the middle of the operating range indicated on the tensioner.

How big of alternator are you running? Belts can only reliably transmit so much power.

From a previous post of mine: .  "Previously (1992 Signature) on another Cummins 6C8.3 had worn water pump causing fraying of two newly installed Napa XL Green Stripe serpentine belts (in less than 200 miles).  Had local reputable shop take belt off, check water pump and alignment and plane of belt on all surfaces, they said all was ok.  Even after paying for this inspection at a respected local diesel truck repair shop, I listened to my trusty tech who said he would still "replace the water pump".  I did so, and no fraying of new belt.  His experience I will always value."

Just curious was the trusty tech who suggested replacing the water pump an older experienced tech? Or a new technology wiz kid?

As far as I know, this belt only runs the hydraulic oil pump.

Tim, you can usually tell for sure the tensioners are bad if you see them bouncing at idle or when you go to fast idle.

So yes Phred, this diagnosis was from an older, very experienced, heavy duty chassis tech that I worked with.  The shop that checked the alignment of the belts, the condition of the water pump bearing was also experienced and that shop has a good reputation.  I put on two new Gates tentioners, all new green stripe XL belts and still had the shredding problem within 200 miles.  I went back and talked to my experienced tech that I worked with, who had moved to a parts job due to back problems from years as a tech.  He said with confidence, "Jack, replace the water pump."  I did, problem solved.

Before replacing the water pump I went back to the shop, for them to recheck the water pump bearing, they said it was perfect and no problem.  Turns out, they were wrong.  So yes, experience is irreplaceable around our rvs.

The picture is of the shredded belt, before any work was done.

Another thing to check since this is for the hydraulic pump is that the bracket that mounts it to the engine is not cracked.

With the belt installed, pull/push hard on the belt and see if there is any deflection of the pump compared with the engine block.

The lower tensioner squeeks loudly at startup. Once warm it is quiet but bounces around.

What is the part number? Gates #38504?

Is it easy to replace using 3/8 sockets without a torque wrench? I have a 1/2 inch socket driver but not the sockets.

I am camping near Los Alamos, NM and have minimal tools.

My tools when I replaced it were limited also,  I had no problem.  The hardest was until I got the breaker bar from Harbor Freight to remove the belt, by repositioning the tensioner, however, it appears you had no problem getting the belt off.

Tim the problem with the hydraulic tensioner at least on mine,  it hits the mounting bracket BEFORE the tension is off it due to the index hole position. It can be a PITA to get it all back together. I use the breaker bar and a large pair of channel locks, as well as some colorful language.

The amount of torque is proportional to the intensity of colorful metaphors.

I just ordered two Gates 38504 tensioners from Amazon at $83 each. Auto zone wanted $150 each.

Should have them by Wednesday.

Automatic tensioners can fail in THREE WAYS:

bearing(s)
tension applied
dampening function.  Failure here results in belt being under/over/under/over...... tensioned.  Hard on belt and on components.

Check this Gates Corp short video: http://www.youtube.com/watch?v=uTLV5IU_IMM

As a co-worker said to me years ago-- when I want good(ie correct) answers to problems I look for gray hair and wrinkles
I always thought that summed up the situation!
Chris

Tim,  This is from our 7 year old Forum posting, with important info about a shim plate...
Removing Hydraulic belt tensioner and Alternator (http://www.foreforums.com/index.php?topic=12734.msg67562#msg67562) We replaced our two tensioners ourselves with new "sealed" Gates tensioners which are much improved over all other "open" tensioners. One new Gates tensioner doesn't hardly move and the other moves a little.
The hydraulic tensioner had a 1/8" flat spacer that I almost overlooked and if not re-used our hydraulic belt would not have tracked correctly. The spacer looked like it was part of the old tensioner could have been trashed with the old tensioner. I had to pry it off the back of the old tensioner.
Barry & Cindy