743 put in new ujoints sounds like something in bind. Can the key to the spline an adaptor be worn out

[foton]

yeah replace that fitting. be carefull when removing it ,hopefully it will not just twist off.

 

[helpnotamechinic]

Could that fluid be coming from the pressure fitting adapter? It looks like it has been hit from the top and is bent at the threads.

I will take a closer look in the morning. Honestly I don't know how it would have gotten hit. I hope it is not a big problem to fix. I am tired of having a new problem every time I think it's done. Thank you for the help.

 

[Gearclash]

Definitely a Cardan style joint so it should be tolerant of a small amount of misalignment. Wing style U joints so there is no concern about the caps being improperly seated or the wrong retaining rings. I will say though that I have seen some of those wing style caps really bind up the cross when the bolts got tightened. Didn't seem to cause problems in that particular situation though.

 

[Dave1234]

I don't know if this will be helpful, but going back to the start here, we never heard why the original U Joint failed. I suspect no one knows, but it may have had the same underlying problem, in which case a new U joint won't last long. Had the engine been out before the current round of repairs, when some shims under the motor might have been lost, leading to the original u joint being misaligned and consequently failing? If the new U joint as installed on the motor was floppy/flexing freely in both its joints, there is no problem with it, assuming there is no way to install it off center of the flywheel. Can we assume the motor turned over properly prior to installing it? If not, could it have a slightly bent crankshaft or connecting rod causing binding at certain positions? We are all assuming you correctly identified the U Joint as the problem, but I am not sure that is a reliable assumption. If the motor cranks without binding when not connected to the pump, and the U Joint flexes properly, then it seems that the only remaining choices are:
1. Elevation misalignment between the motor and hyd pump shafts, which the U joint isn't equipped to correct-- it can only fix angular misalignment. That might not be obvious when installing the motor as I expect there is some fighting involved in sliding the u joint onto the pump shaft, and elevation misalignment might not show up until the motor mounting bolts were tightened. Possibly loosening them might eliminate the problem and point toards a solution.
2. Bent hyd pump shaft--does it turn freely with the motor out?
3. Hyd pressure build-up when cranking--is the Aux control in the detent position with nothing attached, or are drive controls sticky and hence out of neutral position. It might be worth putting it on blocks if this seems likely so the wheels can turn freely, and double check the aux hyd control positioning.
4. Liquid in a cylinder. Fuel, or possibly blown head gasket allowing coolant pumping in and out of one cylinder.

Sorry but all of these except #3 & 4 require partially removing the motor again. . It would also be very helpful to have a more detailed description than "probably binding".

 

[Markle]

When I replaced my ujoint on my 743 2 years ago it lined up with some fiddling, and slid right on the pump drive with a bit of resistance, nothing that would make me think to stop pushing the engine back. The engine mounts have a steel cylinder collar inside the rubber, so once the rubber is squished by tightening it only drops so far. Like tazza said, the hyd pump might need shim adjustment for height. And Dave is also offering a comprehensive decision logic for other variables that could be in play. Keep us posted. It bugs me when the final solution is not posted for closure Of the thread.

 

[Markle]

Hyd pump tolerances/height spec in pic

 

[helpnotamechinic]

I don't know if this will be helpful, but going back to the start here, we never heard why the original U Joint failed. I suspect no one knows, but it may have had the same underlying problem, in which case a new U joint won't last long. Had the engine been out before the current round of repairs, when some shims under the motor might have been lost, leading to the original u joint being misaligned and consequently failing? If the new U joint as installed on the motor was floppy/flexing freely in both its joints, there is no problem with it, assuming there is no way to install it off center of the flywheel. Can we assume the motor turned over properly prior to installing it? If not, could it have a slightly bent crankshaft or connecting rod causing binding at certain positions? We are all assuming you correctly identified the U Joint as the problem, but I am not sure that is a reliable assumption. If the motor cranks without binding when not connected to the pump, and the U Joint flexes properly, then it seems that the only remaining choices are:
1. Elevation misalignment between the motor and hyd pump shafts, which the U joint isn't equipped to correct-- it can only fix angular misalignment. That might not be obvious when installing the motor as I expect there is some fighting involved in sliding the u joint onto the pump shaft, and elevation misalignment might not show up until the motor mounting bolts were tightened. Possibly loosening them might eliminate the problem and point toards a solution.
2. Bent hyd pump shaft--does it turn freely with the motor out?
3. Hyd pressure build-up when cranking--is the Aux control in the detent position with nothing attached, or are drive controls sticky and hence out of neutral position. It might be worth putting it on blocks if this seems likely so the wheels can turn freely, and double check the aux hyd control positioning.
4. Liquid in a cylinder. Fuel, or possibly blown head gasket allowing coolant pumping in and out of one cylinder.

Sorry but all of these except #3 & 4 require partially removing the motor again. . It would also be very helpful to have a more detailed description than "probably binding".

When it was being turned over it had an odd sound and a friend who is a mechanic said he thought it sounded like something was in a bind or too tight. Now the first time I put the engine back in the coupler slid right in and I had very little trouble lining up the engine mount holes. Then I found out the seal on the adapter on the pump needed replacing. This time the engine slid on but I had 2 engine bolts in but it was hard getting the other ones to line up. The mount's that came off originally was worn down and now the new ones are thick so I will try to take the washer out. Thank you for responding. Everything is appreciated

 

[oiu789]

When it was being turned over it had an odd sound and a friend who is a mechanic said he thought it sounded like something was in a bind or too tight. Now the first time I put the engine back in the coupler slid right in and I had very little trouble lining up the engine mount holes. Then I found out the seal on the adapter on the pump needed replacing. This time the engine slid on but I had 2 engine bolts in but it was hard getting the other ones to line up. The mount's that came off originally was worn down and now the new ones are thick so I will try to take the washer out. Thank you for responding. Everything is appreciated

What does the service and parts books say and show, washers or no washers? Some one in the past might have added the washers.

