Loose UJ in prop shaft

[MikeyB Member Find all posts View Profile Close MikeyB]

Hi
Ive a 1999/2000 KZJ95 diesel manual, 560,000 kilometres
I was greasing her yesterday and noticed some play in the front prop shaft UJ area. Perhaps pulling a 3 tonne digger load lately did this.
I figured it was the UJ going so i rang up toyota and then i got a better price at another place. I had another look today and it appears that the play is due to the movement of the cap in the yoke hole. It only moves in one plane the other plane is tight.

Im thinking that replacing the UJ isnt going to fix this and that the problem will be worn eyes in the yoke.
Moneys tight so since they are greaseable UJs and ive noticed no vibration as of yet, im thinking of pulling out the shaft and tack welding the caps in on a couple of spots around the cap.
I will have an inspection of the clips before doing so just to check none have split. The clips are on the inside of the yoke.
Anyone being here before or able to offer some oracle words?
Thanks

[Bear63 Senior Member Find all posts View Profile Close Bear63]

Bundle of worms there i think , the uni joint caps are hardened so welding them will affect them, the yolk is cast i think so you may end up having a worse problem than you have now as the 2 materials wont weld well.

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

I'd be trying the wreckers for a secondhand shaft, a few tacks would likely last a few minutes before they crack. More than a few tacks, i.e. A full weld will possibly hold, but it will bugger the UJ in the process.

Cheers Andrew

[foxclan Avid PP Poster! Find all posts View Profile Close foxclan]

Cable ties, should hold it!

[MikeyB Member Find all posts View Profile Close MikeyB]

thanks for the replies, il ring up some wreckers and also pull it out for an inspection.
i was also thinking of using a centre punch to raise some ridges and give the cap something to grip
il post an update with what goes on.

[MikeyB Member Find all posts View Profile Close MikeyB]

Well i got up early to have a go at inspecting and possibly trying one of the above interventions.
The good news is that the yoke with the loose eyes is the smaller one which is attached to the diff flange so not the long one on the prop shaft. The ridiculous news is that i cant get the four bolts undone. I was straining so hard i was concerned without safety glasses so i will have to bring them back from a shop later on.
Also i saw that the retaining clips were all in, I gave her a grease before heading out.
Does anyone know whether these bolts have splines and you have to undo the nut (there is a washer between the bolt head and the flange, doesnt appear to be a lock washer)? As the pressure i was putting on the nut seemed to me to be starting to bend the nut edges on the way to starting a strip ( i used a 8 point 14mm ring spanner)

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

There is no spline on the bolts on the 120, cant say on the 90 but expect it would be the same.

cheers Andrew

[MikeyB Member Find all posts View Profile Close MikeyB]

Thanks for that Andrew, i will attack the easy accessible bolt heads instead next time with my twelve point socket and breaker bar.
I found a couple of things out today.
A second hand prop shaft including the two yokes and ujs is NZ$200- tempting
A brand new Yoke from Toyota is $190- almost tempting. A second hand one $50
A brand new UJ is $100 from Toyota, $45 from a reputable place.

A couple of other things i discovered is that if you ring a driveshaft place (thats all i googled) then they actually often have second hand yokes, where as the wreckers will not part a propshaft out. The other thing is that when i talked to the driveline places they said they do also repair yokes. They were busy so i didnt press them for what they do but they somehow build up the inner eye hole and then ream it back.
The other interesting thing i heard was what Bear has also said about the caps being hard. Apparently they are harder than the yoke so when they start turning they wear the yoke out quite fast.

So ive got a few options to weigh up, i also need to find out whether if i just get the yoke if i need to rebalance the whole propshaft.
I will update with what happened in due course and any tips for those with this issue in the future.

The last thing i found today is that some parts places thought when i said propshaft that i was after a part for a boat, they said they are called driveshafts on cars, well im not sure about that as the toyota part diagram i looked up had them as propshafts and even though i have very commonly heard them called driveshafts over my life im sure ive heard people talk of driveshafts on boats too!

