Revised eye bolt negative camber

[dalgrae]

The thread matches the original in size but is longer in case I need to add more washers so this may give the impression it is smaller in diameter, the nut was a commercially available one that I had available, I intend to replace this with my own machined version that will have a bigger hexagon and also make the washer to suit including it will be slighty thicker as well, I may well have to reduce in diameter the eyebolt location to body face as at present I have left it bigger to give a larger location mounting area ,but this can be done on fitting it to the car

[IslipMinor]

That looks very nice indeed. I am currently looking for a replacement lathe and a new eye bolt with more shank and thread length is going to be the first job on it - looks like I will have a very high standard to aim for!

[IslipMinor]

Well, it wasn't quite the first job, but yesterday I finished making the 2 new 'negative camber' eye bolts - picture below:
[frame][/frame]
The marks on the main spindle are very annoying and resulted from the way I had to hold the almost finished part in the lathe toolholder for fly cutting the chamfers (I don't have a mill, so had to resort to a bit of ingenuity). I used a thin strip of sheet metal to protect the surface, but it obviously wasn't thick enough. Up to that point the finish was really good!

The originals had been fitted with 3/8" of spacers, in addition to the original 1/8", and that was the maximum I could have and still get a full nut length of thread engagement. That was done in 1970! Originally with a 'U' section spacer, but of course that just let the corrosion develop, so during the restoration it was replaced with solid, but still the same length. The resulting camber was 0° and to get 0.5/1° negative needed at least another 1/8", so the new bolts are spaced out 1/2" more than standard, with a further 1/8" of thread so that I can add a further spacer if required.

The picture below shows the final assembly with the new eye bolt fitted, plus a new pin and polyurethene bushes, although the ones fitted nearly 50,000 miles ago showed very little signs of wear:
[frame][/frame]
The torsion bar is not quite as close to the exhaust as it looks in the picture! The 'U' section around the eye bolt mounting in the chassis leg was needed after the new legs started to crack around the eye bolt tube after a few years - our MOT station had a new 'shaker' installed as part of the test process and it picked it up - very good job too!

Couldn't try it out today, as our road is still flooded, but it is now receeding so hopefully I will be able to test it out tomorrow.

I took some video on my iPhone while making the new bolts and the result is on YouTube:

http://www.youtube.com/watch?v=GHvjjFawfj0

All in all a very interesting project.

[bmcecosse]

Great job Richard. Looks like a LOT of extra length there - pretty sure I have 5/16" plate each side, which makes my wheels very slightly negative. I'm surprised you need as much as 1/2".

[IslipMinor]

Roy,

It depends how much the front suspension is lowered. With a standard (ish) ride height I would think 5/16" would be enough to give ~1° negative camber, but the wheels continue to go more and more positive camber the lower the front goes. Ours is lowered by about 2" and has needed the additional 3/8" (1/2" in total) to get the camber at 0°. Now it has 5/8" in total (the 1/8" reinforcing plate + 1/2" eye bolt) - I have yet to check the camber angles to make sure.

Without the engine/gearbox in the car, the wheels have incredibly negative camber!

[bmcecosse]

Yes - the crazy suspension geometry doesn't help. It's a pity the upper arm on the damper can't be mounted further inboard and lower, so the top arm is horizontal at normal ride height.

[Declan_Burns]

Excellent job Richard!

Regards
Declan

[Sleeper]

Digging up an old thread , does anyone know if extended eye-bolts are available , need one with an extra 12mm ( 7/16") , looks like when the front chassis rail was fixed ( just spotted the weld ) it wasn't aligned properly?
Have made a few phone calls but just reached dead-ends..
Am making do with a stepped nut at the moment.....

John

[IslipMinor]

John,

The first question is are the top and bottom trunnions fitted the correct way round? It is possible to fit either or both incorrectly, with very bizarre effects on camber!

Correction - only the TOP trunnions can be fitted the wrong way round - see next post!

If the chassis rail is out by 7/16", I am not sure that extending the eye bolt is the solution. What is the distance between the inside of the chassis rails and also the outside of the chassis rails? Checking them against a 'correct' car will quickly identify is the chassis rail is seriously out of position.

Where are you based? Someone might be close(ish) that could help?

Front suspension diagram from the BMC Workshop Manual is below:

Front Suspension Exploded Diagram.jpg (97.56 KiB) Viewed 2772 times

[philthehill]

Richard
The bottom trunnion of the Minor cannot be fitted the wrong way round as there is insufficient room inboard of the bottom trunnion between the thick/thin arms.

