JD 2320 Driveshaft U-Joint

[KennyG]

Under the principle that you should share your mistakes in case others are as careless as you, I just did a little unexpected work on my 2010 JD 2320. Those of you who have these machines know about the infamous engine driveshaft universal joints. I have been scrupulous in greasing mine and the tractor now has 820 hours. I was servicing it in preparation for installing my Original Tractor Cab for the winter and had an attention lapse. I was greasing the joints and, as usual I was using a large screwdriver in the rear yoke to rotate the shaft (I know it isn't the preferred way to do it but it's what I've always done.) I wasn't paying attention and stuck the screwdriver in the front side of the yoke instead of the back and broke the grease zerk off.

After a bit of a tantrum I took the joint apart and found it came apart easily because there was just enough movement of the yoke on the transmission spline to separate it. I extracted the broken zerk, put a new one in and it went back together fairly easily.



After this, I thought about what I would have done if I had messed up the joint. With a little searching it seems that the Moog 410 U-joint is the correct replacement. It seems to differ from the original in that it has the zerk fitted to an end cap.

https://www.amazon.com/Moog-410-Universal-Joint/dp/B008M2FPOE

(Summit has it cheaper but the Amazon site has a better picture.) This got me thinking that using the Moog part would make greasing this a lot easier. Has anyone done this? To replace the front joint, it appears there are bolts that attach a flange to the flywheel. Is this how the shaft is removed? It would seem the rear joint would still have to be separated to get enough clearance to pull the shaft out.

With over 800 hours my u-joints are in very good condition and I usually don't do proactive part replacement (I'm more of a run to failure type) but the potential to make the lubrication much easier has me thinking of changing them out at the next service. Any opinions on this?

 

[Wvanatti]

I replaced my u joints with the moog 410 years ago on my 2305. Love having the zerk on the cap.
Couple problems I ran into. With the new 410 joints, I had to grind off 1/16th of an inch on each post in order to get the retainer C clips to fit in there slot. On the front, the zerk broke off a few times. Had to file 1/8th off the frame so when it spun, it made no contact. Not sure if you would have to do any of the above for your model. It is so nice and easy to grease both, even with the mower deck on. Hope the info helps. Good luck.

 

[KennyG]

When you say 1/16 off the post, do you mean the cross piece of the U-Joint? If I remember correctly, I've got lots of clearance to the frame. I'll have to check it if I go this route. Thanks for the experience.

How difficult was it to remove the front of the driveshaft (I think a C-clip and pin)?

 

[Wvanatti]

When you say 1/16 off the post, do you mean the cross piece of the U-Joint? If I remember correctly, I've got lots of clearance to the frame. I'll have to check it if I go this route. Thanks for the experience.

How difficult was it to remove the front of the driveshaft (I think a C-clip and pin)?

Yes. Took the caps off the u joint post, ground 1/16th off each one (4)
The assembled. I had tried to put it on as received, couldn’t get caps on far enough.
As for removal on 2305. On the front, took snap ring- moved out of slot. Long punch- drove pin out ( 2). Ones inside the other. ( roll pin). Then slide shaft to rear. Pull front down. Then pull off the back. Again. Do a check. May not have to grind any off for your model with the 410.

 

[KennyG]

I ordered two u-joints. I'll replace them next spring when I do my regular maintenance. I looked at a parts diagram. I wonder why they have one pin inside the other?

 

[zzvyb6]

Just curious: What is the failure mode of the U-joints in these tractors? Is it rotational torque variation that wears them out ? or is it push / pull force variation that breaks them ?

If a rotation induce failure, it would make sense to move the motor to a location that better aligns the input and output yokes. If this can't be done and the input and output yokes are NOT co-axial (the xmission input and crank shaft do not lie along parallel lines, then a phase angle should be installed in this shaft to minimize torque variation. Of course, if the U-joint yokes aren't aligned for CV operation, then this is the cause of major torque variation with a major vibration peaking at some rpm.

If the motor has a lot of Fore/Aft motion [rubber engine mounts], then a well lubricated spline is supposed to be free to slide. Just about all splines are locked up under applied torque conditions and only slide at constant power levels.

My F935 uses a rubber isolator instead of the 2nd U-joint to absorb torque variations AND manage the Fore/Aft and pitch movements of the engine during operation. The engine is rubber mounted and moves A LOT, especially during idle.

I was wondering if this type of shaft configuration would help 'problems' with U-joint failure on these 2320 machines. I had to replace my isolator once because of engine heat drying out the rubber coupling, but the kind of cracking in this part's rubber element told me that the shaft angle variation was a problem (probably due to pitching of the 3 cylinder diesel at low rpms).

Just wondering. This topic used to be in my line of work. I don't think I've ever lubed the single yoke on the prop shaft on my 935. Wouldn't be surprized if it has no Zerk. Now I'll have to crawl under it to see or check the parts manual. Trouble is, once I get under there, I'll probably never be able to extricate myself, especially with 3 large black dogs wondering how they can help me...

 

[pmsmechanic]

zzvyb6 I also have an F-935. I would check your motor mounts. On my machine the radiator,fan and motor mounts were replaced just before I bought the machine because of excessive movement.

 

[KennyG]

The failure mode for the JD u-joints seems to be wear of the joint bearings from lack of lubrication. There's been a good bit of inconclusive discussion here about why these need to be greased instead of being sealed, but it's clear that, without maintenance, they have a limited life. The shaft doesn't have an extreme angle, it requires the joints because the engine is rubber mounted instead of solid mount. With proper maintenance it's a pretty reliable design, it's just that greasing the zerks in the factory configuration is quite difficult. After 820 hours the joints are in good condition and the splines slide easily. I'm just trying to cut an hour out of the maintenance routine.

 

[Wvanatti]

I ordered two u-joints. I'll replace them next spring when I do my regular maintenance. I looked at a parts diagram. I wonder why they have one pin inside the other?

Know idea... it would make sense if it didn’t have the snap ring over it to prevent coming out. Somebody probably decide to go overkill ensuring it stayed in place. So much so- they over looked no one could access the zerks. Ugh