151 Transmission repair ?

1959 - 1978, M151, M151A1, M151A2, Technical questions and discussions, regarding anything related to the M151.
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67N20
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151 Transmission repair ?

Post by 67N20 » Fri Apr 29, 2022 5:33 pm

I have a M151transmission that really shifts nice but is starting to make a noise, a sliding scraping sound. It started as a part time noise and then only when I had to shift fast, now it is all the time. I swapped out with my newer spare trans, so I'm still good. Who should I contact to see about rebuilding or just fixing ?
Thank You.

Clem


markrdje
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Re:151 Transmission repair ?

Post by markrdje » Fri Apr 29, 2022 7:50 pm

There is no speed shifting with this transmission, a 3 step process in the slow motion
Last edited by markrdje on Mon May 02, 2022 5:45 pm, edited 1 time in total.
change user name to mark

67N20
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Re: 151 Transmission repair ?

Post by 67N20 » Mon May 02, 2022 11:25 am

Anybody else have a suggestion has to whom I can contact that could help my transmission ? I will going to the Findlay Show i can bring it with me.

Clem

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199th MP
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Re: 151 Transmission repair ?

Post by 199th MP » Mon May 02, 2022 1:42 pm

when the time came to repair my transmission, i looked for a shop that did bench work on standard transmissions. fortunately for me, i was in an area that had such a place. they were in the yellow page ads. i took it to them and they went through it, installing new seals and gaskets. check with your local transmission repair shops. they might be the ones you need.

Rickf
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Re: 151 Transmission repair ?

Post by Rickf » Mon May 02, 2022 4:13 pm

As 199th says, any transmission shop that does older style manual transmissions could do the work. You may have to provide them with the -34 manual since it is not something they will be able to look up easily for all the needed specs. And the transfer case/transmission mated design is a bit odd. The actual work is not hard.
As far as shifting fast, Do not do it. This is probably what caused the problem. These are old school truck type transmissions. Pop it out of gear, casually slide it over to the next gear and pop it in. There is not speed shifting. You will bend shift forks and destroy synchros. You have 3 feet of shifter above the pivot point and maybe 3-4 inches below it. Just think of how much force is applied to the shift fork with that leverage if you force it.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

67N20
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Re: 151 Transmission repair ?

Post by 67N20 » Wed May 04, 2022 4:54 pm

I will check and see if I can find a local shop Thank you :)
I just thought maybe there was someone out there that knows these transmissions well that wants the job. Might not be anything wrong with it other than adjustment.

Rickf
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Re: 151 Transmission repair ?

Post by Rickf » Thu May 05, 2022 5:02 am

There is no adjustment. Is it grinding going into third gear? That is a sign that the reverse detent ball spring is weak. Solution is just shift into third more gently and it will go right in.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone


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