Suspension question TR6

[Richard Young]

Hello everyone,

TR6 1972 full rebuild.(Ex USA).See also rebuild blog.

OK, so now I am turning my attention to the suspension...need some advice.

What would be the best set up for a normal road car with taught suspension (not uncomfortable) but improvement on the original.

Reading up,I assume polyurothene bushes all round..what about springs and shockers? standard or uprated? also perhaps telescopic shocks on rear?

Any advice would be really appreciated including any other areas on the subject I have not mentioned.

Thanks in advance and apologies if these questions were already answered somewhere on the forum.

 

Richard.

 

 

[Dex]

Hi Richard.

When I restored my Ex USA 1971 TR6 a few years ago I fitted the blue poly bushes and adjustable telescopic Spax at the rear and new standard at the front. I'm very pleased with the ride, very taut but extremely comfortable as well and no rattles.

 

Regards

Dex

[barkerwilliams]

Richard,

 

My TR6 would not clear speed bumps in the road and bottomed out front & middle & rear even if taken very slowly. Vehicles behind did not anticipate me slowing down for speed bumps and often came very close to rear ending me. I fitted different longer springs (original length) & shocks and can now clear speed bumps "normally".

 

So my advice would be to fit bushes and then use what you have until you can decide if the suspension is suitable for the type of driving you will be doing.

 

 

Alan

[Richard Young]

Thanks for your input Dex..nice example....notice you converted to RHD..Thats another job on the to do list!

Take your point re telescopic on the rear.

And thanks Alan..interesting about the speed bump issue.

 

R.

Edited October 26, 2016 by Richard Young

[Peter Cobbold]

Richard,

Potholed roads and stiff springs are not ideal. I would fit standard rate/height springs and use a rear antiroll bar and see how the handling improves. The rar gets rid of soem of the understeer and roll. PU bushes help. A little bit of negative camber on the front, say -1degree, also helps cornering without upsetting straight line running.

But if you plan to throw it into bends on track days then lower and stiffer will make a marked difference over stock.

Peter

[RobinTR6]

I've had a number of 6 s and tried various setups. The best for me, normal road use including speed bumps, is uprated springs but standard height and uprated shocks, standard lever arms at rear (as noted uprated 25%). Much more sure footed, no wallowing and rides potholes and bumps without bottoming out..result.

[Richard Young]

Peter,

Are you suggesting using standard springs and shockers (the car is being rebuilt for road use only) and only driven weekends.I'm trying to weigh up whether there is much to be gained by uprating from standard.The rear original shockers are in good nick.I'm now wondering whether to fit the bog standard stuff (cheaper option).Also change the bushes for poly..... and then address any driving experience issue if or when they might arise 'down the road'.

[Richard Young]

Thanks Robin..taking all this in.

[Tom Fremont]

Hi Richard,

 

I've got poly bushes in my show car and stock rubber in my driver which does ~ 5K miles/year ( both fitted by me ). I prefer the stock rubber for regular use as it's smoother and doesn't squeak. A little negative camber will help the grip in curves, especially in the rear ( where positive camber is bad ).

 

So much dissatisfaction with the handling in TRs accrues from poor condition of the original components that a cottage industry in " upgrades " thrives, purveying extra features for the casual driver who just wants what the new cars provided.

 

Here's a checklist for suspension rectification:

 

- new bushings, ball joints and dampers

 

- tight, laterally compressed rack bushings

 

- proper alignment with camber negative in the rear, neutral or negative in front

 

- check tie rods for play and renew ball sockets/ shim if required

 

Stock components will give very nice results for road use. Track use is another matter.

 

Cheers,

Tom

[Peter Cobbold]

Peter,

Are you suggesting using standard springs and shockers (the car is being rebuilt for road use only) and only driven weekends.I'm trying to weigh up whether there is much to be gained by uprating from standard.The rear original shockers are in good nick.I'm now wondering whether to fit the bog standard stuff (cheaper option).Also change the bushes for poly..... and then address any driving experience issue if or when they might arise 'down the road'.

