Posts: 1,266
Threads: 160
Joined: Sep 2012
Since fixing the PennTex Alternator a year or so ago I have never heard noise from the alternator but now it squeaks when the engine first starts up and when the slide rooms go out. I tried tightening the belts a few weeks ago and they were shredded within a 100 miles or so. How do tight should they be? I know there is a tool but is there an easier way to guage them? Currently if I push on them (two belts going around the alt, engine flywheel and a/c compressor) I can push them in about 2” as I recall. How do you guys gauge the belts please?
Karen & Adrian Abshire
1998 2 slide 45' Newell Coach 498
Prior: 1985 Foretravel ORED 35, 1988 38' Foretravel U280, 2000 Foretravel 42' U320, 1990 Bluebird Wanderlodge WB40
Posts: 350
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Joined: Aug 2017
The Detroit manual specifies 1/2 to 3/4 inch movement at midpoint of belt with firm push with thumb ( define firm push ) . Also , dual belts should be replaced as a matched set . This is from the 92 series manual , but belt drives are belt drives .
Have you looked at pulley alignment ? It seems that if the noise started with alternator service , the alternator could be hard to rotate when loaded .
Could there be excessive current demand for some reason?
1986 #89
VIN 007
Detroit 8V92 TA 475 HP
Allison four speed
Chris and Sharon Hand
Posts: 5,412
Threads: 255
Joined: Jul 2012
The standard Series 60 belt setup will not handle a heavy load on the alternator without shredding the belts. Once they start to slip, they get hot, and in my experience are soon to expire. Tightening them once they have been hot never worked for very long.
Are you driving with merge switch on to charge house batteries?
Are your coach batteries down on voltage?
Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home
)
Posts: 1,531
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Joined: Jul 2012
One other thing to think about. On 653 (A CAT C12) there was a idler or tensioner pulley. It’s purpose was to apply a tension to the belt. So in reality there was no alternator adjustment.
When I got the coach, the belt would wobble all over the place. Newell could not figure it out. Fabick Cat in Joplin could not figure it out. But a very young mechanic at the Cat repair place in Birmingham spotted that idler pulley was wrong for this engine.
So…does your engine have an idler pulley? If so, it could be the idler pulley is dead?
Bill
Bill Johnson
Birmingham, Alabama
