Boomer the Quadravan 4x4 Camper

spencyg

This Space For Rent
I'm with ya on the 2233L...the more I look at it the less I like it. I'll keep on track with the current high steer arm.

As for the pitman...the controversy that surrounds the modification of these things is pretty large. You read some folks who are against using anything other than brand new unmodified arms, and other folks who put the heat to it without any problems at all.

I am an engineer by both education and trade...some of my time has been spent doing metallurgical testing and from my point of view properly heated forged steel should be fine to bend if the original forging was good to begin win. This particular arm I'm working with is original equipment and has held up fine so far. I heated to the required temperature both times, bent while still applying the correct amount of heat, then slowly cooled the unit overnight in a bucket of sand.

That being said, I'm going to weld (remember, we're dealing with forged steel here) some additional reinforcement to the arm this afternoon before re-assembly to provide an additional level of insurance. Do I think I need it? No. Am I going to do it anyway? Yes.

Any arm I buy wouldn't be what I need so regardless of what the "correct" path forward is, I'd end up heating and bending whatever showed up. This arm is time tested and proven crack free this far. Anything else that would arrive in the mail (used for sure, new possibly) would be a questionable start.....

SG
 

Mwilliamshs

Explorer
Typical engineers: debating 2 "right" ways between themselves. I've done some forged-parts bending myself. Reworked dozens of suspension links rated to 120,000 lbs for a living in a past life. I'd rather bend one 10x than weld on it once.

No disrespect to you, your considerable skills, or your project. I just expected a better suited arm to exist. If it doesn't, you're making the right call by keeping what you have.
 

spencyg

This Space For Rent
Hey...I'm the first to say my way is usually 2nd rate :) If anybody out there has a link to a saginaw arm that has an UPWARD 10 degree bend PLEASE forward it along....

Otherwise, I'll weld a couple plates on this thing and call it a day....

SG
 

Mwilliamshs

Explorer
Second round of second-guessing for the day, should that propane manifold have some check-valves?

To prevent gas flow from small bottle into large, from large into small (or out the Q/D should it fail), etc. Especially since you can turn off the large bottle with its built-in valve but the small bottle has no such thing...so maybe a shut-off valve for the small bottle makes more sense there than a check-valve.
 

spencyg

This Space For Rent
I don't think I explained what I was going to do with the QD hose.

There will only be one propane source....the 20 lb bottle. The reference to a 1lb bottle was to say the quick disconnect hose will thread into a propane appliance intended to be run from a 1 lb disposable propane bottle. Instead of needing the smaller bottle, the appliance will run directly from the on-board propane system.

The hose I'm using...

1lb propane bottle adapter hose

I don't believe a check valve will be required.

SG
 

Mwilliamshs

Explorer
Yeah I misunderstood the propane. Thought you were preparing to use a 1lb bottle as an emergency backup. Re-read the original and your added explanation...cleared it right up. I'd never seen the 1 lb appliance adapter to allow using them with a bulk tank. Good thinking!
 

tgreening

Expedition Leader
Just to put some stink into the pitman arm debate. :)

Forged steel is quite a broad term and by itself doesnt tell you much about the properties of the part. There are many types of forged steel.

Generally speaking if you heat the part enough to bend it without cracking it, you've probably annealed the steal, which means its now soft. This is a good thing when you want to work the steel, not so much a good thing when you want the steel to work.

Next proper step is to temper the part you just softened so its back in a hardness state suitable for its intended purpose.

Then of course there's stress relieving and what-not.

There is absolutely nothing wrong with welding on suspension/steering components, as long as you know what the base material is and you follow the proper procedures for welding on it.

Grist for the mill...
 
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spencyg

This Space For Rent
All very good points. Normalizing the grain structure in the modified arm is going to be important. Once I'm confident I've got the geometry of the arm where I want it I'm going to throw the piece in my gas heat treat furnace. Hopefully this will normalize the grain structure once its left to air cool and eliminate any transitions between heat affected zones. Beyond that, I don't think I'm going to try and harden it at all. We're trying to prevent breaking here. If it isn't hard enough and it bends for whatever reason than at least it won't be a catastrophic failure.

I had a few minutes to reassemble the steering linkage and grab some pics of the situation







As you can see, to maintain parallel geometry between the panhard bar and the drag link than the frame end of the panhard bar mount must be so low that it will most certainly interfere with normal operation of the axle on the driver side. The required drop at the frame is approx. 8 inches in this scenario. Unacceptable.