Richard,

If you do want stiffer springing then fit front and rear that are matched. If you just add stiffness to the front it will understeer even more than standard. If you have never driven the car it might be a good idea to fit the originals and see how it suits you. However in their day TR6s were described as 'boulevard tourers' - they are softly sprung ! If your driving style is more ambitious then stiffer springs will help as Robin has found.

A rear anti roll bar is quite easy to fit afterwards, as is an uprated front.

I dont know if USA cars had softer springing than in UK, but that market dominated sales.

 

Lowering the suspension is potentially dangerous if a rear suspension arm goes solid against the bump stop in a fast bend. The rear tyre will break away very fast, too fast to catch with opposite lock . It is an exciting experience....but....

 

Peter

Edited October 26, 2016 by Peter Cobbold

[Richard Young]

Thanks Peter.....I'm glad I posted this subject.

I was beginning to wonder if all these 'uprate options' strewn around the Rimmers/Moss catalogues were beginning to cloud my thinking a bit.I am beginning to think that for what I want out of the car would be happily satisfied by replacing with standard stuff and then suck it and see. Kinder on the wallet also.

[Richard Young]

Hi Richard,

 

I've got poly bushes in my show car and stock rubber in my driver which does ~ 5K miles/year ( both fitted by me ). I prefer the stock rubber for regular use as it's smoother and doesn't squeak. A little negative camber will help the grip in curves, especially in the rear ( where positive camber is bad ).

 

So much dissatisfaction with the handling in TRs accrues from poor condition of the original components that a cottage industry in " upgrades " thrives, purveying extra features for the casual driver who just wants what the new cars provided.

 

Here's a checklist for suspension rectification:

 

- new bushings, ball joints and dampers

 

- tight, laterally compressed rack bushings

 

- proper alignment with camber negative in the rear, neutral or negative in front

 

- check tie rods for play and renew ball sockets/ shim if required

 

Stock components will give very nice results for road use. Track use is another matter.

 

Cheers,

Tom

Thanks Tom,really helpfull info.

[Richard Young]

Richard,

If you do want stiffer springing then fit front and rear that are matched. If you just add stiffness to the front it will understeer even more than standard. If you have never driven the car it might be a good idea to fit the originals and see how it suits you. However in their day TR6s were described as 'boulevard tourers' - they are softly sprung ! If your driving style is more ambitious then stiffer springs will help as Robin has found.

A rear anti roll bar is quite easy to fit afterwards, as is an uprated front.

I dont know if USA cars had softer springing than in UK, but that market dominated sales.

 

Lowering the suspension is potentially dangerous if a rear suspension arm goes solid against the bump stop in a fast bend. The rear tyre will break away very fast, too fast to catch with opposite lock . It is an exciting experience....but....

 

Peter

Thanks Peter.....I'm glad I posted this subject.

I was beginning to wonder if all these 'uprate options' strewn around the Rimmers/Moss catalogues were beginning to cloud my thinking a bit.I am beginning to think that for what I want out of the car would be happily satisfied by replacing with standard stuff and then suck it and see. Kinder on the wallet also.

[Andy Moltu]

I would go for standard length but mildly uprated springs with a rear telescopic conversion with adjustable dampers which you can play with until you get them set to your preferences. Use the conversion that locates back to the original mountings. (some just bot to the wheel arches and some are coil over conversions but I don't really think these are ideal - will come to that)

Shortened springs are not a good idea for a road car given the appalling state of repair of many roads these days. We may think it's bad here but those of us who went to the recent Euromeet in Tuscany will know that some of their roads are even worse - I've never bottomed on a major dual carriageway before!)

 

I know the originality freaks will say stick with the lever arm dampers but that were out dated in the day. A number of people waffle about the trailing arm not being up to the strain of telescopics, but I an unconvinced of this - essentially the same (but not identical) trailing arms were used on the Stags and saloons mounting telescopics to the trailing arm in the same position the TR4A-TR6s mounted the lever arms. One might suggest the TR4A & beyond were perhaps intended to have telescopics but Triumph never got round to modifying the chassis?

