Fan Clutches and Radiator Fans for a 1988 Chevy C/K1500 pickup Truck with 5.7 Liter V8

Question:

I have an 88 Chevy 1/2 ton 2 wheel drive pick up with a 5.7. I need to know if part numbers D17118 and D21061 are compatible with this vehicle. I have had an overheating condition during the summer months when stuck in stop and go traffic since it was new. Ifootve tried a larger radiator and replaced the fan clutch in prior years. Same problem. The only thing that helps is putting in a lower temp thermostat and that affects gas mileage when it is cool. Thanks

asked by: Rich F

Expert Reply:

There are a couple of different fan clutches that fit a 1988 Chevy C/K series 1500 depending on the rear axle gear ration and if it has air conditioning.

If your truck has a 3.73 or higher rear end or has air conditioning with 3.42 or higher rear end, you will need Derale Thermal Fan Clutch, # D22140. The fan mounting holes will be 10mm.

If your truck does not have air conditioning and it has 3.08 or 3.42 rear end, you will need Derale Thermal Fan Clutch, # D22142.

You will need a fan that is set up for reverse rotation. We have 4 fans for fan clutches with reverse rotation. You will need to measure the space for a fan under the hood to determine which size to use.

17 Inch Fan, # D17917
18 Inch Fan, # D17918
19 Inch Fan, # D17919
20 Inch Fan, # D17920

Another way to approach the problem you are having is to add an electric fan. Electric fans will not reduce horsepower or have nearly as much affect on gas mileage as a belt driven fan. And, if put on a switch, you could turn it on when you needed it or have it set up to turn on at a certain temperature. You are basically only limited to the space you have.

You also want to make sure that any supplemental fans are pushing or pulling air in the same direction as the factory fan. In other words, you do not want the fans to work against each other. I have included a link to our electric fans. I have also included a link to our FAQ article on electric fans.