How far do I need push my shaft into the hole?

[78 GMC Jimmy]

So I am trying to figure out how much shaft engagement I need. Two piece driveshaft, U-joints on either end. Splined slip in the middle.

I'm not in the ideal range. I need to make sure that I'm in the minimum range.

So when the male and female splines meet, how far together do they need to get to be safe?

Here is an example pic (google)

https://4wheelsandamotor.com/wp-content/uploads/2019/03/4WAAM-DS-Spline-Stock-total-spline-e1552946445730-800x600.jpg

 

[Blue85]

how much shaft engagement I need...I'm not in the ideal range. I need to make sure that I'm in the minimum range...So when the male and female meet, how far together do they need to get?

Well if she's complaining/questioning, you probably need...something?

How far do I need push my shaft into the hole?​

I mean, good grief, could you make an easier/more leading topic?

 

[Chickntrk]

Not really a universal answer….depends on how long the splines are and how deep the pocket is. I’d say sitting at ride height you’d want at least 1.5-2” inside. But if you have a lot of droop suspension wise you’ll want more as to keep the shaft from separating when flexed.

 

[78 GMC Jimmy]

Not really a universal answer….depends on how long the splines are and how deep the pocket is. I’d say sitting at ride height you’d want at least 1.5-2” inside. But if you have a lot of droop suspension wise you’ll want more as to keep the shaft from separating when flexed.

It looks like after the shaft was inserted, I am engaged by about inches. With the rig off the ground, and the axle hanging, the numbers don't change. So I think I'm safe from having the shaft separate. No?

 

[78 GMC Jimmy]

I would like to put the shaft into the hole further, to be within the ideal range. Is there some "spacer" that can be used? Installing a CV U-joint on one of the ends would do it, but I would prefer a simpler easier option. Like using a wheel spacer. Is there a drive shaft spacer?

 

[78 GMC Jimmy]

Right now at ride height, I think I am at about 2" and that doesn't change when the suspension is relaxed. Not sure if the suspension is maxed on the shocks, or if its just natural spring sag when the rig is off the ground. But I assume if the number doesn't change between ride and lifted off the ground, then I'm golden - no?

 

[Babaganoosh]

Bottom it out and cycle it back and forth to check for fitment.

 

[nvrenuf]

One a regular non long travel driveshaft the male splines shouldn’t be showing, they should be completely inside the female slip yoke, from that point you would be measuring travel vs engagement.

 

[TJ1978]

is this pigpen worthy or a troll?

 

[Babaganoosh]

is this pigpen worthy or a troll?

View attachment 489823

See two posts up.

 

[Big Ray]

First thing I thought was "if you don't know by now..."

 

[78 GMC Jimmy]

Bottom it out and cycle it back and forth to check for fitment.

How do I bottom out the rear suspension? The last time I did that, I blew out the front diff yoke seal.

 

[78 GMC Jimmy]

Hmm. perhaps I should get something like this. If my shaft was 2 inches shorter, it would fall apart. At ride level its connected by two inches of splines. Ideally it would be sitting at 4 inches, not 2. With suspension relaxed, its still two inches. I don't think fully compressed suspension will cause the shaft to come apart. Any input on this??

Should I find something like this:

Amazon.com

 

[obijuank5]

On a typical road rig, you only need it to be about 1.5” away from fully seated in the yoke.

 

[78 GMC Jimmy]

On a typical road rig, you only need it to be about 1.5” away from fully seated in the yoke.

Ya, that's what I have been hearing from the driveshaft shops. Google agrees. I appreciate the reply, but I need to know the limits, not the ideal. I need to know the info from the other end of the scale. Your saying I should be 1.5 inches from fully collapsed. I need to know what the minimum distance from fully extended. If you pull the ends of the driveshaft apart far enough, it falls into two pieces. So when you stick the shaft back into the hole, how far in does it need to go to get the job done? 1 inch? 2 inches?

 

[obijuank5]

No less than the shaft splines minor diameter and that’s dancing with the devil. In reality, no less than full spline engagement.

 

[78 GMC Jimmy]

No less than the shaft splines minor diameter and that’s dancing with the devil. In reality, no less than full spline engagement.

No less than full spline engagement ?

What do you mean?

 

[obijuank5]

The splines were designed to be under full load with 100% of the splines driving the load. When you don’t have the stub and slip fully grabbing each other then the load is transferred on less of the stub which at some point overloads the material and twists the splines. So full spline engagement is it’s strongest and it still slips.

 

[78 GMC Jimmy]

The splines were designed to be under full load with 100% of the splines driving the load. When you don’t have the stub and slip fully grabbing each other then the load is transferred on less of the stub which at some point overloads the material and twists the splines. So full spline engagement is it’s strongest and it still slips.

Hmm. I sitting at approximately 2 inches of spline engagement.

 

[78 GMC Jimmy]

I can smoke the tires, lifting a tire off the ground and have not had any issues so far. I would hate to have the shaft fail at the wrong time though. Ain't nobody got time for that.