Questions on driveshafts

Just wondering if anyone knows if say a 2 piece driveshaft thats hooked to a 4speed granny low manual transmission be used to hook up to automatic transmission,both trucks are long beds not like mine witch is a 1966 c-10 shortbed,the parts I dont use on my 1966 c-20 parts truck trying to sell here on the form for money for my Sons Truck.

 

In a word ?

YES ! You will need to add the proper yoke and have the front shaft shortened.

Val

 

Thanks DValentine were slowly getting thier on Matthews 66 longbed,taking one day at a time.

 

You Can Also Take The One Piece Drive Shaft From An 80's Long Bed And Have It Shortened And Balanced So You Can Eliminate The Carrier Bearing. Make Sure To Get One From A Truck That Was Running The Same Auto That Your Putting In So It Will Come With The Yoke. And Then You Done.

 

Just my two cents. The yoke from a T350 also fits a 700R4.

 

Thanks Drabo,probably be taking out the driveshaft out of the 66 c-20 parts truck pretty soon.

 

That's actually worth MORE than 2 cents. You should use the TH350 yoke instead of a 700 R4 yoke. The 700 R4 yoke has a bleeder hole that will leak fluid. Those that used it find that the only fix is to have that hole welded closed.

The TH350 yoke has no hole and will not leak. Use the TH350 yoke.

Val

 

I need some information on Driveshafts and compatibility. Yesterday I took my 65 drive shaft and correct modern 700r4 slip yoke to the machine shop to have it shortened and balanced. The fella told me I would need to replace the front yoke on the drive shaft because the old u-joints were smaller than the modern 700r4 u-joints. He also suggested replacing the whole drive shaft with a modern one so the rear yoke would be the "bigger" u-joint size and would take the horsepower. He says the older style u joints wouldn't take 300-400hp.

My driveshaft also varies in diameter, the transmission end of the driveshaft is a little larger. about half way to driveshaft gets slightly smaller in diameter... Is this normal? it appears to be a stock driveshaft that hasn't been rubbing on anything however the machine shop guy says my driveshaft is garbage and should be replaced.

Can I replace the old 65 rear differential yoke with a modern style larger yoke?? will any modern yoke fit onto my old 65 differential?

 

Wish You lived closer to me LELAND,I know a good friend of mine who could cut it and balance it right on the money cheaper than a person taking it to machine shop.My good friend (convertible 66 c-10 John) is going to open a shop pretty soon . I going to try and help him out as much as I can to get their to open it,in process of building it.

 

First off, DONOT use the 700R4 front yoke. It will leak ! Use a TH350 or TH400.
Second, I smell something fishy with your drive shaft guy. Find someone else.

Val

 

DVals 100% right sounds fishy.

 

Thanks... i didn't get a good feeling from him however its a long way to the next machine shop.

Has anyone had problems with using the old smaller u-joints breaking under pressure? say 350+ horsepower...

I'm not drag racing however I do like to play with smoke!

did original driveshafts vary in diameter from front to rear??

also will a modern yoke fit onto an old 65 rear differential?