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Close ratio laygear
Posted: Sun Apr 14, 2024 6:51 pm
by Striped shirt
Hello everyone.
Can anyone shed some light on this question?
I have a late 1275GT close ratio gearbox, rod-change a-series gears. DAM3220 case with small idle gear bearing.
The tooth count on the first motion is 18 teeth, indicating a close ratio gearbox set.
However.... the laygear does not have 22G1040 stamped into it. It does have BW and ME stamped into it (the ME is not very clear).
Has anyone seen this before?
Re: Close ratio laygear
Posted: Sun Apr 14, 2024 8:00 pm
by Spider
I do recall seeing that on laygear and also 1st motion shafts.
The tooth count on the S / GT Laygear is the same as the standard ratio, the way I check which is which is to measure the diameter as best as one can, over the input gear of the laygear (the big one !). if it's circa 77 mm it'll be CR, if it's 78.5 mm, it'll be standard ratio.
Off hand, I * think * these gearboxes had the DAM3168 laygear, these used the late 2 step layshafts.
Re: Close ratio laygear
Posted: Sun Apr 14, 2024 8:03 pm
by OzOAP
I have close ratio laygears (1040) with ME stamped on them.
Re: Close ratio laygear
Posted: Sun Apr 14, 2024 8:34 pm
by LuisM
The ME stamped laygears were mostly found on the ADO16 engines ( 1300GT , MG1300 ) , all the one I’ve seen used the earlier layshaft type , never seen one ME stamped with A+ 2 step layshaft, would be interesting if you could confirm what layshaft type your gearbox has .
Cheers
Luís
Re: Close ratio laygear
Posted: Sun Apr 14, 2024 9:12 pm
by Jason
Hi Tim - The ‘ME’ laygear is identical to 22G1040. Both run on 2 step layshaft. ‘ME’ originally fitted into boxes destined forAustin GT, however they occasionally also ended up in allegro boxes(like the DAM3220 box you have.
I have just taken an identical laygear out of an early allegro box.
A+ close ratio laygear(but with A Series tooth profile) running on 3step layshaft is DAM3168.
Regards Jason
Re: Close ratio laygear
Posted: Sun Apr 14, 2024 9:13 pm
by Spider
Striped shirt wrote: ↑Sun Apr 14, 2024 6:51 pm
DAM3220 case with small idle gear bearing.
I forgot to add in my earlier post, just carefully check around the Mainshaft Bearing Tunnel, in particular, around the bolt holes for cracks, these cases were quite prone to cracking.
Re: Close ratio laygear
Posted: Sun Apr 14, 2024 9:39 pm
by GraemeC
Just stripped my 5626 casing with exactly those cracks in 2 of the 3 bolt holes - I’d check carefully in any rod change
casing!
Re: Close ratio laygear
Posted: Sun Apr 14, 2024 9:47 pm
by Jason
I use shortened bolts and tighten up without the retainer in place as a check when the box is stripped down for that exact reason. Sometimes the cracks are obvious and sometimes they appear when the bolt is in place and tightened up.