looking for allison 748 for conversion

[Ed Hackenbruch]

I had a 64 vw bug that i used to shift up and down without using the clutch.   

[buswarrior]

In order that the novice doesn't get led astray.

The coach belongs to us, and we may spend our ca$h any way we want.

However, grinding senastions felt through the shifter are not a good thing.

Those would most likely be splines grinding against the gear sets as they are being slid along the shafts by the shifting fork. The very edges of the splines on the very edges of the gear sets.

With the weight of the rolling bus on one side, and the power of the spinning engine on the other.

With luck, they'll just round off, without luck, you can twist, snap or burr them, then the gear sets can't slide on the shaft and you will be unable to shift into that gear any more. When they round off enough, the gear will jump out on its own while driving.

If you can time your shifts right without grinding, go ahead and shift without the clutch.

However, using the clutch lets those expensive parts grind against one another with only the weight of the gear set inertia against the weight of the rolling bus, a force that they are designed to contend with.

You will hear many brag of and encourage clutchless shifting, you will hear none brag of the truth behind the transmission repair bill or the decision to switch to an automatic.

Until you can shift it cleanly every time with the clutch, keep using it.

happy coaching!
buswarrior

[NJT 5573]

I don't agree with BW at all. Respectfully of course. I have driven truck for more than 40 years and this is the procedure that has always been used in the industry, starting with twin sticks and right on through the Fuller transmissions.

I think you would have a lot greater chance of destroying a pocket bearing or snapping a shaft with a clutch than without. The clutch really allows you to do something with the gears that they don't want to do, but if you don't use the clutch you can only mesh gears when they are ready to slide together.

The idea that you could ever "round" off a gear by feeling it is absurd. Maybe with a car, but I have seen alot of trannys in pieces on the shop table and that would be a first for me. You are really still trying to feel the gear with a clutch too, you are just going to get a bigger chunk of it, not necessarily all of it, that's when things get torn up, you can even take a tooth off a ring gear in the differential using a clutch if the RPM's are not real close, impossible to do without a clutch, because it just won't go into gear and it can't whiplash the drivelines and differential.

I don't really know any professional truck driver out there who uses a clutch for all of his shifts, with a 4, 5, 10 or 13 speed, you could sure recognise him though from the size of his left leg, It would be huge because all a truck driver does is run a damn gear box all day.

I have taught hundreds of truckers to run gear boxes over the years. Its almost impossible to learn to shift with a
clutch because the clutch takes the ability to feel the gears rolling out of the equation and unless you can come up with some sort of timing thing like a double clutch on a natural aspirated engine that approximates the time it takes for the engine RMP's to drop to the spot where the gears will slide together, it is hopeless. With a turbo engine, the hole will be long gone if you try to time with a double clutch, because the engine drops RPM's much faster than a natural aspirated engine.

Want to know how many trannys I have had in the shop for repair in more than 40 years driving and shifting without a clutch in the transportation industry??? Including my 4 speed Spicer in my first Eagle.....
NONE, ever, never, any transmission failure of any kind.....

Until you can shift it cleanly, every time, without the clutch, don't use it! Use the governor procedure I outlined above, to shift both up and down through the gears.  Remember that your arms strength is not your tranny's friend, throttle finesse, timing and a soft touch are how its done.