4x4 Rear driveshaft slip joint question.

OK. For those of us with 4x4's we have a slip joint behind the center u joint that allows the rear section of the driveshaft to expand and contract when the suspension cycles.

My question is, is this spline on this slip joint indexed so that it can only be put together one way. Or is it splined so that i could be put together in any position in rotation.

If you have pics of it that would be greatly appreciated!

 

no one has teh pics?!?!?!

 

Well considering you are posting back only 3 hours after you asked questions, I am not sure anyone has had TIME to go take a look. Maybe give it a little while longer.

 

It can be put back in any position which is why you mark the shaft before disassembly

 

This is true, if randomly reassembled you could cause unnecessary wear which would most certainly lead to driveline vibrations in which case you would need to replace the u-joints.

 

this is what i needed to know. Now can i rotate the spline 90* and put it back together. Doing some testing as the driveline angles i have necessitate a first and 3rd u joint phasing.

 

if not 'phased' properly, yes, vibrations...they are not 'keyed' so if you don't mark them before disassembly you could potentially assemble wrong...

And 90* or 180* or 270* will not work, it can only go together right one way because of the spline spacing...the reason for this is to keep the u joints in proper phase and also to keep the front shaft and rear shaft in balance the way they came off the driveshaft balance machine...hope that all makes sense to you...

 

Exactly....

Same thing when you replace ujoints. You want to make sure each driveshaft 'ear' is matched.

 

yes i understand this.... but the driveline vibration tsb puts the first and third u joints in opposing similar angles with the center joint at a near 0 * causing the first and 3rd joints to cancel out eachother but they are 90* out of phase by design.

 

If this is a used driveline, which i'm assuming it is, then there are wear patterns on the u-joints. Any rotation other in reassembly will cause a new wear pattern to start...then you have driveline vibs. My recommendation (from experience) is that unless you mark and reassemble the driveline as it was when you pulled it, you are going to need new u-joints and a balance...sooner than later

 

Why do you want to rotate the splines? What's the purpose?

Driveline issues & vibes are a PITA to diagnose - Marking everything and putting them back exactly where they were prevents certain headaches.

But, if you're feeling adventurous.....by all means....have at it.

 

Driveline is brand new.

Like i explained. the way the driveshaft is setup from the factory you have the center and rear joints setup so that they cancel out the inherent velocity changes that u joints create.

With the driveline TSB applied, you go from the center and rear joints at opposing canceling angles to the very front and very rear joint at opposing angles. Problem with this is that those 2 joints are not at a proper rotational phase to cancel out the velocity changes created by the u joints. To fix this you can rotate the slip joint 90* and walla front and rear joints are now in a proper phase to cancel out.

page 17

http://www2.dana.com/pdf/J3311-1-DSSP.pdf


This is more of a test for me. I dont have terrible vibrations at all but i do have a harmonic at 55-60mph that i am almost positive thats caused by this out of phasing.... this is also likely the same cause for the decel vibe people feel from 30 to 20mph after the tsb has been preformed.

its all simple driveline mechanics and how u joints work. Obviously i will make where the factory orientation was so if it doesnt change i can go back to stock, but i just wanted to know before i pulled it apart if it was even possible to rotate it 90* on that spline.... i know my old chevy had an indexing notch so that the slip yoke could only be put back together one way.

 

My stock driveshaft disagrees with that statement.

For the OP's purpose, your idea will work. It has two slots so you can flip the tail section 180*. It's even marked with yeller paint from the factory so you can't hose it up. When you get it flipped and back in, use an angle finder to ensure both the front and rear shaft are at the same angle or you'll get vibes. You can put carrier bearing spacers in to adjust.

 

^ hmmmm.... im not looking to rotate it 180 as that gets me no where... i need to rotate it 90*.

looking at the female side it looks like there are 2 indexing splines (the fat notches). Are there the same 2 larger splines on the male side, or are there 20 total same sized ridges on the male side.

 

I see the "yeller" paint on the male splines... but what about the female splines?

 

I don't understand why anyone would want to run their driveshaft out of phase but if you need to get a joint out of phase for whatever reason would it work to take the center bolted flange that slide off to replace the carrier bearing and rotate that 90° You should be able to do that I don't remember it being keyed when I replaced my carrier.