Hey All - Quick question about U-Joint replacement. I got Moog 235 universal joints for my Cutlass, front and rear. I got the old ones out ok and found that the one up by the transmission was pretty shot. I put the new Moog joint into place and got them installed without too much problem. They are a bit stiffer, but seem ok.

I noticed 2 things though:

1. It feels like the joint up at the transmission can move a lot more in one direction than the other. That is, it can bend a lot further on one axis than on the other. I didn't remember it being that way on the original one, so I am including some pictures of what I mean. I think it is more than enough in both directions, even if the suspension is at full extension. Is it normal that it flexes one direction so much more than the other?
2. It has the grease fittings in the caps. They aren't Zerk fittings, though or at least not the normal type; they are really flat with a visible check ball at the front of the fitting. How do I grease these?

 

With regards to greasing flush type grease fittings w/ the check ball you will need a needle nose adapter fitting which attaches to the extension port on your grease gun. You can pick one up at most local automotive parts stores.

https://shop.advanceautoparts.com/p/...4216/9240029-P

 

 

If the fork on the axis that is
​tight was bent inward during the installation it will bind as described. Support the driveshaft, then using a drift/punch and hammer strike the ear of the fork from the inner side toward the outside. The ears get bent in, they need to be bent out. It doesn't take much to free them up.

Good luck!!!
​​​

 

Thanks for this. I didn't know such a tool existed nor what the name was. First time I've ever seen that kind of grease fitting. I ordered one...

I thought of that as well, but as you can see, both of the c-shaped clamps did fit into place. I'm going to give it a try anyhow, but I don't want to bend the fork on the driveshaft out too much either (shouldn't hurt to move it a bit). The contact point is very clearly on the rubber seal of the cap in the driveshaft's fork, which seems odd. You can see it in the second picture. Problem is, the rubber seal was pretty much gone on the original so I have nothing to compare it to.

Should the amount that it flexes in one direction be exactly the same as the amount it flexes in the other? If so, I must be doing something wrong...

 

In a perfect environment yes same amount of force to flex it. The same amount of travel will vary by the shape of the fork, it will travel until it hits a stop, you should clearly be able to see what it hits as a stop, it's external to the cross joint. If the force to flex in either direction is similar but not exact that is ok as long as there aren't any sticking/hanging points in the range of motion.

It is very common to have to give the fork some light raps to remove the tightness.

Good luck!!!

 

If your rear axle gets displaced so much that the driveshaft comes into contact with either yoke in either direction, take a look in the rear view mirror so you can see which side of the road to start searching for your rear axle.

Seriously, the casting of the yokes isn't very precise or symmetrical, so I don't think it is unusual to see some asymmetry in the max u-joint angle required to make contact.

 

Agreed. My Jeep has a buncha u-joints that have outside retainers and I have found that after pressing the last cap on, I have to go to the other side and press the joint slightly the other way to relieve the tension and allow the joint to move easier.

 

Weber State University Auto Tech has these great educational videos on youtube. They have 5 parts on U-joints alone! I thought this series was great, learned a lot, and gained a lot of respect for quality U-joints properly installed.
ttps://www.youtube.com/watch?v=v0RZVQQVMZs

 

 

Ok, so I gave the yokes a few good taps with a small hammer and the joints did loosen up quite a bit. That's a good trick. I also gave each of those little inner c-shaped clips a tap with a screwdriver to make sure they were completely seated. I installed the driveshaft again and spun it a few times. It is nowhere close on either end of the driveshaft to hitting the binding point. I'd even bet it is not using even half of the available flex space. I was definitely overthinking it.

Thanks for all the help on this. As soon as I get the greasing needle, I'll give each of those caps a good greasing.

 

Good news. If the caps had grease in them you should be fine for a very long time. It may even be better to wait instead of mixing greases.

 

On the Weber State University videos, as a minimum take a look at part 2. There is a good discussion on U-joint construction including the differences in cap construction, thrust surfaces, lip seals. Clip thickness selection to address binding and vibration, and even clip materials for compatibility with steel vs aluminum yoke. Very enlightening.

The same lecturer has a series on differential rebuild which I thought was also excellent.

 

Brian - Having replaced numerous U-Joints, I thought what the heck, let's see what this series is all about. I just dialed in Part 1 and I really enjoy the lecturer's delivery style, what is being covered and his knowledge - it's very well done w/ lots of great information. Thanks for sharing the link(s). I'll have something to look forward to viewing in the next couple days.

I fixed the malformed link (URL) in your earlier post. Somehow the leading "h" was dropped from the link you provided.

 

My kid finished 2nd in the state for diesel on road competition by 1 point. He was slightly out of his realm, being that he studied construction only. Very proud that he did so well! Anyways they do not seem to teach u-joint service! I had to show him how to do u-joints on his truck!

The dealership I work for, it's not uncommon to see 2-3 PTO shafts a week. Fun part is several type of manufacturers and american and metric, cv's torque limiting clutches etc.etc.

Pat