170 pto/bush hog issues
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=162603
Printed Date: 21 Dec 2025 at 3:25pm
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Topic: 170 pto/bush hog issues
Posted By: hickorycreekhoney
Subject: 170 pto/bush hog issues
Date Posted: 08 Jul 2019 at 8:11am
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Info: 6 ft bush hog with lip clutch built in AC 170 tractor with 540 only PTO Issue: I have been mowing the past few days and yesterday the mower would get bogged down while mowing at lowest speed. RPM is at the mark on the guage. When it bogs down, the PTO shaft stops turning as well. The first few times I would disengage the drive mechanism, but leave PTO engaged to get back up to speed and slowly start creeping forward. I finally reached a point where the PTO would not get back up to speed and it seems to spin at a real slow rate, not fast enough to cut anything. I have not tried any other implement on the PTO to see if its an implement issue or a tractor issue, but since the PTO shaft stops spinning when it bogged down, I am assuming its a PTO issue. I am at a loss at this point on what could be the root of the problem. thank you, HCH
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Replies:
Posted By: DrAllis
Date Posted: 08 Jul 2019 at 8:26am
| FOOT CLUTCH. Make sure you have a minimum of 2 inches freeplay in the clutch pedal. |
Posted By: hickorycreekhoney
Date Posted: 08 Jul 2019 at 8:33am
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the clutch appears to be working just fine. I can put the pto in gear and out of gear, as well as the drive transmission and no issues. the pto engage lever seems to work as it should as i can turn on and off the PTO. WHen the mower is coupled up, the mower spins but with no power, bogs down on short grass. |
Posted By: DrAllis
Date Posted: 08 Jul 2019 at 9:18am
| BUT, you said the PTO shaft slows way down or even stops turning, or am I reading it wrong ??? If the PTO shaft slows down or stops turning, the foot clutch is slipping on the tractor. |
Posted By: Stan IL&TN
Date Posted: 08 Jul 2019 at 9:46am
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If RPM of engine stays constant and the mower PTO slows down it is as the Dr.said, foot clutch is slipping. Check free play and if that is correct you may need a new clutch. ------------- 1957 WD45 dad's first AC 1968 one-seventy 1956 F40 Ferguson |
Posted By: hickorycreekhoney
Date Posted: 08 Jul 2019 at 1:42pm
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yes the pto slows way down or even stops without the foot clutch engaged, even with just grass. Next question: difficulty of clutch replacement? I am mechanically inclined, just not auto and tractor type stuff.
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Posted By: DrAllis
Date Posted: 08 Jul 2019 at 1:50pm
| Hood has to come off and tractor split in two right at the rear of the engine. Must be rolled apart about 3 ft minimum. YOU DID VERIFY THAT THE CLUTCH PEDAL HAS 2 INCHES OF REEPLAY, RIGHT ?? |
Posted By: hickorycreekhoney
Date Posted: 08 Jul 2019 at 3:08pm
| I will double check for freeplay and get back with you. but i feel confident that there was plenty of free play as the clutch works just fine to put the tractor in gear to drive. |
Posted By: DrAllis
Date Posted: 08 Jul 2019 at 3:41pm
| If it has zero free-play it will shift just fine and may slip under load. |
Posted By: hickorycreekhoney
Date Posted: 08 Jul 2019 at 3:45pm
| and by free play you mean loose and sloppy travel when not in use? |
Posted By: DrAllis
Date Posted: 08 Jul 2019 at 3:57pm
| Free play is if you stand on the ground and with your hand pull forward on the clutch pedal, (if adjusted correctly) you will move it about 2 inches and it now becomes much harder to move. The point of more difficulty is the throwout bearing coming in contact with the pressure plate fingers. The free play is movement that has no effect on the pressure plate fingers. As a clutch wears, the free play keeps getting less and less and less and less until there isn't any. Then, you have the possibility of clutch slippage because it's like the tractor having the operator with his foot on the pedal all the time. |
Posted By: hickorycreekhoney
Date Posted: 08 Jul 2019 at 3:59pm
| great explanation. thank you. i will check it out tomorrow evening and report back |
Posted By: DiyDave
Date Posted: 08 Jul 2019 at 5:48pm
You say the bush hog has a (s)lip clutch built in. Try this: Take a paint marker, and paint a line across all members of the slip clutch, from front to back, on the side. Now pop it into gear, just like you were gonna start cutting. Now check the reference line. If it has moved, under no load, slip clutch is way too loose. If it hasn't moved, take it out into the high grass, and repeat the test. If line moves, clutch is too loose, for the load. Most slip clutches have 3 or more tightening bolts, having either springs or belvue washers, that apply the pressure to keep the clutch from slipping, and provide adjustment. Consult your BH manual, for the adjustment, if necessary...
