It seems I have been falling a bit behind on updates. Let’s see if I can recall some highlights. Last Saturday I pulled the Jeep back into the shop, jacked it up and did the post break in lube change. There was a little bit of gray metal “fuzz” on the magnetic drain and fill plugs, which I considered to be normal. After draining the drain pan into a recycling container I found a few small shinny specs that I am hoping are just remnants that were missed in the cleanout. Not anything I’m going to worry too much about, but I may do another lube swap on a short schedule, just to be sure.
One thing I also wanted to address was the shock mount angle. The PO had a higher lift, so the shock mount angles tended to twist the rubber bushings a tad at ride height. Ideally I would cut the mounts off, turn them slightly and weld them back on. Here, on the passenger side, you can see how the twist left minimal clearance under the end of the shock body, just enough to chafe a bit of the paint off the bottoms of the shocks in normal driving.
This is the driver’s side after unbolting the lower portion of the shock; contour sanding the top inboard edge of the mount down using a flap wheel in the 4-1/2 inch grinder; and bolting the shock back up.
I still haven’t gotten around to installing the locker air pump; installing/wiring the activation switch in the dash and indicator light for the diff mounted switch that senses when the locker is engaged; or plumbing the air line, but the weather is starting to turn and I wanted to at least plug up the harness connection for the diff switch so that the leads don’t get all corroded. Here’s the end of the two prong connector.
I stuffed an expanding foam ear plug in the connector sideways to act as a filler…
… then smeared over it with a cap of Ultra Copper RTV sealant.
This way I can easily peel the sealant off and pluck the foam out when the time comes to hook it up. Here is the connector hooked back onto its little mounting tab.
I also attempted to reinstall the rear anti-sway bar, but for some reason it didn’t seem to fit. Later after a little research I figured out what I was doing wrong. Should have been obvious, but the dip in the bar goes over the pinion snout (for ground clearance), not under it. Doh. I’ll get that back in the next time I’m under there.
Unfortunately I did find a minor lube leak. The inside of the passenger side wheel rim was coated and there were traces slinging out on the inner sidewall of the tire. Closer inspection found wetness around the axle tube brake flange making its way down the back of the brake backing plate. I pulled the wheel and drum and found that there was no wetness inside the backing plate nor dripping from the lip side of the axle seal where it runs on the axle shaft, so it must be going by the outside of the seal between the rim of the seal and the ID of the axle tube, since it is never making into the drum. I wiped the wheel out and tried to tighten up the bearing retainer nuts a bit to see if that seated the seal any better, but after a few more days I can see that the inside of the wheel is damp again. I’ll have to pull the axle, clean things up and attempt to seal the outside edge of the seal with a small smear of sealant.
Next up I swapped the speedo drive gear out from the stock yellow gear (IIRC it was 30 teeth) to the white gear, 37 teeth. The speedo indication seems to be much more appropriate now, but I haven’t actually checked it with the GPS yet.
Back to the HPD30 prep work. It took several evenings prepping. I cut a piece of threaded rod that went straight thru the housing from end to end. At each end I put a round piece of 1/8 inch rubber sheet (drops from cutting pipe flange gaskets at work), backed up by what are essential very large fender washers (actually 2-1/2 inch slugs from cutting 1/16 thk sheet with a hole saw) and a couple of 3/8 nuts. This did a great job sealing up the ends of the axle tubes and hopefully keeping the blast media and dust out. I put a cut off bolt shank in a short scrap of vent tubing with a couple of worm drive clamps to seal up the housing vent. With the 3.55 pinion still in place and the diff cover sealed back down, it was sealed up nice and tight.
Next the glass window in the blast cabinet had been broken and replaced, but no one had fished out the broken glass. Now glass bead is a common blast media, but this was shards and chips of glass that would generally just clog up the media feed tube and make ciaos while trying to run the blaster. So I used a sieve to sift thru 5 gals of Black Beauty (coal slag) grit (using my respirator, of course).
Now we ran into a bit of an issue. The bare housing is about 58 inches from tip to tip of the inner C’s, and the cabinet is only 50 inches wide. Even on a diagonal the bulk of the housing wouldn’t fit, and there would be no room to move it around inside of the cabinet, let alone reach to the ends with the range of the gloves that are integrated into the front wall of the cabinet. So that meant that I had to feed the housing in thru the small side hatch door on the end of the cabinet, make a sheet metal closer plate (with a horse shoe shaped notch to fit over the axle tube) and secure that in the side hatch opening (sense the hatch couldn’t be closed with the housing sticking out).
At first I drilled a few holes in the temporary shield and screwed it to the rim of the hatch, but this turned out to be a PITA. The whole upper cabinet normally flips up so that you can load items directly onto the grating easily, but the side hatch has a rim framing the opening so with the housing part way in there the cabinet couldn’t be lifted to reposition it.
On top of that, because I was reaching inside as far as I could to get as much coverage as possible w/o having to reposition, the gloves kept popping off of their mounting collars.
Each time I would have to unscrew the side plate, turn the housing to where the pinion snout would fit thru the opening, and drag the heavy housing all the way out in order to lift the cabinet and reattach the gloves. PITA going back and forth, taking several steps to maneuver each nub, bracket and ball joint that wanted to catch on the grate bars and/or lip of the hatch opening.
