Front Suspension rebuild

[RETNJ]

When I bought the '74 MGB I knew that all of the front rubber was in bad shape and that the right front spindle had slop, but thought that it was a project that could wait for winter. Don't think so now. Right front made some ugly clunking noises during our last drive. Got a good look at it today and the pivot bushings are almost gone. Read through the workshop manual and seems like I can do this. I'll use rebuilt swivel assemblies, V-8A arm bushings, etc. While at it, check springs and lever shocks. Will get as complete a kit as possible. I assume that since the bushing is gone the wishbone arm is probably shot. Any argument for or against the "negative camber" variant?
Any special tools that I must have to do this job right? Anyone done this and want to share the "ugly surprises?" Words of wisdom?
Plan is to try to take it apart tomorrow morning and see what needs doing.
BT

 

[DrEntropy]

The most likely stuff is that the A-arms are shot, outer locating holes wallowed out. Kingpin bushings are a bit tricky in that they need to be reamed to size once pressed in, in line. Instead of the V-8 bushings I suggest Polyurethane.

That's my 2p.

 

[fogliner]

I found a page you might be interested in,its on Chicagolands site.
It has a pictorial of the whole process and the problems that Terry encountered.I found it very informative and it shows the Wallowed out holes in the A-arms that you are likely to encounter.

https://www.chicagolandmgclub.com/photos/mgb_susp/mgb_susp1.html

Good luck Mark

 

[PAUL161]

Don't cheat on the front end! If the part is questionable, replace it! B front ends are not that hard to redo. You'll get a dozen different ways to compress the springs, but a small coil spring compressor will make life a lot easier and safer. JMHO. PJ

 

[Randy Forbes]

Don't tighten the pivot point nuts until the suspension is sitting at ride height (weight of the car on the wheels).

I'd be more inclined to use the V8 bushes, as the polyurethane will wear out faster (the steel-sleeved bushes merely flex in operation, the poly ones actually have to rotate; rubbing = wear). The V8 bushes will give greater steering response than the originals, and not much less than the poly type.

As stated, expect the four (4) lower A-arms to need replacement. It's a rare car that had adequate maintenance on the front suspension, to keep the outer pivot from seizing, and wearing on the A-arms. Too much negative camber will wear the inside edge of the tire, unless you drive lots of twisties (at 8/10s or better :wink: ).

If you buy the king-pin/spindle assembly already set to go, there aren't too many pitfalls to worry about.

It would be a good time to service the front brakes, noting the condition of the rubber hoses, and the visible portion of the caliper's pistons (I don't know your skill level, so I'm reluctant to suggest rebuilding the calipers, using new seal kits and replacement pistons).

Regrease the wheel bearings, and put it all back together, leaving the inner pivot nuts and shock link-bolt finger-tight; put the car on the ground and reach under to tighten the nuts stated above. Jack it back up and install all the cotter pins.

Enjoy the new-found precision in your front suspension and steering!

Edit: read the manual about setting the wheel bearing clearance, as this too is vitally important (without having searched, I'm sure there are how to's here to follow; if not, I have a ton of Big Healey pictures showing the same procedure).

 

[fogliner]

Also remember that the front hub bearing setup is done a bit different on MGB's,Here's a link to a University motors video on doing it right.
For when you put it all back together.

https://www.youtube.com/user/Universitymotorsltd#p/u/90/RJYIXZtnIiw


Mark

 

[RETNJ]

Here's where I am right now.
Somebody suggested the Hammer and Spanner site and it has been a wealth of info. Still, the learning curve meant that it took all morning to disassemble the left side and about 40 minutes to disassemble the right side. I bought a spring compressor but it is too big to fit in the springs so I did it with a jack. Worked ok, but I would prefer a compressor for the reinstallation. All the rubber is some degree of bad and needing replacement, but the right side is the worst. The trunnion bushings on the right are virtually gone. The A arms need replacement on right, but I'll do both sides. Good news is that the wheel bearings and brake assemblies appear to be good as new. The exciting news is that the lever shock on the right side was only attached by the two inner bolts, and they are very loose! The outer bolts appear to be missing entirely, not sheared!! Guess that explains the clunk. I think that both shocks are in good condition, but will re-read the test for them and check it tomorrow.
After I clean the gunk off of the swivel axles, I'll need to find out how to check them. Perhaps they are ok. If in doubt they'll get replaced. Not sure about the springs, but will measure them.
Tonight and tomorrow I'll create my shopping list and order the stuff on Monday. Geez, am I greasy..

 

[Randy Forbes]

Verify that the shock mounting threads haven't been damaged before installing new (grade 5 or better; grade 8 or L.9 preferred) bolts.

It would be a good idea to run a thread chaser in those outer holes, just in case the bolts were yanked out of that last thread or two, as opposed to merely vibrating out (not as likely).

Cleaning the threads with a tap will remove a tiny bit of metal, which you do not want to sacrifice, so a thread chaser is a better choice for this application.

Sounds like you've got a handle on it now! For the record, I've always used a jack for compressing the spring, just work smart, as a compressed spring has a lot of energy.

 

[RETNJ]

I'll try to chase down a thread chaser on Monday. Can I assume that shock bolts provided by B Hive, Moss, VB, etc. are grade 5 or better?

 

[RETNJ]

Randy,
I did a little more investigating. The outboard bolt holes for the right shock were blocked with road grunge. Cleaned them out and put a bolt in them - they are in perfect shape. There never were any bolts!! Checked the left shock and all four bolts were loose enough for several pulls with the ratchet.
I will torque them later when torquing the entire installation. Checked previous owner's receipts and this was a "professional installation" in 12/04 by a shop with an excellent reputation, so I guess it was just one of those goofs. The bolts used are marked with WWE and a T.
BT

 

[Randy Forbes]

Nearly six (<6) years, I wouldn't necessarily condemn the mechanic. Those shock bolts live a rough life, and if they're on your maintenance list to check them twice a year, you'll almost always find that they can be snugged up a little bit each time. :wink:

I would hope that anyone supplying bolts for that application would have the correct ones...

Compare markings on both table 1 & 2 with your hardware: https://www.zerofast.com/markings.htm

 

[PAUL161]

Funny you mention the shock bolts missing. My TF chassis had two shock bolts on the right front completely stripped out and I had to go one size over to fit new grade 8 bolts. I would not Heli-Coil them in that position. Because I won't have an odd bolt or two mixed in, I re-did both sides to fit all new grade 8 bolts. PJ

 

[RETNJ]

Gordon got the parts to me on Tuesday and the car is now back together. Rebuilt swivels, new bearings, new A arms, V-8 bushes. Nice. Only took a very short ride as I get the alignment checked tomorrow, though it rides like it's okay there. Much tighter ride.