Misc: Everything Else 1951 Black Shadow Restoration

craig

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This gearbox is couple of new gears and the rest serviceable vintage parts. So the shafts should be an easy fit. G15 fits are great, the E91 is an easy fit, but the G14 on the output G4 is not fitting this beautiful used output. The bearing is brand new , not in front of me right now, but i remember C3 as part of its markings.

GearboxBrgFit1.jpg
 

greg brillus

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Craig, Check also the input shaft G 3 into the output shaft to check the bushes........These tend to wear a bit in service especially the larger innermost one (G 16) if the outer one shows some wear this will cause oil loss from between the 2 shafts. If the fit of the output shaft through the new bearing is too tight, put the shaft in the lathe and linish the OD of the affected area with some emery tape........A long length about 3 foot and with shaft rotating pull the tape to and fro.......this will work well so do it carefully only a bit at a time you don't want the shaft a loose fit........Cheers...... Greg.
 

craig

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Thanks Greg, What grit emery tape? i have some vintage rolls of what appears to be 60grit, probably not the best.
 

Cyborg

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Although you are ok in the G15 department.... just a comment.
I stand to be corrected, but it seems as though in the case of G15, it is usually when a new bearing is going onto an original shaft? At least that was my experience. That is odd given that one would expect bearings to be made with relatively high precision and the shaft would be more likely to be slightly out of spec.
Note to self. measure and take notes next time.
 

Cyborg

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Craig,
Before you button things together ( and before I do mine) I thinking it might be worth having a bit of a discussion about the G35,G36/1, and G32/2AS.
The last one I did had a new spring and G35 detent. The shifting turned out to be a little stiff and notchy. It’s ok and will improve over time, but maybe there are some suggestions floating around out there. I did rework the spring a bit and cleaned up the end of the G35. In my situation the cam plate looked fine, but maybe it could have used some minor surgery.
 

oexing

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In my eyes - well, obviously - the G 35 looked very pointy , maybe grind it for a bigger radius at the top and polish. Also the spring could be a bit softer and still sufficient camplate positioning in all gears. The spring can be changed any time in case later when getting inside the primary. I did a mod with a lever locking design, no plunger type which gets high side load when changing gear and so no smooth action.
As to the bush in the output shaft: This is very critical to be a nice fit, max. 2 thou play with G 3 . I tried to find the logic of how this gets lubrication, added some more grooves and holes. As far as I know there are suggestions made about mods in this respect but I don´t know . Anybody ? The output bearing is meant to be light press fit on the shaft, like anywhere else for ball bearings or so. So press it up the shaft like before and it should be allright. The output shaft with bearing can then be dropped in the hot case , - provided no staking was done before around the bearing bore .

Vic
 

stumpy lord

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HI,
whilst working in this area I would strongly advise changing the guide pins in the gear selector fork for ones that have shoulders on them. These pins have been known to drop out, with ,disastrous results to the whole engine. These are available from the spares company as G31'/s selector fork pins stepped, and cost£10.85
stumpy lord
 
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