 

[Markle]

Mine had No washers or shims For engine height adjustment. Just rubber isolators. See pic.

 

[helpnotamechinic]

When it was being turned over it had an odd sound and a friend who is a mechanic said he thought it sounded like something was in a bind or too tight. Now the first time I put the engine back in the coupler slid right in and I had very little trouble lining up the engine mount holes. Then I found out the seal on the adapter on the pump needed replacing. This time the engine slid on but I had 2 engine bolts in but it was hard getting the other ones to line up. The mount's that came off originally was worn down and now the new ones are thick so I will try to take the washer out. Thank you for responding. Everything is appreciated

The ujoints came apart when I was barely moving, and they had never been any kind of work done before that I know of. I was putting the adapter back on the spline today and when I turned the shaft 360 degrees it looks like 3/4 th of the way around it goes off center. Like it's out of round. I don't know what to do? I don't have the money for bobcat to do anything.

You need to be specific about these shims, the universal does not use shims, the pump mounts do. The manual gives a distance from the bottom of the engine bay to the middle of the pump shaft. I don't remember the allowable limit, but i had in my head 1/4" was acceptable.

when I turn the shaft on the pump it looks like it's warped has I turn it. The adapter looks like it 3/4 of the way around it goes out of round. Is there any way I can do something to know if it's bent

 

[helpnotamechinic]

The ujoints came apart when I was barely moving, and they had never been any kind of work done before that I know of. I was putting the adapter back on the spline today and when I turned the shaft 360 degrees it looks like 3/4 th of the way around it goes off center. Like it's out of round. I don't know what to do? I don't have the money for bobcat to do anything.

when I turn the shaft on the pump it looks like it's warped has I turn it. The adapter looks like it 3/4 of the way around it goes out of round. Is there any way I can do something to know if it's bent

Even though I was barely moving when the ujoints came apart how likely is it that I would have bent the shaft?

 

[Markle]

Perhaps the splined adapter on the end is smooshed a bit. I would start with that. I would think that the force of the engine even at low rpm could bend things when the joint came apart. If the hyd pump shaft and or rotating group is bent…I've never had to take a pump unit out but I'm positive its doable, but not enjoyable. I feel your pain.

 

[helpnotamechinic]

Perhaps the splined adapter on the end is smooshed a bit. I would start with that. I would think that the force of the engine even at low rpm could bend things when the joint came apart. If the hyd pump shaft and or rotating group is bent…I've never had to take a pump unit out but I'm positive its doable, but not enjoyable. I feel your pain.

Perhaps the splined adapter on the end is smooshed a bit. I would start with that. I would think that the force of the engine even at low rpm could bend things when the joint came apart. If the hyd pump shaft and or rotating group is bent…I've never had to take a pump unit out but I'm positive its doable, but not enjoyable. I feel your pain.

Is there any way to check if it is indeed bent. Remember I'm no mechanic I just wondering if it's something that I can do

 

[Markle]

I don't know of a nontechnical way other than what you've already done. When we rebuild engines we use a dial indicator to check for bent or out of round cams, cranks etc. there are you tube videos on how to use a dial indicator. If you can mount the dial indicator solidly to contact your rotating part, and still turn the rotating shaft without bumping the dial indicator…it can achieve what you are asking…"how to check if it is indeed bent"

 

[haymaker]

I don't know of a nontechnical way other than what you've already done. When we rebuild engines we use a dial indicator to check for bent or out of round cams, cranks etc. there are you tube videos on how to use a dial indicator. If you can mount the dial indicator solidly to contact your rotating part, and still turn the rotating shaft without bumping the dial indicator…it can achieve what you are asking…"how to check if it is indeed bent"

An indicator will tell you if the shaft is running true or out of round.
That could mean the shaft is bent a bad bearing or several other things.
It will mean it is probably going to have to come apart to repair.
Make sure the end is not "smooshed" as markle suggested. That sometimes can make it look like it is bent to the naked eye.
Good luck.

 

[helpnotamechinic]

An indicator will tell you if the shaft is running true or out of round.
That could mean the shaft is bent a bad bearing or several other things.
It will mean it is probably going to have to come apart to repair.
Make sure the end is not "smooshed" as markle suggested. That sometimes can make it look like it is bent to the naked eye.
Good luck.

Thank you

 

[helpnotamechinic]

Thank you

I don't understand smooshed? I had a operator tell me that what I see when I am turning the pump is how it works when connected to the motor as the flywheel rotates and that as I was moving at a crawl when the ujoint went out he didn't think I could have bent the shaft

 

[helpnotamechinic]

Could that fluid be coming from the pressure fitting adapter? It looks like it has been hit from the top and is bent at the threads.

I ordered a new one and I have no idea how it got bent. I have it sitting outside an well family member is not a good person so I'm betting it was damaged intentionally

 

[Markle]

I don't understand smooshed? I had a operator tell me that what I see when I am turning the pump is how it works when connected to the motor as the flywheel rotates and that as I was moving at a crawl when the ujoint went out he didn't think I could have bent the shaft

"Smooshed" = smashed or otherwise not round any longer…I was referring to the spline on the hyd pump input shaft.

 

[helpnotamechinic]

T

"Smooshed" = smashed or otherwise not round any longer…I was referring to the spline on the hyd pump input shaft.

hank you. Do you have any idea how come when I turn the spline I'm getting a little fluid leaking out below the adapter? I already put in the new seal? I am about ready to put the engine in and hope that everything is good because I have not got any help from Bobcat and they don't get I don't have 2000 laying around to have them look at it. Thank you