Normal Yoke Play?
 

Hi there,

Ever since i have my car there's a pretty loud 'Clunk" coming from somewhere in the drivetrain when shifting from park to reverse/drive or drive to reverse. Yesterday i climbed underneath the car to check if i had play in different components and noticed some play in the U-joint and where the yoke slips over the trans shaft. My question now is: Is the amount of yoke play, Radial and up-down, normal or am i facing worn bushings or something? And, could the play in my U-joint generate such a audible and feel-able clunk? Also i noticed there's a crack in the yoke, whoops.. so that one needs to be replaced.

1973 Grand safari

Vid > https://www.youtube.com/watch?v=sPDmNVOOVgk

there should be no play. If it is noticeable by hand, you have bad u joints,
"Bill"!

Yes but what about the play at the yoke where in goes into the trans? Should there be some play between the yoke itself and the shaft?

Yes there is. The in-out is to compensate for movement as your suspension goes over bumps and such. I can’t quote allowable tolerances for the in out off the top of my head. Hopefully others will chime in. If you do like Bill said and put new u-joints in hopefully you will be ok.

Thanks! I'm mainly curious about the amount of tolerable radial and up-down play, so when i twist or push the driveshaft assembly upwards so to speak?

The yoke should have no appreciable movement up/down only in or out.
The u-joint may be making it seem like the yoke is what is moving. Are you sure the yoke itself is moving up/down?
You did say it was broken so that would give it movement.
Need to change it and put new u-joint in when doing that.


Try the new yoke on the tranny shaft and see if it works OK.


:)

Max clearance slip yoke OD to tailshaft bushing ID is .008".

I have a bit of radial slop, and my yoke to tailshaft clearance is .006". This is a new bushing and a fairly new 1350 yoke. The yoke did take a beating when I had the U-joint angles wrong. I have since adjusted the upper arms on the rear end to fix that.

Check U-joints for slop in the caps and rear end for R&P backlash. Put the car in neutral, chock the wheels, Grab the rear end yoke and see if you can turn it back and forth before the gears engage. Do the same thing to the u-joints, looking for slack in the caps.

I just watched the video. Your front U-joint is worn out. Looks like its dry and likely the needle bearings are fooked.

Will do!

Yeah, needs to be replaced! Think i'll have to bring my torch to the party because i have the feeling it's still the original plastic style piece

During reassembly apply some wheel bearing grease to the trans output shaft splines .

Grease to the trans output shaft splines only applies with yokes that are sealed at the un-splined end inside by an O-ring on the output shaft.

Yokes w/o this O-ring are lubed by the ATF.

FWIW

True enough!

yep, I see the ujoint cup halves move relative to each other.. R&R ujoint.

George

I just watched your video and need to say please do not drive the car at more then 30-35 mph.

If a front U joint let’s go while your driving ( especially down hill) it can jack knife the car when it it digs into the pavement.

Yeah, in the video you can clearly see some movement there. I will be changing the whole chabang, yoke, joints and see if that solves the problem!

When you go to remove the drive shaft jack the ass end of the car way up and you will only loose hardly any trans fluid.

Be sure to chock the front wheels!

Thanks, Will do!

Allright, I pulled the driveshaft. Nothing wrong with the yoke.. It's only a metal edge which looked like a crack in the video I made. I made another video of the output shaft play and rear end / R&P play. I think the noise I'm hearing when shifting is coming from the rear-end.. You can see how much noise this makes when turned. Normal or excessive?

https://youtu.be/gvjtGRlm-FE?is=Vaz9AUcz3z2ovQ43

Looks like the trans needs a new support bearing in the tail shaft section .
The rear could need new spider gears and a crossshaft and or that play could be from the ring & pinion.

Time to pull the cover and have a look.

You mean a new bushing where the yoke slips through or?

Sounds like no gear lube in there.

It's full!

I'm not too worried about the trans output shaft flop when the yoke is removed. The output shaft is supported by the yoke. The tailshaft could likely use a bushing, maybe a new yoke depending on wear.

But that rear end? That's a clanky boi for sure. Pull the cover, lets see what horrors are hiding inside.
How many miles on this boat? For those of you that may have missed it, a Grand Safari is a station wagon.

Good to know about the shaft. There's no noises or vibrations during driving FYI. The car has a 122k miles and I don't know about the history concerning repairs or replacements. Only that it left California in 2006 to travel to the Netherlands! I will pull the rear end cover soon 👌

Tranny output is fine as it is supported by the YOKE and bushing in the tailshaft housing. That rear diff sounds EMPTY and or 1/2 million miles? That noise is the "clash" between the pinion gear and the ring gear indicating (judging from the amount of rotation) alot of backlash. If it doesn't make noise accelerating or decceratling it must just be MILAGE. If noisey in either direction you should look at pinion bearings.

As mentioned, the diff is full of oil. And only making this noise when shifting from and back to drive or reverse, nothing when accelerating or deccelerating. I will pop the diff lid later today and make another video 👌

My moneys on the spider gears and the crossshaft being worn.

If so hopefully the crosshaft bore hole in the case are not allowing rocking movement.
If so then you really got issues that only a new carrier will resolve.