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MG MGB Technical - LT77 problem

I am about to refit my engine and LT77 box.
I have been setting up the reverse switch and find it impossible to select any gear easily as there is so much free play in the gear linkage.
I have a modified remote specially for the MGB which supposedly has just been rebuilt.
Both of the rose joints and all of the rubber mounts are in good condition. The outer double finger spring is also set correctly.
I can waggle the gear lever from 1st to 3rd without the input shaft rose joint rotating at all.
All of this free play is due to the two supports on the inner transfer shaft, that is the shaft linking the gearlever to the input shaft. There is over 1mm clearance in both bushes.
Is this normal?
I have never seen an LT77 box before and I don't want to fit the engine/box if I have to pull the damn thing straight back out.
Photo below shows clearance in bush.
Any help would be appreciated.
Regards
Dave


D M Tetlow

It is not the problem of the clearance in the shaft supports, i think, as it is the same with my LT 77 and this works in my V8 since 1983. There are some plastic seats / bushes incorporated in the gear selector mechanism. If thy are missing or have worn out, you will have exactly the problem you are talking about. It is also a good idea to renew the rubber bushes at the front mount and at the bracket of the extension, as they can become hard and crack away, making shifts very uncomfortable then.

If you want to have some more details shown upon the assambly, try the site of Rimmer Bros. and look at the SD1 or TR7/8 5-speed, it is the same box and the same extension used there.

Hope this helps

Ralph
Ralph

Thanks Ralph.
Rimmers have the bush but its NLA!!!
I have a swivel joints at the end of the gear lever and on the input shaft. These are in reasonable condition. I have replaced all the rubber mounts.
I can see the inner shaft moving side to side in the support bushes.
On your linkage is there any movement between the supports and shaft? I have over 1 mm.
Regards
Dave
D M Tetlow

Dave,

there is some movement, but i have not checked the with of this 'gap'.

For checking out if it is too much, i would put some tape at this positions around the shaft, just to check out the changes. If this cures the problem, look for some brass sheet metal of adequate thickness and bend it into the supports and add graphogen greas to this 'bearings'.
I think it would be the easiest, fastest and most cost effectice way to fix it.

Ralph
Ralph

Ralph.
Good idea.
I checked the bushes and there was a lot of side-ways movement but not so much up and down. I could just turn them 90deg!!
Your idea with brass shim sounds much better though.
Cheers
David.
D M Tetlow

David,

There should be no play at all in the two bushes.

I'll see if I can lay my hands on some for you tomorrow.
Chris at Octarine Services

This thread was discussed between 30/10/2007 and 31/10/2007

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