D30 High Pinion Axle Swap

[Mike]

Mike if you ever suffer from severe boredom something like this made out of 3/8 thick and 3" wide flat stock might make a nice addition to your truss http://www.undercoverfab.com/156-899...uss-system.jpg

That seems to be a good design. Considering that I have the lower CAs and one of the upper CAs in place tonight, I thin k that I will wait on that addition.

The control arms are not turning out to be the same length. Not a big deal since the arms are adjustable, but I am a little concerned that something else may be out of place. I am confident about the upper arm that is attached. Since it is closer to ride height, the angle seems much better on the drive shaft. But I think that I am going to put everything back together before I put the second upper control arm on. That way I can measure everything and insure that the axle position is correct before attaching the last arm.

[ROBERTK]

The control arms are not turning out to be the same length. Not a big deal since the arms are adjustable, but I am a little concerned that something else may be out of place. .

Well I know others here will call names again, since I am posting about my expertise, but...

With that much welding only to one side of a very thin and small dia tube, and over such a long distance, I would be very surprised if the axle tube isnt bent a decent amount. Might want to try and make up a true bar and see how bad it really is.

If I had to guess, I would say over 1/2 the axles that trusses are welded to, are bent and most are bent beyond what is acceptable limits. If you ever wanted to straighten a axle (without a truss of course) you can simply do so with a torch and small rosette type heating on the axle tube. So that should give you an idea as to how much tweeking, a tube can do with the amount of welding a simple single plate type truss like yours could cause. And Currie wont even weld a bracket on a tube without requiring them to cut the ends off and weldeding them back on true after it all cools.

[Mike]

Well I know others here will call names again, since I am posting about my expertise, but...

With that much welding only to one side of a very thin and small dia tube, and over such a long distance, I would be very surprised if the axle tube isnt bent a decent amount. Might want to try and make up a true bar and see how bad it really is.

If I had to guess, I would say over 1/2 the axles that trusses are welded to, are bent and most are bent beyond what is acceptable limits. If you ever wanted to straighten a axle (without a truss of course) you can simply do so with a torch and small rosette type heating on the axle tube. So that should give you an idea as to how much tweeking, a tube can do with the amount of welding a simple single plate type truss like yours could cause. And Currie wont even weld a bracket on a tube without requiring them to cut the ends off and weldeding them back on true after it all cools.

Good point Robert. I'll check it tonight. I welded the support on in sections so that it had some cooling time between melts. Which is part of the reason that my welds aren't as nice I would have liked. I'll let you know what I find....

[aw12345]

One of the reasons you tension it from the bottom before the welding begins. Welding a little at the time in different spots helps also.
It's a definite issue. another way to solve it if it's bend is simply lay beads on the bottom of the tube kinda like you did on the top.
Definitely doesn't hurt to stick a bar through the tubes to see if it's still true.

[Mike]

Well, I'm a lucky guy. The axle seems to still be perfectly straight. I checked both vertically and horizontally and things seem good. Now to put it all back together!

[RAT]

Well, I'm a lucky guy. The axle seems to still be perfectly straight. I checked both vertically and horizontally and things seem good. Now to put it all back together!

Not luck my man. Mad SKILLZZZZ...

[GP4Play]

Nice job Mike, I love learning new tricks.Thanks for shareing

[Mike]

Okay. When I got the axle to ride height, the pinion angle is sweet with the new HP!:

[aw12345]

Told ya

[Mike]

Well Mr. Green is back on his paws, but I still need to test drive him at highway speeds. Less than 50 mph is smooth so far.

The front ARB locker leaks like a sieve! I can hear it gurgling air out of the diff vent. Checked the copper tube and the air tube sleeve and fitting, everything seems good. I guess that I will have to pull the carrier again and replace the O-rings. I think that I will drive it a bit first.

I'll be replacing the bad bushings with Johnny Joints soon. Hopefully that goes well. Brian Nash with Tri-County Gear got me a great deal on two JJs!!

[6spdYJ]

Mike, looks great. If your lift is 4" and you put in a HP, the pinion is about 3" higher than LP, so your front shaft thinks it's within 1" of stock. It'll be perfect.