 

You can probably get away with the kits that just bolt to the wheel arches but that relies on the arches being in very good condition and securely mounted back to the chassis. But as the bracketry to take the load directly to the chassis are readily available these days it's a no brainer. Some of these also bolt through the wheel arches so may help stiffen the body too. Just make sure your tyres don't foul on the brackets (fit spacers if needed) Also check your shockers don't bottom - take he spring out and jack the wheel up - the bump stop should be contacted not the shocker being maximally closed.

 

The coil over ones sound like a good idea in that the are aligned with the spring they are damping, however because they are nearer to the pivot of the trailing arm they have to work through a shorter operating length and so need to be stronger to achieve the same damping effect. The concerns than are whether it loads the trailing arm where it wasn't designed to be loaded (well it takes the spring loading and there haven't been to many reports of breakage there) however there have been reports of the top end of the damper cracking the diff' bridge. I would say that if you want to use this set up you are best to fit it as part of a body off job so you can beef up the mounting point.

Edited October 26, 2016 by andymoltu

[Peter Cobbold]

The most cost-effective improvement I ever made was solid steering rack mounts. Admittedly I was comparing them with tired rubber ones. And I've no experience of PU, nor of how to clamp them up tight. Thats worth getting right.

 

I fitted telescopics to the standard mountings and the top rocked to and fro, fracturing the bridge- as Andy says above. I had to bolt them through the wheelarch to cure.

 

Peter

Edited October 26, 2016 by Peter Cobbold

[Dex]

Hi Richard.

 

As an additional bit of info from my previous post I have retained the original springs all round, just cleaned and painted them. I also fitted a sports exhaust and this does hang significantly lower than the standard and I do have to be careful when going over speed bumps.

I'm currently restoring another 6 (I must enjoy the pain) and have fitted a standard exhaust so as not to have the problem above, it is also much quieter, the sports one can be a bit too much on a long motorway run.

 

Regards

Dex

[Steves_TR6]

I recommend the Racetorations rear telescopic conversion.

 

Made beautifully from alloy, had it on two cars now.

 

There's even a set on evay at the moment......

 

Steve

[Peter Cobbold]

I recommend the Racetorations rear telescopic conversion.

 

Made beautifully from alloy, had it on two cars now.

 

There's even a set on evay at the moment......

 

Steve

That's where mine came from, c/w shockers. Fractured the chassi plate, had to bolt the top to bodywork.

Peter

Edited October 26, 2016 by Peter Cobbold

[Tom Fremont]

For tightening the rubber rack mounts you can make a perfect tool ( works better than the factory tool as it fits easily into a completely assembled car ):

 

 

 

This one was made from a 3/8" turnbuckle - you just pry the ends apart

 

Someone more enterprising than I could fence these on the ebay by the dozen I reckon .

 

Cheers,

Tom

[Richard Young]

I would go for standard length but mildly uprated springs with a rear telescopic conversion with adjustable dampers which you can play with until you get them set to your preferences. Use the conversion that locates back to the original mountings. (some just bot to the wheel arches and some are coil over conversions but I don't really think these are ideal - will come to that)

Shortened springs are not a good idea for a road car given the appalling state of repair of many roads these days. We may think it's bad here but those of us who went to the recent Euromeet in Tuscany will know that some of their roads are even worse - I've never bottomed on a major dual carriageway before!)

 

I know the originality freaks will say stick with the lever arm dampers but that were out dated in the day. A number of people waffle about the trailing arm not being up to the strain of telescopics, but I an unconvinced of this - essentially the same (but not identical) trailing arms were used on the Stags and saloons mounting telescopics to the trailing arm in the same position the TR4A-TR6s mounted the lever arms. One might suggest the TR4A & beyond were perhaps intended to have telescopics but Triumph never got round to modifying the chassis?

