Front Driveline Options/Advice/Help (1 Viewer)

[Delancy]

It's funny that we all wait until after the lift, holding our breaths in anticipation, that we won't be cursed (or blessed, in some instances) with the dreaded 80 vibe, then the immediate reaction is "part time", even though there's a shaft for every occasion, important here where there's no adjustability, whatsoever, without major surgery or a lift specific arm that'll never happen.

Shafts and vibes.

If you wanna run vibe free, regardless of angles, measure, call Jessie, pay the man a metric chit tonne of money, and call it done, because it's the only way to correct the issue.

(Unless someone wants to buy mine.)

Typed before I read the above:

NASA or not, doesn't matter what the flanges are in relation to anything but each other and the driveline angle.

If any reference point apart from those is necessary, it'd be plumb, achievable with an angle finder, not bevel box, then actual degrees off the centerlines can be measured, opposed to comparing the difference between two surfaces angles to each other.

 

[bryson]

You certainly can re-phase a DC shaft - the phasing at the slip end can be changed exactly as you would with a standard shaft. I don't know if it would make any difference since the whole point of a DC shaft is that the CV joint has a "constant velocity" (duh) that would make the phasing of the slip end irrelevant, BUT, in your case with the angles not being ideal for the DC shaft I figured it was worth a shot. Certainly can't hurt.

I have a similar (at least height-wise) lift as you (OME 850J fronts with Slee CC) and was having the same issue with my stock drive shaft. It is currently removed and CDL locked while I cobble a front CV together from a Tacoma shaft. My angles aren't optimal either - my pinion angle is high too - but I was really hoping the CV was forgiving enough to make up for it.

 

[Dissent]

The concrete "level" was used to confirm the two flange measurements relative to one another. With the angle set to 0* on the transfer flange, the pinion flange reported 9.6*. Let's forget I mentioned the concrete because I think we're getting off topic.

I'll try a plumb bob and protractor but I know the DC shaft isn't perpindicular to the flange. At least the plumb will give me good angles to work with. Thanks for the advice.

Ideally, I would cut/turn and reposition the necessary bracketry but given the other benefits of the part-time conversion, I'd still do it regardless. I don't see the point of having all those parts whirring about while I spend 90% of my time driving to work.

 

[Dissent]

@bryson - You are correct, you CAN change the phase on a DC shaft but from what I've researched, it wouldn't change anything. That 90 degree angle is key.

 

[Delancy]

One more, then I'm out.

If you can accurately fill in the blanks (along with distance between flange surfaces, aka overall driveshaft length) and have five minutes time to relay to Jess at HA, he will tell what will work for the angles you have......his being a money back guarantee.

 

[Dissent]

@Delancy - Thanks, I'll check that out tonight and get those angles. I read that Driveshaft link for Jesse, what a great repository! Thank you.

 

[Dissent]

I measured everything tonight with the OEM shaft installed. The slope is 7*, the pinion flange angle is 10* and the transfer case flange is 3*. If I did the math right, I subtract the slope from each flange angle and get a difference of 4* at the transfer case and -3* at the pinion. Am I to believe that the 4* and -3* almost cancel each other out so my OEM shaft may work after-all?

I don't want to pull the spacers out until I get a brighter brain involved.

 

[Delancy]

I think, being operative, the OE tolerances are closer than a degree and think (again, operative) the reason for the close tolerance is the slightest variation from congruency spins one end faster than the other.

Five minutes to swap, so worth trying, but may play close attention to slip joint engagement, ensuring its not extended beyond the OE (I think the length you gave is longer than OE) and also condition. It's more critical that the joint be tight to operate happily.

 

[Dissent]

I don't have the new joints in yet and I suspect the current joints may be damaged (the rears were).

The slip joint is solid and it's only extended about 1/2, very close to where it ran stock.

From what I've read since posting earlier, the tolerance is 1/2 a degree.

What are you referring to for the 5 min swap? The phase?

 

[Delancy]

Front driveshaft swap and I say five minutes because that's the timeframe (granted, I didn't clock it, but it didn't take long) to swap between the four I had, when trying to figure out why mine vibed.

Before the double DC shaft, the only one I had that didn't was one that the slip joint sleeve had contacted driveshaft, kinda pinching, so a very tight joint.

It didn't vibe, but, of course, that was irrelevant.

Still, joint needs to be tight as do the u joints.

 

[Dissent]

Gotcha. I already removed the SC and put the OEM in with 1.5 year old joints that may not have been lubed enough. The shaft and new joints are going to the shop on Monday.

Should I leave the spacers in or remove them?

I'll tighten the bolts and run it later today to test the shaft as is.

 

[Dissent]

I saw your post about that. The one with the crushed dust cover right? How did you finally resolve your issues?

 

[Delancy]

How did you finally resolve your issues?

Called Jess @ HA....

 

[Dissent]

I pulled the spacers from the front, it lowered exactly 1". I'm now only 3" lift in the front, 4" in the rear. The new measurements and angles for the front flanges and OEM shaft slope are below. Does this look like the front OEM shaft will work given these angles?

 

[Dissent]

That looks like a double-double cardan shaft. $$$$

 

[Dissent]

Put the DC shaft in and it's not at 90 degrees either. Not sure how anyone achieves that angle. It's off about 1.5-2 degrees and has a vibration. I'm still looking at getting new joints in the OEM shaft Monday but I'm getting tired of this.

 

[Delancy]

Not sure how anyone achieves that angle.

Adjustability that is not possible within the confines of the OE radius arm geometry.

Unsolicited advice, again.....

Don't spend another dime until talking to Jess.....

 

[Dissent]

I meant accidentally. I know it's not adjustable which fuels my rage/confusion.

I'm afraid to talk to Jess, he sounds very expensive.

 

[ALX4X4]

My Tattons (not fitted in this pic) runs fine with the aftermarket radius arms. I'm still getting a grinding noise on droop, but I think I can rule out the shaft and put it down to something in the transfer case, to which I'll have to wait until it goes bang before I know what it is...