Topic: Loss of power


Dustbowl    -- 12-21-2015 @ 12:36 PM
  When stop light turned green, I put car in gear, let out the clutch and car did not move. Motor running good, same results in all gears.

I initially thought my problem was in clutch, transmission or U-joint but that now does not seem to be the case.

To come to this conclusion, I have pulled the drive shaft and torque tube far enough backward to disengage the U-joint. Then I find that the clutch and transmission work well so that the U-joint spins with power with car in gear and clutch out. So I now assume that something is broken in driveshaft, differential or axle.

However, I cannot turn the driveshaft at front with the rear wheels on the ground. And when I raise one wheel off the ground and spin it, the driveshaft turns.

So I am puzzled and have following interrelated questions:
- Can something be wrong in driveshaft/differential/axle even when I observe results in paragraph above?
- Can I analyze where the problem is before removing driveshaft and rear end?
- What is your guess on where the fault in the system is?

Thanks in advance
-


cliftford    -- 12-21-2015 @ 12:55 PM
  Check the trans output shaft. Put it in gear and see if you can turn it with the u joint.

This message was edited by cliftford on 12-21-15 @ 1:14 PM


TomO    -- 12-22-2015 @ 6:53 AM
  I did not see the tear of your car in the original post.

Most of the 32-48 Ford cars had a sleeve that connected the driveshaft to the differential. That sleeve has 2 pins in it that can break. I suspect that one of them has broken. You might be able to hear some clicking when trying to move the car.

Tom


Dustbowl    -- 12-22-2015 @ 9:51 AM
  Tom,
Thanks for suggestion. I also suspected that the pin in the sleeve had broken. That is why I tried turning the front of the driveshaft when rear wheels were on the ground.

When I could not turn the shaft, I guessed the pin was not broken. But maybe there is just enough drag of the pin against sleeve that I could not turn by hand but engine power could overcome the drag.

What do you think?
Phillip


cliftford    -- 12-22-2015 @ 10:49 AM
  In reply to previous posts: As I recall the sleeve is splined to the drive shaft and pinion shaft. If the pin was broken,the 2 shafts would still be connected, would they not? My guess is something is broken and the 2 ends of the broken part are hitting together just enough to make it feel like there is nothing wrong when you turn it by hand. Try turning the drive shaft back and forth with something that you can put quite a bit force on and see what happens.


Stroker    -- 12-23-2015 @ 6:57 AM
  I've had that coupler-sleeve retaining pin work loose enough that it would rub the inside of the torque-tube, and make a "clicking" noise when it scr*ped across the weld seam that runs down the length of the inside the tube. That is annoying, but as cliftford states; there is no shear load on the pin, as the drive shaft torque is transmitted by the splines.

So....somewhere between the crankshaft and the wheels something is amiss. I'd start by pulling the rear drums, and look for a sheared axle key.



TomO    -- 12-23-2015 @ 8:04 AM
  Clifford and Stroker are correct and I thank them for correcting my mistake.

Stroker is probably closet to the source of your problem, a broken axle is another possibility. Pull the drums and check out the rear end.

Tom


Stroker    -- 12-23-2015 @ 10:25 AM
  If the axle is broken, you will be able to pull the drum off without even removing the axle nut as long as the brakes are not applied.

Broken axles are fairly common in my sixty years of driving and working early Ford V8's.
They usually break near the base of the axle key, and the wavy break often resembles a miniature Pringle's potato chip in cross-section.

However, when you break an axle, it is often accompanied by the wheel riding out until it hits the inside lip of the fender which "generally" prevents the wheel from departing the scene. In any case, a broken axle has no way of retaining the wheel on the car (ask me how I know).

Given that your wheel hasn't fallen off, I'll put my money on a sheared key. A Ford can be driven with a broken key, as the real "grip" of the axle in the hub is due to the wedging action of the axle taper. In time, due to wear; this may loosen up and no longer apply enough torque to drive the car; but enough friction to turn a jacked-up wheel. At any rate, if you have a sheared key; the upside is you shouldn't need a K.R.Wilson hub puller!

This message was edited by Stroker on 12-23-15 @ 10:49 AM


Dustbowl    -- 12-29-2015 @ 6:00 PM
  Stoker wins the prize. The key between axle and brake drum has sheared into. Many thanks to all for advice
Phillip


Stroker    -- 12-31-2015 @ 1:37 PM
  Glad you found it, and it is an easy fix. Might be a good time to inspect the axle taper and hub internal taper for wear or damage. I used to use shims to get a good "wedge", but some actually lap the drum to the hub. Ideally, the taper does the "driving", and the key shouldn't "see" a lot of shear load. Realistically, it DOES see a lot of shear. Glad for you it wasn't an axle. Kind of a nice Christmas Present; don't you think?



EFV-8 Club Forum : https://www.earlyfordv8.org/forum
Topic: https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=9232