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.

MGB - Front Suspension Refresh (Part 2)

Continuing from my last post, I'm focusing this group of posts on the rebuild of the MGB front end. Today, we get down to the beam, and get it removed from the car. I'll evaluate parts, and talk about replacement bushing options. Part I can be found here.

Shocking
While the beam is in, and you have access to your front shocks is the best time to evaluate them. On the right side, the shock responded relatively well to my efforts to move the arm up and down. It resisted in both directions, but not as much as I would have liked. Still, I probably could have left it alone. The shock on the left (driver) side, however, offered virtually no resistance to my attempts to move it. In fact, I could push it to the top of it's motion and it would slowly drop down. That shock is shot. Suspension shops usually recommend replacing both fronts and/or both rears at the same time. For a front-end like this one, where the shock absorber is also playing the part of the upper control arm, it is all the more important. These are held in place by 4 bolts. The two against the inner wheel well can be difficult to get to, but you can address them with the most basic spanners and ratchet/sockets. Similar to the engine mount replacement (see MGB - engine mounts), a good supply patience is welcomed here.

Set the shocks aside with the lower arms and pans. To protect the threaded holes, finger the old bolts back into the holes. I took one with me to Orchards and found replacement grade 8 stainless steel ones for the reassembly. I strongly recommend replacing fasteners with stainless steel or zinc coated to reduce the rusted-on effect.

Beam Down

image swiped from 'net,
but that's a stock beam

Now, the front beam should only be connected to the car by 4 bolts. Nothing else should be tying them together. No brake lines, steering bits, etc. but it never hurts to stupid-check (so-called for those moments when you don't check, something bad happens and call yourself stupid for not checking).

I used an ATV / transmission jack, but a more standard wheeled floor jack should work; it will just take more patience with balance. The ATV / transmission jack is nice in that it has two long arms to spread the weight, and improve the balance. Still, with the front end way in the air, and the rear on the ground, the bottom of the beam is not parallel to the floor. So, I slid a 2x4 under the front of the beam when the ATV / transmission jack reached the underside of the beam to make uniform contact. Raise the jack until it is holding some weight, but not much. You want the car stable on it's jack stands.

Relieve the torque on the 4 bolts by cracking the 4 bolts on top. you shouldn't need to hold the bottom nuts at all for this. I used the breaker bar with an assortment of extensions. Once cracked, do the same on the bottom nuts, just so they are not rusted in place. Whether you remove the nuts on top or the bottom or a mixture doesn't really matter. In the end, all 4 bolts need to be un-nutted on both ends. You would think that once the nuts have been removed from the bolts, they would just fall out. Fat chance. How about lowering the jack a little bit? Nope. To free the bolts, the top nut needs to be removed. Then, using a socket extension so you can address the bolt, rap the bolt from above with a rubber mallet. When this doesn't work, use a framing hammer, but be very careful with those bolts. They are not normal and if the threads are damaged, you'll need to order new ones.

Once the bolts fall out, either through banging or playing with your jack or maybe you got lucky and they just fell out... you'll see that these bolts are 2 different lengths and that the longer bolts (that fell out of the front) have a lump in the middle like a poorly rolled spliff. I retained all of this hardware, choosing to not try to find replacements, though I thought about it. Simply lower the jack, and the beam will lower with it. Pull out the front under the radiator and bumper.

Parts and More Parts
At this point, I was pretty spent. From the start of the prior posting to the beam on the ground was at least 2 days. Now that I've done it once, though, I could do it again in 1/3 of the time or faster. As I set with a beer, I looked at the pile of parts and the zip-lock baggies of fasteners. The fasteners were all bare steel, and they had plenty of rust on them. I chose to replace all of them except the beam-to-frame nuts and bolts. I added 4 fender washers to fit between the beam and the lower control arms. I felt this would help the bushings last longer. The fasteners probably put me back $50. Then, I turned to the pile of parts:

front shock absorber /
upper control arm

Front Shock Absorbers (2) New, these are crazy expensive. Moss has them for over $330 each. Instead, I found World Wide Auto Parts in Madison, WI who rebuilds originals. After some research I bought a pair from them at $99 each plus core which was returned when I sent my old ones back to them. They really look great, and if they work as well as they look, I just may go back for replacements of the rears instead of doing the swap-out for non-MGB rear shocks that so many folks do. The paint chips off without much effort, so if you're going for a show-car experience, I'd recommend repainting them.