On edit, I see that the shaft is slowing. Nevermind , FOOT clutch... ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: CTuckerNWIL
Date Posted: 08 Jul 2019 at 9:16pm
If you disengage the foot clutch when the mower is in wet grass, the mower will slow to a stop. The foot clutch not only disengages the transmission from the engine, but also disengages the PTO from the engine. If you want to stop forward motion to let the mower "catch up", you have to use the power director, slipped to neutral. ------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
hickorycreekhoney wrote:Posted By: m16ty
Date Posted: 08 Jul 2019 at 10:12pm
You've got a 170 tractor right? If so, the PTO won't work at all with the foot clutch disengaged. The PTO engagement is a collar on a splined shaft. It either works or it doesn't, it won't "slip", well if it does it will make a whole lot or racket and vibration. Does the forward movement of the tractor also slow down when the bushhog bogs down?
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Posted By: hickorycreekhoney
Date Posted: 09 Jul 2019 at 7:40am
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forward movement does not slow down when the pto boggs down. At first when it would bog down, i would use the hand clutch to stop forward movement of the tractor to allow the PTO to catch up before starting forward movement again, but as the day progressed the PTO would no longer catch up to what i thought should be full cutting speed. Even with the PTO on and tractor in neutral with the mower raised in the air. |
Posted By: m16ty
Date Posted: 09 Jul 2019 at 7:47am
That is very strange on a 170. Are you sure it’s not your bushhog slip clutch that’s slipping? |
Posted By: DrAllis
Date Posted: 09 Jul 2019 at 8:03am
| You can't have it both ways. Either the foot clutch is slipping (this is how you initially described it) AND your ground speed is slowing down too, OR there is a slip clutch on the mower and it is slipping (which means the tractor PTO is NOT slowing down). The only way the PTO shaft coming out of the tractor can slow down is if the foot clutch is slipping. |
Posted By: bradley6874
Date Posted: 09 Jul 2019 at 12:07pm
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Leave the pto off Bushog up drive into some tall grass put a bushog down put the PTO in gear and let the clutch out if the PTO shaft turns it’s probably not the foot clutch it’s the slip clutch On the Bushog if the PTO shaft doesn’t spin it’s the foot clutch end of discussion. That better ------------- You can wash the dirt off the body but you can’t wash the farmer out of the heart and soul |
Posted By: Tbone95
Date Posted: 09 Jul 2019 at 12:17pm
 
 Can you try that again? In English?
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Posted By: bradley6874
Date Posted: 09 Jul 2019 at 1:16pm
Darn smart phone it has its own language 👍👍  ------------- You can wash the dirt off the body but you can’t wash the farmer out of the heart and soul |
Posted By: Tbone95
Date Posted: 09 Jul 2019 at 2:17pm
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Well, I have a smart phone. It can be challenging to say what you want at times. But it also has periods, commas, the ability to capitalize.....and what auto text complete comes up with Bushong??? Just pokin' ya'. No offense intended.
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Posted By: bradley6874
Date Posted: 09 Jul 2019 at 4:50pm
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You really have to be careful with supposed !!! I almost proposed and It would’ve been bad news ------------- You can wash the dirt off the body but you can’t wash the farmer out of the heart and soul |
Posted By: Stan IL&TN
Date Posted: 09 Jul 2019 at 6:05pm
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What happens to the engine rpm when the PTO bogs down? If nothing is slipping the engine rpm should also drop. If the engine rpm stays the same then the foot clutch is slipping OR the mowers slip clutch if it has one is slipping. ------------- 1957 WD45 dad's first AC 1968 one-seventy 1956 F40 Ferguson |
Posted By: Lynn Marshall
Date Posted: 10 Jul 2019 at 7:39am
| If the foot clutch is slipping that badly, I would think that putting on the brakes would bring it to a complete stop. |
Posted By: CTuckerNWIL
Date Posted: 10 Jul 2019 at 8:54am
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If forward motion continues the same and the PTO shaft slows down, you have an internal problem with the PTO connection. Shut the engine off, engage the PTO and put a pipe wrench on the PTO shaft. If you can turn it without the engine turning over, there is something out of wack inside the rear of the tractor. ------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: Lonn
Date Posted: 10 Jul 2019 at 11:02am
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I'm thinking slip clutch on bush hog drive line. Can you video what's happening. ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: TimNearFortWorth
Date Posted: 10 Jul 2019 at 12:30pm
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Have you tried hooking it up to something else to check the pto? |
Posted By: bradley6874
Date Posted: 15 Jul 2019 at 10:52pm
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Did you figure out what was sloping yet ------------- You can wash the dirt off the body but you can’t wash the farmer out of the heart and soul |
Posted By: Alex09(WI)
Date Posted: 16 Jul 2019 at 2:25pm
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I had this same problem a couple years ago when I ran my friends Brady green chopper with my 170 gas. It seemed like the pto was slowing down when I went through a thick spot and the chopper wouldn't throw up into the wagon, but I couldn't notice the tractor speed slowing down at all. I haven't ran a green chopper since but I run a small baler just fine. Theoretically it could only be the foot clutch causing the problem. ------------- www.awtractor.com A&W TRACTOR 920-598-1287 KEEPING ALLIS-CHALMERS IN THE FIELDS THROUGH THE 21ST CENTURY |