--------------------------------------------------

Negative camber eye bolts are not available off the shelf.
They use to be produced by Minor Mania. I purchased the 2nd to last pair from Minor Mania a few years back.
The last pair were purchased by a forum member.
Minor Mania have no plans to produce any more.
You should be able to attain at least negative camber using the original bolts with packing between the eye bolt and chassis rail.
I would advise using a piece of plate instead of washers so as to spread the load over a greater area of the chassis leg.
Minor Mania negative camber eye bolts below with camber adjustment packing pieces.

100_1740.JPG (523.83 KiB) Viewed 2769 times

Minor Mania eye bolts with plastic bushes, grease nipples and spreader plates all ready to fit.

Negative camber eye bolts 2.jpg (193.48 KiB) Viewed 2769 times

Phil

[IslipMinor]

Phil,

Thanks for that - I have added a comment to the previous post.

[Sleeper]

Richard/Phil

Looking at the above diagram, if the upper link (part 6 ) is shown correctly , surely fitting it the wrong way round would pull in the top of the swivel pin and give more negative camber ?...
( maybe that's the answer )
On mine it would be rubbing on the tyre side-wall...

I have managed 0.5 negative camber but only by shimming the eye-bolt out by approx 7/16",hence the need for longer eye-bolt.

" What is the distance between the inside of the chassis rails and also the outside of the chassis rails?"
good question....does anyone have that figure?

The only other thing I can think of is ..

1098L lowlightR.jpg (51.99 KiB) Viewed 2755 times

1098 on left,Lowlight on right...or so I have been told...

Thanks

John

[philthehill]

The outside width of a front chassis leg is 71mm.
The inside of the chassis leg in the area of the eye bolt has additional reinforcing and a tube for the eye bolt to pass through so no modification can be made to the inside of the chassis leg.

As regards turning the top trunnion through 180 degrees - even if you could it impacts on the steering rack and it would result in massive toe-in.

The only acceptable and workable way is to pack the eye bolt way from the chassis to increase negative camber.

It should not be assumed that both sides are the same as regards the packing - the amount of packing required to obtain the same amount of camber can vary.

[IslipMinor]

Sleeper,

Can you measure the distances between the insides and outsides of the chassis rails on your car? That way they can be compared with one that is believed to be correct.

[Sleeper]

I was wrong,I thought the chassis legs were not parallel , they seem to be OK , 535mm outside dims. 400mm inside dims... (give or take a few mm.s as the sump/gearbox was in the way.)

Maybe the chassis is not true , maybe the body is not true , after all it is 60 years old...

Looks like I'm still after some longer eyebolts.

John

[IslipMinor]

John,

I am happy to make you 2 'negative camber' eye bolts for the cost of the material, which looking on line will be about £40 for the 2. Postage would be on top, unless you can collect from the Oxford area?

I will need to hunt out the original eye bolts to get a starting dimension, and then add 7/16" to it. Have you lowered the front suspension, as 7/16" seems a lot if not?

Would probably take around 10 days, assuming the material is available.

Phil,

On an original eye bolt, can you help out with the dimension from the centre of the 7/8" hole to the edge of the shoulder, where it reduces down to 11/16" please? In your picture that would be from the edge of the caliper RH jaw to the centre of the 7/8" hole.

[IslipMinor]

John,

I have measured our chassis leg dimensions and they are very close to yours - 538mm outside and 404mm inside. Without knowing the absolute standard, they are similar enough to be right.

[Sleeper]

Phil
That is most kind of you,will pm you with details...

Many Thanks

John

[IslipMinor]

John,

It's me, Richard, that is offering to make the eye bolts for you!

[philthehill]

Richard
I have just picked up on your request.

Taken from a NOS eye bolt.

The most accurate way of measuring as I cannot pick up the dead centre of the 7/8" eyebolt bush hole is to measure from the inner edge of the 7/8" eyebolt hole to the flange where it reduces down to 11/16" and which is 7/16" (0.4375)

or (dimensions (metric equivalent) taken from ZEUS Metric revision data chart).

7/8" hole...………… 0.8750 Divide by 2 = 0.4375 (hole dead centre).

The distance from 7/8" hole dead centre to 11/16" flange is 0.4375 + 0.4375 = 0.875.

The measurement you requested is (7/8") 0.875.

Phil