Driveshaft doesn't turn on 48 DeSoto

[MarcDeSoto]

Installed my driveshaft with new u-joints today.  The problem is the driveshaft wont turn by hand or when cranking engine.  It used to turn.  The only thing different is I installed the handbrake.  Maybe it's too tight?  

[Sniper]

4 hours ago, MarcDeSoto said:

The only thing different is I installed the handbrake.

 

Did it spin before you mounted the hand brake?  You know you can back off the adjustment on it to loosen it up and eliminate it as the issue.

 

You also forgot the other thing you did, replaced the U joints, they could be binding.

[MarcDeSoto]

I took the handbrake off.  Now it turns.  I put the driveshaft on, but have a question about the rear ujoint.  Are the c-clamps supposed be flush with the other side like the front ones?  Front ujoint is on the top.  Rear ujoint is on the bottom, and you can see a gap at the edge of the C-clamp.  What should I torque the nuts to?  Can't find the torque specs anywhere except I found a general spec of 20 to 30 ft. lbs.  

 

 

Edited July 19, 2022 by MarcDeSoto

[desoto1939]

I would think that the flange should be up tight and there should be no opening or space.  I would think that by having the space then this also puts stress on the bolts holding the unit together and then the stress is going to weaken the bolt becasue of the twisting action.

 

Just my 25 cents worth od idea not a full mechanic but might ask a driveline shop mechanic of what should be the correct answer.

 

Rich HArtung

 

 

[MarcDeSoto]

I think I'm going to disassemble the rear ujoint and try to find what is making have that gap there.  

[kencombs]

That is definitely wrong.   All parts should fit together snugly.   No gaps

[desoto1939]

Marc: on your driveshaft to you have a slip joint style or is this the original driveshaft and one continuous shaft?

 

If you have a slip joint style then the end that has the slip joint needs to be adjusted and pulled out and then the rear ujoint assembly will fit snug and then you lock down the slip joint end.

 

 

Rich Hartung

[MarcDeSoto]

I do have a slip joint type drive shaft.  It is original to the car.  I don't know what you mean about adjusting it?  Are you supposed to put the rear u-joint in first and then the front?  We can get one C-clamp on flush, but not the other side.  We have jacked up the diff to make the drive shaft more level, but still can't get the rear c-clamps flush.  

[kencombs]

1 hour ago, MarcDeSoto said:

I do have a slip joint type drive shaft.  It is original to the car.  I don't know what you mean about adjusting it?  Are you supposed to put the rear u-joint in first and then the front?  We can get one C-clamp on flush, but not the other side.  We have jacked up the diff to make the drive shaft more level, but still can't get the rear c-clamps flush.  

That sounds like there is a needle laying in the bottom of the cup making the assembly to wide for the yoke.  Happens a lot!

[MarcDeSoto]

My handy man found the problem.  It's flush now.  Bet no one can guess what it was!  

[desoto1939]

Marc: when people are building a new driveshaft and using the modern cross style u joint instead of the trunion and pin style they make a new drive shaft that at the fron near the trans one tube slide into th eother tube that goes to the rear u joint. There is a  ring that connects the to section together and this hold the two halves together. That is the slip joint so the drive shaft is adjustable to compensate for length.

 

Rich Hartung

[MarcDeSoto]

Yes, but my DeSoto never had a ball and trunnion joint.  Here's how we fixed the problem.  We took the old ujoint and put it up to the flange to see if it would fit.  We noticed that it would fit one way, but not the other.  So my helper said is there anyway you could have put the the bushings on the wrong cross.  So I said I don't think so because I was careful to put bushing on the same cross as they were in the box.  That turned out to be the problem.  Some factory worker maybe 70 years ago put the bushings on the wrong cross where the blocks should go and put the blocks where the bushings should go.  So we knocked the bushings out of the yoke and put the bushings on the other cross, and now it fit.  Check out the new pics!