Brake shims/Rough front end alignment

[bluemiata90]

I'm rebuilding the front end of my TR3A and also converting to rack and pinion steering. My first question is, I rebuilt my brake calipers and lost the pictures of when I removed them. Do the thin metal shims go on the inside of the caliper bracket or on the outside between the bracket and the dust shield. I put them between the dust shield and the bracket and the space between the new pads and rotor don't look even, actually, the rotor rubs on the inside pad.
The next question is with my new rack and pinion, How do I get a rough alignment. I've look in several books, but I can't find anything that tells me how to adjust the wheels, so I can get it to the alignment shop. All I want to do is make sure is will track somewhat straight, so I can tow it to the shop about 10 blocks away.
thanks /ubbthreads/images/graemlins/confused.gif

 

[MGTF1250Dave]

Aloha,

The Victoria British catalog shows the the shim installation as you did it.

On older member (he probably has about 50 years of LBC experience) of my club showed me a quick way to check alignment. That a length of sting and attached to the car behind the rear wheel, the spring shackles work well. Pull the string forward to the front wheel, keeping the string parallel to the ground and in a position on the outside of the tires (no part of the wheel or hub caps touch the string). With the string taut, site down the sting to see if it appears in a straight line, adjust the steering wheel until it is straight. Now repeat the process on the other side of the car, with out turning the steering wheel. If the string is straight, you have a good alignment, if not adjust the tie rods as necessary. Stings on each side makes the job quicker and easier to check adjustments. Because radial tires are more flexible, when you think you have a good alignment, move the car forward a few feet and recheck the alignment. I've used this on my TR3 and MGTF very successfully, since the only adjustment they have in toe in or out.

Safety Fast,
Dave

 

[Alan_Myers]

Hi,

There are two types of shims used with the front brake calipers: mounting shims and anti-squeel shims. The latter are thin steel that go between the back of the pad and the piston face, are usually about the same size and shape as the backplate of the disc brake pad, with holes for the retaining pins and - usually - an arrow pointing toward the front of the car to help correctly orient the shims.

But, I think you are asking about the mounting shims that go between the caliper and the mounting bracket, along with the mounting tabs for the brake dust shield. Often, these shims are unnecessary with a new, unworn rotor. Just shim as needed, or possilby not needed, to centralize the rotor in the caliper as best possible. It needn't be super exact, because the brake pistons will centralize themselves. My TR4 didn't need any shims last time I installed a new pair of rotors. But, I keep a set of shims handy anyway, in case a rotor wears unevenly.

With regard to a rough alignment, there are more elaborate ways to get it more accurate, but for a quick trip to an alignment shop I've just used a tape measure and a pair of long 2x4s that eyeball as relatively straight. Lay the 2x4s alonside the car, measure the distance from the rear tires is the same and measure that the 2x4s are parallel, then try to set the front wheels to straight ahead, adjust as needed, possibly eyballing it or using a framing square as an aid.

You can also use a piece of string, but I find the 2x4s easier to measure between. With modern tires, 0 to 1/16" toe-in is correct, so just try to get the tires running roughly straight ahead. It's most accurate to set this with the car "mormally laden", i.e. with the car's weight on the suspension (not up on a jack or jack stands) and with about 150-200 lbs in the driver's seat, tank of gas, etc., just roughly what the car's suspension will normally see out on the road.

/ubbthreads/images/graemlins/cheers.gif

 

[Geo Hahn]

A more elaborate method is described in this thread, but for a 10-block drive the string method is easier and certainly gets it done.

https://www.britishcarforum.com/ubbthread...true#Post168447

 

[bluemiata90]

Thanks for the replies. I think I'll use the string method and eyeball it the best I can. One of the problems I realize that I'm going to run into is that I don't have the body on or the engine in. I'll have to just do the best I can for now and when everythings together I'll take it to the alignment shop. As for the brakes, I'll just leave them the way they are until I can drive it and see how they work. Thanks again. /ubbthreads/images/graemlins/smile.gif