I recently bought a 78 f150. It has a 6" lift and 38's. The shop I bought it from had replaced the rear driveshaft the day I got it and I put maybe 20 miles on it before the rear you joint went out. Bought the same exact u joint at Napa and when installed it doesn't move freely. Is it supposed to be a two piece shaft or have a cv joint? I just have a single shaft with a u joint at either end. Thanks

 

Yes, it should have a slip yoke at the axle end and a CV or "Double Cardon" joint at the transfer case end. I don't think you're shop is too swift and they installed the wrong shaft. Also, it Sounds like you have some extreme angle on the axle. Do you have blocks or all spring? If blocks, are the wedged? They should have a wedge to rotate the pinion upwards to help with u joint angle.

 

Well someone put the shaft in backwards. The slipe yoke is on the transfer case end. Just wondering if someone put the wrong u joint in. When I ordered one at Napa the one that matched the one that's on it is not an oe size.

 

These guys?

 

This is what your driveshaft should look like.

 

The slip joint end goes to the axle.

 

It doesn't have the Cv joint

 

Well there ya go. You need the right drive shaft. And with 6 inch's of lift, the stock shaft will have to be lengthened. Here is a link to a stock replacement.

http://www.carid.com/1978-ford-f-150...-35565316.html

 

Sounds expensive. $$$ so much for making any money off of this thing

 

Any pics of the truck? Sounds like you bought it for a quick flip.

 

 

It's not a bad truck I just can't sell something that I know is going to give someone else trouble.

 

So here's the million dollar question. Will a single driveshaft with u joints at either end work if installed properly with the slip yoke at the rear end ? If so what u joints will it use ? It has a custom driveshaft with the factory yokes

 

Can you get a picture of the driveshaft so I can see what you're dealing with? Also, your saying it does have a slip yoke dive shaft like in the picture I posted correct? If so, you need to check to see if the fron and rear u joints are in phase, meaning lined up. If someone assembled the shaft out of phase then it will eat u joints like crazy.

 

Not a bad looking truck. Where are you located?