For the first time since I've owned it, my little Mazda pickup has cried out for some unscheduled repair work.
A couple of days ago, while backing it into my driveway, I heard that unmistakable squeak of a dry u joint.
The overwhelming consensus among Mazda truck guys is that you must just replace the entire driveshaft since the u joints are staked into place from the factory. "Just go to the junkyard and grab another shaft" is what everyone parrots. Well, I couldn't find one of these trucks in a junkyard (DFW Texas area) if you held a gun to my head. And even if I did, it's liable to be worn out too.
So, off to do research. It seems Mazda had a long tradition of using these type of u joints, to include Miatas and RX7s. Well the Miata guys "just go to the junkyard and grab another shaft" or even buy new. Not an option on the pickups. The RX7 fellows seem to be a bit heartier crowd since their cars are even more rare than the pickups. In short, they have figured out how to overcome this hurdle.
There is a company called Rockford that sells replacement u joints for this application. Then you're just left with the challenge of removing the original peened in part. That wasn't terribly difficult to be honest. Just working slowly and diligently and resisting the urge to Hulk out with hammers and heavy implements of destruction.
You can see the dry cap with the rust if you look closely. That was my squeak.
So, long story short, I have it all apart and I have a tracking number for the new u joints. Tomorrow should be interesting. I have no designs that this is the ideal way to handle this situation. But, this is not a high speed truck. I just drive it to and from work. Nothing sporting. I'm betting that I can get it back together and it will be balanced enough to not cause any problems.
I'll report back honestly when I get it back together, and if it's shaky and out of balance I'll own up to it and mark this experiment as a failure. But, what else was I to do ? Throw away a good pickup over this issue ? Mail order a used driveshaft of unknown lineage from somewhere ? Not my style either one.
I wonder if those are better or worse than the plastic injection ones that Opel used back in the day that also were not supposed to be serviceable?
GM also used the plastic glued in u joints. They weren't supposed to be changed either but it took about a minute for the aftermarket to step up with clip type joints. You just melt the plastic and the old one comes out like normal. I've changed a whole lot of those over the years, so I'm hoping doing this one has similar success.
I had a yota with "nonserviceable" type. Took it to a farm tractor place and they put some 1330's in it. Done.
I did that on my rx-7, and put tens thousands of miles on it with no problem. I think I replaced it at ~205k and had the car until after 230k sometime...
The hardest part is going to be re staking them in place with out braking the ears on the yokes. I use to reman u joints in Porsche steering shafts and I would tack weld a washer over the cap. That was the easy part. The thing you have to be carful of is not bending the ears of the yokes during removal or installation of the u joints as this puts the yokes out of alignment so the bearings in the u joints are not happy.
I ended up making a jig I would use that supported the ears while putting the u joints in to prevent bending them out of alignment.
WonkoTheSane (Forum Supporter) said:
I did that on my rx-7, and put tens thousands of miles on it with no problem. I think I replaced it at ~205k and had the car until after 230k sometime...
I'm glad to hear of a positive experience. The worst I read was that sometimes you have to machine a tiny amount inside the yoke with these new u joints. Just enough so the snap rings can encircle the new cups.
dean1484 said:
The hardest part is going to be re staking them in place with out braking the ears on the yokes. I use to reman u joints in Porsche steering shafts and I would tack weld a washer over the cap. That was the easy part. The thing you have to be carful of is not bending the ears of the yokes during removal or installation of the u joints as this puts the yokes out of alignment so the bearings in the u joints are not happy.
I ended up making a jig I would use that supported the ears while putting the u joints in to prevent bending them out of alignment.
I'm not expecting any of those issues. The new u joints come with snap rings to retain the cups. Apparently there is sometimes a little shoulder inside of the yoke that precludes the snap rings from seating fully. A little whiz with an air sander or even a Dremel gives the required clearance. We shall see. Other than that, it's just normal u joint install stuff. I tend to be more careful than most when installing u joints to avoid closing up the yokes with any binding or undue installation stress.
Your photos show what looks like the marks for the setting tool. I don't see a grove for the snap ring
They're inside snap rings
I successfully put those same style u-joints in my Miata (Exocet now) driveshaft. I just recall taking careful measurements of the width between the two opposite inner ear surfaces, and touch up as required with a good quality flat file. 10k miles later (on a limited use vehicle) and I've had no problem so far.