[MikeyB Member Find all posts View Profile Close MikeyB]

Well ive done a bit of driving around. I did 150k one day and when i came home there was about half a mm more play so everyday before i went out, normally i do about 30k a day, i would grease her tight which would normally last the day fine.
Im about to head to Auckland to get a few things and getting this sorted is top of the list. I didnt want to drive down with her like this. Ive read stories of these things breaking at high speeds and ending up even in the drivers/passengers compartment not to mention the damage they can do if they dont get that far.
So today i set about removing it. With the plan being to drive down to Auckland with just the rear one doing the driving. Im not towing anything and its just me in the car so i figure it wont strain the rear gearing too much, especially if i go easy on her and i plan to bring her back with the front prop back in.
I will be putting the gear selector to HL so that it locks the centre diff otherwise i would be going no where.
If anyone thinks thats an issue please let me know.

Andrew was right, the bolts arent splined. I put a 14mm socket and put my ratchet on and loosen up they did. My only issue was due to way the UJ pivots it goes up at an angle and i got lazy and put the socket on while it was at an angle. I couldnt get the socket on it flush, it was the last bolt of course. So instead of just rolling the car forward the distance of one foot i ended up breaking the end off the socket, so lucky i had doubled up on that size in my shed.
The transfer case bolts are pressed in or something arather as to get the back yoke off you undo the nuts which are facing forward and are easy but when i put the nut back on to remove the bolts by tapping them with a hammer they wouldnt budge so ive just left them in for the journey.

Heres all i used. 14mm socket, extension bar, torque wrench, jar for contents and 14mm spanner (which you need as the nut will spin as you loosen the nut once the tightness has gone) flatblade screwdriver to just pry the yokes off the flanges, they come loose easy as.

[MikeyB Member Find all posts View Profile Close MikeyB]

Well heres the worn Yoke. It was easy to get the cups out (29mm) they could just be pressed out by hand on one side and the other side didnt require much more. In that photo i pressed them both in by hand, one side showing it was more worn. As you can see i could almost press it by hand all the way from the outside right through I cant see any signs of bending/cracking.

There are multiple roller bearings in those cups so im keeping them clean and the bearings in place as best as ive can, ive reinstalled them back on the uj and taped the whole thing up.
I will report back what the driveshaft shop says for people to have for future reference. Perhaps they might have a cheap option for building up the eyes half a mm or so. My back up option is the wreckers for a whole driveshaft.

By the way the clips holding the cups in are on the inside and come out easy by pressing a heavy screwdriver on one end of the clip and knocking the other end with a screwdriver with a hammer

[MikeyB Member Find all posts View Profile Close MikeyB]

Well i drove about 400k without the front shaft and she drove very well. I even got back up my vehicle entranceway which is a steepish 1 in 4 powerline access track made of soft brown rock with bits of just clay n parts where the winter rains have washed away the Gap 30.
The only difference i noticed in driving is that there is a slight but definitely noticeable understeer and the light is on the whole time to say that the centre diff is locked so that kept on grabbing my attention.

I went to the driveshaft place and im glad i did go in person. They had a spare but on inspection i noticed it had a slight crack so when i pointed it out the owner of the shop apologised and went and got me a brand new replacement with a brand new UJ in it for the same price. I looked at it for a long time later in my car, the grease was still the factory grease and the Yoke had no dirt or anything indicating wear on it so i was pretty smiley about that. The cups were firm in the yoke

Here it is with the two cups removed, ready for install in the propshaft

[MikeyB Member Find all posts View Profile Close MikeyB]

So the smiling ended about there when i took that photo. I decided to remove the old UJ off the propshaft and use this new UJ in the Yoke. I took the clips out and put the prop on some wood and tapped down on the UJ cross to move it and push the bottom cup out. Well after a couple of light taps with my hammer i picked it up and the cup was half way out. I could then grab it with the pliers and turn it out. The other side came out easy too. I was starting to think this is probably a little too easy, although this was my first UJ change.

