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: 22 Nov 2024 at 10:11pm
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. ------------- 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. ------------- 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! 
|
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 ------------- 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 |
Posted By: Freewheeling
Date Posted: 28 Sep 2024 at 4:09pm
|
I adjusted the fingers to 1/4". Also adjusted the clutch rod so there is only 1/4" free travel before making contact. With the tractor at low idle and the pedal all the way to the stop, it takes 30-40 seconds to get into low gear with no or minimal grinding. I've never encountered this on my other tractors. The rod is backed out to where there are no threads showing. It's longer than the one that was in it but that one was a cobble job. I could make another longer rod but I don't think it will help given the minimum free travel and the fact that it takes a lot of pressure to bottom out the pedal. I believe the service manual says that with finger/bearing gap of 1/4" there should be 1 1/4" of free pedal travel. I didn't measure at the pedal but I'm sure it's less. I have no clue where to go from here.  |
Posted By: Les Kerf
Date Posted: 29 Sep 2024 at 7:43am
| Well, at the risk of sounding like Captain Obvious, it would appear that something isn't quite right Since going 'by the book' isn't working out, try adjusting everything down to bare minimum clearance so as to shove the clutch levers as far as possible. There are really only two possibilities, either the clutch isn't being pushed far enough to fully release, or the pilot bushing is dragging. I suspect the latter. |
Posted By: SteveM C/IL
Date Posted: 29 Sep 2024 at 1:40pm
| Could it be something to do with spacing pressure plate away from flywheel and it messes up the geometry of how it releases? |
Posted By: Freewheeling
Date Posted: 30 Sep 2024 at 3:19pm
|
Never considered the bushing.I installed a new one and lightly greased it. I guess I could split the tractor one more time and lube the hell out it. |
Posted By: Alvin M
Date Posted: 30 Sep 2024 at 4:25pm
| If you used a punch to drive the bushing in it might have nick on the end I always used a bushing driver if it is use a round file clean the inner edge |
Posted By: Freewheeling
Date Posted: 30 Sep 2024 at 4:49pm
| I had the machine shop press in the bushing when I had the flywheel resurfaced. It was an Oilite bushing so I didn't use a bunch of grease as I would with a regular bushing. |
Posted By: PaulB
Date Posted: 30 Sep 2024 at 5:53pm
There ya go, The machine shop could have possible deformed the bushing or it possible may not have the correct clearance for the stub on the end of the clutch shaft after the press fit into the flywheel. Whenever using NON-spec parts it is a MUST to make sure that they will do what is desired. Next time you split the tractor check the fit of the flywheel to the shaft. Maybe just ad a finger of grease in the bushing. ------------- 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 |
Freewheeling wrote:Posted By: Freewheeling
Date Posted: 30 Sep 2024 at 5:59pm
| I used 6 non-plated grade 5 washers that mic'd out at 057"-.059". I sent a photo of the assembly to Kentucky Clutch since they were the ones who suggested the washers. They said the fingers looked good. |
Posted By: PaulB
Date Posted: 30 Sep 2024 at 6:17pm
|
I've NEVER needed to put washers between a pressure plate and flywheel if all the components were properly rebuilt. That's a shade tree fix. However if your flywheel has been re surfaced way beyond a usable limit, that can create a dimension problem. I've done more engine installs in CA tractor than probably anyone. That's why I made the jig to get the setting right the first time. I've also found that for my service (mainly pulling tractors) 1/8" clearance works just fine instead of the service manual of 1/4".
------------- 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: Freewheeling
Date Posted: 30 Sep 2024 at 6:17pm
| I used a metal alignment tool when installing the disk and pressure plate and there was no binding. I'll try the plastic tool that Kentucky clutch sent and see how it fits. |
Posted By: Freewheeling
Date Posted: 30 Sep 2024 at 6:36pm
| I agree. The only thing I didn't replace was the flywheel.What is the spec for the flywheel? I couldn't fund it. I posted that the new ring gear extends .065" from the flywheel but didn't get any feedback. If it's the original I'm sure it's been resurfaced multiple times over it's 72 years. I looked for a new flywheel but all I came up with on the internet was used. I haven't checked with Agco. |
Posted By: Freewheeling
Date Posted: 01 Oct 2024 at 6:57pm
|
I split the tractor again and disassembled everything, flywheel included. First, new flywheels are not available anywhere includng Agco. Second the bushing doesn't appear to be deformed at all and a .868' alignment tool fits and turns without binding. I also slid the flywhel on the input shaft and it turns freely. However, since the flywheel is off I'm going to have it reemed to .879" as per the service manual. Does anyone know the diameter of the input shaft end that fits in the bushing? Hard to measure but mine appears to be .873". Also I would appreciate the minimum flywheel thickness. Mine is: Face to crank mount 1.418"; Face to step flange 1.596"-1.616" ; Face to the back side rough casting 1.227"-1.230. The throwout bearing moves approx. 1" so with 1/4" gap the fingers should compress 3/4" which would seem to be sufficient. Whadda-ya-tink? I have an auxiliary engine off a combine that I could pull the flywheel from but only as a last resort.
|
Posted By: Les Kerf
Date Posted: 03 Oct 2024 at 8:14am
Since I have only had a Model C apart three times Iam just guessing, but it seems to me that it should be adequate. For testing purposes even one thousand (0.001") is enough. I still suspect that oilite bushing is a bit tight and needs some grease. |
Posted By: Freewheeling
Date Posted: 03 Oct 2024 at 4:30pm
|
I measured
the bushing again with a caliper and with a telescoping gage and found it is.874” -
.875” and within spec per replacement
bushings. Nevertheless, I ran a hone
in the bushing and finished it with 600 grit wet-and-dry. I measured the input shaft again as best I could and got .871" -.873". I have not been able to find a spec for the shaft end. So there is .004"_ .001" clearance between the bushing and the shaft.c for the shaft end. I'm wondering if that's too tight. Yesterdays Tractors has a bushing with a .883 ID for B, C, IB. They couldn't confirm that it was the correct size and told me they have multiple souces for the bushing and that some are .875" ID. I'm checking with AGCO. The throwout bearing moves
forward 1” with the clutch rod having 1/4" free travel. With a 1/4” gap until it engages the fingers, that means the
bearing can move the fingers ¾”. Per Kentucky Clutch, the fingers only have to move half of that
or 3/8”.
|
Posted By: Les Kerf
Date Posted: 03 Oct 2024 at 6:30pm
0.010" clearance is not too much, I would prefer to not have more than 0.020" though. |
Posted By: Freewheeling
Date Posted: 04 Oct 2024 at 7:05am
| Note that it's not .010 but rather .001. Like I said it's difficult to measure the shaft but but I'm pretty confident in my findings. There are some minor scratches on the shaft but I've smoothed it with 600 grit and don't believe they would cause binding. |