Farm Equipment - AC B Transmission Noise

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AC B Transmission Noise

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=140355
Printed Date: 22 Aug 2025 at 3:22am
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Topic: AC B Transmission Noise

Posted By: mscheiper
Subject: AC B Transmission Noise
Date Posted: 12 Jul 2017 at 6:18pm

I have a 1949 Allis Chalmers B that I am trying to figure out. When I put the tractor in 1st, 3rd or reverse, there is a terrible gear noise coming from the transmission. When I am in 2nd gear, there is no abnormal noise. Took the shifter fork plate off the side of the transmission and looked inside. Haven't found any damaged gears. Any help greatly appreciated!! Thanks!!

Replies:

Posted By: Bill Long
Date Posted: 12 Jul 2017 at 8:57pm

Check a little back. there was a recent thread that talked about noise in a B transmission. May be some help.

Just a reminder you may want to check the oil level. The plug is on the left hand side of the transmission facing front If you have a hydraulic you want to put Hydra Trans oil. If not you can put the heavier gear oil - 80 or 90. To be certain you may want to drain the oil and replace it. Can't hurt. There are drain plugs on the bottom of the transmission housing and if you have one on the bottom of the PTO. If you have the heavier oil you may want to flush it with kerosene

Just remember you have a unit that is 68 years old. Hard to tell what it could be. Bearings come to mind first.

In any event take good care of my favorite.

Good Luck!

Bill Long

Posted By: mscheiper
Date Posted: 13 Jul 2017 at 12:09am

Bill,

Thanks for the reply and suggestions! I will search the past posts and see what turns up.

Thanks! Matt

Posted By: Stan IL&TN
Date Posted: 13 Jul 2017 at 7:47am

It could be that 2nd gear is the only gear that it is going into fully. I would look for rounded teeth and the amount of slop in the shifter/forks themselves.

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1957 WD45 dad's first AC

1968 one-seventy

1956 F40 Ferguson

Posted By: mscheiper
Date Posted: 13 Jul 2017 at 11:08am

Stan,

Thanks for the idea! Working on it today. Will let you know what I find out.

Thanks!

Posted By: mscheiper
Date Posted: 13 Jul 2017 at 9:30pm

Well, we split the transmission from the torque tube today and found out that the input shaft is in good condition as was the bearing. When we took off the shifter fork assembly, we were better able to see the condition of the gears. Almost all of the gears were rusted and pitted badly. The search now begins to find a new/good set of gears or a new to me transmission.

Posted By: Bill Long
Date Posted: 14 Jul 2017 at 3:15pm

Sounds like you are doing a through job.

Let us know how it goes.

Thanks for taking such excellent care of my favorite.

Good Luck!

Bill Long

Posted By: Dusty MI
Date Posted: 14 Jul 2017 at 4:57pm

The B, C, & G, all use the same transmission.

Dusty

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917 H, '48 G, '65 D-10 series III "Allis Express"