Eventually I got the gloves sorted out; removed the expanded metal grate leaving just the larger grate bars, making it easier for the pinion snout to swing under while still in the cabinet; and switched to using duct tape to hold the side closer on for quicker changes.
After about 3 evenings (2-3 hrs each session) of juggling the axle housing in and out I declared that I was done with that task.
After blasting you can see the trouble areas better. These probably would have never been a problem if I just chose to ignore them, but I found that thought to be, “unacceptable”. After all, I am here, and this axle isn’t as much of a rush job as the rear was.
It was kind of strange. Although the front shock mounts each consist of two nested stampings (essentially a shallow ‘C’ within a deeper ‘C’ forming a box section with both sets of toes down and flush at the bottom), and the rust only occurred in the side wall of the top piece, it acted like it was two layers rusting; first thru the outer portion and then starting into the inner “layer”. I also saw this effect on the spring perch ‘hat’. The best I can figure is that this is a result of stress in the metal grain as a result of the deep drawing process when these parts were stamped. It’s as if the inner most fibers, that took the least strain when drawn out, were the most susceptible to rusting.
Here is the inside wall of the passenger side shock mount marked for cutting. At the top you can also see the spring perch hat where it rusted thru.
Here’s the same area (mirror image) on the driver’s side after cutting the bad stuff out.
I used a piece of card stock (scrap toothpaste carton material) and the hammer technique to mark a template for the patch piece. You can just see the faint outline made by holding the oversized piece up and tapping around the opening with a ball peen hammer (or small slug of brass where the hammer wouldn’t fit).
After cutting out the template with scissors; transferring that to a piece of 1/8 thk steel stock using a sharpie marker; rough trimming that to shape on the big Do-All vertical band saw; and tediously doing the final fit using the big belt sander, and a file, the plug fits the hole pretty well… snuggly enough to hold itself in place. Yeah there are a few uneven gaps, but, “if I can walk across it I can weld it!”.
Here’s the other side also ready to weld.
I stuck a couple of magnets on them to help keep me from nudging them thru with the torch or filler wire, just long enough to get a few tacks on.
There were a few areas where the surrounding metal was a bit thinner than the patch… partly due to the stamping draw and partly due to rust… so I made sure to lead and hold the arc on the thicker patch piece, and just weaved over to the edges of the bracket long enough to progress the puddle along (i.e. heat control). Here are the two patches after welding and a little touchup grinding with a flap disc. Nothing crazy, just knocked down the areas that had extra filler; by keeping the heat on the thicker metal I knew I had good weld penetration along the edge.
The spring hat was much thinner material to begin with and I wasn’t entirely sure that I could do the repair as well as I would like to hope. The biggest concern was not having enough metal to work with. The second concern was not encroaching on the inside diameter of the spring coil and buggering up how it fits into the pocket (not having a spare spring on hand to check this fit meant that I would have to be super careful). The third concern was that the damage extended around the side of the hat near the steering dampener bracket, which blocked my access to get in there with the TIG torch, even the smaller one. My final concern was whether I had the skill to fit a patch piece that was shaped like a conical banana; the latter was somewhat allayed by the fact that my work had recently purchased a small bench mount slip roll former.
Here’s the spring hat marked for cutting. The steering dampener bracket is the one sticking up on the left with the bolt hole thru it.
As with the shock mounts, I cut it out using a combination of a small cutoff wheel and conical rotary file in the die grinder.
Template was first rough cut and hammer transferred, then transferred to some 1/16 bare steel.
Here’s the slip roller in action. By varying the gap between the two idler rollers (on the bottom) and the crank roller on top it is easy to form curled shapes. By varying the parallelism between the rollers you can form conical shapes. The trick is to creep up on the shape you want by trial and error.
I’m happy to say that it was more trials and no serious errors!
After a lot of fitting, tedious filing and just kissing the patch piece here and there with the belt sander, then going back and forth to the roller a few times once the piece started to fit well, I had it close enough that it mostly fit and held itself pinched into place, except for the far end… which I was confident could be tapped down into place once I started getting some tacks in place… “heat and beat”.
This pic taken during the fit up stage makes the gaps at the closing end look worse than they ended up being in the end. With the piece up out of the hole at one end or the other it didn’t quite match the true radius until it was tamped down in at both ends, at which time it grew to fit better.
Here it is after welding. I ended up struggling to get the last little bit behind the dampener bracket, and it was getting late, so I packed it in for the night and came back to it this evening. I moved the housing over to the other welding bench that is setup with the smaller TIG torch and finished that last little bit of welding behind the dampener mount.
I wanted to make sure that there weren’t any weld bead nubbies that would poke on the inside edge of the spring creating any stress or chafe points, so I went to the trouble to grind the high points down using a small stone disc on the die grinder.
Then it was two coats of Rustoleum gray primer, followed by a good solid coat of satin black.
What weld repair?
Actually, if you look closely in person you can still find the repairs, and I’m not actually trying to hide anything, but I am quite pleased with how well it has turned out.
Now I can get on with the gear setup and assembly.