How much slack is tolerable on prop shaft Universal Joint?

Hello all, on rebuilding my rear end after it all locked up a couple of years ago I have just sat the UJ in the pinion carrier / yoke and there is a little slack there, nothing much, probably about 1mm / 1.5mm, I certainly can't get a thin washer in there. I don't remember there being any before it all locked up and the UJs broke up and wonder if the carrier / yoke has spread though doubt it as is cast? Is this slack likely to give me future trouble or is it about the norm? Thanks.

 

I am unsure, but are you describing the loose-ness of the universal joint as it is held by the yoke it is clamped into? Or, looseness within the joint assembly itself? The yoke to joint fit should be tight, with no 'slack'.

 

Are you referring to a gap between the end caps of the u-joint and the little cast-in stops in the yoke seats? If so a 1mm or so gap is normal.

 

There should be no slack, it needs to be held exactly centered. Bad things happen if that much mass is spinning that fast and it's half a mm off center

 

Yes, Voodoo Twin has it - with the UJ caps tight and the UJ UNclamped in place there is about 1mm gap between top of end cap and the cast in stops, that's 1mm at just one end so very minimal. What do you think folks?

 

There should be NO slack, the U joint has to be firmly clamped in place. Get a new yoke if yours is damaged.

 

It isn't visibly damaged and that slack is when unclamped Squirrel, just offering the UJ up to the yoke, there would be no slack when clamped and easy to centralise with just the 1mm I guess. Who's to say I get another ( 58 Lincoln ) yoke and it too doesn't have the same 1mm slack?

 

Ok, I give up.

 

I'd take Squirrel's word over mine every day of the week and twice on Sundays.

My uj-to-yoke has a slight gap.....less than a millimeter TOTAL. Maybe my yoke is worn too though.

 

Ok, I guess a forged item can stretch then Squirrel? Thanks, will go see if I can get another.

 

Funny- As a former tech instructor I feel your pain

 

Thanks Voodoo, have you been running it long like that? Mine is exactly the same and obviously will not move once clamped central ( .5mm each end ) but guess should try another, if I can find one as it seems to be an early production odd ball size by all accounts and not easy finding hence asking here. Thanks.

 

Give us a break man, I asked a further question to clarify. Jeez.

 

No doubt man, I didn't take you as questioning his authority, just a clarification, like you said.

 

First question do you have the correct ujoint?My old ujoint catalog shows it uses a 1310 series Spicer type ujoint. And it is possible that the yoke has gotten deformed.

 

Three years, about 15,000 miles. Haven't noticed any ill effects.......but I drive relatively slowly.

 

Thank you Jeem & Voodoo.
JohnEvans I haven't it to hand but was supplied by my usual reputable and knowledgable 50's Lincoln dealer in Florida and does fit the prop shaft end perfectly. I have a picture of one side of it but all I have from that ID wise is USA P, the number 5 on one leg & 429 on another, will check at the weekend for other id just to be sure. With just that 1mm of gap it's a good chance then that the forged / cast yoke has deformed then rather than cracking as I felt it would. Thank you.

 

No its not normal yes it will cause you troubles

 

Those yokes are forged,and they will bend a long way before breaking.

 

No slack. I have seen a number of yokes deform when the u-joint blows up from my 4x4 days. We have beat the ear back tight during a trail repair but would replace it when we got back. If there is any slack it will shorten the life of the joint.

 

I know this sounds crazy, but measure the value between the stops.

Contact your Florida source on the tele', and have him measure one.
A caliper is suitable for this measurement.

 

I also notice you said the old joints blew apart.
Any chance those were a conversion joint where one axle of the joint is different than the other axle of the joint ? There's plenty of those out there.

 

Yeah, I'm sorry I didn't know you didn't know that steel bends. It usually takes quite a bit of load to reach the yield stress.

Generally if you have a catastrophic failure, then parts will be damaged. It's good to figure out what went wrong the first time, so you can do things differently the second time and make a lasting repair.

There are many sizes of new yokes available for the ford 9" rearend, I think that's what a 58 lincoln used but I'm not sure, it's been decades since I've looked under one.

http://www.summitracing.com/search/...fferential/Axle-Model/Ford-9-in/?Ns=Price|Asc

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