how do I flush my clutch fluid? anyone have a how to?

[darkone]

hey all, ive never changed fluid on a clutch before, wondering what all is involved? i have a 70 chevy c20 with a corporate ho52 rear end but dont know anything about the clutch other than its a 4 speed with one of the gears being granny.

[John Pasinski]

Are you sure it's a hydraulic system?

[68 TT]

Originally Posted by darkone

hey all, ive never changed fluid on a clutch before, wondering what all is involved? i have a 70 chevy c20 with a corporate ho52 rear end but dont know anything about the clutch other than its a 4 speed with one of the gears being granny.

The early SM465 granny gear 4-speed like in your truck does not have a hydraulic clutch. The linkage is all mechanical. No clutch fluid to change. If it isn't working right you may be able to adjust the linkage a little to give it more grip.

Most times it is a clutch disc that has gotten oil on it from a rear main leak or valve cover / intake leak and it will need replaced. No amount of adjustment will fix it if this is the problem.

[darkone]

it looks like it has a drain plug on the under side, and there appears to be fluid leaking from the bottom....

[camrycurt]

Originally Posted by darkone

dont know anything about the clutch other than its a 4 speed with one of the gears being granny.

Originally Posted by darkone

it looks like it has a drain plug on the under side, and there appears to be fluid leaking from the bottom....

I think you're maybe just talking about the transmission itself, and not the clutch? If you're looking at the huge hunk of metal underneath the middle of your truck with the gearshift sticking out of the top, that's your SM465 transmission.

If yes, then yes there is both a drain plug and a fill plug on it. All you need to do is get an 11/16" 8 point socket to fit the square plugs and take them out. Just make sure you take the fill plug out first so you're sure you can fill it back up.

Put a pan underneath to catch the old fluid and let it drain out. Once it stops, replace the drain plug and fill it up with plain old 90W gear oil through the fill plug hole until it runs out of the hole, then replace that plug and you're done. That's all there is to it.

[darkone]

Originally Posted by camrycurt

If yes, then yes there is both a drain plug and a fill plug on it. All you need to do is get an 11/16" 8 point socket to fit the square plugs and take them out. Just make sure you take the fill plug out first so you're sure you can fill it back up.

can anyone provide a picture of where the fill plug is? i looked under the truck a while yesterday to no avail

[camrycurt]

Originally Posted by darkone

can anyone provide a picture of where the fill plug is? i looked under the truck a while yesterday to no avail

Sorry for the kindergarten artwork, but here's the plug. It's a little less than halfway up on the driver's side.

[darkone]

thanks curt!