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Topic: Tensioner Topic - trials of trying to find... (Read 969 times) previous topic - next topic

Tensioner Topic - trials of trying to find...

... a replacement for the squeaking kind.

One of the tensioners on my FT is squeaking.  A shot of WD-40 silences it for a minute or so, so I am sure of the source of the noise.  My question is what do I do?  I tried to locate a replacement tensioner on the web.  The 7E 3999 is apparently a Dayco 89429  (Read wrong - 89408).  None on Amazon, none on ebay.  Other sources show prices from about $99 (calls it a "belt")  to over $200 (shipping weight one pound?!?).

Can I replace just the squeaky pulley?  The tensioner is not dancing about.  I didn't see any numbers on the pulley, though I did not remove the tensioner nor the pulley.  Where do you guys get parts like these?

oldMattB
Matt B
1998 u-320

Re: Tensioner Topic - trials of trying to find...

Reply #1 –
I bought a Cummins tensioner from FOT. The tensioner was for the belt for the hydraulic pump. It was certainly not the most economical route, but I was confident that it would be the right part. I put it on, and still had the squeak. It sounded like a bad bearing to me. After service at FOT, it squeaked no more. At the previous service event at another shop in NAC, they installed the wrong belt. FOT installed the proper belt and it squeaks no more.

I now have a spare tensioner. I also carry a spare belt of the proper size.

FOT will probably have a tensioner. My local Part Plus store has a catalog with a bunch of tensioners. You may be able to find one at a good parts store if you have part numbers. A really good parts store might be able to find a replacement bearing.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Tensioner Topic - trials of trying to find...

Reply #2 –
Matt,

If it is just the bearings that are bad, they are a standard bearing available in most auto parts houses.

But, look at this video to make sure that the dampening portion of the tensioner has not failed: Failed versus a good belt tensioner.

I like Gates tensioners for both serpentine and fan.

Brett
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: Tensioner Topic - trials of trying to find...

Reply #3 –

Matt,
Not sure if you can use this spec tensioner, but here is where I bought mine.
Amazon.com: Gates 38504 Belt Tensioner: Automotive
Peter

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Tensioner Topic - trials of trying to find...

Reply #4 –
I noted with great interest Brett's comment in a prior thread that the reason for failure of the hydraulic pump is overtensioning from the standard belt tensioner.  He recommends that the pump mount be redrilled to relieve some of the strain....makes great sense to me.  I'm wondering, though, in lieu of doing this if the belt could be replaced with a slightly longer one to achieve the same effect. 

Chuck
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: Tensioner Topic - trials of trying to find...

Reply #5 –
Matt,

Here are some part numbers for our coach: 

Serpentine Tensioner Caterpillar 7E3999= Gates 38509.
Hydraulic Tensioner Cummins 3937553= Gates 38504.

Gates belts: water pump 9345HD, serpentine K070735HD, hydraulic:  K060445. 

Belt idler bearings (2 each) for Cat 7E3999: NTN 6203LU.  Fed Mogul BCA203-FF.

Brett
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: Tensioner Topic - trials of trying to find...

Reply #6 –
Quote from: Chuck Pearson –
I noted with great interest Brett's comment in a prior thread that the reason for failure of the hydraulic pump is overtensioning from the standard belt tensioner.  He recommends that the pump mount be redrilled to relieve some of the strain....makes great sense to me.  I'm wondering, though, in lieu of doing this if the belt could be replaced with a slightly longer one to achieve the same effect. 

Chuck
When the belt for my hydraulic pump was a bit to long, it squealed like a bad bearing. With the specified belt, it is quiet. Your results may be different.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Tensioner Topic - trials of trying to find...

Reply #7 –
Here is our recommendation on tensioner replacements. Photos also included. We did it ourselves and they work great. Hydraulic does not move about at all.
Replacing Hydraulic Pump Tensioner

Re: Tensioner Topic - trials of trying to find...

Reply #8 –
Olsmatt, When my tensioner was going bad a guy from Gates explained the difference in the original one and the Gates is that Gates has a flat spring that applies pressure across the entire pulley instaed of a round spring that applies tension on only one area.  Don't know if this is true but after I replaced both with the Gates I have had no problem.
Gary B

Re: Tensioner Topic - trials of trying to find...

Reply #9 –
Thanks all!

The Dayco I have uses a flat spring, about 1/2 inch wide.  I removed the pulley and removed the bearings.  It uses two 6203v281.  One was nice and smooth, one was very resistant.  I conclude that the resistance in the bearing was causing the inside of the bearing to chatter on the mounting bolt.  The bearing is apparently a commonly available "6203" bearing - it matches the dimensions listed online.  One online source sells them for under $3.  I will try my local auto parts store.

Brett is so damn smart, and the rest of you are pretty impressive, too!

Matt B
Matt B
1998 u-320

Re: Tensioner Topic - trials of trying to find...

Reply #10 –
Quote from: oldmattb –
Thanks all!

The Dayco I have uses a flat spring, about 1/2 inch wide.  I removed the pulley and removed the bearings.  It uses two 6203v281.  One was nice and smooth, one was very resistant.  I conclude that the resistance in the bearing was causing the inside of the bearing to chatter on the mounting bolt.  The bearing is apparently a commonly available "6203" bearing - it matches the dimensions listed online.  One online source sells them for under $3.  I will try my local auto parts store.

Brett is so damn smart, and the rest of you are pretty impressive, too!

Matt B


There are five different grades of bearing available for each number plus some brands have a better reputation than others. The guys behind the counter at NAPA may be able to steer you to to the best one.

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