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MG MGB Technical - Front Suspension and Brakes

After a short stint on the road, I'm taking the '75B back off the road once again to address a few items.

Main issue was the front suspension. I bought V8 bushing to install hoping that would help freshen up the front end. Upon closer inspection there is vertical movement at the wheel that is traced to the swivel set. Assuming this is a worn lower bushing. I don't have the finances right now to tackle that job. My question is should I go ahead and install the a-arm bushings or should I wait and do it all at once. Will the a-arm bushings alone make much improvement if I've got some wear in the king pin assembly? The car only has minor vibration at speeds of 60-70mph. My biggest concern is the wobble crossing railroad tracks, etc.

My second concern is the braking system which works fine. However, the brakes pull slightly to the left when pressed hard then rebounds hard to the right when let off. What's up with that? Recently rebuilt the rear brakes. Thinking maybe I should tackle the front calipers althought there are no leaks in the system at all. It has fresh pads all around. When pressed really hard the braking characteristics get all whacked out and feels like the car is dragging a little. If I stop and press the brakes really hard to reset them, then everything settles down again and the overall characteritics improve. Suggestions?

I feel pretty good with the rest. A carb rebuild and fresh fluids in the tranny and rear end.
Brad Batchelor

The longer you wait to fix your brakes, the more expensive it's going to get. The pulling could be caused by the front or the rear brakes, so I'd consider completely rebuilding the entire system. That's probably more important than the front end at this point.
I don't want to say that worn bushing in your front end is ok, but unless its really bad, its not a safety issue - and keep in mind that I don't know how bad they are. You could always try putting a replacement sleeve and bolt through the bushing for now to try to tighten things up until you ahve the cash.

Jeff Schlemmer

Pulling brakes are MUCH worse than a little shimmy.

I suspect old swollen rubber flex line at the caliper is your problem. Best solution is to replace all the rubber lines with nice new teflon/braided units. Do the clutch while you are at it.

Then a good flush with new fluid and all should be good to go. Unless the calipers leak there is no real reason to rebuild them.

The sudden rebound to the right is because you are unconsiously dialing in more right correction as you brake than you realize. When you let up all that correction is trying to make up at once.

If the front bushes are so rotten that the ring on the inner end of the a-arm rubs on the washers, then definitely replace them now. The bronze bushes in the king-pin take much longer to go bad so you have time. Really bad inner bushes can cause some funky braking effects too.

Shimmy can also be caused by wear on the steering rack. If the wheels trun really easy when jacked up (turn wheels by hand and watch steering wheel spin!), then removing one shim from the rack cover (messy job) will put a little more pre-load on the internal damper and end the shimmy. Re-balancing the tires can have an amazing positive effect too.

Mike!
mike!

Brad if you have wear in the suspension it can cause pulling under brakeing. Sitting in the drive and crusing worn components will find a happy balance that may give a fair drive. Under brakeing all thet energy is transferd into the suspension. Things can and do move. Your alignment could be shifting dramatically.

The problem may be with a bad hose or caliper but I have seen lots of $$$ sunk into brakes when the wobbles and bobbles were caused by worn suspension components.

Doug
Doug Gordon

You wrote you have recently rebuild the rear brakes. It could be that the left brakepads are misaligned and therefore don't touch the drum. If your problem started since your brake rebuild, I'd suggest you took off the drums and inspect the springs and pads. Don't forget the adjuster.

Good luck !
Jan

Thanks for the suggestions.

I've started on the lower suspension and the only real problem is the lower trunion pin on the left side of the car was basically welded to the distance tube. The PO had put poly bushings in the a-arms that appear to be in good shape. They just needed recentering. They'll do until a total front rebuild can be done.

I'm leaning toward the right front brake caliper being the suspect right now. The problems only started after a REALLY heavy braking situation where someone ran a stop sign and I had to all but lock it up. I'm thinking the right caliper is a little rough forcing the left to carry more load under braking and the right to drag a little upon release.
Brad Batchelor

Do your brakes rebound right when you let off because you countersteer to reduce the effects of pulling left?

Jeff Schlemmer

Brad, saw your post on the other thread as well. Swivel axle wise it does sound like the wear you have is the sort that will give you sloppy handling and so forth, but hasn't progressed to being outright dangerous yet; just be aware of what you have and what your car will do, and keep an eye on the A-arm holes.

Getting the brakes fixed is what needs doing now, as you know.
Safety Fast, Wade
Wade K

This thread was discussed between 15/06/2004 and 19/06/2004

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