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Clutch problem

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=203176
Printed Date: 28 Sep 2024 at 11:19am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com


Topic: Clutch problem
Posted By: Freewheeling
Subject: Clutch problem
Date Posted: 12 Sep 2024 at 11:38pm
I resurfaced and balanced the flywheel on my IB, installed a new clutch disk, pressure plate, and throwout bearing. The bearing yoke and tube are in good shape and  lubed. The pressure plate fingers are adjusted to 1/4". The pedal rod is adjusted to just bottom on the stop when engaged.  However, even through the fingers are depressed, the pressure plate continues to spin.  Any ideas before I split this critter again?  



Replies:
Posted By: WF owner
Date Posted: 13 Sep 2024 at 5:10am
Is the clutch disc in backwards? It's very easy to do that (from experience).


Posted By: Jim.ME
Date Posted: 13 Sep 2024 at 7:12am
The pressure plate is bolted to the flywheel, it spins when the engine is running.  Pushing the clutch pedal does not stop the pressure plate.

When the throwout bearing pushes the pressure plate fingers, the pressure plate is supposed to release the clamping force on the clutch disc.  The clutch disc, between the pressure plate and flywheel, is what is supposed to stop spinning

If the clutch is not disengaging the clutch disc may have been installed backwards, as has been posted.  Not an uncommon happening.


Posted By: Freewheeling
Date Posted: 13 Sep 2024 at 7:57am
Well duh, what was I thinking.  Of course its bolted to the flywheel.  Brain doesn't engage sometimes when I'm pissed.  Can't believe i put the disk in backwards but it's been one of those weeks. I'll find out this morning.  



Posted By: Freewheeling
Date Posted: 13 Sep 2024 at 11:40am
The disk was installed correctly. Everything looked good.  I remembered seeing a spec that called for 1 13/16 between the face of the disk and the contact point on the fingers.  Not even close.  With the adjustment screws all the way I get 1 3/8. That would explain why I'm not getting separation.


Posted By: Freewheeling
Date Posted: 13 Sep 2024 at 10:34pm
I called Kentucky Clutch and they said I should add a washer under each pressure plate bolt or replace the finger bolts with longer ones.  Moral of the story - Don't just adjust the fingers to 1/4". Verify that the initial setting on your reman pressure plate is correct.


Posted By: Eric B
Date Posted: 14 Sep 2024 at 12:42am
To be able to work in the access hole for clutch adjustment is very tricky to say the least. I have adjusted the clutch on several and I'm not really sure where you are making the 1/4" measurement? When you have good adjustment you only have a few thousands of an inch between the fingers and the throw out bearing. Please share your success story once you get the clutch working right, thanks.

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Currently- WD,WC,3WF's,2 D14's B. Previously- I 600,TL745,200,FL9,FR12,H3,816 LBH. Earth has no sorrow that Heaven cannot heal!


Posted By: PaulB
Date Posted: 14 Sep 2024 at 6:42am
In all the years I've pulled CA tractors, I've done a lot of engine switching. I found that matching the distance from the rear of the engine block to the throwout finger tips resulted in better clutch function than measuring the distance to the tips from the driving disc. This would be because of the variables involved: resurface flywheel, resurfaced driving member in the pressure plate and varying driving discs thicknesses. To this end, I made a jig for adjusting the fingers, it make a one time installation.



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If it was fun to pull in LOW gear, I could have a John Deere.
Real pullers don't have speed limits.
If you can't make it GO... make it SHINY


Posted By: Alvin M
Date Posted: 14 Sep 2024 at 7:52am
Make sure the bushing in the flywheel is lubed good if not the shaft will turn


Posted By: Freewheeling
Date Posted: 14 Sep 2024 at 10:00am
The 1/4" is the space between the throwout bearing and the contact point on the fingers, I have a 1/4" square bar bent to allow it to fit through the hole.  My I&T shop manual says to just adjust the fingers to 1/4" with each of the 3 being within .010 of each other. (Good luck with that.) Then the clutch rod to where it has 3 threads showing.  Since the rod that was in mine was a cobbled job, that wasn't reliable.  

