MC5A Blower Gear box, belt adljusting
 

MC5A Blower Gear box, belt adljusting

Started by FolkBus, July 28, 2014, 12:44:17 PM

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FolkBus

Hi All

I have a 1967 MC5A. I just replaced the blower belt with a stock belt ordered from MCI. The belt I replaced was a slight bit longer then the stock replacement but within the adjustment bolts range.  I noticed that the vibration rubber doughnuts on the blower mount seem a bit worn. Suggestions on where to get replacements??

Another question is how much deflection should there be in the blower belt when at the correct tightness?

Sure wish MCI had gone to the idler pulley for the blower belt sooner.

Thanks

--Mike
Mike and Debbie McNeil  Ridgway - Montrose, CO
1949 Crown SuperCoach (Amazing Grace) Conversion 1972  Pancake 220 Cummins  Fuller 5 Speed

1967 MC-5A  (Serenity)  Conversion 1986  8v-71N   Allison MT-644

bevans6

You might be able to find replacement mounting rubbers at an industrial supply place like McMaster Carr, that is where I would start if the usual sources like Luke at US Coach come up dry.  As far as the tension, I presume you don't have the stock air cylinder so you have a turnbuckle of some sort.  I would just add tension until the belts stop whipping at idle and when you rev the engine, it doesn't take a whole lot.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

luvrbus

Most 5A's just have 2 bolts to tighten the belts don't twist the bolts off those suckers are special and no one has those,Tom needs 1 and a shop quoted him 300 bucks to make it
Life is short drink the good wine first

Fredward

The stock belt may not fit. When they converted it to the automatic, they may have shimmed the engine upward which would make the stock belt too long. The only adjustment on the MC-5 blower drive belt is as Clifford mentioned, tightening the bolts that move the gearbox upward.

(don't ask me why I know the engine may have been shimmed upward when the auto was installed)

Fred
Fred Thomson

Boomer

On our MC-9's we changed the blower gearbox bushings and radius rod bushings over to urathane.  MCI (Coach Guard) used to have the bushings in yellow urathane. They never wear out.  I used them for engine mounts on my Eagle too.  Or you could get them at www.energysuspension.com
'81 Eagle 15/45, NO MORE
'47 GM PD3751-438, NO MORE
'65 Crown Atomic, NO MORE
'48 Kenworth W-1 highway coach, NO MORE
'93 Vogue IV, NO MORE
1964 PD4106-2846
North Idaho USA

RobSedona

there is a lot of play in the belt on a mc 5 or at least mine does ! at idle it moves a lot as the rpms go up it has a lot less movement :)

FolkBus

Thanks all for the information, now on to adjusting for the least belt movement!

--Mike
Mike and Debbie McNeil  Ridgway - Montrose, CO
1949 Crown SuperCoach (Amazing Grace) Conversion 1972  Pancake 220 Cummins  Fuller 5 Speed

1967 MC-5A  (Serenity)  Conversion 1986  8v-71N   Allison MT-644