Gunson Trackrite?

[Bronteboxer]

Does anybody have any experience of using a Gunson Trackrite to do their tracking?

I need to redo mine and was wondering about the best DIY way to do this. I have seen these and thought if they work, they seem to be a cost effect solution to getting it right?

Any thoughts or other options please?

Kind Regards, Graham.

[Keith Clements]

The tracking on the Jav or Jup needs to be done at three different loadings in order to set the track ball height correctly. As a quick and dirty method of adjusting the track then a drive over tracking device at least will sort the normal load track. The wear on the tyres should tell you if the tracking is out even if your steering feel does not. Getting the tracking and ball height (as well as ride height, camber and castor) correct makes a huge difference to roadholding , tyre squeal and ease of steering.
viewtopic.php?f=1&t=3885&p=21535&hilit=tracking#p21535

For Jupiter (Jav is different)
Castor Angle* 1.25º
Camber Angle* 0º
King Pin Inclination** 10º
Front Wheel Tracking Parallel to 0.125 in. (3.2 mm) toe-out
Chassis Height from Ground 8.25 in. (209.55 mm)
This is a long posting but contains some detailed pictures on how to set up the steering geometry using a good spirit level and some straight bars.
viewtopic.php?f=1&t=4206&p=23020&hilit=camber#p23020

This video explains but uses the Gunson range of tools.
https://www.youtube.com/watch?v=J-yiJpe1sIA

One important check is to make sure the steering moves freely and without play from lock to lock and at full bounce and full droop. Incorrectly adjusted or worn steering rack balls, track rod length, track ball height or steering pinion mesh or worn rack can be issues. In particular positions you may find extra play or tightness (which could be fatal). It is by far the best to do this yourself as very few garages would take the care.

[David Morris]

Hi Graham,

Yes, I have used a Gunsons Trakrite. It's sitting in my garage now! As Keith says, it's a good basic tool for getting the tracking right but again, as he says, there are lots of other things to consider. However, most of them are determined by things like the shims behind the top suspension boxes as one example and probably won't shift once set up correctly. However, the tracking can be so easily upset, it pays to have a simple tool like the Gunsons Trakrite.

In use, I have found you need plenty of space to use the device, with being able to roll the vehicle forwards over the whole length of the platform. I used a quiet car park, which was also nice and level, at the local university. Going back to the advice from Keith, I should add that you need to be careful with the adjustable ball joints, if you have that sort on your car, there are at least two types at least on a Javelin, one adjustable and the other fixed. You cannot swap them unless you change the steering arms, which is a right pig! The height of the ball is critical on the adjustable type and it can be trapped under the top part of the joint when on full bounce, if the ball is set too high. Also, be very careful with the cone nuts ( if you have a Javelin ) on the steering box link. Yes, they probably need adjusting if slack and need to be perfectively round and not worn into an oval. What you need to be very careful with is that the locking tab MUST be folded over both the cone nut flats AND the lock nut. It's tempting to just knock it over the locking nut, but the net result will be that the steering will soon LOCK UP SOLID!! Not a good idea and you will need lots of effort to get it undone, if you haven't already been thrown into a hedge!

So, have fun and I hope you find the Trakrite works well!

David

[Keith Clements]

Do not assume that after 65 years the steering geometry is correct. It may well have never been checked since manufacture and the car will have had a life. IT IS WORTH CHECKING ALL THE ANGLES!

Also check that when you rotate the track rod it is straight and does not deflect. You may be able to straighten it, if it is. Although Jowett track rods are strong it is worth cleaning thoroughly and checking for cracks (preferably using crack testing system).

[Bronteboxer]

Thanks for all the responses and good advice. I will be tackling this job over the coming winter months when I have the time, ready for next season. So I will be coming back to this thread many times to follow your tips!
Cheers, G.