In this image below the panhard frame side mount has been moved up where I want it. This is approximately 4" of drop from the bottom of the frame. Unfortunately, this position really screws up the parallel relationship between the panhard bar and the drag link.



So I went back to the high steer arm as the only way to permit the panhard frame side mount to be as high as I wanted was to lower the axle side drag link mounting position.

If the drag link could be mounted to the arm in the position I'm holding it in the picture than the links could be parallel and everything would be swell.



To accomplish this I'll need to modify the high steer arm a bit. This shouldn't be a big deal since its just 1018 CR steel. There isn't enough clearance between the bottom of the high steer arm and the top of the stock arm to have the drag link TRE fit, so I'll need to offset the position of the drag link as well as offset the plane in which the link fastens to the arm. This will actually work well since it will give me a very large weld surface area.



So the stock high steer profile will get cut back around the point where the rod end tapered hole currently exists. I'll cut a second 3/4" plate which sits on top of the arm and protrudes out to offset the link. Instead of the link being installed "top up" it will be installed "stud up" which will allow everything to line up.

A bit more work than I had planned but not by much.

SG
 

spencyg

This Space For Rent
OK.

I got to choppin' last night.



I picked up some 1018CR 3/4" for mods to the high steer arm as well as the new pitman arm. After some liberal pre-heat I was able to get 4 passes with the TIG on each side. I then ground everything flat and made a couple cheek plates. They probably aren't necessary, but more steel in this area won't hurt.



The high steer arm is bulletproof now and the angles I'm getting from the revision are going to be outstanding.





I then moved on to the pitman arm. I realized that there wasn't a good path forward with the stock arm. Had I left it alone to begin with I may have been able to reverse the taper on the TRE side which probably would have been fine, but hindsight being what it is....

This happened.


Followed by this.


I threw the lump of 1018 in the mill and bored a circular pocket to accept the splined chunk.


Then I stood behind the bandsaw for half an hour cutting away bits of thick steel, followed by another 20 minutes behind the belt sander to get the shape I wanted.

Beveled ready for preheat and welding.


Welded.




I let everything air cool overnight. I'll bore the taper for the TRE this afternoon and install it to check fitment. I am expecting to need a little more removal of steel on the frame side of the arm due to some possible clearance issues, but I'll leave all the steel on the passenger side of the arm. This thing weighs like 3 lbs so removing a little material isn't going to cause me any worry.

Hopefully I'll be sitting on all 4 again by tomorrow night.

SG
 

spencyg

This Space For Rent
After a little more tweaking I finally have a linkage configuration that will suffice.





I ended up flipping the taper on the new pitman arm. The first go with the new components had the drag link at an angle that forced the panhard bar into a collision path with both the pitman arm as well as the oil pan. I was also rubbing the lower radiator hose. Not good.

So I added a little weld material to the taper bore and re-did it from the other side. With the pitman arm end of the drag link a bit lower everything started to work. The frame side mount for the panhard bar is now sitting at 4.5" below the center of the frame which is exactly where I wanted it to be.







I didn't have much time tonight beyond this, but did get the drag link welded up for good. Tomorrow night the panhard bar frame mount will start as well as getting the panhard bar finalized on each end. I'm going to do my best to match exactly the length of the panhard bar and drag link. The angle is already going to be fine, and with equal length I am hoping the steering and general suspension dynamics will be so good that I'll forget about how miserable Boomer has been to wrestle down the road within a few miles of the test drive.

SG
 

why3zx

Observer
Great work, I had to make an account on here to say how much I have enjoyed this build thread. Working on a 91 B190 myself and this thread has been an inspration.
 

Mwilliamshs

Explorer
HELL YEAH! Looking real nice, spencyg! The speed with which you seem to move through these projects is impressive and the fab-work is top notch.
 

philos

Explorer
Outstanding.
Question, will your awesome new pitman arm clear the panhard/track bar at full turn left/right? Looks like it might hit in the pics, but it could just be the tight angle of the camera...


Sent via flux capacitor
 

Mwilliamshs

Explorer
Outstanding.
Question, will your awesome new pitman arm clear the panhard/track bar at full turn left/right? Looks like it might hit in the pics, but it could just be the tight angle of the camera...


Sent via flux capacitor

panhard isn't mounted to anything but the axle in these pics. the driver's side end of the bar is hanging from a piece of wire for mock-up. I'm sure whatever mount the builder of boomer comes up with will not cause interference.
 

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