#Early volvo laycock overdrive manual#

The propeller shaft linking gearbox and rear axle is thus overdriven, and a transmission capable of doing this became termed an 'overdrive' transmission. the gearbox output shaft rotating faster than the engine. Achieving an overdriven ratio for cruising thus required a gearbox ratio even higher than this, i.e. The gearbox was designed so that, for efficiency, the fastest ratio would be a 'direct-drive' or 'straight-through' 1:1 ratio, avoiding frictional losses in the gears.

rear axle) ratio for fast cars was chosen to give the ratio for maximum speed. With the early development of cars and the almost universal rear-wheel drive layout, the final drive (i.e. Therefore, a car needs one gearing to reach maximum speed but another to reach maximum fuel efficiency at a lower speed. At travel speeds below this maximum, there is a range of gear ratios that can match engine power to air resistance, and the most fuel efficient is the one that results in the lowest engine speed. There is therefore one specific gear ratio at which the car can achieve its maximum speed: the one that matches that engine speed with that travel speed. At the maximum possible speed, the engine is running at its point of maximum power, or power peak, and the car is traveling at the speed where air resistance equals that maximum power. A car's speed is limited by the power required to drive it against air resistance, which increases with speed. The point of maximum power is somewhat lower than the absolute maximum RPM to which the engine is limited, the ' redline' RPM. The power produced by an engine increases with the engine's RPM to a maximum, then falls away. Sandy has already shown that its doable to gut the case for this purpose, so I guess all that's left to do on that option is find a 904/208 4wd truck in a junkyard for proof of concept.ДЄnd on the other side we'll see if Ceej's friend has an adapter worked up.Laycock de Normanville 'J type' overdrive unit Just not 100% that its a 208 case which that Particular adapter would mate up to. I've already shown that an adapter exists for the 904 to a t-case. What's the lowest numerical gearset ratio available (stock) for an 8+3/4? With 3.55s underdriven via t-case I would have a 9.59 (holy crap!). That would be a 2.77 highway cruising gear.(Volvo O.D is 0.78 thanks josh) Whereas the volvo/laycock/gnk overdrive I believe could be set up to be completely automatic.ДЄdd in the fact that I have 3.55s in the 8+3/4 and I think the overdrive would work better. Then it would just be like shifting into fifth.

#Early volvo laycock overdrive manual#

I think both options could be made to work well though honestly I think the t-case underdrive would be better suited to a manual trans car. I don't mean to be confusing, but when sandy brought this up I knew I had to investigate. Especially the bit about swapping the 4X4 transfer case onto a 904 for overdrive. I am watching this thread with MUCH interest. I used a clutch disc hub for the shaft adapter. !st and reverse were removed from the case. I actually have a DeSoto project here that was to have a 727/ Ford 3 speed manual underdrive. Before welding we cut out the openings for the trans and TC as well as indexing the mounting holes. I made the dapter out of 1/4' steel welded into a box. A 208 minus extra parts would weigh about 40 lbs. The case was locked in 4wLOW losing lots of pieces. I built an adapter once that put a NP208 behind a 2wd TH400. A modern transfer case low range is just a planetary shifted by a fork. Is there a bolt on 4x4 transfercase for the 904? It would not be difficult to lose the chain, lower shaft and lower case on a NP208 or similar. Mount the OD on its own crossmember/subframe.ДЄnother way to do this is an underdrive.

If I were to put a m46 behind a 904 I would consider to do it like a divorced transfer case.with a short drive shaft. It might be easier to adapt the 4 speed trans in front of the OD at the same time.The 4 speeds in the six cylinder cars were pretty sporty and strong. The ones that dont work usually need a filter or wire harness work.