I've used Rockford joints on a non-replaceable Nissan, and a non-replaceable Toyota.
I broke my bench vice trying to press out the original Toyota. Broke the dang moveable-jaw-end clean in two.
I have a nasty scar on my left hand from using a FAIRLY Big Hammer to remove the Nissan. And missing. Or hitting, depending on how you look at it.
I've since made my own 20T hydraulic press which works like a charm.
SkinnyG (Forum Supporter) said:
I've used Rockford joints on a non-replaceable Nissan, and a non-replaceable Toyota.
I broke my bench vice trying to press out the original Toyota. Broke the dang moveable-jaw-end clean in two.
I have a nasty scar on my left hand from using a FAIRLY Big Hammer to remove the Nissan. And missing. Or hitting, depending on how you look at it.
I've since made my own 20T hydraulic press which works like a charm.
I feel fortunate. I cleaned everything quite well before beginning, but my OTC ball joint press and a Milwaukee impact just walked the cups right out. Really no drama. I dodged a bullet I suppose.
Interesting removal method. I'm not sure if i should be ashamed to say that the first thing i would probably have tried was just to give it the old F U and see if the u joint would have pushed out the staking as part of the normal process anyway.
I tried those on my 87 Mazda. In my case they were not an exact fit and required some filing to get the snap rings in. Apparently I did not do it perfectly and the shaft was out of center and had a bad wobble. I ended I getting a whole new shaft,
Be VERY careful about getting them, PERFECTLY centered. I was in a bit of a hurry and paid the price. Not as easy as implied (at least not on my 87 B2000).
aircooled said:
I tried those on my 87 Mazda. In my case they were not an exact fit and required some filing to get the snap rings in. Apparently I did not do it perfectly and the shaft was out of center and had a bad wobble. I ended I getting a whole new shaft,
Be VERY careful about getting them, PERFECTLY centered. I was in a bit of a hurry and paid the price. Not as easy as implied (at least not on my 87 B2000).
I believe you're going to be right. The parts arrived yesterday late and I didn't have the mindset to put them in but I did open the boxes and size up the job. I believe there is some filing in my future. I'm getting a sinking feeling about the outcome.
So here is an update and some closure.
To give clearance for the internal snap rings that this u joint uses I had to do some filing like @aircooled alluded to. In the name of keeping it centered I stroked the file 25 passes on each side and alternated back and forth between the sides until I had sufficient clearance. After that it was just a matter of installing the u joint like any other.
Now, here is where the compromise happens, and in my opinion, it's a bodge. Notice down in the bores the shiny part where the original u joint sat. You can see the old peen marks from the factory. Notice how much further down into the driveshaft ears the new cups sit. While the bearing cups have the proper O.D. the whole u joint yoke dimension is significantly shorter than the original.
It all works smoothly in the end. No binding. No forcing anything. Smooth feeling and all four cups greased equally when I pumped grease into it. That illustrates that there is no binding and nothing is too tight.
Perhaps a better picture illustrating that the u joint is simply smaller than the original. While it works fine for my ferocious 80 horsepower hot rod engine driven by an old man, I wouldn't do high horsepower with one of these. There simply is less bearing surface that the originals had.
Road test confirms it's absolutely smooth. No vibrations whatsoever. So I call that a big win. Overall score though, I give these u joints a "C". They pass, but they don't deserve any praise beyond that.
I really hate doing stuff like this. My mentality is to ALWAYS finish a job at least as good as original factory if not better. But, this was one of those situations where I had no other option. It was either this method or become the proud owner of a Mazda pickup sitting in the driveway without a driveshaft.
I wouldn't be too concerned about the exposure on the outside. The cups have all the support they are designed to need, but the yoke is thicker than it requires.
It's a smaller joint. Grease it regularly.
Congrats on getting it centered. That's can be a problem with staked or glued joints. The factory jams the yoke in the tube, welds it up, then uses the location of the joint to remove any error in the tube rotation. I've had GM glued ones that needed to be retubed to get rid of the shake.
That is interesting. I did a similar thing with the mumpkin driveshaft and don't remember doing any filing or having the cups so set in.
That's odd. The three Rockford joints I did looked just like factory when done. Odd.
Having never dealt with Rockford before I just used their recommended part number. This u joint fits a pretty good range of applications according to the lookup, even some BMWs.
