Rear wheel alognment

[rvwp]

Hi all, having restored my 72 6 from a large pile of bits purchased as an abandoned project, not therefore having the benefit of taking it apart, I am seeking advice with regards realigning the rear wheels. The pile of bits came with a rebuilt CTM chassis (nice job) which the rear suspension arms have been fitted with nominal shims based on the diagrams in the Moss cat and the workshop manual. Now that the car is nearing completion, any ideas on how to line up the rear wheels without going to the expense of optical alignment, even if I can find a local tyre firm with such equipment. Mind you I'm not sure I would want some tyre fitter at Quickfit messing around with the suspension! Thanks Rich

[Guest ron]

Rich, you would really be better trying to get someone to set it up who has the gear to do it, otherwise you are going to have to try and do it with homemade devices. I have used a homemade wooden thingy successfully for years to set front wheel toe-in but I wouldn't really fancy trying to set up the rear suspension from scratch using similar methods, although you could set it up approx till you can get it done properly.

Ron

[Lockley210]

Hi Rich

Have a look on the 5 Forum, there was recent topics on home made templates and tips.

 

http://www.tr-register.co.uk/forums/index....showtopic=12387

http://www.tr-register.co.uk/forums/index....showtopic=12392

 

Regards

Mark

[Richard Crawley]

You can do quiet a successful job of initial settings using string & chewing gum & this will certainly be enough to get you rolling but, as Ron says, you really need a session on a 4 wheel alignment rig with someone who understands these cars to get it set up properly; it makes such a difference!

 

There used to be a guy called Daniel P who posted on here for a while (try looking up his posts) who has done a few 4 wheel alignment checks on IRS TR’s.

[wheeler]

Hi Rich

 

Have a look at this which may be of use, looks very technical to me! http://web.archive.org/web/20040328222056/.../RSGeometry.htm

 

Best regards

 

Bill

[littlejim]

I guess if you find someone like Daniel P or someone who sets up ones that race you will get a good result.

 

If you go to a normal wheel aligner who doesn't know about Triumphs and all the different notched brackets, he's just going to play around with the shims same as you.

I did my 4A with the homemade gadgets and it was a lot better than what the PO's 'expert' had done. He'd put several bits in the front suspension round the wrong way.

 

When you see all the shims are the same thickness (depending on amount of rust) you get the message that, when new, the wheel alignment wasn't done in angstrom units, it was a pretty coarse sort of science. This encouraged me to be happy with the 'home' alignment.

 

The racers like MadMarx will know the real story but when mine's back together I want to have it with zero toe in and Zero camber on all wheels. If I can't get that I'll go for slightly negative camber. Don't want it changing from positive to negative on the bends, which it used to do when first purchased. Felt like the motoring equivalent of a snap roll.

[harrytr5]

The company I always reccomend is Discount Tyres and Exhaust in Hemel Hempstead.Make sure you book Daniel (or Harry as he is called by his workmates) to do your lazer four wheel tracking.He has all the information in his computer base for TR4a-TR6.I will shortly be taking in a very early TR2 in and add the data to his computer.Phone no 01442 240838.Post code HP3 9AL.

I do not have any gain out of reccomending this company but reckonise a bloody good old fashion

service which is very rare these days.Quite a few of our members now go there and come away feeling the same.

Regards Harry.

[Richard Crawley]

Hi Rich

 

Have a look at this which may be of use, looks very technical to me! http://web.archive.org/web/20040328222056/.../RSGeometry.htm

 

Best regards

 

Bill

Nelson Riedel obviously put a lot of time & effort into that excellent article, it does a terrific job of helping to understand the intricacies of the IRS set up & it's been doing the rounds for a number of years. There are 3 important settings on the trailing arms; the front/rear wheel centres, toe in & camber. The article primarily covers camber settings & how using the 3 brackets available can be used to make adjustments; thing to remember is that adjusting the shim packs doesn’t affect the camber, only the wheel centres & toe in. This is why it’s so important when replacing rotted out trailing arm chassis sections to get them welded back in as accurately as possible, get them wrong & it'll be the devil of a job setting up the rear wheel alignment & you may need custom made brackets to get the required offset.

[TR NIALL]

Nelson Riedel obviously put a lot of time & effort into that excellent article, it does a terrific job of helping to understand the intricacies of the IRS set up & it's been doing the rounds for a number of years. There are 3 important settings on the trailing arms; the front/rear wheel centres, toe in & camber. The article primarily covers camber settings & how using the 3 brackets available can be used to make adjustments; thing to remember is that adjusting the shim packs doesn’t affect the camber, only the wheel centres & toe in. This is why it’s so important when replacing rotted out trailing arm chassis sections to get them welded back in as accurately as possible, get them wrong & it'll be the devil of a job setting up the rear wheel alignment & you may need custom made brackets to get the required offset.

Hi Rich you could also try jigsaw racing based somewhere in the midlands according to what i have read they have just put in a complete set up to carry out this kind of work,have not heard any reports good or bad.they are also big time into Triumphs both road and race.

[TIMS]

Guys

 

Jigsaw Racing did a superb job on my car. The difference was noticable.

 

http://www.jigsawracingservices.co.uk/classmthjan08.htm

 

Here is my car up on the rig.

