Transmission Translation

[S2Jay]

This may not be important, but part of the instructions in the Shop Manual regarding transmission assembly seem a bit obscure. I may not be reading this correctly, or just missing something here.

I have a March, 1970 edition of the Elan Workshop Manual, part No. 36 T 327.
In section F ? Gearbox, page 13, under ?To Re-assemble the Gearbox?, instruction 2 reads:

?Scribe a mark in line with the centre of the key-way on the outer edge of the bush flange on the mainshaft and another one along the centre line of the speedometer hole as far as the boss of the first and second gear synchronizer hub splines.?

I think I get the part about the line along the speedometer hole, but the first part of that sentence has me baffled.

Not sure if this is a translation problem or if I am just this dense, but if anyone can help with any clarification, explanation, translation, suggestion, clue or remote hint about what this means, I will be most appreciative. I have not found anything in the archives relating to this.

Jay

[Jeff@Jae]

What is the purpose of the scribe marks ? I've rebuilt lots of these without doing that.

[S2Jay]

What is the purpose of the scribe marks ? I've rebuilt lots of these without doing that.

Yep, that was my main question.

Thanks for the input Jeff, but then that is the difference between an experienced practicing technician and an occasional bumbler trying to discern some meaning from an overwritten pseudo-technical instruction manual.

Checking the manual to avoid missing a step & the need to start over, it struck me that I could think of no reason to align any of the components. Later the manual describes alignment marks on the synchro Hub & sleeve, but it never mentions actually aligning anything with the lines on the mainshaft that the builder had been asked to mark.

Apparently, "it just doesn?t matter" [to quote Bill Murray in ?Meatballs?].

Jay

[AHM]

It is considered good practice to reallign mating surfaces.

[S2Jay]

It is considered good practice to reallign mating surfaces.

Agreed on that, AHM. And I am one of those more likely to lean to the obsessive side of putting things back as they had been than not [maybe why I take so long to get anything done].

This also makes the post from Jeff more interesting since he is a practicing professional & having done a number of these has apparently not noted these alignment marks, and more important has had no problems by assembling without alignment of these components.

Maybe I should just let this go, but I am still [edit] ?a bit curious about? trying to understand why it was thought necessary to have the synchro hub & sleeve assembly mated with the Mainshaft.

Since I do have match marks to mate the synchro hub with the sleeve as shown in the pic, it is easy to set them back as they were, and I am more than pleased to do that.

It is a bit more difficult to align the Hub/Sleeve assy with an imaginary line on the Mainshaft, but while I am willing to do that it still bothers me that I can not see any operational or mechanical reason to align those components, other than good common practice as noted by AHM.

It would also seem that if common practice were the main or only reason to align those items, then why would it be necessary for the Workshop Manual to place such emphasis on it? Why not just consider that an experienced mechanic would expect to apply accepted practice?

Then I thought that Workshop Manual instructions would not ask the individual to try to align mating marks that had not been instructed to be made during disassembly. This led me to look back into the manual for disassembly instructions, and voila, there is a ?note? after instruction 25 that reads in part: ?The synchroniser hubs and sleeves and also the mainshaft are mated together. Mating marks are etched on the corresponding splines of the hub and sleeve, and near the hub and mainshaft splines. ...? This suggests [to me at least] that these mating marks would have been originally made at the originating Works shop. However, from the limited responses seen here, it does not seem like anyone else has noted such marks during other rebuild jobs [edit] ?, or no one has placed any significance to them.?

Maybe that answers my question. Mated parts are mated parts and should be re-mated upon reassembly. This is common good practice and minimizes possibility of stress from a mismatch or poor alignment. [edit] ?The practical experience of Jeff noted above, however, suggests that mating these parts is apparently not of any importance.?

I appreciated the time of those who have read this, and for the responses.

Jay