1975 Ford Bronco Front Driveshaft U Joint Replacement?

[MerganserMaster]

Whenever I am driving in 4wd in my 1975 ford Bronco it starts to shake a lot when going above 20 mph. I dont have this problem when in 2wd mode so I believe that my front drive shaft U joints are worn out. My question is where is the best place to get replacement U joints? I know that there is a difference in which U joints the early EBs and later EBs use and this has led to some confusion for me.

 

[JB Fab]

Could be a sloppy slip-yoke too..
You could just remove the driveline and drop it off at a driveline shop to have it inspected/freshened up.
If you do, have them quote you before you commit, it might be cheaper to buy a replacement (some driveline shops are expensive if your an average joe walk-in customer).

 

[MerganserMaster]

Could be a sloppy slip-yoke too..
You could just remove the driveline and drop it off at a driveline shop to have it inspected/freshened up.
If you do, have them quote you before you commit, it might be cheaper to buy a replacement (some driveline shops are expensive if your an average joe walk-in customer).

I do happen to have a replacement front driveshaft (it was under the back seat) when I got the Bronco, should I just swap them out with new U joints and see if it works?

 

[Oldtimer]

I would pull front drive shaft, lock the hubs, and go for a drive. Verifying vibration is not in front axle.

 

[Bruners4]

I would be checking and inspecting the spare driveshaft first before removing the current one. It might be worse than the one installed. Slip yoke wear is only fixable by replacing the male and female splines.