Jumps out of gear
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=25227
Printed Date: 24 Feb 2025 at 9:34pm
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Topic: Jumps out of gear
Posted By: BobDinNC
Subject: Jumps out of gear
Date Posted: 04 Feb 2011 at 3:37pm
| The D10 I bought jumps out of 3rd gear. So I get into the transmission to fix it and don't see what's wrong. Gears aren't worn and nothing looks bent. What is wrong that lets it jump out of gear? |
Replies:
Posted By: Chris/CT
Date Posted: 04 Feb 2011 at 3:47pm
| Most likely nothing would be "bent" inside transmission, I guess maybe a shift fork could be bent. Do you know what to look for on gears as far as wear in critical area's is concerned. The teeth on the gears really don't cause much jumping from what I have learned. You need to inspect the "lugs" on the gears trhat engage into sliding collars forks attach to. Also the inside of these shift collars could be worn and unless transmission is out , and fully disassembled you cannot see the wear there. I forgot to ask if transmission shaft/gears are out of housing or are yopu doing inspection from access plates? Advise more, pictures would also help. |
Posted By: BobDinNC
Date Posted: 04 Feb 2011 at 4:41pm
Chris, Here is a picture that shows the 3rd gear. I had not noticed the wear on the hub where the gears lockup.
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Posted By: tbran
Date Posted: 04 Feb 2011 at 4:47pm
| use some mod clay - even playdough - and put between shifter collar and 3d gear then install shift cover and shift in 3d - then remove and inspect - should squeeze clay in to less than 1/16" inch. Shift fork and or detent on shift rail may have to be moved to shift completely in. 3d gear or any gear should not have lateral play on shaft. |
Posted By: tbran
Date Posted: 04 Feb 2011 at 4:48pm
| btw this may or may not fix as your teeth look really worn. |
Posted By: D-17_Dave
Date Posted: 04 Feb 2011 at 6:55pm
| Low oil sometime in it's life and running in 4th gear will ruin a small D-series tranny. It spins the lower gears so fast with low oil that it gaulds the bushings that the gears run on. When the bushings spin on the main shaft(which they shouldn't) it grinds out the sides of the bushings and loosens the gear pack and allows the gears to float front to rear. They should have no float. This float translates into movement so when load is applied and released while using the tractor it works the gears away from the shift coller and the gear jumps into neutral. There are lots of these trannies that the shifter doesn't allow for full engagement but this just speeds up the wear problem after the bushings are damaged. The only truse fix is a complete rebuild with good gears, bushings, bearings, and properly shimming the bearings on the shaft so there is no float in the gear cluster. |
Posted By: Bill Long
Date Posted: 05 Feb 2011 at 10:29am
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Very good explanation of what causes the "jumping out of gear" on a constant mesh transmission. At first we could sometimes cure it by inserting a larger snap ring at the end but that was not the best fix. New gears with new collars was. After that not shifting on the go was the answer. There were not made for on the go shifting.
Good Luck!
Bill Long
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