Is There an Easy Way to Know Which Size Clutch I Have?

[maverickmk]

I have now come to the part where I can actually drive my truck and on it's maiden voyage I realized why it most likely was parked. The clutch is gone. So, with that said, is there a way to tell if it's an 11" or 10" before I pull the trans? All the places I search have both listed and I would like to have all the parts on hand when I start so I can finish it in one effort. Does it even matter which one I get? It's a '69 250 cid 3 on the tree. Those are the specs I search under and get both clutch sizes.

[bubbasimms]

FWIW......I've got a 69 250 3 on the tree and it has an 11 inch. I just happen to have it laying here.

[twoskies]

got an 11 in my 72 with a 4 on the floor, granny gear, i would make sure you buy a good flexplate, i went cheap and it flexes, ill probably end up having to drop the transmission at some point, not something you want to do twice

[maverickmk]

Originally Posted by twoskies

got an 11 in my 72 with a 4 on the floor, granny gear, i would make sure you buy a good flexplate, i went cheap and it flexes, ill probably end up having to drop the transmission at some point, not something you want to do twice

Flex plate? Those are for automatic trannys. There are 3 parts to a clutch setup: flywheel that is attached to the crankshaft, the actual clutch plate that has splines and is attached to the trans input shaft (slides over it) and then the pressure plate which is what the clutch pedal is attached to. What do you mean by "flexes?" Could it be a stiff pressure plate and you're getting some deflection in the clutch pedal mechanism/arm? There shouldn't be any flex in a clutch setup, unless you maybe need a different descriptor for your issue - ?

[Abomb]

Originally Posted by maverickmk

I have now come to the part where I can actually drive my truck and on it's maiden voyage I realized why it most likely was parked. The clutch is gone. So, with that said, is there a way to tell if it's an 11" or 10" before I pull the trans? All the places I search have both listed and I would like to have all the parts on hand when I start so I can finish it in one effort. Does it even matter which one I get? It's a '69 250 cid 3 on the tree. Those are the specs I search under and get both clutch sizes.

Do you have your SPID? If it says HD clutch, it will be 11 inch...if not, it will be 10....UNLESS, a previous owner has changed it...so, there’s really no way to tell until you have it apart...sorry...

[maverickmk]

Originally Posted by Abomb

Do you have your SPID? If it says HD clutch, it will be 11 inch...if not, it will be 10....UNLESS, a previous owner has changed it...so, there’s really no way to tell until you have it apart...sorry...

My SPID has "Nothing here to see" printed on it
Nope, no HD on it at all. Thanks for the info, I appreciate it.

[rsavage]

Originally Posted by bubbasimms

FWIW......I've got a 69 250 3 on the tree and it has an 11 inch. I just happen to have it laying here.

That looks like a 10 1/2" to me (often listed as a 10 3/8")

[Steeveedee]

If you can get at the pressure plate, you can measure the distance between the bolts. Different diameter parts would have different separation distances. The bigger clutch would, of course, have the bolts farther apart. Then you can go to the parts store and have them pull both pressure plates to compare. It's been a dog's age (or two) since I've put in a clutch, but if there is just a thin sheet metal cover on the front of the flywheel, I think the bolt holes are tapped through. You could still measure it that way. HTH

[twoskies]

yes

[maverickmk]

Originally Posted by Steeveedee

If you can get at the pressure plate, you can measure the distance between the bolts. Different diameter parts would have different separation distances. The bigger clutch would, of course, have the bolts farther apart. Then you can go to the parts store and have them pull both pressure plates to compare. It's been a dog's age (or two) since I've put in a clutch, but if there is just a thin sheet metal cover on the front of the flywheel, I think the bolt holes are tapped through. You could still measure it that way. HTH

I understand what you're saying, I'm just trying to cheat the system. I hate having to stop in the middle and run to the parts store. Not a huge deal, just one of my pet peeves. I'll just pull it and get the same. I was really hoping someone would say it makes no difference.

[maverickmk]

I got the clutch pulled out today and now I am stumped as to the size. Do I order an 11" or a 10"??? It measures almost exactly 10 1/2".





And isn't that clutch a beauty

[Steeveedee]

Missing pieces usually means someone was side-stepping the clutch.

[RustyPile]

Originally Posted by maverickmk

I got the clutch pulled out today and now I am stumped as to the size. Do I order an 11" or a 10"??? It measures almost exactly 10 1/2"........................….And isn't that clutch a beauty

It's exactly what the tape measure says --- 10 1/2 inches.. Don't "order" anything.. In these hard times, support your local economy.. Take your wore out pressure plate, clutch disk, and throw out bearing to the local auto parts store and tell them you want a 10 1/2 inch clutch kit.. They'll want the old stuff for a core.. If your flywheel looks anything like the pressure plate, it'll need refacing also...

