View Single Post
Old Jun 12th, 2021, 10:37   #31
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Yesterday 21:57
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by loki_the_glt View Post
Actually, that's not quite correct. The BMC ADO16 1100/1300 that had the Automotive Products autobox could be towed without destroying the box; IIRC the innards were configured in some strange fashion that permitted this; possibly because the box sat in the sump and space was at a premium?
One of the exceptions that proves the rule. I wonder (never having seen the inside/cutaway view) if those boxes used a conventional manual gear train with hydraulically operated clutch packs in place of the synchro hubs and would therefore be free-wheeling when not powered and also the higher level of oil to cope with lubing the engine as well as providing hydraulics for the box.

A bit of digging online reveals my guess is partly right - only partly right and i didn't foresee how the 4-speed Mini/ADO16/Allegro/Metro 4-speed auto does in fact work. Interesting reading :

https://web.archive.org/web/20131018...A/page172.html

In very simplistic terms, a set of differential style crownwheel and pinions arranged as a two-speed gear train to give one intermediate and one direct ratio. Couple this to a second similar unit and you can create at least a 4-speed box.

With that in mind, oil-splash lubrication would happen while towing so wouldn't be a problem. I suspect i could tow my other beast although the warning exists not to so i don't want to risk it. That uses what is essentially a manual gear train and hydraulic clutch packs which are operated by electronic controls and solenoid valves, shifts quicker than a manual and no heavy brake bands to incur power losses - win-win situation!
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote