He also developed a two speed planetary transmission (non Ford) on his side of the pond and was working on a Three speed planetary which never reached fruition. Yes, epicyclic as in planetary! He just held things differently to obtain overdrive instead of underdrive. Not that you would do it Donald, but I thought that you should know.Īnd on an interesting related note: This overdrive unit, designed by Englishman Edgar de Normanville, is an Epicyclic gearbox. The clutch within the OD does not like to spin in reverse. The four speed transmissions to which these ODs were attached had safety lock out switches to allow OD engagement ONLY in fourth gear (direct drive). The 'older brother' M41 D type uses 30w motor oil while the M41 J type uses 80/90w gear oil. The manual states to use ATF type F in the M46 transmission/overdrive unit and to fill to the filler plug on the side. To the center of the shafts sounds about right.īy William Harper on Wednesday, Janu12:38 pm:Ī couple of my older Volvos (1980 & 1983) are equipt with the Laycock de Normanville overdrive. The Volvo was filled in the side of the transmission so there again you'd have to make a mark on the overdrive housing. The MG and Healeys had a dipstick in the top of the transmission so if you only have the overdrive the builder had to make a line for you. The fluid level is quite high up on those units as I recall. The normal oil was 20-50 for the transmissions that had overdrive.Ĭan also use straight 30 in warm climates. If it came from an MG or a Triumph or a Sunbeam I would use 10-30 motor oil. If it is from a Volvo use ATF (auto trans fluid). Thanksīy Aaron Griffey on Wednesday, Janu12:04 am: If anyone has any knowledge of what the level should be I appreciate knowing. The static level of the fluid is above the bottom of the shaft seals. The line is at the middle of the case - at the same height as the middle of the input and out put shafts. The fluid level is marked by a white line on the side of the case. The unit works fine but I question if the fluid is correct. I purchased the unit several years ago at Hershey.

I have a Laycock overdrive that has been installed in the torque tube. Model T Ford Forum: Laycock Overdrive question Laycock Overdrive questionīy Donald Conklin on Tuesday, Janu02:22 pm:

Laycock j type overdrive oil