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Ukmax

Front suspension and track width

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Looking at your picture posted earlier in the thread I can see that you don’t have the 4a/5/6 type trunnions and vertical links so all looks good there. 

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I’ve just measured my TR4. 

Wheel centre to lip is 375mm front and rear  

I have Revingtons 450 lb (red stripe) front springs and 161 lb rears  

Fronts have standard thickness Superpro Poly isolators with no spacers  

 

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Here is mine with a standard 60 spoke wire wheel and 165 tyre fitted. 

The sidewall just protrudes at the front and is tucked in a bit at the rear  

camber is the standard +1 degree  

 

93411084-7F2A-495E-883F-429FC0A5B653.jpeg

Edited by Drewmotty

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When visiting Stoneleigh at the weekend, I took the opportunity to measure the height to wheel arch on a couple of TR4s and was pleased to find that the measurement was the same (within a few mm) as that on my car.

I am now happy with the ride height but I still have to square the body up properly on the the chassis to complete this part of the job.

Thanks to all who gave such helpful advice.

David

PS. Andrew, I'm sorry but I missed your posts until I had posted this reply. Thank you for the confirmation re the vertical links, the height measurement and of course the photos

Edited by Ukmax
To add postscript

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Hi David. How did your Stonleigh measurements compare with mine?

 

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Stoneleigh 'car 1" was 365 and "car 2" was 370mm,  mine is also 365mm

There are of course be potential errors caused by having to "best guess" both the exact wheel hub centre, the exact position (vertically to wheel centre) on the wheel arch from which the measurement is taken and the the exact profile of the wheel arch, so it is by no means a scientific test and errors could be <> 5mm or maybe more!.

David

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David - - were your fulcrum mountings on the right way round?

Cheers

Rich

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Hello Rich,

Good to meet and chat with you on Sunday.

I haven't had time to check the fulcrum pins yet and I won't get back on to the job until next week but I'll let you know.

David

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Rich,

Because the car is up on the ramp with it's wheels on until next week, I didn't think I would be able to see the fulcrum pins but it occurred to me that I could photograph them with my phone.

Both fulcrums are fitted the same way around as shown in the attached photo  (Yes, I have new bushes to replace those!)

I understood you to say that the fulcrum pins should be fitted the opposite way around to the "apparently obvious" way, i.e.with the concave side facing away from the shocker, therefore it appears that mine are the wrong way around.

David 
IMG_3203.thumb.jpg.c6a2ee95534e74f465ef06c6a999e434.jpg

 

 

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David - that’s definitely wrong if your car was a 4A but I just have a nagging doubt that a tr4 was different to a 4A 

I’m sure someone will be along to confirm

Not at home otherwise I would go and do same as you on my 4!

cheers 

Rich

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Rich, I'm even more confused now!

Image 3204.jpg is from the factory WS manual (2nd edition 1965) shows the fulcrum orientated with the concave side facing inboard which  is the opposite way to mine.

Image 3205.jpg is a drawing marked as TR4A in the same manual shows the orientation as being the same as mine. This seems to indicate the opposite of what you have just stated in your post. 

I'm not doubting you but  since the fiasco over the distance piece above the spring, which is clearly shown as being present in this drawing, with no qualification as to the spring length, I'm beginning to have doubts about the accuracy of this manual.

David

IMG_3204.jpg

IMG_3205.jpg

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Yours are correct for a TR4. They were fitted the opposite way around on later cars. 

 

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David

To summarise then - for a TR4 , which you have, your fulcrum brackets are correctly fitted. For tr4As, they are fitted the other way round.

Cheers

Rich

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Thank you both.

It seems that it is best to treat the manual as a guide to procedures rather than a "bible"  because drawing E627 (which is marked on the other side as as being TR4A) is clearly not correct, unless only SOME TR4As had the fulcrum this way around.

Andrew, I should have noted your footer "40 years of TR ownership and still learning!" !!!

I've only had mine a few months.

David

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The car has been stuck up in the air for a couple of weeks following a hydraulic ram fault on my ramp and because I store another car under the ramp, I dare not let it down in case I can't get it back up again! (it's supported by acrow props just in case!)

As I said in a previous post, the ride height now appears to be correct but the left side wheel is further back in the wheel arch than the right side wheel and only a couple of millimetres clear of the wing on right lock.

However, I have been able to carry out more measurements because and It's clear that the chassis front or the suspension is still not correct.

Using plumb lines and laser, I have measured the relative positions of the lower trunnions and find that the centre of the right hand trunnion is about 10-12 mm further forward than the left hand trunnion. The line runs on the chassis cross member as near as damn it equally from the edge along the full length so that is square.  I also noted that the left side centre line is well off the centre line of the wheel when viewed from wheel side. I can't easily measure the castor angle at the moment.

 I cannot accurately do all the chassis measurements I need until I get the car down and am able to strip both sides of the front suspension again. 

