by 58limited » Fri Jan 08, 2010 9:00 pm
There were two different fan clutches used on '58 Buicks. The base of the fan clutch has a hole cut into it that fits over the end of the water pump shaft. On A/C cars the water pump shaft is bigger than non-A/C cars. Unless you get NOS/NORS, you basically cannot find a new clutch that fits an A/C car. I took my new clutch to a machine shop and they fly-cut the hole to the bigger size for me.
There were four different water pumps used also. The first part of the year used cast iron water pumps, bigger shaft for cars with A/C, smaller shaft for non- A/C cars. The pump was changed to aluminum later in the model year, keeping the same differences in shaft size.
My shop manual states that the five bladed fan was used on A/C cars.
1958 Buick Limited Riviera Coupe Model 755
Other cars:
1953 Chevrolet 3100 Pickup
1957 Pontiac Transcontinental Safari
1968 Ford Galaxie 500 HT
1977 Lincoln Continental Convertible