![laycock overdrive solenoid laycock overdrive solenoid](https://www.uniquecarsandparts.com.au/images/how_it_works/Overdrive/Laycock_Overdrive_A_D_Type.jpg)
Oil was full and it was recently drained for shipping and handling. Everything rotates from the input shaft through to the output /drive shaft and nothing is frozen. There is no wear evident anywhere and everything is very tight with no slop. The gears on the layshaft were also inspected and they also look perfect from what I cold see. I have checked every tooth in every gear that I can get to and there is no wear, chips, or other damage. Cannot have been more tha a handful of these made. Complete with the Laycock DeNormanville overdrive unit.
![laycock overdrive solenoid laycock overdrive solenoid](http://www.spannerhead.com/wp-content/uploads/2011/10/Laycock_OD_2.jpg)
The suffix letters "CR" indicate that it is a close ratio transmission.
![laycock overdrive solenoid laycock overdrive solenoid](https://uploads.tapatalk-cdn.com/20210814/93a5774d48e262cc05bd78b83362271e.jpg)
Marked numbers are JLS41492CR, which according to the jaguar archives is correct fitment to the Jaguar XK 150S sports cars. I installed two drive shafts, one from the to transmission to the overdrive, the second from the overdrive to the rear end.Up for bid is an authentic original factor issue vintage excellent used overdrive gearbox assemply as shown. I began a search that led to a Laycock model J overdrive, about the size and shape of a small watermelon. The sun gear was mounted on a sleeve which slid over the gearbox output shaft and splined to the sun gear was a cone clutch. In the Laycock overdrive unit, the annulus was mounted on the output shaft of the unit and drove the propeller shaft and the planet carrier was splined on to the output shaft of the main gearbox. As all-in-one 5-speeds with integrated overdrive became de rigeur, the Laycock Overdrive faded from the scene. The solenoid in particular could be finicky on higher mileage cars, and frequently the overdrive unit had its own fill and drain plug separate from the “main” transmission, requiring a unique maintenance interval. Is the Laycock solenoid an overdrive unit? Until the late ’80s, the Laycock Overdrive was fitted to a wide variety of cars, not just Volvos: Jaguars, MGs, Austin Healeys, Alpines and Triumphs, among others, were available with the unit. What kind of cars can a Laycock overdrive be fitted to?Īs all-in-one 5-speeds with integrated overdrive became de rigeur, the Laycock Overdrive faded from the scene. When the transmission was in direct drive, oil was pumped past the crowns of the operating pistons to a relief valve. The solenoid for this overdrive unit had only one winding which drew about 2 amps and the solenoid plunger acted directly on the control valve. What kind of transmission did a Laycock J have? Where is the annulus on a Laycock overdrive? These are often listed on ebay-without the front drive shaft. The Laycock overdrive is common on older Volvos. That wasn’t such an issue-the tank needed to be replaced, anyway. This running surface on the cone clutch isĬan a Laycock overdrive be replaced on a Volvo? These move a cone clutch attached on splines to a sun gear, to stall them both onto a brake ring attached to the O/D body.
#Laycock overdrive solenoid driver#
How does a Laycock type a overdrive unit work?īrief description of the unit: The Laycock O/D has a number of working components including a pair of hydraulically operated pistons which move after the driver selects O/D. According to the 1990 United States Census, Laycock is the 22,119th most common surname. Laycock is an English surname, likely originating from the placename Lacock, in Wiltshire (which is pronounced Laycock) or Laycock in West Yorkshire. It can either couple the input driveshaft directly to the output shaft (or propeller shaft) (1:1), or increase the output speed so that it turns faster than the input shaft (1:1 + n). How does overdrive work?Īn overdrive consists of an electrically or hydraulically operated epicyclic gear train bolted behind the transmission unit. This raises the pressure in the circuit and forces the operating pistons down their bores. Pressurized oil is fed to the positions when the solenoid lifts a lever and raises the control and ball valves. Laycock Overdrive A and D Type cone clutch, which was operated by hydraulic pressure.