Rack swap - removing tie rods

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Grrrmachine
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Post Sun Apr 13, 2014 8:23 am

I'm planning on fitting an E46 rack today, and the only thing I'm not sure about is the tie rods. I'm planning on keeping the original E30 ones (rods and ends) as they're fairly new. Do I still need to undo them from the hubs, or can I just undo them from the rack end?
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Post Sun Apr 13, 2014 8:52 am

Popping the balljoint and un-screwing from the rack will leave the track adjustment unchanged,whereas seperating at the ajustment point will certainly need the tracking setting up again.

You will need to check tracking either way,but leaving the rods in one piece will give you a sporting chance of being 'nearly' right!
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Laith
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Post Sun Apr 13, 2014 9:32 am

I would undo them from the joint under the rubber boots then attach them to the e46 rack. You'll probably need to take them off the hubs too so you have some working room.

That way you'll keep as much geometry as you had before. Don't undo the adjustments nuts on the tie rods!
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Brianmoooore
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Post Sun Apr 13, 2014 10:11 am

If you change the rack (or any other component on the front suspension, then the tracking will need checking and almost certainly need adjustment, so yo may as well undo the rod end/track rod joint and have done with it.
There always seems to be some air of mystery, talk of laser devices, etc., and considerable expense on here whenever tracking is mentioned. All you need is a level surface, a couple of scraps of plywood and a length of string.
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Post Sun Apr 13, 2014 10:26 am

Brianmoooore wrote:If you change the rack (or any other component on the front suspension, then the tracking will need checking and almost certainly need adjustment, so yo may as well undo the rod end/track rod joint and have done with it.
There always seems to be some air of mystery, talk of laser devices, etc., and considerable expense on here whenever tracking is mentioned. All you need is a level surface, a couple of scraps of plywood and a length of string.
I never understood this method and always wanted to learn how it is done.

You got any pictures or links Brian?
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Brianmoooore
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Post Sun Apr 13, 2014 10:52 am

The idea is to set up parallel lengths of string each side of the car, level with the centres of the wheels, close to, but not touching the tyres, and then to measure from the string to the front and back of the wheel rims.
First of all you need to make a one off measurement of your front and rear track (plank of wood under the car, a tape measure and a set square).
On a standard E30, this should be 1407mm front and 1415mm rear, so the rear track is 4mm greater per side than the front.
You now need 6 small pieces of 4mm plywood (35mm square is enough) and a length of ordinary string. (I cleared out an ex butcher's shop years ago, and have enough for the next 100 years or so.)
Tie the string tightly around the car, half way up the wheels, add a piece of ply under the string where it touches the sidewall of the tyre at the front of the front wheel, and add two pieces each side at the rear of the rear tyres.
You now have two parallel lengths of string down each side of he car.
Measure from the string to the wheel rim at the front and back of each front wheel, and, with the steering wheel pointing straight ahead, adjust each track rod so that the gap to the rim is 1mm greater at the front than it is at the rear. This will give you exactly 2mm of toe in.
It can help if you park each front wheel of the car on a glossy magazine.
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Post Sun Apr 13, 2014 11:40 am

Thanks Brian, I think I get it now. The string goes all the way around the tyre and alloy rim right. Tied horizontally around the wheel parallel with the ground. Make the end of the string work as a plumb weighted against gravity.

I just need a bit more clarity on this part:
"Measure from the string to the wheel rim at the front and back of each front wheel"
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Post Sun Apr 13, 2014 11:53 am

Sorry for letting you re-type that essay Brian; your string method was documented in the Wiki a while back:

http://www.e30zone.net/e30zonewiki/inde ... ed#Testing

and I've used it before with great success.

As for the rack, it was such a pain trying to separate the rods from the rack in situ (upside down and fighting the rubber boot) that I ended up popping the rod ends out of the hubs, then dropping the rack and rods all as one. It can then be dismantled, lubed and refitted so that I can do the tracking.
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Post Sun Apr 13, 2014 11:53 am

Sorry, ignore my previous comment. I have cracked it!

Thanks Brian
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Post Sun Apr 13, 2014 1:32 pm

Don't forget to measure the rear wheel track as well while the string is all set up. You might learn something that you might rather not know!
I've used this method on single seat race cars, competing in international championships, on £100k + budgets, per year, per car, and if it's accurate enough for that, it's good enough for an E30.
Does the wiki also have my matching DIY camber gauge?
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Post Sun Apr 13, 2014 1:50 pm

You should get some pics uploaded into that guide Grrrrr, especially the camber guide, it might even help to get some wheels back close to the vertical :)
NoTurbo
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Post Sun Apr 13, 2014 1:52 pm

I didn't check the Wiki, actually found the same method used on an MX5 website and followed the pictures then cross referenced it to the method described in Puhn's book.

Do you have a link tot he wiki article? would be good to have it bookmarked
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Post Sun Apr 13, 2014 2:08 pm

NoTurbo wrote:I didn't check the Wiki, actually found the same method used on an MX5 website and followed the pictures then cross referenced it to the method described in Puhn's book.

Do you have a link tot he wiki article? would be good to have it bookmarked
Grrrmachine wrote:Sorry for letting you re-type that essay Brian; your string method was documented in the Wiki a while back:

http://www.e30zone.net/e30zonewiki/inde ... ed#Testing

and I've used it before with great success.

As for the rack, it was such a pain trying to separate the rods from the rack in situ (upside down and fighting the rubber boot) that I ended up popping the rod ends out of the hubs, then dropping the rack and rods all as one. It can then be dismantled, lubed and refitted so that I can do the tracking.
:wink:
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Post Sun Apr 13, 2014 5:54 pm

Rack in and out in a day, on my own. It's LHD though, so there's less ballache than you RHD folks, and I still haven't done the tracking yet - that'll have to wait till tomorrow.

Will be nice to drive places without leaving a purple trail behind me :D