Steering, Suspension, & Brakes

I'm replacing the steering box in a Tr3 with rack and pinionlike the TR4's and up.Moss has a kit to do this but it cost moneyand in the spirit of the hobby ,why not do it yourself.I'm going to build a couple of brackets to bolt onto the old brackets like in the Moss pictures bur alittle different. Am I correct in making the rack ,when it is bolted in , on line with the steering arms when the car is sitting on the ground fully loaded with the motor in etc?The rack should also be centred.Also the track on the TR3 is forty five inches and on TR4 and later forty eight. Can I shorten the tie rods an inch and a half and re-thread as necessary.Not only will it steer better and park better but it will give me more room to install a Ford2.3 turbo engine in the car which is the next part of the swap.That way I get a five speed and more horsepower to make life more interesting.Before I go making brackets etc am I on the right road? Tim

Tim, I'm no expert on front suspension, but there are a couple of things that you need to check or you may wind up with bump steer problems. As I understand what you want is that the steering arm moves as little as possible as the suspension moves through it's range. Depending on the width of the actual rack portion of the steering that outer joint determins the pivot point of the steering link to the arm and the inner a frame bushings on the bottom and the shock arm pivot all need to move in alignment. That may require that the rack is actually mounted a bit lower than you'd think to compensate for it's width. It's sort of a trial and error thing, so sticking with the Moss kit which has the benefit of engineering expertise might be a wise thing to do. If you do want to do it yourself then there are software programs around that you can plug in your measurments and get a visual representation of the bump steer at different rack positions.

Thanks bill for the response.This is the kind of onfo I need before I start. I've read all the suff on bump steer on the site but going over it again and again would be a good idea to clarify my understanding. Thanks again Tim

Here's another thought on the problem. Since the track of the TR3 is 45 inches which is the same as the early bugeye, why not use a bugeye rack installed at the same height as the rack on a TR4. All the suspension pieces are identical so geometry is the same also. Any thoughts on that anyone Tim

I've heard of people using TR7 manual racks with different (spitfire?) ends. I can measure one up if you want.