In the meantime, does anyone know of anything else that would /may cause this discrepancy?  Bearing in mind that the first problem was caused by the lower wishbones being refitted upside down by the PO. 

David

 

right trunnion.jpg

left trunnion.jpg

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What are the comparable measurements on both sides of the car wheel centre front to wheel centre rear?

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As my initial problem was that the wheel was too close to the top of the arch, I only did a quick cursory check of each side wheel centre to centre measurement by "guesstimating" the centre of the spinners and I recall that it was more-or-less the same each side,  but but given I am now only talking about 10mm or so, then "more-or-less" is obviously not good enough!  I will therefore accurately mark the exact centres of each wheel and carry out that measurement again.

Before I do this, I will need to set the track on the front wheels again.

David

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Err...measuring from the rear axles centre forwards ? don't assume the axle is affixed in the correct place or angle without checking.

Mick Richards

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Have a look downwards at the inner lower wishbone mounting cross pin area, I have had to correct several chassis where they have taken a hit on the front lower down and its bent the lower mounting, it can be bent in at the rear or in at the front if the hit has been taken the other way, this will mean your trunnion is further forward or further back on one side. Easily repairable with a complete section from CTM.

Best explained by pictures below although they are from a 3a principle is the same.

Stuart.

 

Chris Veal ts57995 038.jpg

Chris Veal ts57995 039.jpg

Chris Veal ts57995 041.jpg

Edited by stuart

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Gents, thank you very much for the advice, which is much appreciated. 

Mick, I did check the rear axle, early on in my investigation and is was square with the chassis. However I don't know if it is in the right place do you have a measurement from an easily identifiable datum please?

I'll certainly carefully examine the areas you suggest Stuart but if nothing is obvious, I may decide to take the body off this car and jig the chassis up properly for my own peace of mind if nothing else.

I'm further frustrated by the problem with my ramp because it's holding me up from cracking on getting this car ready for a forthcoming rally.

David 

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"a measurement from an easily identifiable datum please? "

TR4 chassis diagram with measurements attached... number 41 I believe from the front spring pin dia where it goes through the chassis to the centre of axle = 18" or 45.72cm.  Make it easy and measure from centre of the  pin to the leading edge of the axle tube and add on half of the tube dia.

Mick Richards

 

TR4 Chassis drawing.docx

Edited by Motorsport Mickey

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The above chassis document also gives you the distance between the lower inner wishbone mounting pins, they should be parallel and if not will be caused by damage as illustrated in my above post.

Stuart.

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As suggested by Mick, I measured the rear axle for squareness in the chassis and found it be square within a mm. 

Close examination revealed a straigthening repair to chassis, roughly between the point where the left side forward body support tube joins the chassis and the first bend, where the chassis starts to taper towards the front. Also the fact there are ground down welds each end of the front crossmember, indicates this has been replaced (or cut out and reattached) at some time.  Because of the damage repair, I followed the procedure in the blue manual to ascertain the squareness of the chassis and found it to be within acceptable limits

I checked the wishbone pin mounts for damage as suggested by Stuart and there was no obvious damage but on the left side there is considerable deviation from the measurements given on the chassis dimensions diagram.  The deviation from the recommended  273.6 mm (pin centre to chassis centreline) is as follows:-

Left front +11.4mm - Right front +1.4mm

Left rear -11.2mm -  Right rear -1mm

It is more than likely that as part of the chassis repair, the wishbone pin mountings have been replaced out of alignment, which accounts for the position of the wheel in the wheel arch. I will attend to this when I strip the suspension next week to replace the spring, shocker and bushes.

Thanks again to all whom assisted with these problems, ironically caused by errors made during previous repairs.  I wonder what the next problem will be?

David

 

 

 

 

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12 hours ago, Ukmax said:

As suggested by Mick, I measured the rear axle for squareness in the chassis and found it be square within a mm. 

Close examination revealed a straigthening repair to chassis, roughly between the point where the left side forward body support tube joins the chassis and the first bend, where the chassis starts to taper towards the front. Also the fact there are ground down welds each end of the front crossmember, indicates this has been replaced (or cut out and reattached) at some time.  Because of the damage repair, I followed the procedure in the blue manual to ascertain the squareness of the chassis and found it to be within acceptable limits

I checked the wishbone pin mounts for damage as suggested by Stuart and there was no obvious damage but on the left side there is considerable deviation from the measurements given on the chassis dimensions diagram.  The deviation from the recommended  273.6 mm (pin centre to chassis centreline) is as follows:-

Left front +11.4mm - Right front +1.4mm

Left rear -11.2mm -  Right rear -1mm

It is more than likely that as part of the chassis repair, the wishbone pin mountings have been replaced out of alignment, which accounts for the position of the wheel in the wheel arch. I will attend to this when I strip the suspension next week to replace the spring, shocker and bushes.

Thanks again to all whom assisted with these problems, ironically caused by errors made during previous repairs.  I wonder what the next problem will be?

David

 

 

 

 

That is quite a way out! It definitely explains a lot.

Stuart.

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