Laydown gearbox

I haven't got anything in that format, but if you don't get anything else buy the NOC DVD on the gearbox strip, it covers the laydown box. I had never stripped a gearbox completely before, the DVD makes it very easy to do and you obviously can see an expert doing in front of your own eyes (as many times as you like with the pause and rewind buttons!). Highly recommended.

Ride Safe

Andy.

Previously wrote:

help!! does anyone have printed details of a strip and rebuild on a 1955 laydown gearbox, GT202 VAF. stamped also GB84392,will pay for copy or will send e-mail addressto anyone who can send me one: thanks Terry

Hi Terry, I've attached a diagram of a laydown gearbox, I could also post the written images of the dismantling and re-assembly instructions but each one would need another reply on the thread, e-mail <rggittins@tiscali.co.uk> and I can do it in one go,

Rob.

Attachments
138a.jpg

I am curious as to what machines these GT202 "laydown" gear boxes were fitted. The main case has some, call them oversized square bosses at the top mounting bracket. Most of these boxes have rounded off top lugs.

I am going to try to attach a couple of photos illustrating the box with the square lugs which looks to have a different lug location forward/aft, an AMC box, and a standard "laydown" box that fits the '53 downtube frame.

Unfortunately, I turned the AMC box upside down. The top and bottom lugs on the AMC gearbox are close enough for a comparison.

Thanks in advance.

Attachments
Box1.jpg
Box2.jpg
technical2-

Previously geoffrey_morgan wrote:

I am curious as to what machines these GT202 "laydown" gear boxes were fitted. The main case has some, call them oversized square bosses at the top mounting bracket. Most of these boxes have rounded off top lugs.

I am going to try to attach a couple of photos illustrating the box with the square lugs which looks to have a different lug location forward/aft, an AMC box, and a standard "laydown" box that fits the '53 downtube frame.

Unfortunately, I turned the AMC box upside down. The top and bottom lugs on the AMC gearbox are close enough for a comparison.

Thanks in advance.

Hi, can anyone tell me if the single gearbox can fit the twin and vice versa. I have a picture of a laydown box showing I think G102 and 581C or 6 on the main casing and what looks like 6225 or similar on the inner casing. Anyone know if that numbering fits a 1955 88?

Thanks for any info

Regards, Roger

Previously roger_wilson wrote:

Previously geoffrey_morgan wrote:

I am curious as to what machines these GT202 "laydown" gear boxes were fitted. The main case has some, call them oversized square bosses at the top mounting bracket. Most of these boxes have rounded off top lugs.

I am going to try to attach a couple of photos illustrating the box with the square lugs which looks to have a different lug location forward/aft, an AMC box, and a standard "laydown" box that fits the '53 downtube frame.

Unfortunately, I turned the AMC box upside down. The top and bottom lugs on the AMC gearbox are close enough for a comparison.

Thanks in advance.

Hi, can anyone tell me if the single gearbox can fit the twin and vice versa. I have a picture of a laydown box showing I think G102 and 581C or 6 on the main casing and what looks like 6225 or similar on the inner casing. Anyone know if that numbering fits a 1955 88?

Thanks for any info

Regards, Roger

Can't help you with the numbers, although I understand case castings with 101 were intneded for singles and 102 for twins. I have seen the cases interchanged. I think the difference would be on the input shaft (and possibly the output shaft depending on the frame). The input shaft would protrude a bit further to allow for the wider crankcase of the twin. There is a thread here on NOC site about the various input shaft numbers and lengths. To summerize, I think you would have to trade out the input shaft and possible the output spud, otherwise (watch me here, never have done this) I think that the case would be very close or identical.

Geoff