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BrianC

TR4A Ground Clearance

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Since acquiring Lynda's TR4A a couple of years ago, I have been concerned over the extremely low ride height and had intended to carry out a thorough investigation and possible overhaul during the winter. However, personal circumstances prevented this and the car was submitted for this year's MOT test as it was. Apart from needing one new rear shock absorber (the other had already been recently replaced by the previous owner), no other suspension problems were detected. However, the front silencer had taken such a battering from speed humps that it was leaking slightly, so although it was a new system and probably repairable, we replaced it with a stainless steel system. Since I don't want to have to replace this every year, I decided to check the ground clearance, which according to the workshop manual should be 6".

 

Measurements are as follows, unladen and, in brackets, two-up:

 

Height at centre of hardtop 49.5" [48.5"]

 

LHS (N/S) RHS(O/S)

Front wheel arch 25.75" [25.6"] 26.6" [25.5"]

Rear wheel arch 25.5" [25.7"] 25.6" [24.8"]

Min chassis ground clearance 4.3" [4.1"] 4.1" [3.9"]

 

Note: Front silencer clearance is just under 3"

 

I have checked the springs and all are inact and look fairly new but there are no spacers (sleeves?) fitted.

At present I cannot remove the springs to measure them, but as the car drives quite well (for an IRS car) I am inclined to leave well alone for the summer and drive very slowly over speed bumps and hump-backed bridges.

 

Meanwhile, if anyone can give me any comparable measurements or suggestions as to whether or not it is feasible to simply insert spacers in all springs, I would be grateful. At least I can formulate a plan for next winter.

 

Apologies for strange space-compressed layout - does anyone know how to create tables in this editor?

Edited by BrianC

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Car doesn't look significantly lower than some others I have seen but, assuming standard springs, I guess it should be about 1.5" to 2" higher. Both chassis and exhaust are uncomfortably near the road for my liking.

 

Will try to attach picture later or tomorrow - they seem to be too big at present and I don't have image reducing software on this notebook.

 

Well, reduced images are now attached, but you may need a magnifying glass :mellow:

Edited by BrianC

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Brian

A possible cause for the chassis and exhaust being too close to the road when the body looks ok could be the chassis itself.

If the chassis has been repaired in the cruciform area it's possible that the rear section could be lower than it should.

My TR6 has this problem - easy to see on a TR6, if you look at the chassis legs from the rear you should only see about 1/4"'below the rear valance. More than 1/2" would be suspect.

You can also have a look at the rear body to chassis spacers to see if extras have been added to get the right gaps.

Hopefully this is not your problem, but worth checking that the chassis is true first.

Regards

John

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Hi

 

I suspect that if the chassis is sound, then there is a spring-length issue.

 

You probably have sport springs fitted with no aluminium spacers. No spacers will give an even drop in ride-height like that which you have.

 

Worth checking as it's a relatively easy fix

 

Adey

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Brian

 

Id put money on that fact that that the springs are actually TR6 type / spec, and therefore about 1 inch too short ....... using spacers on the front (as the TR4) sorts this out mostly, and you can make some difference by using the superpro / polybush spring collars on the rear and / or cut down some front alloy collars a shade to make the back work.

 

Do you have positive or no camber in the rear ? another tell tale sign .....

 

I had this with my own 4a until I was told by MOSS that they avent made a spring for the TR4a / TR5 for years, but supply the TR6 spec item instead.

 

Regards

 

Tony

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If TR6 springs are on the rear would that end not tend to sit slightly high on a 4A due to the higher lb/foot rating leading to longer fitted length?

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Thanks for all the suggestions so far. If it stops raining long enough to venture outside, I will check the chassis packing pieces. However, I think the only repairs have been to the rear sections and looked to have been done well (I'm not able to jack the car up or put it on ramps at present but will have a good look when I get the chance). The visibility of the rear chassis legs is as mentioned by John.

 

My suspicion is that the springs are either short replacements which should have spaces fitted, or are originals which have weakened. I will re-check the bills which came with the car, but I don't recall seeing anything about springs. I suppose the previous owner could have left out the spacers to intentionally lower the car.

 

Would counting the coils help in identifying which springs are fitted? I suspect I will eventually need to remove them and measure them, in which case I suppose it would be sensible to replace them with longer springs or fit spacers all round.

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Brian,

When I got my 4A it sloped up to the front. As I've said elsewhere I had to sit on tip toe to see over the bonnet. I've put the notes I made before and after getting the correct springs, below. Maybe the measurements will help, maybe not.

 

Height off ground (before) (measured to wheel arch)

 

Driver front driver rear passenger front passenger rear

69.5cms 68.5 69.5 67.5

 

ie front level rear lower especially on passenger side.

See info on spring height.

 

Springs

 

from Buckeye Triumph Newsletter July 2002

 

“Rear spring free length 11.5in”(292mm)

 

“Front fender Ht left right

28in”(711.2mm) 28.2in”(716.3mm)

“Rear fender Ht 28.1in”(713.7) 28.2in”(716.3)

 

“Rear wheel camber -2.3Deg -1.6Deg”

 

 

from my TR4A(before)

 

rear spring free length 10.709in(10 11/16in)(272mm) short by 20mm

10 coils

width is 94.5mm,

wire thickness 13mm.

Appears as though existing rear springs are actually ‘front’ springs rather than rear springs.

 

 

22 Aug 06

 

New rear springs arrived today.they are about 11.5” high (292.1mm) 20mm longer

11 coils and are

width 97mm (3.82”),

wire thickness is 13.8mm

uneven. Put longer side to outside of bottom mount.

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