Build thread 37 Dodge PU

[rspears]

..... My biggest problem was the pressure switches was they wouldn't allow the overdrive to turn off until the pressure dropped below the switch range. I tried different PSI switches and got tired of messing with it so went to toggles.

Ryan/Mike, that problem is caused by the switch having too much hysteresis, or non-adjustable hysteresis - big word for the value between the set and reset points is too wide, and/or cannot be adjusted, caused by the stiffness of the spring/diaphragm in the unit. What you really need is a unit that allows you to adjust the set point, and then set the value where it resets, or opens back to shelf state. You might even consider a digital pressure transducer if you want to get fancy, but one of the dual adjustable units is good if you know the pressure range and set points you're working with. Google 'pressure switch adjustable hysteresis' and you'll see a bunch of options. Hope I'm not preaching to the choir here....

[Mike P]

".......Hope I'm not preaching to the choir here...."

You're not to me anyway Roger. This is the first time I will be playing with one of these transmissions. I'm doing all the reading up I can and any suggestions and first hand knowledge (thanks Ryan) I can get is appreciated.

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[40FordDeluxe]

".......Hope I'm not preaching to the choir here...."

You're not to me anyway Roger. This is the first time I will be playing with one of these transmissions. I'm doing all the reading up I can and any suggestions and first hand knowledge (thanks Ryan) I can get is appreciated.

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I will have to look into this. I had a friend that was working on producing a controller for these but stopped due to life getting busy for him. I'd definitely be interested in using something different. It would take away the wife drivability issues. Oh, I did just type that. I tried some adjustable pressure switches but they were only adjustable on the closing side not the opening.

[40FordDeluxe]

I quickly looked through google and the noshak 300 series presure switch looks like it would work, but it only goes up to 30psi. I think if I remember correctly, we need a switch to go up to 45psi. I'll have to find my notes and see. I do remember that the gov pressure is 1lb/MPH. That may be different for the gas transmissions. I'll have to get the manual back out and check that.

[Mike P]

"......I do remember that the gov pressure is 1lb/MPH......."

It seems I remember reading that too, along with a note that that is based on stock gearing and tire size. I remember wondering what issues I'm in for running 4.56 gears. I'm glad this came up, it reminds me I need to do some more reading


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[40FordDeluxe]

Mike, I hate to cludder up your thread. I found this switch that might work for this application. If I get some and install them, I'll let you know how I like them. Thanks Roger for sharing this info. All the times I spoke with PATC regarding the problem with the pressure switches, they never mentioned these type of switches.

NOSHOK 300 Series Zinc Plated Steel Compact Mechanical Pressure Switch with Adjustable Hysteresis, SPDT, 1/4" NPT Male, 7-115 (870 psi) psi Pressure Range: Voltage Transducers: Amazon.com: Industrial & Scientific

300 Series Compact SPDT Mechanical Switch With Adjustable Hysteresis

[Mike P]

"......Mike, I hate to cludder up your thread......"

You're not Ryan, this is all stuff I'll be dealing with and it's pretty nice to know there is someone who has traveled the path before.

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[rspears]

Glad to help, guys. I got educated on switch hysteresis on one of my first power plant projects that had one of the last pneumatic control systems built. Your problem brought back 40 year old memories!!

[Mike P]

I’ve been pluggin away on getting the rear end in. As I’m a firm believer in never throwing anything away, I have a few spring packs laying around from cars I’ve parted out. After going thru what I have I settled on trying Mustang II springs I had. They moved the center bolt back a couple of inches, were 2 ½” wide and I had 2 sets so I could use one set as a donor for extra leafs.

The original springs were 1 ¾” wide so the front spring brackets were too narrow for the new springs. Rather than re-invent the wheel and build new brackets from scratch, I elected to modify the originals to hold the new springs.



After I sandblasted all the leafs I assembled the spring packs and added 2 leafs to each side as a starting point. They are a little shorter than the original springs (not a big deal as rear spring hanger is easy to relocate), and a good deal softer than the originals.


There is a lot of love and parts availability for the Mustang II front suspensions…..not so much for the rear suspension. After spending ½ a day trying to find urethane bushing for the front spring eye (the best I came up with was they could be special ordered but at least a 2 weeks wait time (plus about twice the price of the on the shelf bushings). While the cost was not really a show stopper, the wait time sucks so I moved on to plan B which was to order a set of B Body MOPAR spring bushings. They are the right width and center bolt size, but 1/8th inch too big around. It took just a few minutes to build a spindle and mount them on the drill press and turn them down with some 80 Grit sandpaper.



With the front of the springs mounted I was able to roll the rear end under the frame and start figuring out where the rear spring bracket will go. They are kind of hard to see in the picture, but I ordered a set of bolt on spring perches a while back. Anyone who has set a rear end up with standard perches and get everything centered and pinion angle set then tack weld the perches and hope nothing has shifted before final welding can probably appreciate these. I can snug these down and if I don’t like it just loosen the bolts until I’m happy with it. After I get everything set I can either weld them to the axle tube of replace them with conventional perches.

I was not at all happy with how the spring were on the initial set up. The front spring angle was really ugly and not even close to lowering the truck enough.




The cure turned out to be pretty simple, I flipped the front spring hangers. It looks like that did the trick, the spring angle looks good and it drops it to where I can fine tune the height with reasonable length spring shackles.




Dorman make replacement rear spring brackets and they probably have something I can use for the back mount. I’m still researching to find a chart on the dimensions for rear spring brackets but I have wait to make the final decision on that until I get the bed set back on and see how far the springs compress. If anybody had a link to a chart that shows the dimensions (bolt hole spacing, width, eye bolt size etc) for Ford/Dodge/Chevy trucks I would appreciate it.


Thanks for the lead on Eaton Springs site Mike, but they I couldn’t locate a chart there.

[34_40]

And thanks for the update Mike. I'll keep looking for a chart of some type, maybe in an old copy of Street Rodder...

[Dave Severson]

Nice work Mike, no idea on a chart but I'll look around and let you know if I can find something that would help.

[Mike P]

Still looking for a chart, I'm going to try to call Dorman today and see if someone can answer any questions. Last resort will probably be going to the wrecking yard to see what will work and get an application.

After shoving the Dana 60 around for the last few day I started wondering what the drive train in this thing was going to weight. Looking up the weights, with the Hemi, 46RH, and Dana 60 it looks like the drive train comes in at just a bit over 1200 pounds.

For comparison the lightest hot rod drive train I had over the years, SBC, aluminum glide and 10 bolt was right at 800 pounds.

Way too much time on my hands in the evening I guess
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[Mike P]

Well I got the bed temporarily set back on so I could get an idea on ride height and see how the tires look in the wheel well. As I mentioned I used a shorter/wider tire in back. I also used a little taller and narrower front tire on a wheel with more offset.

After years of looking at it with the wheels/tires/rake it had it definitely looks different to me now.






I'm open to any comments or suggestions on how it sits.


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[NTFDAY]

In the bottom picture the wheel/tire appears to be better centered in the wheel well though I would prefer more rake and would probably go down a tire size or two in the front.

[Mike P]

I tried a bigger tire on the back and I do like the rake better. I agree on the front, but may be a bit stuck there because of ride height issues. I'm at the point where I've stared at it too long and need to step away from it for awhile.