912 Manual Checking and Adjusting V-Belt Tension
Checking V-Belt Tension
The generator and air blower are driven by a V-belt. The loads created
by these two accessory units impose considerable stresses upon the
belt at high engine speeds and, especially, during downshifts. For
this reason, we recom- mend that the V-belt tension be frequently
checked and adjusted when necessary.
Loose V-belt tension results in belt slippage in the pulley causing
the engine to run hot.
excessively high V-belt tension leads to belt failure and, possibly,
premature wear of the generator bearings.
||When servicing the engine, care should be excercised to keep oil and
grease off the V-belt; oily V-belts should be washed in a soap or
detergent solution and then thoroughly rinsed in clear water although
it is always of advantage in such cases to install a new belt. V-belts
contaminated with oil or grease for any length of time are usually no
longer serviceable and must be replaced. When correctly adjusted, the
V-belt can be deflected by 15-20 mm (5/8 - 3/4 in.) under slight thumb
pressure applied midway between both belt pulleys. The belt should not
show any signs of wear such as frayed edges or split flanks.
Adjusting V-Belt Tension
New V-belt will stretch after a short time of use so that they no
longer have the proper tension after 50 - 100 km (30-60 miles). For
this reason it is absolutely necessary to recheck the belt tension of
new belts within a short period subsequent to the installation.
Attempts to remove the V-belt by means of a screw- driver, without
loosening the generator pulley, will result in damaged V-belt and
Last modified: Mon, 17 Jan 2005
||1. Remove generator pulley retaining nut (36 mm wrench); to lock the
pulley in place during this procedure, insert a square-edged
screwdriver into the recess in the inner edged of the pulley and
brace, it .against the top bolt protruding from the generator hous-
||3. Arrange spacers between pulley halves as needed. The belt tension
should be so adjusted, by adding or removing spacers between the two
pulley halves, that the belt will yield by about 15-20 mm (5/8 -
3/4in) under light thumb pressure. Removal o|.ipacers increases the
belt tension, addition of spacers decreases the tension (see
Fig. 72). ...More