'51 CA PTO locking up
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=197834
Printed Date: 28 Jun 2024 at 5:14am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: '51 CA PTO locking up
Posted By: mosstrumpet
Subject: '51 CA PTO locking up
Date Posted: 22 Oct 2023 at 6:25pm
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Hello everyone. I've been working on a restore in between using my CA for actual field work. I was getting ready to take it out today to brush hog and when I put the PTO engagement shaft in the active position the engine bogs down, and the gearing in the PTO make alot of noise - clanking tick almost. When i try to disengage the PTO the shaft is locked and the PTO seems to be locked also. i had to put it in reverse to get tension off the gears and lower the arms. Was planning on pulling PTO this winter anyway to replace the leaky gasket but not sure where to start with this new issue. It had been working no problem beforehand.  |
Replies:
Posted By: steve(ill)
Date Posted: 22 Oct 2023 at 10:01pm
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the TOP SHAFT thru the transmission goes all the way back to the PTO drive... If you can run OK thru the gears then that shaft and bearings are OK... On the PTO housing there is a small PTO shaft with bearings on each end, and a slide to engage that.. You might have a bad bearing in the PTO housing... With the tractor in gear , not running, and the pto DISENGAGED, you should be able to turn the pto shaft by hand.. all you are turning is the short shaft with the two bearings, and the belt shaft with its bearings. ( and the pump !).. If it does not turn, then one of those four bearings are probably bad... ( or the pump) If it does turn by hand, then put the transmission in neutral so the top shaft will spin.. Now engage the PTO and see if you can turn the PTO by hand.. If not, then there is something wrong with the slide / engagement area of the housing.
------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 22 Oct 2023 at 10:10pm
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OOOPS... that small PTO shaft has a couple LOBES on it that drive the hydraulic pump.. If your PUMP is locked up, that could case things to drag... If the PTO shaft will not turn, or turn real HARD when in neutral, you might remove the pump/ valve and try again to see if the problem is the shaft bearings... or in the PUMP.. ------------- Like them all, but love the "B"s. |
Posted By: mosstrumpet
Date Posted: 24 Oct 2023 at 6:35pm
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I ran both diagnostic tests. The first passed tractor was in gear, not running with the pto disengaged and it was able to turn freely. I then put the tractor in neutral and engaged the pto - the pto / pulley would not turn by hand. I have pulled the fenders, seat and deck. As i said, I planned on doing this anyway to replace the pto gasket but might as well disassemble the hydraulic pump to clean it out and inspect springs replace components as needed. I was thinking that since I could disengage the PTO when the lift lever was in the down position that possibly several pump pistons are in the extended position at the same time causing it to lock up. I'll recheck the neutral with pto engaged when the pump is removed to validate if it is a pump failure. Once I get into it I'll repost and put some pictures up. Thanks for the insight. |
Posted By: steve(ill)
Date Posted: 24 Oct 2023 at 7:06pm
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when your turning the PTO shaft, you are also stroking the pump... If it TURNS when the PTO lever is disengaged, then i would think the pump is OK.?? Your problem is when you ENGAGE the PTO to the top shaft ??.... I would think that would be in the ENGAGEMENT / slide area. ?? ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 24 Oct 2023 at 7:13pm
Your problem would appear to be in the back end of the top shaft, with the ENGAGEMENT lever / gear ....... as everything in the BACK works when not connected to the top shaft ? ------------- Like them all, but love the "B"s. |