Lower Control Arms (4) These looked okay, but without tight tolerance measuring tools, I couldn't tell if any of the important holes on the ends were out of round. Replacements for all 4 was $70 with OEM British steel, and the originals could have been worn from the bad seals, so I coughed up the $70.

lower control arms

Spring Pans (2) Like the arms, I couldn't tell for sure if the mounting holes were out of round, but on very close examination none of the holes looked oval. Since no pivoting happens with these pan holes, even a little out of round probably wouldn't matter so I chose to keep the spring pans, and just clean them up instead. New-steel replacements are $32 each at Moss, so they're a little steep cost-wise compared to some of the other bits. Still, if the spring pan won't firmly attach to the arms, your suspension won't be safe, so spend the $64. In the end, there was 0 play after everything was put back together, so my assessment was correct.

Front End Rebuild Kit (1) This was the whole point of this work. I found a few different suppliers for this kit, and resolved to buy from British Parts Northwest for $120. While their return policy is crap, their price is $35 less than Moss. These kits include:
- king-pin set and bushings. These run vertically between the arms and through your swivels
- upper control arm nut/bolts. They call them "fulcrum pin and hardware" and they attach the top of the swivel to the control arm / front shock absorber.
- upper control arm bushings (rubber or all-poly). These pair with the upper control arm nut/bolts to complete the set. I ended up swapping out the kit-supplied ones with some Poly/Graphite bushings I got from a new friend, Basil, in California ($6)

- lower control arm to swivel bolt/nut and bushings. They call these "Lower Trunnion Kits".
- lower control arm to beam ("A-Arm") bushings and bolts (rubber or all-poly). Again, I went with Poly/Graphite ($20) from Basil instead of the kit-supplied ones.

To do the front end rebuild, that's really all you need. I decided, though, that as long as its open, replace the beam-to-frame bushings.... and the sway bar bushings. Again, I sourced these from my friend in California. frame bushings ran $23 and the sway bar bushes were $10. When I consider there was no extra labor for the beam bushings, and very little on the sway bars, this was a very low cost to get the front end as rock-solid stable as possible.

Rubber, Poly and Poly/Graphite
Just for an aside, I wanted to touch on the differences between these three types of bushing. As a general rule, it's best that you pick one and stick with it through the front end. Since they behave a little differently from each other, the front end could be less predictable if your lowers and uppers are not the same material and respond to stresses differently.

Rubber - this is what you had originally. When squeezed between two pieces of steel which want to twist, the rubber twists with it. This smooths out the twisting motion, giving an easy, forgiving ride. For a cruiser, this is great material.

beam to frame bushings

Poly - this is the more common "upgraded" bushing. Unlike the rubber, the poly does not twist with the steel; it resists the twisting motion. This resistance reduces the degree of the twist, allowing more of the force through to the ride. This is a much less forgiving ride, but gives you a much stronger "sense of the road". Installing these bushings can be very difficult, requiring water-based lube or other tricks, maybe the use of a shop press. Once installed, most owners report loving them.

Poly/Graphite - this is in-between the Poly and Rubber in terms of road feel and difficulty of install. Basil described this far better than I could, so I will quote: They look like black plastic that has some give to them. You can put one between your thumb and forefinger and feel it give a little. The polyurethane matrix has a slippery substance called "graphite" (a crystalline form of carbon) in the polymer matrix so a slippery bit is always exposed and thus self-lubricating the bushing. No special install efforts needed.

This post got long again, so I'll continue in another post. At this point, we have the front beam completely torn down, our parts are ordered, and fasteners sourced at the local hardware store. We'll start next time with some painting and then assembly. Thanks, as always, for following along...