My Allis Chalmers service manual says to adjust the fingers to 1 13/16 from the clutch disk to the contact point and then adjust the clutch pedal to get the 1/4 ".  It states there are usually 1-2 threads showing and to make sure the pedal hts the stop on the torque tube.  The trick with getting an accurate 1 13/16" is to place the clutch disk where there is not a spring under the finger.  


Posted By: Freewheeling
Date Posted: 14 Sep 2024 at 10:02am
You should market this! Thumbs Up


Posted By: Tracy Martin TN
Date Posted: 16 Sep 2024 at 6:42pm
I have a jig similar to Paul's. I also have a fixture to set the clearance between fingers and throw out bearing while tractor is split, no guess work. HTH Tracy

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No greater gift than healthy grandkids!


Posted By: HudCo
Date Posted: 16 Sep 2024 at 8:25pm
the wick in the end of the crankshaft didnt get pulled out to far that keep it spinning 


Posted By: Freewheeling
Date Posted: 16 Sep 2024 at 8:59pm
Nope.  I installed an oilite bushing instead of a wick.



Posted By: Freewheeling
Date Posted: 16 Sep 2024 at 9:08pm
What's the distance from the block to the finger?  


Posted By: Freewheeling
Date Posted: 24 Sep 2024 at 9:14am
The saga continues. I tried a longer 3/8 UNF bolt in the fingers and found that where the head on the existing bolts are 1/2", the head on the standard bolt is 9/16" which would make adjusting the fingers even more difficult once the clutch is enclosed since both the bolt head and jam nut woud be the same size. The 1/2" head allows a 9/16" socket over it.  Also, the standard bolt should probably be rounded on the end like the originals since there are sharp edges. 

I'm thinking that the flywheel has probably been resurfaced many times over the past 70 years. If the reman disk & plate are to spec, then the flywheel is the logical variable. The new ring gear I put on the flywheel extends .065" from the flywheel. Is that excessive? 

It appears that adding washers between the pressure plate and the flywheel is the better option.  I don't understand all the geometry of the pressure plate but will washers extend the fingers any more than their thickness?  I checked the thickness of a couple 5/16 gr.8 black coated washers and they are .058-.059.  Is that enough to give me another 5/16" on the fingers?  I see that McMaster-Carr has a USS 5/16" Grade 8 oversized black washer @ .100 +/- .10.  I'm thinking I should avoid the wider tolerances (+/- .020) of zinc washers.

Thoughts?




Posted By: SteveM C/IL
Date Posted: 25 Sep 2024 at 12:48pm
I don't know if there's a way position the throw out brg fwd but you need the pressure plate bolted to the flywheel. Your idea will reduce clamping force if it even works.


Posted By: RedHeeler79
Date Posted: 25 Sep 2024 at 1:26pm
In my experience, yes, the washers will affect the fingers distance much more than the thickness of the washer. Trial and error on this method. As Steve pointed out, it also affects the clamping force. I don’t think you’re going to have an issue to that end, but i would not go over .100” thick for sure. I had about .060” washers under a clutch pressure plate before and got the proper gap at the release bearing that way. Flywheel has been machined several times, apparently


Posted By: Freewheeling
Date Posted: 25 Sep 2024 at 6:41pm
I installed the .058-.059 washers and got the 1 13/16 but there is less than 1 turn on the jam nut. I'm debating whether to leave these or go to a slightly thicker version. There's not much adjustment left.  The manual says to adjust the clutch pedel to get the 1/4" between the  t/o bearing and the fingers after establishing the 1 13/16 but with the course thread on the rod I'm thinkig I may have to fine tune the fingers.  I would hate to have to split this tractor a 3rd time.


Posted By: Freewheeling
Date Posted: 28 Sep 2024 at 6:40am
I left the pressure plate with the .058 washers, set the fingers at 1 13/16, and put the tractor back together. Now I have zero (0) clearance between the T/O bearing and the fingers.  WTF?   I'm going to leave it as-is, back off the fingers to 1/4",and see what happens.    


Posted By: RedHeeler79
Date Posted: 28 Sep 2024 at 7:02am
It sounds like you’re at the final step in which you adjust the clutch rod to achieve the 1/4” gap between clutch fingers and the throw-out bearing… per the manual. As long as you have enough threads on the rod to make this happen, I would think you should be good to go



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