 

You can probably get away with the kits that just bolt to the wheel arches but that relies on the arches being in very good condition and securely mounted back to the chassis. But as the bracketry to take the load directly to the chassis are readily available these days it's a no brainer. Some of these also bolt through the wheel arches so may help stiffen the body too. Just make sure your tyres don't foul on the brackets (fit spacers if needed) Also check your shockers don't bottom - take he spring out and jack the wheel up - the bump stop should be contacted not the shocker being maximally closed.

 

The coil over ones sound like a good idea in that the are aligned with the spring they are damping, however because they are nearer to the pivot of the trailing arm they have to work through a shorter operating length and so need to be stronger to achieve the same damping effect. The concerns than are whether it loads the trailing arm where it wasn't designed to be loaded (well it takes the spring loading and there haven't been to many reports of breakage there) however there have been reports of the top end of the damper cracking the diff' bridge. I would say that if you want to use this set up you are best to fit it as part of a body off job so you can beef up the mounting point.

Thanks so much for your reply...really useful information.

[simonjrwinter]

30% updated lever arms on mine, lovely smooth ride, nicely damped and comfortable.

Simon

[astontr6]

+1 for Andy! BL modified the spring rate on the rear at least 3 times that I know of, always upwards? So what are standard springs for the rear? I have used SAH ex BL special Tuning rear springs rated at 420lbs standard height for 40 years, along with Spax Shocks mounted directly to the chassis at 3 points and had no problems. Lastly, I believe that the Carb. versions of the TR6 had a different front spring rate to the PI cars. I kept the standard PI springs on the front but I do not know what the spring rate was for certain. It may be 312lbs?

 

Bruce.

[Tim D.]

You can always go the whole hog and replace the chassis as well..

Removes any worries about rusted out sections leading to unwanted chassis flex.

One you probably a bit OTT. Although in my case it did some some considerable corrosion issues :-)

Otherwise thumbs up to the telescopic rear dampers through the original mountings and not going to aggressive on the spring rates. Tempted now by a rear ARB. But is it really worth it.

Also recommend solid rack mounts. Had me on my spit and tr.

Cheers

Tim

[Graze]

Richard

 

Hope you don't mind me asking a related question

 

Just fitted new uprated Racestorations springs and adjustable Spax shocks all round

 

Car is sitting about 50mm too high at the front - do I need spacers top and bottom on the springs (as I can fit thinner ones) or can I get away without any spacer between spring and mountings

 

Graze

[BlueTR3A-5EKT]

Richard

 

Hope you don't mind me asking a related question

 

Just fitted new uprated Racestorations springs and adjustable Spax shocks all round

 

Car is sitting about 50mm too high at the front - do I need spacers top and bottom on the springs (as I can fit thinner ones) or can I get away without any spacer between spring and mountings

 

Graze

 

Apologies everyone - this is off topic

 

Graze,

Is this car a TR2/3/4? or a TR4A/250/5/6

 

If this is the TR6 then no aluminium spacer should have been fitted originally and should not be required not fitted now - only the rubber insulators top and bottom.

 

Do you know the free length of the new springs you have fitted at the front?

If this is a TR2/3/4 and it had spacers above the front springs as orig I suggest you should stand the repalcement springs next to the orig springs to see if the orig aluminium spacer (about an inch or 25mm) is required to even up the unloaded heights.

 

Have you driven the car round the block, has it settled on its springs?

 

Does the front suspension 'work' as in go up and down when bounced - not something silly like a frozen shock or the internal shocker bump stop (rubber donut on shocker stem) restricting movement (remove it on TR2-4 cars as they have wishbone arm mounted external bump stops)

 

Which part number springs do you have in the front? TT4001PR or TT4102PR

 

IF these are, as I suspect Triumph Tune spec springs (hint in the part number) then the 4001 are 6.7 " fitted length-390 lb and the 4102 are 6" fitted length-420 lb.

 

You would need to check with Racetorations to be double dog sure - http://www.racetorations.co.uk/contact-us-i3

 

Cheers

Peter W