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Hiem Joint Conversion Write Up
I have owned my '03 PSD for a little over a year now and since I got it the clutch always grabbed as soon as you came off the floor and I thought it was out of adjustment until I did some research and found that there was a bushing on the pedal arm that might need to be replaced. Low and behold it was chewed up and fell out in 3 pieces. Long story short the truck chewed up 3 more at roughly $10 a pop in the matter of a couple months. I finally decided that all the older (Pre '99) guys did a Hiem Joint conversion with that $40 kit off ebay, why couldn't I do it on my own and make it fully adjustable at that?
Pics will come when I get a chance to pull them off my camera.
Warning: This is a basic fabrication project not a bolt on so if you are uncomfortable fabricating from scratch you might want to take the specs to a machine shop and have them make it. I take no responsibilty if your fabrication skills are not able to create a copy of mine.
Warning: This project includes disabling the Clutch Safety Start switch. Proceed at your own risk.
Materials needed: (all found at any decent hardware store)
1- 3/8 Right Hand threaded Hiem Joint
1- 3/8 Stock rod (usually comes in 3' sections but if you can find a 1' section that will work)
1- 3/8 Nylock Nut.
2- 3/8 Flat Washers
1- 3/8 x 1.25" Grade 8 Hex head bolt
1- 3/8 x 3" Grade 2 bolt
Bench grinder or lathe (if you don't have a steady hand and a micrometer then you might want to get a machine shop to do the turn down portion)
Basic metic and sae sockets and wrenches
Angle grinder or cut off tool
Drill and Bits up to 3/8
3/8 x 24 Die tool Right hand thread
3/8 x 16 Die tool Right hand thread
T30 Torx head driver
Small triangle metal file
Total Time Required: Between 3-6 hours depending on the person
Pop the clutch rod off of the pedal and remove it from the master cylinder. You might have to wiggle and turn it till you find that spot where it releases. You will also pull the rod through the Clutch Safety Start switch and out of the truck.
At this point you might want to skip to the fabrication section if you don't think you will have the time to do this all in one shot so you can put the clutch rod back in and drive away and back to finish later.
Next find the two torx head screws holding the upper pedal spring mount in place and loosen the top one and remove the bottom one. You are now able to pull the spring out. This step might be able to be omitted but it is so easy you might as well help yourself out.
Under the hood you will twist the clutch master cylinder a quarter turn to disengage it from the pedal assembly. While under there go ahead and remove the 2 nuts on either side of the master cylinder. Back inside remove the two nuts that hold the clutch pedal assembly up on the cowl. At this point you should be able to remove the whole assembly. I had to remove the screws that mount the computer to the cab so it could move just slightly so the assembly would clear it.
This part is very subjective to the the hiem joint you use. I used a Hillman joint found at Ace and Do-It-Best hardware among other. You can order one from McMaster-Carr for about half the price, but I needed one right away so I bought local.
First I threaded one end on the rod with the 3/8 x 24 die with 1" worth of threads. I then screwed the hiem joint onto the rod and left 2-3 threads exposed. At this point take a spare 3/8 bolt and pas it through the eye of the hiem joint and the eye of the factory rod. This will give you the total length of rod needed. Mine ended up being right at 5" (5.05" on the micrometer). Cut the rod with about an 1/8" to spare so you have plenty of extra to grind when you flush it up.
Now comes the painstaking part of turning down the rod. You need to turn down a minimum of the last 2" of your new rod. The stock you are using is 3/8" (.375") you will need to turn that down to 1/4" (.250") with a variance of +/- .005" If you take your time this isn't that hard of a task but you need to grind and measure and regrind if you use a bench grinder. If you are using a lathe it can be a bit easier to get it just right. Make sure you grind evenly across the 2" shank but the KEY area is the final 1/2" as that is what will lock into your master cylinder. I placed the shank on the grinding guide of my grinder and used a box end wrench lightly pressed against it and held it on the threaded end with my gloved hand. This allowed the grinder wheel to rotate the shank as it ground giving me an even grind all the way around.
Once you have it ground down, put the hiem joint back on with 2-3 threads left exposed and measure to your factory rod again. In you need to grind the tip of your new rod a bit to get it to match the length of the factory rod, grind it to match. Remember to measure from the bolt center to the end of the rods, not from end to end.
Now to notch the new rod I laid the factory rod on my grinder guide with the wheel placed on the angled portion of the rod and used a sharpie to mark the guide for the correct angle. Measure the length of the tip of the old rod to the cut and then mark that same length on your new rod. Next measure the diameter of the smallest part of the shank in the cut (mine was .185"). Now begin grinding your new rod at the angle you marked. Cut away a very little bit at a time till you get it down to that diameter. You will need to manually file the edge of the cut so that you have a nice 90* angle from the tip into the cut. This is important because this cut is what keeps the rod from popping out of the master cylinder so make sure you have a nice clean edge and cut.
To finish it off you need to round of the tip of your rod on the grinder, it doesn't take much to round it off.
Congrats you now have a new rod, but alas we are far from done.
Now we turn to the pedal that you removed from your truck. As you can see, the nipple on mine was wore over half through and hence the cause of my destroyed bushings.
With you angle grinder or cut off tool, grind down the welds for the nipple till they are flush with the pedal arm. Flip the arm over and grind/cut the nipple off flush with the arm. Now you need to drill out the remainder of the nipple starting with a small bit and working your way up until you have drilled a 3/8" hole.
Finally you need to take your 3/8 x 3" bolt and thread the shank with the 3/8 x 16 die all the way to the head. (You can use 3/8" threaded rod with a welded nut if that works better for you).
This is the quick and easy part. Begin by replacing the pedal assembly, all 4 nuts and locking the master cylinder back into place. Now we will use the 3" bolt to disable the Clutch safety start switch. Find the switch under the dash (the black box your old rod ran through). Now thread the bolt into the hole closest to the clutch pedal and screw it all the way down till the head touches the box. Tuck and zip tie it out of the way.
You can now put the spring back in and tighten the torx screws down again.
Place the tip of the rod into the master cylinder. Now you can line up the hiem joint with the hole in the clutch pedal. Push the grade 8 bolt (make sure you use a grade 8 so it doesn't snap under pressure) through the hole, add a flat washer, the hiem joint, another washer and finally the Nylock nut. Please use a Nylock and not a standard nut with lock washer. Tighten it all down good 'n snug (the most specific and technical spec in the whole process).
Now you are ready to test your clutch pedal. If it is to low for your taste turn the rod clockwise, if too high then counter clockwise.
I absolutely love the feel of the new rod! Much more solid, no play and I was able to put the pedal exactly where I wanted it.
I have had it on there for a few days now and it seems fine but if it does start to walk either in or out of adjustment I might pull it, add a few more threads and a jam nut, but as of now I don"t think I need it.
I hope this helps someone else as much as it helped me.
So one hiccup... I didn't think about the Clutch Start Safety switch being the same switch that kicks the cruise control off so after driving over 280 miles on the interstate this weekend I realize I need to find a solution to this issue. I am about to pour over the schematics I have (Haynes Manual) to see if I can figure out the pinout on the switch and delete it completely with the proper jumper wires.