Pulling Final Drive from JD350 w/ pix

[p0g0]

One can pull the final drive and repair a failed steering clutch on a JD350 with less effort than it might first appear. I am working up a full howto with pictures here: http://www.appal.org/webnewspro/140922658578100.shtml

Once I get the brake drum resurfaced, I'll do the rebuild pix too, so stay tuned.

[DrLoch]

Nice writeup and pictures, keep sending them. One other question/statement, please tell me that the galvanized pipe and fittings I see are on the return/low pressure side.......

[p0g0]

For the most part those are return lines, but for the top frontmost two sections. The front plumbing and 3 valve set were added on in 1972, and have been no trouble. The valves have run hitched equipment like a log loader, or a crane without any unusual flaws, and the piping has outlasted all the hoses. This is a private machine, mostly used for logging, farm construction and road work.

[jthornton]

Good write up and glad to be able to see the photos. I need to change my brake band bolts in my 350 and seeing the inside with the brake band in place helps.

Thanks
JT

[original possum]

Good write-up but I would add a step. After the final is slid out on the rods there is enough room to reach in and shove the shaft into the ring gear carrier. After that, alignment and protection of the TO sleeve and seal are moot. On assembly, put the shaft in first.

[p0g0]

original possum: You are right about pulling the drive shaft free of the final drive. There is room, tho in my case the shaft was tight at the pilot bearing so I didn't fight it loose. If that shaft stays with the bulldozer, the risk of damaging throwout bearing carrier tube is nil, as you observed.

I have written up the rebuild with photos here: http://www.appal.org/webnewspro/14126839842412.shtml

Refinishing the brake drum has proven to be ideal and this rebuild is a complete success.

[wizner85]

Anyone have any idea the point of the retaining clip on the hub? I just put mine in today on the wrong side and installed it, bc book doesn't mention this correctly........
Back apart it comes.....

So do you need the retaining clip on the hub?

[lurch85]

the only thing i would ask, is maybe a note to give a tip about reassembly.

I had a problem with needing the first clutch plate to be behind the large snap ring, as the problem wouldn't be apparent until having problems, pulling it apart again and finding broken clutch teeth. The manual I had did not state such an issue.

Because of the above... I have WAY more experience removing final drives than I would like....

[wizner85]

Im on pull number 3 for this side now. Put it all together first time with new clutches. Go to drive the thing, and it slips, immediately pull it back to the shop. (Only drove it about 50 feet). Pull the final apart (try #2) and the pressure plate springs are weak. checked everything, it looked okay, threw it all back together, and now clutches won't release. I know I did not put the clutch fiber and steel on the otherside of the retaining ring.

So - try number 3 today. Pull it all apart (which is easy now), change the fibers that I know I broke, because I was pushing some serious dirt and trying to get the clutches to release......
Put the fiber and steel in correct position and slam it back together. I've got this down to about 3 hours worth of work now.......

I replaced the other sides clutches and steels as well, and I'm having issues with the brake band now. I don't think I adjusted it right because the band mechanism isn't moving as it should. It was a new brake band I put in, so one would assume that isn't bad yet.....

[p0g0]

wizner85: If you look at the rebuild link I posted ( http://www.appal.org/webnewspro/14126839842412.shtml ), and examine the photos there, you will see this one ( http://www.appal.org/pix/jd350_1/pix_jd ... .jpeg.html ). It shows the jf350 final drive with the first fiber and steel plate INSIDE the hub and its clip. That is the RIGHT WAY to install them.

My JD350 tech manuals are wrong: they detail that all the fiber and steel plates lie on one side of the hub and clip. That is incorrect, and like you, I had the dealer mess it up, and have to take a couple of passes at the drive repair because of it.

To be repetative and clear, BEFORE you place the internal hub+clip into the brake drum, first place a fiber plate and a steel plate, and then hub and clip, and then the rest of the fiber & steel plates. If you bolted the whole mess down wrong, you'll likely break some fiber plates and may distend the clutch pressure plate.

