First time in this section.
I’ve put a 79 cab on a 81 F250 4x4 frame and running gear. I’m needing to install a I-joint on the steering shaft. This will be a daily driver.
are those small set screws all that hold the u-joint on?
this makes me a little nervous, especially on the DD end.
I’d like to find a U-joint that clamps to the shaft and gear box rather than just small set screws.

 

I know that on a 78/79 4wd F250 that steering shaft in the engine compartment mini u joint up near the fire wall is not (easiable) replacable. Well with a grinder and a welder it can be. And they do not have a flex (rag) joint either, that is a 1/2 ton 2wd and 4wd set up.

Borgeson has you covered. With a complete cut to slip fit shaft. Measure X3 and cut once. Account for compaction of shaft.
https://www.borgeson.com/?target=sea...&including=all

If you just want to use the replaclement u joint only and cut the bad out. Use the D shapped shaft and the D shapped u joint end to make for a more secure set up besides the set screws and the set screw lock nuts. And a little bit of welder tack tack.

Also Flaming River has u joints and D shaft matrial. https://www.flamingriver.com/steerin...joints?cat=125

 

I plan on using the steering shaft from the newer frame but it doesn’t couple up to my 79 2x4 steering column. I need to buy a splined to DD
U-joint. Just don’t trust the little set screws on the DD shaft. Welding would make me feel better

 

I am sure that either company I link above, will have what you need.