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Gearbox Identification HELP!

Posted: 23 Dec 2018, 19:04
by The Hairy Camper
Anyone have any idea what code this is? Previous owner had no idea as he bought it as spares. No bell housing so i think i pretty much just have this code to go by!

First letter looks like a "D" Second an "L" maybe?? Can't find a box with a DL code though.
Image

Image

Cheers!

Re: Gearbox Identification HELP!

Posted: 23 Dec 2018, 19:21
by Aidan
two letters before the rib, probably a ABD from 1984
check the number of teeth on the crown wheel probably 29, maybe 34

Re: Gearbox Identification HELP!

Posted: 23 Dec 2018, 19:27
by 937carrera
I think you are looking in the wrong place.

The format for a 4 speed is as follows, according to Bentley, page 56:

AA dd [gearbox web]mm Y, where AA is the gearbox code.

Your picture shows the gearbox web, 01 for January and 4 for 1984

The 5 speed is in a different location, same structure, but no web in the middle.

I found using a brass brush in an electric drill worked best to clean the case up, followed by an oily finger to highlight the number.

(Aidan the expert beat me to it :) )

Re: Gearbox Identification HELP!

Posted: 23 Dec 2018, 19:49
by The Hairy Camper
Aidan wrote:two letters before the rib, probably a ABD from 1984
check the number of teeth on the crown wheel probably 29, maybe 34

Thanks for stopping in Aidan, can you see ABD in the picture? Or have i scrubbed the wrong spot?
I will have a count of the crown wheel teeth tomorrow.

Re: Gearbox Identification HELP!

Posted: 23 Dec 2018, 20:03
by The Hairy Camper
937carrera wrote:I think you are looking in the wrong place.

The format for a 4 speed is as follows, according to Bentley, page 56:

AA dd [gearbox web]mm Y, where AA is the gearbox code.

Your picture shows the gearbox web, 01 for January and 4 for 1984

The 5 speed is in a different location, same structure, but no web in the middle.

Hi carrera, i think you may be right about that being the date. It was where the code was on my old 5 speed, but this may indeed be a 4 speed??
This box seems to say 01 20 94.

Re: Gearbox Identification HELP!

Posted: 23 Dec 2018, 20:04
by Aidan
AB(rib)D12 03 4 that's 12 March 1984, the rib was deleted from the area that is stamped after 1984

Re: Gearbox Identification HELP!

Posted: 23 Dec 2018, 20:21
by The Hairy Camper
Aidan wrote:AB(rib)D12 03 4 that's 12 March 1984, the rib was deleted from the area that is stamped after 1984

What would we do without you Aidan :ok

I'll count the crown wheel teeth and update the post tomorrow.

Cheers!

Re: Gearbox Identification HELP!

Posted: 24 Dec 2018, 18:44
by The Hairy Camper
34 teeth on the crown wheel. I also noticed the numbers 42 and 236 written on the crown wheel. Are these clues Aidan? :lol:

Image

Image

Cheers.

Re: Gearbox Identification HELP!

Posted: 25 Dec 2018, 08:17
by Aidan
34 tooth crown wheel 7 tooth pinion so box is 4.86 final drive so is a very early ABD, after 84 they have 29/6 crown and pinion sets 4.83 final drive
crown and pinion matched pair number 236 and pinion height is 63.42mm

Re: Gearbox Identification HELP!

Posted: 25 Dec 2018, 09:12
by The Hairy Camper
Merry Christmas Aidan. Thanks for replying today.

Turns out that it's not a suitable box for me then, but at least i know what i've got now :lol:

Re: Gearbox Identification HELP!

Posted: 25 Dec 2018, 16:46
by Aidan
but worth keeping in case you fit a 1Y or similar in future

Re: Gearbox Identification HELP!

Posted: 25 Dec 2018, 19:24
by The Hairy Camper
Thanks Aidan, I'm slowly fixing up a 1Y. I would need different gear linkage I believe, as mine is currently a 5 speed :lol:

Is this early ABD box better than a late one? Or not a lot of difference?

Re: Gearbox Identification HELP!

Posted: 02 Jan 2019, 13:44
by Aidan
Not a lot of difference, it should have the later 3rd and 4th gears in, but it's possible it has the earlier fine toothed ones like a DU as it's crossover period hence it has the 34/7 crown and pinion same as a DU. It will have the early synchrohub on 3rd 4th if it hasn't been replaced yet which 97/100 times is cracked/will crack. It could be argued the 34/7 crown and pinion set is superior to the 29/6 one as it is Klingenberg rather than Gleeson pattern and the extra teeth means that duty cycle is less for each tooth.

Re: Gearbox Identification HELP!

Posted: 03 Jan 2019, 00:14
by The Hairy Camper
Cheers Aidan, I'm not sure why i enjoy absorbing all this information...but i do :D

Except the part where you said i basically have a 97% chance that the "synchrohub" will be cracked or will crack :rofl