I have not checked to see if John Deere ever repaired their technical service manual, but the one I have from the early 1980s is clearly incorrect, and I guess that reporting it to my local dealer in 1985 and making them eat a bill for bad service wasn't enough to get those facts passed upstream to JD inc.

You have my sympathy for the bad manual info. I wrote this R&R howto largely because the JD manual was a trap.

[p0g0]

wizner85:
Does actuating the steering lever ever bring the steering clutch brake adjusting screw into contact with the brake actuator (don't know the official name for that part). If not, you may have not gotten the pressure plate set right, and the clutch is releasing way too soon because the clutch pressure plate fingers are too high.

The only other notions that comes to mind are that the retaining pin has lost its cotter pin and slid into the wall, or you have over tightened the big detent bolt (right hand side of this photo, http://www.appal.org/pix/jd350_1/pix_jd ... .jpeg.html ). As well, there should be free play in the brake band that pulls up as you step on the brake pedal or engage the steering lever. Did the band bind on the drum as you installed it? A sharp rap with a light hammer or messing it about with a screwdriver or such might get that to unbind without having to take the final drive back off.

If you engage the foot pedal, can you see the brake actuator move on its gunnion pin?

[wizner85]

The right side clutch I messed up and fixed. I followed the steps you posted and the clutch releases properly, brake engages properly and steers to the right properly.

The left side brake isn't working quite so well. The piece the screw pushes down to engage the brake is down about half and inch too far.
I loosened the brake band, no brake engagement at all. I tighten brake band and it steers okay. If I could suck up that half inch, the brake band would engage properly. The screw bottomed out and the brake band is like new.
Should I buy a longer screw for this? Or is something else out of adjustment? Maybe pressure plate fingers are out too far?? Or I can adjust throw out bearing alittle closer to the fingers? Thoughts?
I don't want to Tare that side apart again......

[lurch85]

im too tired to think through this ALL the way... but is the arm that actuates the brake frozen to the shaft? (I had that problem too)

[p0g0]

wizner85:

I would not try a longer bolt, it might bend and be a bear to get back out without damage. I have tried that myself in the past, and it proved to be not much of a solution, even without the risk of bending the bolt. If you still want to try, be sure to find a hi grade bolt, say a 5 or 8. A regular softer bolt will be much more prone to bending.

It is plausible, if you have bolted the thing up with the fiber and steel plates all on one side of the hub clip, that you have spun the topmost lever on the post out of its correct position (or possibly the lower throwout bearing fork, and that would be Bigger Trouble, but it has a detent drilled into the post). The top lever is tied down to the post by a gimlet screw that bites the post. You might scribe a line so you can return the lever to the current position if this idea doesn't pan out. Loosen the gimlet, and repostion the lever on the post to where the brake screw can be properly adjusted. I have had to weld an additonal gimlet mount (a bit of pipe with a hole and welded on nut) on that lever to get mine to hold well after such a readjustment, but you may not need anything like that . You could use Permatex Stud Mount or the like if you don't want to weld anything to the lever.

Another thing I think may be wrong, and you'll ask others to see if they agree and consider the mechanics yourself too, is that the clutch pressure plate fingers are too far out. I'll guess that you did guage them, and if you got that right, this 2nd guess won't be correct. However, I think you can check that in situ. If you pull off the clutch adjuster off its ball stud (the threaded rig with the spring loaded clip at sits on the ball attached to the lever that turns the upright post that moves the throwout bearing fingers), I'll guess that you cannot rotate that lever & post enough to get into the adjustment range of the brake screw because the throwout bearing engages too soon, and the throwout bearing wont travel far enough to get into the brake adjustment zone. If that is the case, I think that means you have to readjust the pressure plate fingers so the clutch fork travels into the brake adjustment zone ( I hope this makes sense).

Others might have better ideas.

[wizner85]

Fixed the brake issue today. Pivot point was jammed somehow. The piece with two holes that connects the brake band to the actuator piece.
All is good now, and steers perfect both sides.