 

 

 

Regards

 

Tim

[yoda motorsport]

if you are in weymouth ctm is reasonably close in soton and colin does a good job alternatvely buy some dunlop gauges from ebay just think how much you will save in the future on tracking and tyre costs also whilst you are about it do not forget to use thread lock on the retaining bolts even nylocs can work loose in unf pitch and stsinless spacer shims can be had in a multitude of sizes to get it just right but avoid over shimming to many is not a good idea 2 or 3 per side is ideal

[rvwp]

Thanks guys for all the info. I did speak with Revingtons who's fairly close to me , but they were quoting 8 hours at £42 odd per hour to set it up which seemed a tad expensive! I will check with Colin at CTM to see what he charges. Thanks Rich

[rvwp]

I guess if you find someone like Daniel P or someone who sets up ones that race you will get a good result.

 

If you go to a normal wheel aligner who doesn't know about Triumphs and all the different notched brackets, he's just going to play around with the shims same as you.

I did my 4A with the homemade gadgets and it was a lot better than what the PO's 'expert' had done. He'd put several bits in the front suspension round the wrong way.

 

When you see all the shims are the same thickness (depending on amount of rust) you get the message that, when new, the wheel alignment wasn't done in angstrom units, it was a pretty coarse sort of science. This encouraged me to be happy with the 'home' alignment.

 

The racers like MadMarx will know the real story but when mine's back together I want to have it with zero toe in and Zero camber on all wheels. If I can't get that I'll go for slightly negative camber. Don't want it changing from positive to negative on the bends, which it used to do when first purchased. Felt like the motoring equivalent of a snap roll.

 

I agree with you. I reckon that the factory did'nt use modern 4 wheel optical alignment gear, so it must be possible to set up reasonably accurately with made up gadgets. Tell me more, Thanks Rich

[rvwp]

Thanks for all the advice guys. I do at least need to set up the suspension alignment so that I can run the car for a few 100 miles before embarking on a long round journey to specialists who all seem to be some distance from me down in Weymouth.

 

However I can't seem to see clear statements in the various handbooks re: what the basic set up should be. As my chassis is as new jig repaired by CTM, I assume that the rear wheel alignment should be zero toe in/out with the camber set by the brackets, ie 3 notch inside, 1 notch outside, by fitting equal shims inside and outside. Adjustment of the shims being used to fix front and back wheel centres and wheel alignment if necessary in due course.

 

What should be the front wheel toe and camber on the front for a standard road car? The setting of the front should not present too much of a problem.

 

regards all, Rich

[Richard Crawley]

Details for a PI car taken from the BL manual:

 

*Wheel base = 2240mm

Track: Front = 1276mm

Rear = 1264mm

Wheel alignment 2 up; Front & rear = 0 - 1/16” toe in

Ground clearance 2 up = 152mm

Camber 2 up; Front = 0 +/- ½ degree

Rear = 1 degree negative +/- ½ degree

Caster 2 up = 2 ¾ degrees +/- ½ degree

King pin inclination 2 up = 9 degrees +/- ¾ degree

 

*The actual wheel centre measurement is not critical as long as they are both the same.

[John L]

Richard

I presume when you say ground clearance, you mean from the floor to the chassis, at somewhere in the middle of the car. usually they say from static, then add 150lbs in each seat, should be the same I guess?

Regards John

[Richard Crawley]

I’m not sure where BL intended this to be measured; mine was only 5 ½ inches clear max but some of that will be down to the slightly smaller rolling radius of the 185 section tyres I run. Ground clearance is not that critical & what I would be more interested in is that all 4 corners of the chassis are more or less equal. All the suspension settings are supposed to loaded, 2 up & will be slightly different if measured on an unloaded car.

 

One thing to watch is the centre exhaust clamp bracket fixing bolts. I initially fitted mine from the top with the threaded section protruding slightly below the clamp but at the first MOT, there was not enough clearance to drive the car onto the ramp. Good job the MOT bloke was watching as I drove it on or I could have ripped the bracket off; we had to gently lift the rear end!

[johnny250]

Have you seen these? From the USA but look interesting,

 

http://www.goodparts.com/shop/index.php?categoryID=13

 

website is a bit slow but worth a look,

 

john

[Toss A Triumph]

Revingtons, a couple of years back they set-up a Wedge for me. Estimated up to 6 hours, sorted the job in just over 3. I'd much rather have a pessimistic estimate and be pleasantly surprised than the other way round. The bloke doing the work was a former F1 suspension technician, probably knew more than a dozen fast fit shop staff put together. You get what you pay for, I rated that value for money.

[murrayarnold]

The front toe is set very easily using 4 axel stands and a string line. However, this is great when you have a true aligned live axel. So you have to get the rear wheels aligned. So if there is no toe designe for the rear, then believe so.e basic geometry with string lines can be achieved. In my head its all straight forward. I plan to do this process soon and will take photos to help explain. 

[John L]

I have used one of these with some success,Trackrite,  I know that Stuart also uses these to get somewhere very near and almost perfect.

https://www.youtube.com/watch?v=X0ytDJ0mJoQ

 

[murrayarnold]

Interesting. 

[stuart]

The Trakrite is a good tool and does the job, works best on a nice flat floor.

Stuart.

[John L]

Dont forget Trackrite will only do the Toe In, I dont remember witch brackets you should have on your car, notches on the trailing arm brackets. I guess you have to start with the originals and work from there.

This site has good info.  https://static1.squarespace.com/static/5c6dec53b10f25d4edf0b3f7/t/5d0196c7f7754c00012d7787/1560385225242/Rear+Suspension+Geometry.pdf

John

[JochemsTR]

I made some recommendations getting some decent trailing arm brackets. They are being sold thru Revington, but you can buy them also direct from the manufacturer for a better price. (just a recommendation, not getting paid)

 

Jochem