[Steeveedee]

Originally Posted by RustyPile

It's exactly what the tape measure says --- 10 1/2 inches.. Don't "order" anything.. In these hard times, support your local economy.. Take your wore out pressure plate, clutch disk, and throw out bearing to the local auto parts store and tell them you want a 10 1/2 inch clutch kit.. They'll want the old stuff for a core.. If your flywheel looks anything like the pressure plate, it'll need refacing also...

Yup.

[maverickmk]

Originally Posted by RustyPile

It's exactly what the tape measure says --- 10 1/2 inches.. Don't "order" anything.. In these hard times, support your local economy.. Take your wore out pressure plate, clutch disk, and throw out bearing to the local auto parts store and tell them you want a 10 1/2 inch clutch kit.. They'll want the old stuff for a core.. If your flywheel looks anything like the pressure plate, it'll need refacing also...

So I need to get a 10 1/2" clutch? That's absurd, they are only available in 10" or 11". I'm not telling anyone I need a 10 1/2" clutch Have you ever replaced a clutch? It always helps to do a little research.

[Grumpy old man]

Summit about $200.00 with free shipping

Zoom MU Series Clutches MU5473-1B

Pioneer Flywheels FW-100

double check part #s and buy new ARP flywheel and pressure plate bolts and you'll only have to do it once . don't resurface heat checked flywheels .

[maverickmk]

Rock Auto has clutches for $75.00 with $10.00 shipping. I have a 5% coupon code which just about covers shipping. Locally, the cheapest I can find is a 10" for $120.00.

[RustyPile]

Originally Posted by maverickmk

So I need to get a 10 1/2" clutch? That's absurd, they are only available in 10" or 11". I'm not telling anyone I need a 10 1/2" clutch Have you ever replaced a clutch? It always helps to do a little research.

They ARE available in 10 1/2, you just have to know where to go shopping.. Obviously, you don't know who you're talking to.. I'm a retired automobile mechanic.. Started my first job when I got out of the military in 1966.. I worked the field for over 35 years.. The last 10 years I worked as a drivability technician. Along with my wife, we owned a shop for 12 years. Among other areas, I'm certified in electrical, ignition systems, power trains, brakes, and cooling systems..

Son, I've had wrenches in my hands for over 60 years.. How many clutches have I replaced?? Counting front wheel drive and foreign built, oh, probably somewhere in the thousands..

So can the smart ass attitude in my presence..

[maverickmk]

Originally Posted by RustyPile

They ARE available in 10 1/2, you just have to know where to go shopping.. Obviously, you don't know who you're talking to.. I'm a retired automobile mechanic.. Started my first job when I got out of the military in 1966.. I worked the field for over 35 years.. The last 10 years I worked as a drivability technician. Along with my wife, we owned a shop for 12 years. Among other areas, I'm certified in electrical, ignition systems, power trains, brakes, and cooling systems..

Son, I've had wrenches in my hands for over 60 years.. How many clutches have I replaced?? Counting front wheel drive and foreign built, oh, probably somewhere in the thousands..

So can the smart ass attitude in my presence..

So, you are stating, unequivocally, that GM put a 10 1/2" clutch in and all of the auto parts stores & online parts sites are wrong. I challenge you to find a 10 1/2" clutch for a 1969 GMC 250 3 speed. Not one that is listed as a 10" or 11" and actually measures 10 1/2". I'll wait.

[RustyPile]

Originally Posted by maverickmk

So, you are stating, unequivocally, that GM put a 10 1/2" clutch in and all of the auto parts stores & online parts sites are wrong. I challenge you to find a 10 1/2" clutch for a 1969 GMC 250 3 speed. Not one that is listed as a 10" or 11" and actually measures 10 1/2". I'll wait.

You "challenge" me??? What a joke. I have nothing to prove.. I'm not the one looking for a clutch.. They're out there, go find it yourself.. You've pissed me off so I'm done with helping you...

[AussieinNC]

Gentlemen please....some manners please...

10 1/2" clutches were common on a variety of Chevrolet products...

see

https://www.partsgeek.com/gbproducts...AaAst3EALw_wcB

A simple google search using Chevrolet 10 1'2 clutch kit will return many results....

Have fun everyone and stay safe

[maverickmk]

If anyone cares, if you pull out a clutch from a 250 cid I6 and it physically measures 10.5" you need to order a 10" clutch, not an 11".

[geezer#99]

Interesting!
If the disc measures 10.5 then what does the pressure plate measure?

[maverickmk]

Originally Posted by geezer#99

Interesting!
If the disc measures 10.5 then what does the pressure plate measure?

If you look at the picture I posted it measures 10.5" as well.