No left hand steering 420C, how remove big plug under final?

[BigV]

I had managed, through following the FSM, to adjust the left had steering on my old 420C. I had great right hand steering but no left hand steering.

I took and pushed out the throwout bearing towards the steering clutch, until it engaged and I then pulled back the steering handle, wired it in place, and tightened down on the adjusting cap screw. I tightened up the brake unit and then I tried it. The brake was engaging first, so I had to back it off.

Finally, I got it right, it was weaker than the right, but it seemed to be okay. I tried adjusting some more, and it got stronger, so I said I can live with this.

I built a small creek dam with it. I rescued a Bobcat with it. I built a fording spot to cross the creek and access the timber I was cutting. I built a three tree skid unit, and I used it for skidding and loading.

I went to skid out a rolling car chassis for cash, and I felt kind of a pop making a left hand turn.

It just bogged down the engine and it died.

I tried readjusting, but to no avail.

It is like you pull on the handle, the clutch engages, and then something causes it to pop out of engagement and it lets loose.

Dunno if that makes sense or not, but that is what it feels and looks like it does, is that engages and then it doesn't hold and pops out of engagement.

I readjusted it, tightened the brake, but it still does the same thing.

I can see the band if I look at the right angle, and the band's liner looks okay, there seemed to have been plenty of adjustment at first, still seems to be some, but it won't tighten any more.

Is there some part that could cause the steering to suddenly disengage ?

I've never had this one apart, so even if I take it apart I'm not sure what to look for.

At this point, I don't think that if you disconnect the brake synchronizer on the clutch pedal, that pulling back on the left hand steering clutch would even stop the left side. It would just result in the engine bogging down.

I know I will have to take it apart and look, but what do I look for ? A broken spring ? A broken rod ? Lining ?

I started up the hill towards the barn where I've got the gantry crane, but for whatever reason, the crawler just died on me on the crest of the hill. So I've got that to look forward too, to.

Also: On the bottom of the final drive unit, there is a plug that takes a 3/8" square breaker bar to open, there is a plug that has a square 3/8" head, and then there is a plug that has a square opening that is bigger than 3/8" and smaller than 1/2". This is on the very bottom of the final drive.

Thank you all for reading, thank you all for your help. Your spending your time this way means a lot to me. Thanks again. Bye.

[DukeofDeere]

Sounds to me you have maxed out your adjustment.
Look in the top with the cover off and watch what happens.
Sounds like time to rebuild that side.
Back the brake band off some and you may be able to drive it farther.
Plugs may need some juice, heat and patients. Square socket gets the out.
Have made a square stock to get the other in.

Happy wrenching,
Duke

[Lavoy]

Popping is normally what you hear when the clutch is grossly out of adjustment. How far is your handle coming back from the dash? It should be only 3" or so at full brake lockup. A couple inches more than that, and you will be getting close to running the balls up out of their cups and that is where the popping noise comes from.
Lavoy

[BigV]

Popping is normally what you hear when the clutch is grossly out of adjustment. How far is your handle coming back from the dash? It should be only 3" or so at full brake lockup. A couple inches more than that, and you will be getting close to running the balls up out of their cups and that is where the popping noise comes from.
Lavoy

When you say grossly out of adjustment, and given I've tried doing the service procedure, should I just take it apart and see ?

[Lavoy]

No, usually brake band is too loose, and brake band actuating screw is too far out. Brake should start applying when tip of steering lever is 1 5/8" back from rest. If the threaded rod between steering lever shaft and throwout bearing is worn or too long, this becomes difficult to impossible, so in that case, yes, probably pull the final.
Lavoy