Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

AC 620 Drive Clutch ,Front Axle and More Questions


620Doc

Recommended Posts

I have the motor out of my 620 to repair the starter. I have been following the "Kicking around engine ideas for the 4040" thread below. In a post by D-17 Dave on 01/04/09, he suggested inspecting the clutch drive bearings. It does seem to make some noise when the clutch is engaged and quiets when the clutch is disengaged. My question is, is there a way to inspect the bearings or should they just be replaced? Same question with the drive belts. He also mentioned "tightening up the front axle." I'm interested in what to look for and how to tighten it up. I must add that this site has been an outstanding resource for me. It has helped me immensely in keeping my old Allis-Chalmers in running order. Thank you in advance, gentlemen, for your kind help.
Link to comment
Share on other sites

What A lot of guys do, including myself, is to weld some plates behind the front axle. This will keep it from pivoting from front to back when you move the wheel. I think I welded 1/4" plates on my last Powermax. On the front PTO, I would think the bearing would make most noise when disengaged. On the machines I had, both had worn bearings on the pto clutch.
Link to comment
Share on other sites

The foot clutch bearings there are 2 of them in the cast mounting, I have had good luck in just taking the nut off and taping them out toward the back of the tractor. Some need to be taken to a press to get out, so watch the shims if you unbolt it to take it out of the tractor to press. The are nothing more than lawn mower arbor bearings.
Link to comment
Share on other sites

The bearing on the clutch only spins when the clutch is dis-engaged. ie, the crankshaft turns but the pulley does not. An old, dry bearing will make a lot of noise say when you have no belt on the clutch and shut the engine off, the pulley will free wheel till it looses it's momentum and you will here the noise very prevalent without the engine running then. Most of the time you don't realise how worn and noisy they are till they are replaced. You need to pay attention to the same bearing in the rear pto if so equipped and as Levi mentioned, the clutch bearings. The front axle pivot bushings wear and let the front axle flop around. The torque from the drag link pushing forward and backward doesn't help either. The best thing to do is to fix the bushings properly first. Replacing the bushings and pivot bolts will help a lot but will not likely last very long as the pivots were too close together to start with. Small design flaw. What most do is after repairing the bushings is to weld a couple of 1/4" plates a few inches long inside of the frame channel where the axle rests. When you place the axle back into the tractor be sure to shim the bushings to match the new plates and tighten the pivot bolts and lock them. This will last a long time and not allow all the load of the front axle to be put solely on the bushings.
Link to comment
Share on other sites

Thank you D-17 Dave. I have to say that, after several years of watching you give input on matters such as this, you are probably considered the ABSOLUTE WORLD EXPERT for advise on large frame Allis-Chalmers/Simplicity tractors. Keep up the great work.
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...