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Topic: Cat 3208 AC compressor belt adjustment (Read 851 times) previous topic - next topic

Cat 3208 AC compressor belt adjustment

My compressor belt squeals and I believe it's due to a belt that's not tight enough. It looks like it's adjusted out to its max tension. Do I have any options other than removing all the other belts and replacing it with a shorter belt?
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 AC compressor belt adjustment

Reply #1 –
I think not Elliot, like I mentioned earlier I only did that once on my 3208 so it's been a while but if I recall correctly everything toward the fan from that belt has to come off first. I hope I'm wrong but I fear not.
Dub McBride 1996 270

Re: Cat 3208 AC compressor belt adjustment

Reply #2 –
Try adjusting the "looks like" may be decieving.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Cat 3208 AC compressor belt adjustment

Reply #3 –
You could put a shim under the compressor.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Cat 3208 AC compressor belt adjustment

Reply #4 –
While you are dealing with those belts, take a look at the tensioners. The bearings on one of mine went bad so I replaced the bearings on both of my tensioners. The bearings were much cheaper than new assemblies but you need a press to remove the old ones and install the new. I had the CAT dealer do that for me at their shop.
1993 U225 Build #: 4285
500 Watts Solar
Honda CRV AWD
Former 1981 Foretravel Travco
Retired, Full Time Off Grid Snowbird

Re: Cat 3208 AC compressor belt adjustment

Reply #5 –
Often, even a bench vice can be used to change bearings in the tensioner pulleys.
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: Cat 3208 AC compressor belt adjustment

Reply #6 –
Do you have a tensioner pulley,looks like you just move the compressor.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Cat 3208 AC compressor belt adjustment

Reply #7 –
Quote from: John44 –
Do you have a tensioner pulley,looks like you just move the compressor.
No tensioner unfortunately, you adjust it by sliding it on the slots in the plate that it's mounted to above
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 AC compressor belt adjustment

Reply #8 –
I was hoping to help but your belts are laid out totally different to mine, on the 3208 in my coach the compressor and the alternator are on the same double belts and adjusting is with the alternator mount.
My compressor is mounted on the driver's side and the alternator is on the passenger side, double shiv double belts to both.
88 Grand Villa 36' ORED 3208 (throwaway)Cat.
 Build # 3150
Happiness is the maximum agreement of reality and desire.

Re: Cat 3208 AC compressor belt adjustment

Reply #9 –
Quote from: Olde English –
I was hoping to help but your belts are laid out totally different to mine, on the 3208 in my coach the compressor and the alternator are on the same double belts and adjusting is with the alternator mount.
My compressor is mounted on the driver's side and the alternator is on the passenger side, double shiv double belts to both.
It seems like an odd place to put a compressor to be honest. It's very susceptible to damage if you drag the tail end as you exit a steep driveway.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 AC compressor belt adjustment

Reply #10 –
That is how the compressor was mounted on our 84 with the 3208. On the unicoach with the 3208 the compressor was mounted in a different location.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Cat 3208 AC compressor belt adjustment

Reply #11 –
Quote from: Elliott –
It seems like an odd place to put a compressor to be honest. It's very susceptible to damage if you drag the tail end as you exit a steep driveway.
Yes.  Mine had scuff marks on it before I removed it. You might try a Dayco belt 1/2 in shorter .
I mounted my gm alternator in the same place.  I have scuffed it also. I still have a mild squeal on occasion    . It needs to be really tight . Imho

Re: Cat 3208 AC compressor belt adjustment

Reply #12 –
For my '87, I fashioned a spreader out of a turnbuckle to get the belt tighter.
1994 U280, Build 4490
Deming, NM.

Re: Cat 3208 AC compressor belt adjustment

Reply #13 –
Quote from: Twig –
For my '87, I fashioned a spreader out of a turnbuckle to get the belt tighter.
Twig do you have any pics you could share? I'm having a hard time envisioning it.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 AC compressor belt adjustment

Reply #14 –
If you want to just tighten it for now put some large area washers between the compressor and the plate.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Cat 3208 AC compressor belt adjustment

Reply #15 –
Quote from: Elliott –
Twig do you have any pics you could share? I'm having a hard time envisioning it.
Unfortunately no. I gave it the the guy I sold it to. But it was one of these and at one end I put a bolt so it would fit flat to an engine surface and at the other end I think I cut a groove to place either the pulley or the pulley arm, into. Then turned it to extend it.
1994 U280, Build 4490
Deming, NM.

Re: Cat 3208 AC compressor belt adjustment

Reply #16 –
Look in the Grainger catalog for a electric motor belt tension tray,may be able to mount it someway,and look for some of that
rubber/plastic material they put under side by side vehicles,comes in half inch,could glue it to the bottom.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Cat 3208 AC compressor belt adjustment

Reply #17 –
On the 3208 there are two belts on the passenger side of the engine that are pretty short and there is a pulley that is the adjustment for their tension. They drive the alternator and and the air compressor. If they are not really tight they will squeal especially when you first start because the alternator is charging full blast and the air compressor is building up air. I made a spreader to help get it really tight. I used 2 sockets with a bolt and nut so I could force the pulley to tighten the belts. I replaced the belts on lots of the 3208 rear radiator. Flat rate paid 2 1/2 hours to replace the belts. I think there was 9 belts to change.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Cat 3208 AC compressor belt adjustment

Reply #18 –
Finally tackling this while I'm at my parents house. Can anyone tell me the adjustment specs for the AC compressor belt? Or give me some guidance on getting it close? We are going to put a thicker plate in between the mounting surface and the compressor and as I understand it overtightening is worse than being too loose so I want to get this right
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Cat 3208 AC compressor belt adjustment

Reply #19 –
Tight , plus a little.
It pulls opposing the items driven above it.  So really tight counters the rest of the stuff.
  I added a large spring in lots of tension to drive my alternator.  It still squeals occasionally .