7045 Power shift 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=201621
Printed Date: 23 Sep 2024 at 2:33am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 7045 Power shift issues
Posted By: rfunk1929
Subject: 7045 Power shift issues
Date Posted: 03 Jun 2024 at 8:15am
| Looking for some insight for my power shift valve on a A/C 7045. Tractor runs great drives great and all gears work until it gets warm. after that have no 1st or second gear. 3rd up work great. Guessing Maybe bad seal in powershift valve but cannot for the life of me find a breakdown for seals. |
Replies:
Posted By: DrAllis
Date Posted: 03 Jun 2024 at 9:44am
| No seals in the PST valve to blow. There are two sandwich gaskets, but I've never seen one of them fail on that transmission. A black 7000, yes. Not a 7010 and up. I don't have my service book in front of me, but it sounds like a tractor with a ton of hrs on it. The seals on the clutch pistons could be hard and not sealing when the oil is warmed up. Pressure checking each of the six clutch packs cold and hot would be a plan to see what in Sam Hill is going on. Especially the clutched that affect 1st and second gears. |
Posted By: rfunk1929
Date Posted: 03 Jun 2024 at 12:13pm
| I will try that. I had a feeling it was an oring leaking by some place. Was weird only for first and second to go out at the same time and same temp. |
Posted By: 8070nc
Date Posted: 03 Jun 2024 at 1:15pm
|
This is question for my own information. Ive had 5 powershifts. Still got 2. If testing shows leaking in those clutches and the higher gear clutches are ok will it damage more if you just dont use 1 and 2. I hope im clear with my question ------------- 1984 80780 1957 D14 DES 300 with 25000 engine 616 tractor |
Posted By: rfunk1929
Date Posted: 03 Jun 2024 at 1:36pm
|
From past experience starting out on the higher gears puts more strain on the higher clutch you start out in. eventually wearing that one out. |
Posted By: bigal121892
Date Posted: 03 Jun 2024 at 6:07pm
You only do that, to get it home, and in the shop.
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8070nc wrote:Posted By: DrAllis
Date Posted: 03 Jun 2024 at 6:34pm
| The problem appears to be in the B-1 clutch. First speed is A-2 and B-1 clutches and second gear is C-1 and B-1 clutches. So, B-1 is the common link between the two speeds that aren't working when hot. I suppose there could be something wrong with the B-1 plunger in the PST valve, but I wouldn't know what it was. Maybe loose internal hardware on the valve itself ?? The B-1 clutch is the most forward located clutch and doesn't rotate and is inside the front half of the transmission housing itself. Should be a test port on the right side of the trans housing for testing. Around 185 to 200 lbs pressure. Compare pressure to other clutches. |
Posted By: rfunk1929
Date Posted: 06 Jun 2024 at 6:33am
| Thank You for the reply's. I will check into it as soon as I have some down time. |
Posted By: rfunk1929
Date Posted: 06 Jun 2024 at 6:37am
| Is B1 clutch only for 1st and 2nd gear? |
Posted By: DrAllis
Date Posted: 06 Jun 2024 at 6:39am
| YES. I'd have to look in my service book, but B-1 could also be for the transmission "Brake" along with "C-2" clutch applied simultaniously. |