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Steering improvements


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The Revington kit is to help eliminate "Bump Steer".

 

 

This is where when one or both wheels hits a bump (or hollow ) in the road which changes two things at once. Firstly it changes the camber angle and also the tracking of the car, gives an impression of a drunken passenger leaning over and snatching the steering wheel.

 

To give you an idea of how bad it is when you have the body off the car take out the suspension springs from the front and jack the car up on a trolley jack to the top of it's operating range (probably to about 6" from ground level to the bottom of the chassis). If you have the body off the car you can observe the front of the road wheels and tyres as you drop the chassis on the trolley jack smoothly. You'll be amazed at the amount the tyres and wheels first point one way and the other whilst the chassis travels through it's suspension range, I've altered over half a dozen race or road cars and the worst I've found is a change from to toe in to toe out of 14mm ! That's a major steering change and when it happens in action and in real time makes the car handle very badly. On a windy up window model (TR4 through to TR7) it's easy and cheap to check and change the steering geometry by lifting or dropping the steering rack to eliminate it. The sidescreen cars are more difficult because the steering box is fixed but you can alter the Steering arms by heating and bending (this is what Peter W describes in his earlier post), and what Revington can supply with the work cut out for you.

If you want an easy way to measure your Bump Steer that you can do yourself PM me your e mail address and I'll send a little article (with photo) that describes and shows how to do it. This is also available to all other members who may want it (currently over 100 other members have so far requested it).

 

Mick Richards

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Having fitted the above geometry kit, I can say that bump steer is considerably reduced, but the most noticeable improvement was that the car would almost want to go around a corner, rather than resisting it.

 

Bob.

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Thank you Bob

 

I was quite happy with the steering until I changed to a LHD. Then, I got quite a lot of play, and having fallen out with my "good" mechanic I took the car to a "bad" mechanic that screwed it all up! back to the good mechanic, a quick fix was to tighten things. But now I want to do a proper job. I think there is a problem with the shims in the box, and I am not too sure how it can be resolved if there are no spare parts.

 

Thanks

 

Camilo

 

The steering box can suffer from these problems:

1) Worn ball races(above & below the spiral grooved shaft)

2) Incorrect shimming on the lower plate (this sets up the free play on the ball races - there should be practically none)

3) Wear in the spiral groove, this can be offset by using the sprung peg modification.

4) Wear in the lower bush through which the main shaft to the steering arm goes.

5) Leaky seals, causing all the oil to disappear which in turn causes all of the above

The shims are available in two sizes from the usual suppliers, in fact most parts are available.

Bob.

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Answer to your questions as pdf here.

This is from the original parts catalogue with the two items your are asking about marked.

NB the idler is drawn inverted.

 

Hope this helps

Peter W

 

TR2-3 steering.pdf

 

Edited by BlueTR3A-5EKT
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Thanks Peter

 

You're not going to believe this, but I think I finally got it!...

 

Just one more thing: I take it that the Silent bloc & pin only exists on one side of the car near the steering box, right?

 

Thanks

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Hi Bob

 

I think that's what I meant... in my amateurish language.

 

the Silent bloc & pin only exists on one side of the car near the steering box, right?

 

 

In my case (a LHD), they are on the left hand side of the car, and there is not another a similar set-up near the right hand side front wheel.

 

I hope I'm right as I have already ordered the parts!

 

qim

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Hi Bob

 

I think that's what I meant... in my amateurish language.

 

 

In my case (a LHD), they are on the left hand side of the car, and there is not another a similar set-up near the right hand side front wheel.

 

I hope I'm right as I have already ordered the parts!

 

qim

My pdf clearly denotes where the two silent bloc and pin assemblies fit. There are two on a car, one either side of the centre steering cross bar Look again at the pdf I posted and you will see them.

 

Peter W

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Hi Bob

 

What's confusing me (still!) is that earlier there are mentions of

My pdf clearly denotes where the two silent bloc and pin assemblies fit

 

 

 

So, I expected that for both sides you would need FOUR parts (silent bloc x2 + pin x 2), but the image in the link only shows TWO

 

Sorry for going on and on

 

qim

Edited by qim
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Image is correct, there is only one silentbloc bush situated at either end, therebye making a total of two units.

 

Mick Richards

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As per the diagram the Silentblock bush is bonded inplace onto the pin (inspect diagram) and so all is fitted when bolted into place on either end of the rod. These attach to the steering box and the other the other end to the slave unit steering arm which mimics the steering input ( I think, over 40 years since I fitted them !). Check out Stans diagram it shows the silentbloc bushes/pins in place on either end of the rod where the arrows are.

 

Mick Richards

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TBH Im not too keen on that type of bush and use the Nylatron version instead, they are a direct fit replacement unlike the Revington one which require machining to fit.

Stuart.

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In my earlier picture (the photo with the two arrows) the bushes in my drag link are the Delrin bushes from Moss. While not universally true, many of us have found repro components made with modern rubber dont last long so I stayed away from the rubber silenbloc bushes and went with the delrin. I got them from Moss in the US, here is what they say about them:

 

This kit replaces the troublesome Silentbloc bushes in the steering linkage center tie rod (drag link) with precision machined stainless steel and delrin assemblies. These were originally designed for racing use, but have proved to be very effective on the street.

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