Tue Dec 17, 2013 8:48 am
I own and run a Farmall Super A and a Cub. Both have Rockford clutches. Plowing snow recently, the Rockford clutch was damaged and required replacement on the Super A. I replaced this tractor's clutch in 1992 with an "as-original" Rockford clutch so I know that these last about twenty-one years and provide about 2600 hours of life. I noticed during the summer that this clutch had run out of pedal adjustment...I mean that adjusting the clutch pedal to the correct free travel brought the throw-out bearing (TOB) carrier ears too close to the clutch pressure plate finger pivot tabs. When I would depress the pedal fully, the TOB ears would come into contact slightly with the tabs and result in a "ding-ding-ding" noise until I would let up on the pedal. I should have ordered parts and found time to make the replacement because breaking-down during a snow storm is very inconvenient.
I was plowing heavily when I had to stop quickly...that's when I forgot about my pedal problem and depressed it too far..."bang", the TOB carrier crashed into one of the pressure plate tabs and broke/sheared it off! The clutch would not disengage and getting the transmission out of gear by force was the only way I had to stop. Getting the unit back to my shop while stranded in deep snow reinforced the lesson learned.
So, I had a clutch replacement job on my hands. The Super A had a non-turning type TOB. Since I had all the work of splitting the tractor, I made the decision to replace all clutch system components, including the TOB. The only option was to install a rolling type TOB for which an "adapter" was necessary to complete this portion of the clutch. Negotiating the parts acquisition portion of the project was harder than doing the work...knowledge of these old tractors (sixty-two years old) is quickly disappearing and prices for the parts have doubled since 1992.
I read in this forum notes about how these tractors are used for heavy work. My tractors are used heavily but not too heavily. I recognize the limitations of my tractors and avoid over-working them...there's always a way to get the tractor work done without unduly loading and abusing the machines. Super A's and Cubs have a charm that almost everyone recognizes...that's why they're popular (here) and continue to be sort of heirloom items. By today's standards, these machines are light-duty and limited including snow plowing like I have to do. They only perform well when judiciously maintained and operated with care and in a safe manner.
I am grateful for the advice, direction and tips provided here by the forum members and moderators. The resources offered on the website are nothing short of awesome. Since there's no living person around my area to seek advice about these units, this forum is my life line. As long as there are repair parts that I can afford and install myself, I can continue to use my tractors to tend work on my property. I guess I have turned into a Red Power enthusiast...be careful, this disease is catchy.
Thu Dec 19, 2013 6:07 pm
What a great story, John. Nothing pleases me more than stories like yours and how this community helps others keep these "heirloom" tractors working.
Thu Dec 19, 2013 8:01 pm
All of the Super As that I have seen had a regular through out bearing in them. I have never seen or heard of a SA with a graphite bearing , are you talking about the cub and saying SA?
Fri Dec 20, 2013 3:30 pm
Boss Hog...Since it's been twenty-five years since I first replaced the Super A's clutch, I have a time trying to remember the details about the first replacement parts...the throw-out bearing (TOB) could have been the roller type. My memory is that I did make a TOB replacement (21 years ago)...I have the receipts but the description is too cryptic to identify specific parts. I cleaned the twenty-one year old TOB last evening and it looks and feels pretty good. The rolling part is pressed onto the carrier...I'm thinking about just saving the replacement that comes with the kit so I don't have to risk injury to the carrier getting the old one off.
Weather in NW PA is calling for steady rain for the next three days...it's great to have an interesting indoor job! I can't wait to get it put back together and fired-up! As you can see, I've got the fever.
Mon Dec 23, 2013 10:19 am
I installed the new Super A clutch kit and have some feed-back for the forum readers. The new clutch kit came with an "oil-lite" sleeve bearing (that supports the end of the transmission shaft) which should be an improvement over the fully bronze guide sleeve. To install it, I used a saws-all to cut a curf in the old one which loosened it for removal.
My Super A has a six-land transmission spline that goes into the clutch friction disk. The replacement disk came with a ten-land female spline bearing (ugh!). The old disk measured consistently 0.040 inches less in thickness than the new one. The release finger height on the new one varied 0.065 inches in height. The old disk had plenty of wear left in the friction pads and was in overall descent shape so I re-used it by adjusting the two fingers on the new pressure plate to be the same as the tallest one.
After re-mating the two halves of the tractor, I found the clutch pedal with no free travel so I adjusted it to 1 to 1-1/8 inch free travel. Boy, I've got a lot of clutch now!
A lesson learned is that I should have crawled under the Super A last summer, when I first noticed the pedal linkage bottoming slightly by colliding the throw-out bearing linkage with the pressure plate finger bosses, and adjusted the pressure plate fingers. Turning the finger set screws in some and re-locking them would have provided the linkage clearance that, lost via disk wear, ultimately lead to the destruction on the clutch. Users simply cannot rely on pedal linkage adjustment to keep a Super A clutch working properly. The manufacturer must have known this when they decided an under-clutch access was a necessary part of the torque tube design.
I'm betting I can get 1000 or more hours out of the used clutch friction disk before it will need replacement based on what I saw...it has something like 2600 hours on it to date.
Making these tractor splits is a lot of work by anyone's measure. I had a rainy weekend to accomplish it and experience from twenty-one years ago when I last serviced the clutch. The all-bronze transmission bearing sleeves that were used in the old days wear-out before a new friction disk is needed. Hopefully, the oil-lite replacements will perform longer.
Mon Dec 23, 2013 10:27 am
Thanks for the input John. My SA clutch is ok now, but I plan on keeping it for a long time.
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