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Re: Where's The Squeek?

To: Nels Anderson <nels@flightsim.com>
Subject: Re: Where's The Squeek?
From: Dave & Liz DuBois <ddubois@sinclair.net>
Date: Sun, 07 Sep 2003 11:32:54 -0700
Nels,

I would suspect that the squeek you are listening to is comming from 
your generator and is a result of  an excessively tight fan belt (and 
probably one purchased from Moss Motors).  The fan belt on the T series 
cars need to be run extremely loose.  You should be able to push on the 
belt between the generator and the water pump (rather than on the 
longest leg) and see almost 1 inch of slack.  This is quite tight enough 
for the T series because it is not driving  an alternator that requires 
a lot of torque to turn when it is producing current and the fact that 
the fan belt is a large cross section truck and bus belt, which brings 
up the other point, belts purchased from Moss Motors.  Years ago Moss 
got a large supply of solid backed belts that were barely long enough to 
get on the T series engines.  Even running these belts extremely loose, 
put enough force ont he generator pully to cause excessive wear on the 
rer bushing.  After the bushing wears far enough, the armature starts to 
rub against the field poles and produces that elusive squeak you ar 
hearing.  It will also destroy the armature (thus the generator) if not 
corrected.  I am pasting an article that another member and I wrote for 
the newsletter of our local Register recently on this subject.  The 
article gives the part number for two different fan belts that should be 
used on the T series engines (Nels, you will also need to get your 
generator overhauled by a compentent auto electric shop).

Cheers (and keep your belts loose),
Dave

KEEP YOUR BELTS LOOSE
(DON'T BE SO UPTIGHT - LOOSEN UP)
by Dave DuBois AND Stuart Locke

All of you who have been around me for any length of time have heard me 
preach about keeping the fan belt on the T series cars loose.  A tight 
belt will do really bad things to the generator (kind of like what over 
tight underwear does to a person, but that is a subject for other 
publications), like causing excessive wear on the rear generator bushing 
and in severe cases, actually wearing through the bushing and into the 
housing.  It also causes sloppy water pump bearings and water leaks 
according to Stuart Locke, who has rebuilt numerous generators and water 
pumps for people that keep their belts too tight.  The same thing is 
true for the MGA and the early MGBs that use generators rather than 
alternators.  I have always followed my own advice and kept the fan belt 
in our TD EXTREMELY loose.  So you can imagine my surprise a couple of 
months ago when I traced the source of squeaking in the engine 
compartment to be the generator armature rubbing on the field poles 
because the rear bushing was worn excessively.  I pulled the generator 
and did a quick overhaul, cleaning it up, replacing the rear bushing and 
brushes and repainting it.  Then I started puzzling out why the rear 
bushing wore so quickly (if you consider 15 years to be quick).  
Interestingly, at the same time I was working on an article, Stuart 
Locke was doing the same thing some 600 miles south in Sunnyvale.  His 
article arrived about two days after I had given mine to Liz for the 
Bonnet, so after consulting with Stuart, I am combining the two articles

Since the fan belt that was originally on the car when I bought it in 
1974 was a bit over sized, I had replaced it when I restored the car in 
the early 80s.  At that time the belts from Moss were a solid and very 
stiff belt, but I didn't give that much thought at the time.  In 
revisiting the situation after rebuilding the generator, I  took a more 
critical look at the belt I had been using and dug around until I 
uncovered the original belt (the one that was too long).  What I found 
was that the original belt was a Gates Green Stripe belt that was 
segmented on the inside edge and was, therefore, a very flexible belt.  
When installed, it could be run very loose and as a result, put very 
little sideways pressure on the generator pulley, which results in very 
little pressure being transmitted to the rear bushing through the 
armature.  I then embarked on a search for one of these really flexible 
fan belts and through trial and error and a very helpful auto parts 
store in Bremerton, who special ordered goodness knows how many 
different sizes of belts for me from Seattle, found the proper size 
Gates Green Stripe II belt.  This belt is also segmented on the inside 
surface.  Although the segments are much wider than on the original 
Green Stripe belts, it still results in a much more flexible belt than 
what I bought from Moss.  The part number on this belt is TR22392 and it 
is a 11/16" X 39 3/4" (17mm X 1005mm) Truck and Bus series belt made by 
Gates.  In his article, Stuart tells us that the Goodyear 22394 belt is 
22/32" X 39 1/2" (17mm X 1005mm) and that the Moss belt is not only very 
stiff, but is also considerably shorter at 17mmX 925mm (about three 
inches too short), which I found when I was special ordering all those 
belts trying, to find the right one.  Additionally, Stuart found in a 
1949 book, Exploring Auto Mechanics by Harold T. Glen that the fan belts 
on the TCs and TDs (and by extension, the TFs) should be adjusted to 
have ONE INCH of slack between the generator and the water pump (not on 
the longest leg as we are used to).

By the way, as I said earlier, the same problem exists on the MGAs and 
early MGBs, but is not so pronounced since they use the later style 
narrow fan belts which are much more flexible than the ones used on the 
T series cars.  The fan belt still needs to be run quite loose (one half 
inch of slack between the generator and the water pump, rather than on 
the longest leg) on the MGAs and MGBs to prevent premature wear on the 
rear generator bushings.

My source for the belts over here in Kitsap County is Westbay Auto.  
Those of you in Seattle, Tacoma and other areas will have to check 
around for the Gates belts or Stuart tells us the Goodyear belts are 
available from Skip Kelsey (Shadetree Motors Ltd) at 925-846-1309.  So 
now you have no excuse not to loosen up and get comfortable.

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