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TR4 front suspension


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In Autumn 2020 i had new rear springs, dampers, bump stops etc fitted to my TR4 and yesterday was completed the replacement of front suspension with new springs, shocks, bushes and top pivot point.  Previous to this work the car would easily ground including on / off my mate's four post ramp fitted with longtitudonal lifting beams.

I am pleased to say that on a drive out including rough farm type track she did not ground once. However, the gap above the four new Continental 195x65xR15 tyres (72spoke CWW) to the body is now quite a bit higher. Main reason for changes were front wheels clipping the front wings. The gap is now about 2.5" above the crown of the tyre or perhaps slightly less.

Will the springs settle down with some use such that the gap might reduce by say by around an 1" which would look better? If I knew how to post a photo I would do so.

Thanks

Steve

Car owned since February 1980 and last suspension overhaul around 1990.

 

 

 

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Is the issue front only?

Which springs did you fit?  TR4 front springs are NOT TR4A-6. Plus there were two lengths of TR4 front spring.

Did your front springs have an aluminium spacer fitted to the top of them?  That is the compensation for the two different lengths of spring. Use only with the approx 9" spring.

Did you add 'special' insulating collars to the front coil springs?

Did the wishbones move freely up and down once fitted before the springs were fitted?

They are the things that will adjust/affect ride height, if you re-assemble exactly as standard.

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I had two problems some years ago:

1st too solid PU isolators lifting the front, and

2nd too tight upper PU bushes, they glued on the falcrum pin in the „wishbone down“ position and also lifted the front

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Evening and thanks for the replies.

The problem is just at the front.

New springs from a TR specialist are 10.5" in length which is same as old ones and I believe are rated at 450lb/in. The invoice states TR2/4 front springs.

There were no aluminum spacers fitted on either side but rather some worn out insulators which have been replaced with new.

Cannot comment on wishbone movement as i did not fit, my role was to dismantle and then had to go to work Will find out.

New Koni shocks fitted.

What does PU stand for above?

Thanks Steve

 

 

 

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It sounds like you had either worn out springs or ones that were inappropriate for road use. 1” clearance between the tyre and the bodywork is far too small and would lead to frequent bottoming and inadequate ground clearance as well as problems with the tyres hitting the body. You might like the look of the car lowered like that but you will have to accept the downside. 
My 4A has TT4001 springs on the front which have a 390lb/in rate and standard height. I have a clearance of 60mm or about 2 3/8” with 185/80 tyres. I would leave the front as it is and level it up at the back. It will still look good!

Rocky

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On 12/7/2021 at 9:00 AM, Z320 said:

I had two problems some years ago:

1st too solid PU isolators lifting the front, and

2nd too tight upper PU bushes, they glued on the falcrum pin in the „wishbone down“ position and also lifted the front

The ‘seizing’ of new pu bushes on fulcrum pins in suspension was a reason the London Taxi vehicle road worthy testing was very critical of the use of such bushes on Taxi Cab suspension.   It was suggested they would shear/twist off fulcrum pins if seized.   Ooops!

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Unbelievable what ideas people have when they want to worry!

“I don‘t know - but it could be“…..

After a short time of using the PU bushes seized in a lower position when I jacked my TR, and moved some way up again when the car was on the wheels.

And with the spring out only „some“ force was needed to move the bush, get it  sliding and the wishbone up again.

But I had to „overmove“ it up in a higher position to get back to zero, this position was out of reach with driving.

The issue is called „hysterese“.

In this case it means, with a tight „seized“ bush you have to „overmove“ the wishbone in both directions before it starts to slide.

I kicked the poor PU in the bin and fitted Superflex, they are inside grooved to keep always some silicone in there.

Ciao, Marco

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On 12/9/2021 at 10:07 PM, Malbaby said:

Steve....450 lb springs are way over standard...are you sure about the rating...standard are about 320 lb and give a "firm" ride.

At 450, your car would ride like a truck.:rolleyes:

 

I have 450s on my TR4, they are Revington's rally/fast road springs. They're certainly firmer than the standard springs but not outrageously truck-esque.

Nigel

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