8070 pto clutch
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Category: Allis Chalmers
Forum Name: Farm Equipment
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=50302
Printed Date: 27 Jul 2025 at 1:47pm
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Topic: 8070 pto clutch
Posted By: BStone
Subject: 8070 pto clutch
Date Posted: 09 May 2012 at 4:06pm
| My 8070 has had a 540 PTO put in it.It's slipping when in a hard pull.I have removed the PTO clutch pack.When I buy the clutch disc do I buy them for an 8050? |
Replies:
Posted By: MACK
Date Posted: 09 May 2012 at 9:55pm
| Should be the same if not use 8070 plates because you don't change the clutch to make it a 540. I would also check the pressure. Clutch may not hold the 8070 with 540 speed. MACK |
Posted By: BStone
Date Posted: 10 May 2012 at 5:45am
| MACK Are you saying to check the hid pressure going to the PTO clutch? Not for sure what you mean when you say clutch may not hold the 8070 with 540 speed. |
Posted By: DrAllis
Date Posted: 10 May 2012 at 6:23am
| There are some things that never fail.....the PTO clutch on a 7000 and 8000 series is one of those things. In 35 plus years I have repaired TWO pto clutches.....the first in 1982 on a 7020 under warranty (had a bad casting causing low clutch pressure) and in 1990 on an 8030 running a hay tub grinder that was plugged with a wet bale of hay. After killing the engine, it took 8 full throttle attempts to unplug the grinder and by then there was smoke coming from the fill cap on the rear end. Those are the only two I've ever seen fail. On the clutch cover top there are two pipe plugs....one for brake pressure and one for clutch pressure.....they should be the same and around 280 to 350 psi at full throttle. |
Posted By: MACK
Date Posted: 10 May 2012 at 7:20am
| The 540 PTO was never ment for that HP. That is the reason for 1000 speed to lesson the torque load on PTO. MACK |
Posted By: 427435
Date Posted: 10 May 2012 at 8:31am
|
I'll defer to the mechanics that have worked on the PTO, but I believe the clutch is "upstream" of the gear reduction. If so, the torque on the clutch is the same for either 1000 or 540 PTO's. The torque at the output, of course, is much higher with the 540 PTO due to the greater gear reduction. Using the full engine power of an 8070 on a 540 PTO implement could lead to lots of broken pieces and possible serious injury to any bystanders. ------------- Mark B10 Allis, 917 Allis, 7116 Simplicity, 7790 Simplicity Diesel, GTH-L Simplicity Ignorance is curable-----stupidity is not. |
Posted By: tbran
Date Posted: 10 May 2012 at 4:25pm
|
hmmm. unless it was bad when you put it in - my bet would be cable - we have had several brought in for "PTO slippage" NEVER has it been the PTO - always either valve is not being detented due to bendage or cable froze up _OR the torque limiter is slipping.
As Dr. said the PTO's are bullet proof unless really abused.
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Posted By: ncrc5315
Date Posted: 10 May 2012 at 10:08pm
Sometimes, it's nice to have that option, because sometimes you need an extra 540 PTO. On one of our 8070's, we converter it to a 540/1000, because every once and a while, you would need a second auger tractor, or a spare feeding tractor, or on the manure spreader, the honey wagon, etc. None of these items required high horse power, just a 540 shaft.
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427435 wrote:Posted By: MACK
Date Posted: 13 May 2012 at 7:54am
| 427435- The PTO clutch still sets between power sorce and load. Then why does the PD(which sets between power sorce and load) always have more plates on low side than it does on HI side? MACK |
Posted By: Hurst
Date Posted: 13 May 2012 at 8:36am
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Doesn't the PD always start in low, thus the low side is the feathering side as well, thus requring extra plates to maintain durability and reliability even if they both carry the same maximum torque? Hurst ------------- 1979 Allis Chalmers 7000 5800 Hours |
Posted By: MACK
Date Posted: 13 May 2012 at 2:44pm
| All the D series, 170 -200 have more plates on lo side than Hi and you can start off in either side. The PS"s I know of have fewer plates in heigher gears than lower ones. The Oliver 3 speed had fewer plates in Hi than the other ranges. Look inside a manual trans. Lo gear will be wider than the faster gears. MACK |
Posted By: 427435
Date Posted: 14 May 2012 at 9:17am
While inching is something that enters into a clutch design, the most important thing is the torque the clutch has to transmit. A clutch that is the first thing in the drivetrain behind the engine only has to handle the max engine torque. If you put a 2:1 gear reduction between the engine and clutch, the clutch will need to handle twice the torque-----------and gets bigger (diameter or pressure or number of plates). ------------- Mark B10 Allis, 917 Allis, 7116 Simplicity, 7790 Simplicity Diesel, GTH-L Simplicity Ignorance is curable-----stupidity is not. |
Posted By: Jordan(OH)
Date Posted: 14 May 2012 at 10:29am
|
Never made sense to me why the 8070 had large 1000 only PTO. That would be like Ford welding a 2 5/16 ball to a F350 and telling customers "you can't pull a small trailer with this." Remember the saying "you can do a small job with a big tractor but you can't do a big job with a small tractor"? |
Posted By: 427435
Date Posted: 14 May 2012 at 10:38am
So if there would have been a factory 540 PTO on the 8070 and someone tried to use full power on a 540 implement, breaking the shaft off and someone got injured, who do you think gets sued??? ------------- Mark B10 Allis, 917 Allis, 7116 Simplicity, 7790 Simplicity Diesel, GTH-L Simplicity Ignorance is curable-----stupidity is not. |
Posted By: Jordan(OH)
Date Posted: 14 May 2012 at 10:56am
| 8050 and 7060 have plenty of power to do the same thing. |
Posted By: DrAllis
Date Posted: 14 May 2012 at 12:54pm
| But, at that time in history, tractors over 165 pto HP were required to have the large 1 3/4" shaft by law.....and no 540 pto even offered. |