Unijoint & yoke - help needed

-
R

RandomBytes

New Member
Joined
Jun 19, 2017
Messages
4
Reaction score
0
Location
Nhill
Hi folks
Ok, this may sound odd for you US guys but Australian 4 speeds with the heavy diff option run much the same yoke as your 727 - 29 spline, 7290 uni-joints. Now, the problem.

At one stage, some 20 years ago, I could not get any 7290 - Moog 316 - uni joints at all so I took the tailshaft & yoke with me to a bearing store and they sold me some Precision/Moog 534G ones which fitted well. Now these are totally unavailable in this country but I did get some 316 units - they just don't fit the same. The 534g are .065" less wide between the outer snap ring lands (2.563") . Measuring the tailshaft ends, they measure 2.625" between the "ears" which leaves 0 clearance for the 316's (2.6248") so the uni's are tight.

On the bench, if you tilt the yoke up, it will fall back under it's own weight and you can rock the uni at the other end back and forth with a push but is this ok? Strangely, the uni in the actual slip yoke moves fine and it measures slight less - 2.615...

The 316's are 2.6248 according to Moog - perhaps just not enough clearance? I have done the cap centering routine and tapping all around the yoke with a brass hammer. This did free them up enough to move as when the circlip was first driven home, nothing moved at all.. Circlips look to be far enough down in the grooves.

Other big problem is the slip yoke. Current ones intended for the later tranmissions will not fit the old 727's - the spline "pitch" is different it seems and it was hard enough to get a replacement yoke in Australia 30 years ago let alone now! Scared to hit it too hard...

So, is it okay to hope that the uni joints will loosen up a bit with wear or will I just grind the crap out of the end of the rollers?

Is the 534g ok with the extra clearance? I did try the 316's with less thick snap rings - those that were used on the 534G - but you could see space in the circlip lands and there was a really bad vibration in the drive line felt through the seat frame and the pedals...

Any help much appreciated!

Glen - Chrysler Valiant Charger 1972 Six-Pack.
 
You would be better off ordering the correct joints from the US.
 
Moog/precision u-joints are crap.
Spicer and recently a/c delco are
Much better.
I have had many battles with moog universals and continously thought it was something i was doing wrong.
And vibrate. 3 precision u-joints before i got one that didnt.
My supplier has all but dropped the line...
I will pay the money for a better product. Saves me time. Saves customer money out the door.
 
I noticed that some joints use different rubber boots, and have had problems with fitment. If you look closely, the crosses are machined to fit the boots. If you install the wrong boots for the cross, I had trouble with the cups being too far apart. That said, putting them in a vise revealed similar installed widths. I put everything together and gave the assembly a few whacks,to loosen it up and that was that. If you look inside the cups, you will see that the bottom surface is a bearing, just like the tips of the crosses. I used moly grease and it's been together problem-free for many years.
Some joints however, compressed in the vice, showed that there was no way the snapring grooves were gonna work. I had the same numbers as you and do not remember which worked and which did not.
For some reason, additionally, 354 sticks in my head...............IDK if it means anything
 
Last edited:
Thanks folks. So it looks like my purchasing a few Moog 316's and 534G's was a waste if they have gone to crap but the last ones I had were "made in USA". Perhaps this is that new southern state that makes all the Hemi 5.7's and 6.4's? :)

Either way, just about anything is better than the crap Chinese junk that floods the market here. I will try for Spicer from Rockauto. No idea that tolerances varied that much or that I wasn't the only one who couldn't get the snap rings on! I have measured all the uni's I have between the lands and they all measure the same so perhaps the only real diffeence with 534G is thinner snap rings? I did try some thin circlips on the 316s - the only way I could get them to fit freely - but the vibration was really too much and worse at speed. I will measure the 534gs when they arrive.

Though they are listed for Chevy Silverados, Blazers, Dodge Ram 3500 and some AMC stuff, I did find that the 534G were listed as replacement part for the 7290 in some service conditions. Perhaps a quick fix if the yoke was too narrow?

So, should I pull the 316's and go back to the 534's? Thet were much freer to move...

Thanks
Glen
 
Hi folks
Going further - yes "Moog Mexico" does lack the precision of a US part!! The 543G's arrived and fit ok in the tailshaft at one end - nowhere near as much drag when turning as the 316 ones -but one cap at the other end just pushed in. Locktite 222 to the rescue!

Worse at the yoke - both caps rotate in the yoke as opposed to rotating around the needle bearings. Again, Loctite. So much for a 1.125" cap as specified by both 543 and 316 by Moog.

Anyone had to do this before? Seems like I may have to leave the car up on blocks and order a Spicer equivalent proto.

Thanks

Glen
 
I've found that often it's just better to spend the extra money on the best stuff the first time around. Spicer solid u-joints are the best that I've found. Been running the 7260 size for years with a billet steel rear end yoke with no issues - 3,540+ lbs with a best 60' of 1.47, wheels-up. They also have a good selection of conversion/adapter u-joints.
 
Hi folks - next installment! Well, I pulled out the 316/7290's as gentle as I could and fitted the 534G units - with loctite bearing retainer to stop the caps rotating - and everthing moved a lot easier. Pretty confident that the cross will move in the cap before the caps rotate in the yoke or tailshaft.

Looking back at the 316 I pulled out - the diff end - one cap would not compress properly and it did not turn well. Pulling it off to look in the end showed a missing pin which was then discovered in little pieces in the grease. Not sure if it collapsed in use or if the unit was fitted up with the pin wrong in the first place. Certainly mangled it.

Hopefully the new unis will work out fine - they won't see a lot of mile but it looks like I will have to chase another yoke at some stage and possibly go back to a 316 - just for the caps - but with a thinner ciclip - something between the heavy stock 316 ones and the half thickness 543G ones ( I used the stock 316/7290 ones).

Thanks for all the help - I will post how it drives.

Cheers

Glen
 
You must log in or register to reply here.
-

Back
Top