winch drive shaft "retubing"--"dead-spline" in line with ear or 90 degree offset?

winch drive shaft "retubing"--"dead-spline" in line with ear or 90 degree offset?

I am in the process of having the winch drive shaft "re-tubed" for my M817. I took the shaft in and the guy wants to know whether the "dead-spline" of the receiver is "in line with the universal ear" or 90 degrees offset. Well the truck is at the farm but I did happen to take a picture of it (attached) and it looks to me that the "dead-spline" is neither in line with the ear nor 90 degrees offset. First of all, I am assuming that this is critical to re-tubing the drive shaft--he seemed to think so.

Second of all, he says the shaft is way to long to be just 2 inches in diameter. He wants to put a 3 inch tube on there. It looks like there is clearance under the truck, but I thought I would check with the collective brain power of this website. I would hate to have it re-tubed only to find it won't fit. I cannot find a reference to any of this in the TM's.

I would appreciate any help that you can offer.

Rebar

I believe 3" will be to wide, others have used thick wall tubing because of the length, the U-joints need to be timed (on the same plain at both ends)

I would guess it's a dead spline, as in the yokes are fixed at each end, and the shaft does not have to move shorter/longer while running.

Think doghead did a retube on his 5 ton.

Look through this thread. http://www.steelsoldiers.com/showth...ne-wrong&highlight=winch+cable+broke+backward

You can't go larger diameter, not enough room.

Also, if you would simply continue one thread on your winch, it would help to know why your posting things like this. (then your one long thread would be useful later on for others)

Thanks doghead--had not thought of adding it to the other winch thread since it is different issue, but get your point.

Also, your reference thread is great. Answers a bunch of my questions. Had seen it before with first winch problem and forgot about it. My bad.

So, can anyone educate me on the importance of that notch in the splines (missing spline) and whether it is important that it be lined up with the universal ear on either end of the drive shaft? Is it supposed to be in line with the ear on both ends? Does this optimize u-joint function? Does it matter?

Thanks.

Rebar

From what I recall, there is no significance for that one missing spline.

That odd missing spline is normally used for phasing. The slip yoke on the truck should be at the driveline shop so it can be properly phased. Phasing is probably less critical with a winch driveshaft but it costs no more to do it right. Take him the slip yoke.

Found on a driveshaft shop website, http://www.dennysdriveshaft.com/frequently_asked_questions.html

My slip yoke has a space where it appears that one
spline is missing.

Yes you may find that your slip yoke has the space where one spline
is missing. When counting splines you will always add one more to your total
count when you see the space. For example on a GM TH-350 slip yoke you may see
26 internal splines and a space...this is in fact a 27 spline slip yoke. This
applies to ALL splined parts that have the space. For Chrysler owners you may
see some companies list their 904 slip yoke as a 25 spline when in fact it is a
26 spline. The 727 slip yoke may be listed as a 29 spline when in fact it is a
30 spline. This can be very confusing when selecting a slip yoke. The space is
found on the slip yoke but is not found on the output shaft of the transmission
or transfer case. There is no need to try to match the space with a
corresponding spline on the output shaft. You can install the slip yoke in any
position on any spline and it will perform the same way each and every time.
Remember this and you will never be confused again.​

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Rebar said:

Thanks doghead--had not thought of adding it to the other winch thread since it is different issue, but get your point.

Also, your reference thread is great. Answers a bunch of my questions. Had seen it before with first winch problem and forgot about it. My bad.

So, can anyone educate me on the importance of that notch in the splines (missing spline) and whether it is important that it be lined up with the universal ear on either end of the drive shaft? Is it supposed to be in line with the ear on both ends? Does this optimize u-joint function? Does it matter?

Thanks.

Rebar

Click to expand...

It INDEXS the slip joint so the U-joints on a drive shaft are timed right. not needed (why not found all the time) but sorta makes the timing "about" idiot proof

There is no corresponding spline on the shaft, to match the missing spline on the slip yoke.

In order for a shaft shop to index the splines to the opposite ends U joint position, they will need a/an(original) slip yolk.

The blank spline serves no purpose.

Eric and OP, in regards to this the info you posted is correct......when related to a yoke that slides onto a trans or transfer case output shaft. In regards to a slip and stub yoke, there is usually a corresponding spline on each part. The driveshafts that slip right on an output shaft already has the yokes welded in phase. With the slip and stub, if it weren't for the indexing spline, you could slide them together out of phase. As I mentioned earlier, phase is probably less important on a winch shaft vs a regular driveline shaft. Still best to drop off the slip yoke so that phase can be set.

If there are any angles or deviation in the driveline, and the "shaft" yokes are out of phase, the cross/u-joints will bind with respect to driveline angles regardless if it's a propeller or PTO shaft. If there is "no" angle in the driveline, then crosses and yokes are not necessary and a lovejoy type coupling (with slip-shaft) is used, they tend to absorb harmonics. But, with automotive installs, there is usually some degree of angle in the line, and the angle of the input should match the angle of the output (u-joint and yoke angles). The most common reason for PTO shaft u-joint failure are shafts installed with little or no angle, and cause the u-joint bearing caps not to roll and allow the needle bearings to "beat" into the caps, create joint looseness, and ultimately fail (usually coupled with a lack of PM).
Regards, Bob