5Spd/4WD Input Shaft Failure

[the flying scotsman]

Recent posts have mentioned the single most common reason for input shaft failure: excessive wear of the crankshaft pilot bearing area. Also mentioned is the impossibility of finding a good one used as well as the fact that the supply of OEM replacements is dwindling. Some have suggested that a defective clutch somehow causes this condition. My own feeling is that the both the input shaft and pilot bearing are undersized to begin with and that when the original bearing grease dries out from heat caused by prolonged holding of the car in gear at lights, the bearing seizes up and the input shaft then turns only in the inner bearing race. For me, it's the single most irritating aspect of an otherwise exceptional vehicle. Anyone else have a theory for this issue?

[jtgh]

correct, put car in neutral and save this tiny bearing. many last over 200k ,stock.
and when replacing it , get a quality US or German bearing. like ones made by Timken.
bearings come in quality grades, check out the codes at Timken.
you might want to try a new style ceramic bearing too,

they make some of the finest tool steel in the world. too.

there are choices .
Timken

neutral, clutch out. let the tranny spin a little oil around. ive done this for over 40 years. with autos put car in neutral and save 1.2kw of wasted energy. ( and that gas)

imho

[kelikran]

And in fact, to save even more on the clutch, you can slip it into neutral without the clutch as you come to a red light, and coast up to the light. I do this out of any gear from 4th down, a habit from years of driving heavy trucks, where you can burn out the release bearing or clutch brake easy with over zealous use of the clutch. You just have to release the torque on the drivetrain as you slow down, or it might be hard to get out of gear. You do this by giving a slight bit of gas, as soon as you remove that decelerating torque, it slips easily into neutral, and you brake gently to a stop. I do this
with autos too, so that they sit idling gently at a light instead of pulling against the brakes.

[the flying scotsman]

I agree-same principle when the clutch cable breaks when you're out in the bhundu-move off in first w/ the starter and then gently adjust engine load and speed so the gear changes can be made w/o the clutch until you can get it repaired.

[jtgh]

double clutching they call it,
I used to drive a Ford 5sp +3 speed Bownie, dump truckh with NO syncos.
had to split shift too. (only a 192 cu inch engine)

the trick is to match the speed of the input gear to the output.
with no clutch , one must match the engine speed to the out put gear speed.
if you do it correct, it will just go , click no grind.
practice on a beater car.

you can skip gears if you practice.

hope that helps.
the first race cars ran without the syncos removed ( the break too easy being alloy)