Check my thinking on drilling a hole for the universal joint pin.

[Reno Speedster]

I have shortened the driveshaft to allow the rear end to fit the Muncie transmission and my drop brackets (which move the axle behind the cross member. The issue is that I need to drill a new hole for the universal joint pin. After thinking about how to properly locate it, I made a guide that threaded into the hole in the housing where the pin goes in. This allowed me center the punch on the hole, which in theory, should place the universal joint in the correct place.

Before I go ahead and drill the whole, I thought I would throw it out to the experts to see if my thinking is good. To be clear, I am using a modern tapered drive shaft bearing which uses a collar to set the gear position, but I plan to set the universal joint bushing as a back up.

[Jerry VanOoteghem]

I have shortened the driveshaft to allow the rear end to fit the Muncie transmission and my drop brackets (which move the axle behind the cross member. The issue is that I need to drill a new hole for the universal joint pin. After thinking about how to properly locate it, I made a guide that threaded into the hole in the housing where the pin goes in. This allowed me center the punch on the hole, which in theory, should place the universal joint in the correct place.

Before I go ahead and drill the whole, I thought I would throw it out to the experts to see if my thinking is good. To be clear, I am using a modern tapered drive shaft bearing which uses a collar to set the gear position, but I plan to set the universal joint bushing as a back up.

Great thinking all the way around. One small change I would make, would be to get it all assembled and use the pin hole in the u-joint as a guide for a transfer punch to mark the pin location. The threaded hole in the torque tube is not necessarily perfectly aligned with the pin hole. At the very least, do a trial assembly and see if your current center punch mark aligns with the u-joint pin hole.

Another consideration, as a double check, would be to measure the distance from the pin hole to the backside of the pinion, using a stock, unmodified shaft. Then, if you cut say 12" off your shaft, reduce your measured dimension by the same 12" and locate the pin hole accordingly.

[speedytinc]

In theory..........
Confirm your prick punch location by sliding the U-joint on & looking thru the pin hole before you drill. How far off are you?
A better way is to put in the U-joint & drill thru the pin holes 1/2 way thru on each side. Ideally with a smaller drill & some thin wall tubing as your first pilot holes. Then remove the tubing & drill a thru hole the correct size..

[Pep C Strebeck]

This may be helpful:

http://www.mtfca.com/discus/messages/50 ... 1421063243

[RGould1910]

Just to add if you are off a bit on the position of the hole you can make the thrust bearing flange whatever thickness you need to fit

The biggest concern I would think is to get the right size hole so the pin fits snugly. If you happen to drill the hole a bit oversize I guess you could make a pin to fit, but youd have to enlarge the holes in the ujoint. Hmmm
I wouldnt trust pounding the head of the pin or using Loctite to keep things solid. Not good practice I think.

I once had a good driveshaft that someome carelessly drilled thru for the pin that required dilling oversize for a bushing. All doable but care must be taken to drill perpendicular to the horizontal plane of the driveshaft and position the hole accurately.

[Norman Kling]

I would suggest that after you measure and test the locations of everything and center punch the location, that you remove the driveshaft and secure it in a vise or clamp attached to a drill press so that when you drill it would be exactly perpendicular and straight through the driveshaft.
Norm

[Reno Speedster]

Thanks for the tips. I will drill it in my milling machine.

I went to check the alignment of the universal joint and the pin hole barely comes into the hole in the housing, so I need to cut the bushing back.

[Reno Speedster]

Well, this is odd. It does not appear that I can take off enough of the bushing to allow me to install the pin through the hole. This is an NOS ball that I installed and it appears that I need to machine the casting back to allow for the required clearance.

[kmatt2]

When you installed the NOS ball on the old driveshaft tube how did you buck the new rivets ? It is possible that the new brass driveshaft bushing is not properly seated in the driveshaft tube because it is hitting the end of a bucked rivet. If you are fairly close you can face off the back of the U-joint some to get the pin hole to line up.

[Reno Speedster]

No, the rivets are well clear of the bushing.

[Jerry VanOoteghem]

Well, this is odd. It does not appear that I can take off enough of the bushing to allow me to install the pin through the hole. This is an NOS ball that I installed and it appears that I need to machine the casting back to allow for the required clearance.

There are sometimes reasons why some parts were never used, a.k.a. NOS.
I used a NOS intake manifold once that I ended up throwing away.

[Reno Speedster]

I thought that myself. I will check it against another that I have an see how it compares. If needs be, I can machine the part to get the clearance I need. It’s just unexpected.

[Reno Speedster]

After doing some measuring, I figured out that I stuck the driveshaft tube a bit too far into the ball when I riveted it. I can take it apart, shorten the tube, and put it back together. My lathe is just a bit too short for me to shorten the tube without taking it apart. Not a big problem, just one more thing to fix.