major tracking problem

[Welleh]

a problem ive been trying to solve for ages! finally though i'd post it here to get some opinions!

about a year ago before the car was off the road again , i installed some alloy subframe bushes that i made to some specifications i accumulated! so i turned them out, put them in, they seemed fine, < .5mm movement in each one, measurements were exactly to spec! so i thought nothing of it and carried on with the rest of the prep. i even undersealed the subframes after i had them blasted and got the bushes done with a coat too! just to protect them a bit more from salt on the road etc!
once car was all ready, got the tracking done. after a couple of days of giving the car a bit of there was some tracking issues after hard or soft cornering, so bad causing the car to crab badly and each wheel to go stupidly offset! it kept changing all the time, after any sort of bend! before taking it back, i checked that all the track rod adjusters joints etc were tight, which they were, so i took it back and got it done again f.o.c. but once again it decided to move itself.

so i came to the conclusion that i could be the subframe bushes i made being .5mm out.
only untill last night... i went to sal's to pick up some parts, he lent me a darvic version of the bush so i could check it against mine. checked it against mine and his is less than .1mm bigger than mine and still moves in my frames!!! one thing i did notice on his tho was there was a small chamfer on the inside edge of the 'tophat', and i swear the ones i saw on ebay a while back had a radii there. where as i made mine with dead square edges all round, would that make a difference at all?

has anyone else thats done this mod had a tracking problem? or know what the problem i have is?
also were your bushes a tight fit? not quite press fit, but a hard push with your hand fit?

also would the subframe moving an overall of 2mm over the 4 bushes cause the tracking to be so far out? surely worn rubber bushes are worse than that?

ta
steve

[sal_s2]

Maybe the thread in the chassis that the subframe bolts go into are knackered?

[Welleh]

i'll check the threads tomorrow, think there fine, did wind a tap thru a few too clean them out before i put the frames back on after blasting and spraying them. bolts were all new, and were all torqued correctly aswell, cant remember exactly but i think it was 70nm + 180deg.

[Welleh]

checked this morning, threads are good and clean! any other ideas?

[volcano rs]

is everything else ok on your suspension ?
top mounts wishbone bushes anti roll bushes etc ? even with standard rubber bushes i'm sure the subframe must have some movement.
so i can't see the nylon bushes causing that problem .

[Pirvu Eugen]

i have same problem and the subframe is not mooving. I have made some marks to see iff is moving but not.
everithing is tight and new.
I thought is from the top mounts, i changed them and same problem.
Is posible that the chasis to bend?
Hope not!
The steering wheel is straight and after a tight corner or a bump, the steering wheel is out off center and the car is everywhere on the road.

[Welleh]

the configuration was as follows when i started getting the problem
brand new variant 1 KW coilovers + brand new 'blue' topmounts all round, new front track rod arms, new powerflex wishbone bushes all round + alu subframe bushes that i made,
the things i diddnt replace were. ARB bushes front and rear, i didn't replace as they were not perished and in g.w.o also reciept in S/H about 3 years ago for them, bottom ball joints on wishbones, none of the boots were perished nor had loads of play in, rear track rods or ends, as they also seemed fine, its quite random like pirvu says, car is all over the place, and it got so bad you could even feel it crabbing! also if you stopped you can see the wheels are physically mis alligned by loads!

[Pirvu Eugen]

I understand that when i change to hard suspension and lower and wide tires the car can have this comportament like is "copying the road" but i dont know why the steering wheel
is not in same place like after tracking done?

[owdlvr]

A few years ago I was working on urethane replacement top mounts. One of the things we discovered while working on these was they would 'hold' misalignment after tight steering maneuvers or sometimes large bumps.

Based on that experience, I would say you have something that's binding in your suspension, whether it's top mounts or something else.

I have self-made aluminum subframe bushings and they are made to fit tight in the subframe. A little bit of a chamfer makes it easier to press them in straight. Mine are made tight enough that I lightly heated the subframe with a torch, to expand the hole, and then pressed them in.

I would mark your subframe and body with paint to see if it's moving, and then look elsewhere in your suspension to see if you've got something else binding.

-Dave

[Acidburn]

Have you tried standard subframe bushes?

I have heard of another subframe recently that sounds like the holes are oval shape but don't know how common this is getting.

[Welleh]

not yet, did want to try and avoid going the standard route again!, holes dont seem too look ovalled in any way, diddnt seem it when i was trying the bushes inside either! will have a check if i get a chance! any other ideas?

[Pirvu Eugen]

I dont know about Welleh but I have new oem subframe buschings mounted properly and blue top mounts. The subframe is not moving because i marked the position. The suspension is realy tight. I dont know what to check?
I will change soon the entire suspension wit KW Variant 2 Coilovers and again the top mounts (blue again) and all the buschings involved there!
Iff somebody knows something more? Pls
Thank You!
Eugen

[Acidburn]

The places that have done the tracking on these cars have they done all the adjustments that can be done, toe, camber etc all of them as I know most places like kwik fit and ats are useless when it comes to s2's I took mine to imperial tyres in swindon and they did a brilliant job.

[Welleh]

took mine to a family friend who owns a reputable garage near me with a brand spanking laser system, was there whilst he done it aswell, as for camber i asked for custom which was 2deg front and 1.5deg rear so he sorted that also!

[pastures16]

i had this same problem before on a 7a i changed everything but still it tram lined it turned out to be the top mounts but even then the tracking was way out