‘70 300 - Universal Joints

[Samplingman]

I’ve been refinishing the driveshaft including replacing the U joints in my ‘70 vert. In a box of parts I have, I came across two NOS u joints, one from NAPA the other from Precision. I have no idea what car these were intended for, but they did com from an old Chrysler mechanic. I measured these against the original that I just removed, and they are identical in every way, except for the part numbers stamped in the cross. I ran part numbers on the boxes and couldn’t find a specific application, although both the NAPA and the Auto Zone websites both say “wont fit your 1970 Chrysler 300”

My question, is there any reason I can’t use these new parts that measure up in every way?

Fits perfect in the rear yoke. Yeah, I know, made in Japan:

Cap end to cap end:

Lock clip to lock clip:

Cap end diameter:

 

[twostick]

If it measures the same, it is the same. The only dim you don't have is the shaft diameter and the only thing that might affect is how much torque the joint can take.

Kevin

 

[Samplingman]

Shaft diameter is 4 1/4, and I’m running a stock 350 hp. None of the part numbers showed the torque tolerance for the joint.

 

[Davea Lux]

The replacement u-joints with the grease fitting were after market and had a different part number. Computers are very stupid and will default to "it won't fit" unless the exact part number is referenced that shows in the data base. Remember if you use those that they will need grease every 10k or so, otherwise as long as the dimensions are the same, go ahead and use them.

Dave

 

[traintech55]

Also, if you keep them greased you probably never have to change them again.

 

[Samplingman]

Also, if you keep them greased you probably never have to change them again.

The u joint in the front was in very good shape, but I didn’t think it was wise to leave it after going through all the work.

 

[The Goose]

The replacement u-joints with the grease fitting were after market and had a different part number. Computers are very stupid and will default to "it won't fit" unless the exact part number is referenced that shows in the data base. Remember if you use those that they will need grease every 10k or so, otherwise as long as the dimensions are the same, go ahead and use them.

Dave

So true. We just wrote a check to a customer for $242,000 over a factory warranty on a dry u joint. It was on a brand new $1.3 million 777 haul truck w only 200 hours on it. Not filled at the factory. Took out the drive shaft and snapped off the tail of the transmission. All for a buck worth of grease...

 

[66 Monaco 500 365]

When you install a greasable U joint, make sure the zerk is under compression when installed.
Looking from the driven end, put the zerk clockwise of the driven ear, so the torque tries to close the hole, not open it up.
My $.02