Fx28 Front end issues?

[jgendr]

Ok I have had my fx28D for about 2 years now and work the heck out of it. Well I have had my first issue with the old girl!!!! I was out disking in the field when all of a sudden I started hearing some popping in the front end. Yup you guessed it The 4wd was gone! I stopped immediately and shifted out of 4wd made my last pass and parked her. It's dark now so I haven't had a chance to really look at the situation.


Ok guru's Clue me in on how bad of a job will it be to rebuild the front end? And where can I get parts if needed " I know I know Erine and hoye's, Hoyes don't have a lot on line but I'll call them and erinie first part of next week .

If I'm gonna rebuild it I'm going all the way, New bushings, seals and maybe bearings to be safe.



Pipe in with any help you can, Thanks in advanced

 

[jgendr]

Everything in the front end seems to be functioning ie Diff, spiders, and ring and pinion. there is some slop (ie ring and pinion lash) in the ring and pinion if you try to rock the tires in the same direction forward and back, but smooth differential freewheeling in oposite directions. This leads me to believe that either a cv joint in the drive shafts ( if it has them) may be popping under load. or the engagement gear in the transmission ( god I hope not ). It definately sounds to be up front and i can feel the 4wd shift lever jump when the poping ocurrs.


Won't know more untill I pull the axel and check the front end drive shaft. can anybody tell me if I undue the 6 bolts on the front axel that holds it to the frame will it slide out from the drive shaft or is there a trick to removing the front axel?

 

[Kays Supply]

Start with the drive shaft. It is the easiest to check. Don't trear into the hard things first. There is a cover over it. It will slide back and expose the U-joint. You can then see how it comes apart to take it out.

 

[jgendr]

ok Pulled the drive shaft out this morning and BAM!!! found the problem!

Question is what is the best CORRECT way to fix it! See Pics.


The out put shaft of the transmission where the ball bearing/cv joint connects is where it was slippin. the front seems fine !

 

[jhunt1x]

You emailed me offline about this and your problem was exactly like mine. Your damage looks no worse than mine was. I sent you a couple of pictures of mine in your email. You can see my pictures below. It's hard to tell them from yours - except your pictures are much better. Mine were taken with a cell phone.

I was able to fix mine with no parts needed, just some grinding and a shim under the tension spring. Basically I ground off the damaged part of the transmission shaft, removed the spacer from that shaft and put it (or something with the same thickness) under the spring on the front of the driveshaft. This allowed the collar to go further back on the transmission shaft to get the bearings back onto good splines, and the spacer under the tension spring assured that the coupler would stay in place. It has been a good while since I fixed mine and it still works perfectly. I have not been gentle with it.

In the future, only use 4wd when absolutely necessary. Remove the loader when not in use to gain rear wheel traction.

When reassembling, use moly paste grease to hold the bearings in place. This is not a high friction joint but it is an extreme pressure joint, which is what the moly grease is used for. If your local tractor supply place can't supply it, try a Honda motorcycle dealership. They use it to grease the splines in shaft-drive motorcycle driveshafts and wheels. You can get a lifetime supply for less than $20.

I do not recommend using wheel bearing grease or any other type grease in this joint. Use a grease recommended for a coupling or a CV joint. It has very different properties than bearing grease.

 

[jgendr]

Thanks for the great resopnce, I'm gonna follow your steps but with a slight addition. I'm thinking for trying to build the grooves back up with the mig welder and work them back down. I think if I take it slow and pay attention to the original dimentions I can get it all worked back in shape. I'll use a die grinder with a carbide bit to recut the grooves. I'll take pics as I go along so if anybody else has the same issues they can see how I fixed it.

 

[MJPetersen]

1) If you weld this shaft you will have to have it out of the transmission. 2) A shaft of that nature is a hardened, ground, and polished piece; welding on it will be difficult and may destroy the hardening; a die grinder will never get the precision necessary for long life, and will never get the polished smoothness of the original. I will let the experts make further comments on that. CV joints are pretty fussy things.

I once did what you are talking about doing, but on a shaft that it was only a half moon key way and the shaft was not hardened and polished. It worked--for how long I do not know the machine was not mine, but the companiy's and they asked (told) me to do it.

I like the option of simply shortening the shaft and pushing the CV further onto the shaft. That seems to me to be a very good idea. This seems to be a weakness of the Fx series maybe?

It has got to be encouraging that someone else has been there and come out successful.
Mike

 

[jgendr]

I see what you mean by the tempering in the shaft. I was just worried about the possibility of bottoming out on the caseing. a 1/4 inch shouldn't effect the front coupling because it's a slip joint. jhunt said just add the 1/4 of spacer behind the spring to keep the factory tension.

 

[jhunt1x]

As we discussed on the phone, my fix only lasted for a while and then stripped out again. There is a separate thread about fixing the 4wd in a Jinma 284 which sounds like what we need to do. Basically they replaced the ball bearings with rollers so they contact the full length of the output shaft instead of a tiny portion of it.

That's my next fix, when I can find the time to do it. I'm going to use some Grade 5 or possibly Grade 8 smooth bolts for the rollers. My concern is making this the bullet-proof part of the joint also makes some other part of the drive train into the failure-prone part. It would seem to be desirable to have some bolts wear out every few years rather than a hardened shaft or coupler.