4AD gearbox sticking to first gear

The 4A, 4AB, 4AC, 4AD cars, including the SM 1500 Roadster and SMX
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kabu
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4AD gearbox sticking to first gear

Postby kabu » Thu May 09, 2013 11:01 am

Hi,

While doing the preparation to get my 4AD registered and driving the first very short runs with it I noticed that the gearbox occasionally sticks to first gear so that it is very hard to get the gear lever away from first. I suspect that it may be due to some excessive play in the gear transfer mechanism. I haven't yet opened the gearbox cover and started diagnosing the problem. Has anyone else had similar problems with the gearbox and any clues what might be the problem?

BR/
Pekka
4ADT Roadster, 1954 --- http://www.guru-group.fi/kabu/singer

Ron
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Re: 4AD gearbox sticking to first gear

Postby Ron » Thu May 09, 2013 9:22 pm

Hi Kabu, I had the same problem.

I fixed it by the rear nut in the square flange to unscrew half a rotation, and again with a cotter pin to secure.

Remove the cardan shaft first.

Kind regards Ron Ledel

klaus
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Re: 4AD gearbox sticking to first gear

Postby klaus » Wed Apr 12, 2017 2:32 pm

hi guys, i took the liberty to hijack this old post.

copy paste :
Re: 4AD gearbox sticking to first gear
Postby Ron » Thu May 09, 2013 9:22 pm

Hi Kabu, I had the same problem.

I fixed it by the rear nut in the square flange to unscrew half a rotation, and again with a cotter pin to secure.

Remove the cardan shaft first.

Kind regards Ron Ledel

i have never seen anywhere that you can adjust a sticking first gear.
i found the article and photos of the first/second synchro gear on removal of a small peg inside the tooth wheel.

it would be nice if anyone can enlighten me on where to find the adjuster mentioned above and so on.

klaus
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mikeyr
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Re: 4AD gearbox sticking to first gear

Postby mikeyr » Wed Apr 12, 2017 2:59 pm

I have never seen a solution to this problem. My 4AD had the same issue and I thought I was the only with it, didn't know others had it. I drove it that way for 30 years, I just had to remember to always get out of first quickly. One time when I didn't get out of first in time, I had to drive home about 12 miles in first gear, picked all the slow roads of course. I got home and next morning when I went to take the gearbox apart it shifted easily, as a result I always thought it was heat related and I had something to tight in the gearbox, but it never went away.
Mike Rambour. Site Administrator
1953 Singer 4ADT (sold), 1934 Singer 9 Le Mans, 1934 Singer 1 1/2 4-Seater Sports, 2009 BMW K1300GT

klaus
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Re: 4AD gearbox sticking to first gear

Postby klaus » Thu Apr 13, 2017 10:15 am

hi mikeyr
thank you for your reply.
i have not been driven my car yet, apart from a short testdrive some 20 years ago. i do not remember i had issues then, apart from boiling cooler !

i took off the geabox cover yesterday. nothing wrong to see, everything looks like new.

the adjuster that ron mentioned i cannot find. aprently it is somewhere next to the driveshaft.

i found the adjuster bolt with a locking nut, on the topcover of the gearbox in front of the shifter lever and between the two front nuts, ( of the 6 nuts on the cover)
it adjusts the stroke of the shifter lever to 1. gear.
that means possibly that the "peg" inside the first gear, (and of course the gear wheel), can be adjusted a little bit backwards away from eventual wear on the gear axle, as seen on the photos from Rons topic on removing this "peg".
klaus
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kabu
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Re: 4AD gearbox sticking to first gear

Postby kabu » Thu Apr 13, 2017 11:57 am

Hi,

I did find a solution to this problem. After taking the gearbox apart, I concluded that the first gear sleeve occasionally moved so much that the spring loaded ball retainers that hold the sleeve in the neutral position when the gear is not on, managed to came out and lock the sleeve in the first gear position.

As a solution I turned a thin spacer ring and installed it on the gearbox axle so that it limits the first gear sleeve movement so that the above does not happen. After this fix the gearbox has functioned perfectly for a couple of years and a several thousand kilometers without sticking on the first.

I checked my photo library but unfortunately did not find any detail photos of this solution.

Best Regards,
Pekka
4ADT Roadster, 1954 --- http://www.guru-group.fi/kabu/singer


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