I then reinstalled the yoke and UJ into the prop end and put the caps in and then tapped them in. They went in very easy and i then put in the clips and greased her and thought id give it a bit of a test. Well thundering typhoons there was play in these prop caps too. I was thinking i should of just got the $200 replacement driveshaft and now I would just have this brand new yoke and UJ i paid $60 for and id need to go back to Auckland and get another secondhand propshaft.

So as can happen i just got a bit red eyed and took it back apart and picked up my 2.3mm punch (the only one i had) and with the prop wrapped in a towel i tapped away quite lightly with the punch and my mini sledge to make indentations all the way around both yoke eyes on the prop shaft. I probably did 20 in each eye. I could see them but when i put my finger in there I could hardly feel them.

I then coated the eyes in blue thread locker ( I would of used red thread locker if i had had it, such was my displeasure at this stage) and i then started reinstalling the yoke and uj caps on the prop. Straight away I noticed that there was a major difference, the caps could hardly go any way at all by hand and so i was lucky i had coated the bearings in thick lithium grease as it took quite a few decent knocks with the mini sledge to get both caps seated to the point where the clip on each could go in. Without adding that grease the needle bearings would of fallen inside the caps.

She is now tight as with no play and i will let the blue threadlocker set overnight and reinstall the shaft on the car tomorrow.

What i found interesting is that originally this prop side had no play in it at all, it wasnt until after the cups were removed that there was now a change that allowed play to happen. So it seems like it isnt actually much that is needed to keep these cups in place where they should be. The very very slight indentations (which therefore have the correspondijng ridges which the cups then grab) made by the centrepunch made a massive difference so it doesnt take much to make the fitting tight.
Im glad i didnt weld (thanks for that tip Bear and Andrew) as who knows what that could of done to the needle bearings cap or the eyes. I will do a follow up write up if this doesnt work and it comes loose again in short order.
Not with standing that happening my only suggestion to people doing this is to make sure you get a greasable UJ and then consider using the red thread locker which holds much better but pretty much wont come back undone again without ruining the shaft. The UJ itself on the shaft was fine, i regrease mine every 4000k or after a water crossing.

The main thing i was thinking about this is if there gets to be significant play in the cups then the clips could flick out and then the cup would fall out with very serious implications for the car and personnel safety. A guy was even killed here in NZ when a UJ in a truck on a motorway going the other way came off and decapitated him. So anyone with play in your UJ i suggest you check your cups a tight before concluding its the UJ. Im pretty sure it was towing the heavy digger which caused this so it is probably a good idea to check for this issue when you are using your Prado to move heavy loads.

Cheers
Mike

[MikeyB Member Find all posts View Profile Close MikeyB]

I thought i should add two other points, i didnt mark anything as the prop is balanced as a unit which doesnt include the diff/transfercase flanges. People on numerous videos/ threads mark where the yoke flanges attach to the diff flange and the other end where the other yoke attaches to the transfer case flange, this is unnecessary. Those two flanges arent part of the balanced set up. Also the driveshaft place said i dont need to rebalance with the new yoke flange.
You only need to mark the propshafts if you slide the shaft apart into two pieces as those splines need to be lined up again in the same position to maintain balance.

The other point i should say is that retaining compound is the more specific product that should be used rather than threadlocker but both products according to manufacturers a very similar so i just used what i had on hand as theres no shop for miles around.

[Nova Member Find all posts View Profile Close Nova]

I had one let go 2 weeks ago, really scary at 110kmph!!!

Don't play with these, if there is any play get it fixed ASAP. When mine let go it smashed the auto (not a prado) so I need new driveshaft and auto $$$$$.

Glad you got yours sorted.

Nova

[MikeyB Member Find all posts View Profile Close MikeyB]

I had one let go 2 weeks ago, really scary at 110kmph!!!

Don't play with these, if there is any play get it fixed ASAP. When mine let go it smashed the auto (not a prado) so I need new driveshaft and auto $$$$$.

Glad you got yours sorted.

Nova

Oh no, id imagine that would only be like half a step down from a roadside IED.
Yes i agree, there should be absolutely no play at all, not even a fraction of a hairs breadth. Its important to add that play must be checked for before you grease them as that grease will temporarily hide any play.
Good luck with your repairs Nova