Tuesday, June 20, 2017

MGB - Front Suspension Refresh (Part 3)

I'm continuing the front end rebuild I started in Parts 1 (See MGB - Front Suspension Refresh Part 1) and 2 (See MGB - Front Suspension Refresh Part 2). At this point, the front beam is stripped and removed from the car. We've evaluated the parts, and made determinations about which to keep and which to replace. Today starts the work of putting it all back together again. WooHoo!

Pivot on the Swivels
There some things really are best left to a shop. I want to do as much as I possibly can myself, but it's not a religion. It's just a strong preference because I want to learn and because I find it fun. I read through the process for removing and replacing the king pins and bushings within the swivels (wheel assemblies). This requires a shop press, which I don't have nor do I have the space for, and a trained eye for determining the viability of the wheel assembly as a whole. So, I contracted the fine folks at British Auto Works to do it. Like so many things, I expanded the job from just swapping the king pins and bushings to also include replacing and grease-packing the wheel bearings. Doing the wheel bearings didn't really increase the cost, and it gave me the peace of mind that the entire front end had been updated. British Auto Works completely strips, and then chem-tanks all of the wheel assembly. after testing and measuring everything, they assemble the wheel and finishes the job with fresh paint. All told, it took them three days, and most of that was because they wanted extra time in the chem-tank. The finished product looks fantastic and delivered that piece-of-mind that they were properly done.

Paint
While the swivels were at British Auto Works, I started working on the beam. For being exposed to the elements, and road debris for almost 40 years, I would have expected more damage or rust. In truth, it was in pretty good shape. So, I cleaned it up, first with a power washer, then by hand with Simple Green. Once cleaned, I could see a few scratches, but it was in really fine shape. I threaded the rusty old bolts which held the front shocks back in. I did that so paint wouldn't gum up the threads. Then I sanded it, wiped it down with mineral spirits and shot it with high-gloss black paint. Since I had the time, I let the paint cure for a week, light sanded it, wiped it down and shot another coat. At this point, I removed the old shock bolts so the paint would cure without them. While I had the materials out, I cleaned up the spring pans and springs, sanded and painted them too. Truth be told, I had lots of other parts around that I intend to re-install, so I cleaned them up, sanded, wiped and shot them too. I'll share some of the tear-down and re-assembly of those things in other posts. Everything got high-gloss black except the springs. Those I shot burnt orange which from afar looks like the vermilion on the body, but its not an exact match. I decided it wasn't a deal-breaker so I also sanded, wiped and shot the underside of the frame where the front beam mounts to it. I figured I wouldn't have that exposed again any time soon so why not?

Beam Me Up
Once the paint has been shot and cured, I was able to start assembling things. First, was the re-install of the bare beam. Since I was working on this by myself, this was a great deal harder than the removal. Why? The beam is held on with 4 bolts. Each bolt has a nut on both ends, and it passes through 2 poly/graphite (or rubber of simply poly) bushings, one on either side of the beam. The drawing on the side, here, with parts labelled 1 through 7 show the front bolt. The rear is similar. Note the orientation of the bolt in the drawing: the lump is on the bottom. This is important since the thinner stretch of the bolt runs up into the frame. If you try to send the lump up, it will not make it through the frame. Yes, I did try it that way. If you're doing this on your own, I fumbled my way into a process that works:

Get the beam onto your jack, and roll it under your front bumper. Looking from above, roughly align the rear of the beam with the rear frame holes, but still a few inches below it.
Pick a side. It doesn't matter which. Take the shorter, rear bolt, and load the bolt, stacking from the bottom: nut, plate, bushing. twist the nut onto the bolt a few turns. Slide the bolt up through the rear hole from the bottom of the beam, placing the top bushing onto the bolt. I found that these bushings sort of held the bolt in place.

With the bolt held in with friction, get more precise with your alignment, but just worry about that one hole and bolt. Raise the jack and re-check. Repeat until you have the bolt and hole lined up. Then, while holding the bolt to the beam, raise the jack, pressing the bolt into the frame. Once the bolt peers through the top of the frame, put the top nut on. Again, thread the nut on just a few turns so the bolt can hold the beam, but there is still a couple of inches between the top of the beam and the bottom of the frame.
The one bolt creates a pivot point so you can align another hole. I did the other rear bolt, following the same routine. With the rear bolts loosely in, the fronts are much easier. Stack the front bolts again from the bottom: nut, plate and bushing. Set the upper bushing, and set the bolt through the frame hole. Thread on the top bolt.
Now you can start tightening the nuts. On all 8 nuts you want some threads to peek out from the nut. If you don't see threads, you may not have enough bite on the nut to withstand the pressures during intense driving. Then, torque to spec (54 to 56 ft/lbs).

Shock Me
Once I had the beam in, I shifted to installing the front shocks. If you remember, the removal was only difficult for the rear bolts because of how close they are to the wheel well. The install is also challenged by this. If you painted your beam, did you paint with the bolts out? I accidentally left one out: the one I took to the hardware store. That bolt hole was a real pain to get a bolt into at this stage. The others just took a little windex on the bolt, and it threaded right in. Once finger tight, it doesn't take much to torque it down... except getting a torque wrench in there is impossible. You'll need to feel it, as you're aiming for 43 to 45 ft/lbs. I actually came back and torqued after I did the lower control arms because the torque settings are so close, I got a good feel for what 45ft/lbs is supposed to feel like.

Lower Control Arm
Now for the fun part. Whether you bought new arms or cleaned up your originals, there are two different arm shapes: one for the rear and one for the front. The "front" has a hole specifically for the sway bar that's reinforced. Pick a side. Grab a spring pan, three sets of spring pan fasteners (1/2" nut-washer-bolt combinations) and your lower control arm bushings. If you got the fender washers like I did, grab them too. You don't need the lower trunnion kit nor the spring yet. On each arm, press in the bushing. If you got the poly bushings, this may require a press. The rubber and poly/graphite fit in without much difficulty.

Slide a fender washer onto each front-back side of the pivot (the thing on the beam that the lower arms attach to). Then fit the rear and front arms on that same side, making sure to have them pointing towards each other and making sure you're using a front and a rear arm in the right spots (rear on rear, front on front). Yeah, that sounds obvious and all, but once you get on the ground all those arms start to look the same. Consider that the flat side on the arm faces the pan (see the picture).

Let the arms hang down and grab the spring pan and one set of fasteners. Holding the pan with the dish facing towards you, lightly thread the bolt through from the outside of the arm through to the pan. Set a washer on the bolt and then finger a nut onto the bolt. Do not tighten yet. Do the other 2 fastener set the same way: 2 on the rear, one on the front. With the spring pan loosely held to the arms, slide the other fender washers on and follow with the castle nuts. Once everything is on, but loose, start tightening things, moving from castle nuts to spring pan fasteners so no bolt gets hung up because it has been left untouched for too long. When everything is snug, torque to spec: 22 ft/lbs for the spring pan fasteners and 45 ft/lbs for the castle nuts.

For the castle nuts, align the castle with the cotter-pin hole and put in the cotter pin (or bailing wire, if you're like me). Better to torque a little too much than not enough, IMHO, but you shouldn't need to go higher than 50 ft/lbs. If you do, re-check your work. Maybe something is hanging up.

That's it for this time. I should be able to finish this up in just one more post. I'll get the swivels and springs on, and then the major efforts are completed. Thanks for following along. This has been an incredibly rewarding effort.

No comments: