7040 pressure plate conundrum
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=206765
Printed Date: 18 May 2025 at 2:58pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 7040 pressure plate conundrum
Posted By: Mattman
Subject: 7040 pressure plate conundrum
Date Posted: 18 May 2025 at 8:00am
| I did my research...... So I thought. I split my 7040 powershift this morning (serial 6146). I had purchased a torque limiter disc ( Agco 70268718 4 pad) which is what Agco says I should be using. I also bought a second belleville washer to add some holding strength. I pulled it apart today to find it has a pressure plate with blue springs and a 6 pad disc. I have a couple questions. Has anyone ever added washers or put in heavier springs to acheive a better hold on a pressure plate TL? Is the 4 pad disc compatible? I'm assuming it is from past forum chatter about the advantages of a 4 pad vs a 6 pad. Is anyone interested in my belleville washer? I'm actually kind of pleased to find a pressure plate. It seems like a better design to me. Am I wrong? |
Replies:
Posted By: Mattman
Date Posted: 18 May 2025 at 8:17am
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Posted By: Alex09(WI)
Date Posted: 18 May 2025 at 10:21am
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I don't have much experience with the 7000/8000 tractors and if I'm wrong someone will correct me and we'll both learn. I don't think a 2nd belleville washer would have worked in the first place. When the 1st washer is compressed, the gap is less than the thickness of the washer. Ergo, if you added a 2nd washer there would be no room for the washer to flex when the torque limited disc slips. It would be bottomed out, negating the purpose of the torque limited in the first place. ------------- www.awtractor.com A&W TRACTOR 920-598-1287 KEEPING ALLIS-CHALMERS IN THE FIELDS THROUGH THE 21ST CENTURY |
Posted By: DrAllis
Date Posted: 18 May 2025 at 10:53am
| I think I may have been among the first to "double-spring" the Power Director type torque limiter back in late 1976 on a strong 7080 tractor. You must use longer grade 8 bolts (at least 1/4" longer/maybe 1/2" longer) and add a 1/2" lock washer under the stool to make up for the second Belleville pressure spring thickness. It works good and can still slip a little bit under severe shock loads. The early Power Shift transmissions used the coil spring design flywheel and pressure plate design because they were concerned (in prototypes ) that they may need release fingers and a throw out bearing to uncouple the engine for easier severe cold weather starting. As it turned out, that feature was really never needed, so they dropped that design and made both transmissions the same torque limiter style. If that was my 7040 pressure plate, and knowing what your intentions are, I'd buy 6 Gleaner combine feeder beater slip clutch springs (M2-L2) and stick them inside of six of the existing springs, equally spaced. The Gleaner springs might have to be shortened a bit with a cutting disc, and you'd have to measure that, but it will make things so they don't slip with more HP. |