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Discussion Starter #1
Hi All:
I am experiencing some strange road/handling behavior in my (just back on the road) 80 Spider.
I have some small hills in a nearby road, pretty low (10~15' rise from bottom to crest) but close together and fairly steep angles. On a dirt motoX track they would be called 'whoop de doos'.
If I take these at speed, at the bottom the car veers left, at the top it veers right. Nothing dramatic but still not right. I have looked at the front and rear suspensions and both seem tight with no obvious wear (front end recently aligned).
Anyone experience a similar condition? Any ideas as to diagnostic checks I could do to isolate where the problem lies?

Cheers & TIA!
Dave G.
 

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Discussion Starter #3
Yes, I think so, at least I never noticed it before, but the car had many engine/driveline problems and has been off the road for over a year getting sorted. It could be that I just never noticed before. In all other respects the handling seems quite good, there is the usual cowl shake over quick, small bumps (washboard) but nothing else I am aware of. I am thinking of adding a frame stiffiner but would like to get everything sorted before I do this.

Cheers!
Dave G.
 

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Without seeing the car and knowing what has been done to it......
It sounds like bump steer, common in our cars especially if lowered and running wider tires. Basically as the front suspension travels from full droop (when the car is light) to full compression (at the bottom of the hill) the toe of the front tires changes from toe- out to toe in. So while you are holding the wheel straight, individually they are turning opposite each other. So why right one time and left the other? The tire that is the most loaded controls the direction.
Alfa's are tempramental ladies. When you drive them hard they tend to squirm more :cool:
 

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If you are on a straight & level road does it drift from one side to another as you accellerate & decellerate (no brakes just foot off throttle)? If so, that'd indicate worn rear suspension bushings - allowing the rear axle to turn slightly under the torque of accell/decell.

If not then the 'bump steer' answer remains most likely.
 

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Discussion Starter #6
Thanks for the replies! To ghnl - I tried this experiment and no, there is no throttle steer evident (under power or trailing throttle). I did dial in some more toe-in which has resolved some of the problem, though my steering wheel now must be turned a little right of center to maintain a straight line. I used the center link to do this and turned out (lengthened) it about 3/4 turn, or about .2" longer.
As I understand it the toe-in is set to 3MM (.19") but I am not sure where this measurement it taken from (axle to tire, or front of tire to rear of tire). Anyone have a diagram or experience in where this distance is taken from?
I suspect the shop (generic) that did my alignment recently was unfamiliar with the sequence and measurements necessary to get the car right. I found a post on the "string method" here and plan to check things out using it to get things at least close.


Cheers & TIA
Dave G.
 

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While you are under the car sometime with the front wheels off the ground, grab the passenger tire and try to turn it as though you are turning the steering wheel. This is the easiest way to find a loose inner ball joint. If you can get the suspension upright to move around without the steering wheel or opposite side upright to move, this looseness will also cause a constant change in toe on the road. That is until the ball joint completely fails and you only have control of steering one wheel.
 

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I did dial in some more toe-in which has resolved some of the problem, though my steering wheel now must be turned a little right of center to maintain a straight line. I used the center link to do this and turned out (lengthened) it about 3/4 turn, or about .2" longer.
As I understand it the toe-in is set to 3MM (.19") but I am not sure where this measurement it taken from (axle to tire, or front of tire to rear of tire). Anyone have a diagram or experience in where this distance is taken from?
I suspect the shop (generic) that did my alignment recently was unfamiliar with the sequence and measurements necessary to get the car right. I found a post on the "string method" here and plan to check things out using it to get things at least close.
I thought I had posted a clip from the Alfa Shop Manual describing the alignment procedure. But I can't find it.

The basic procedure is to 1. center the steering wheel 2. adjust the left front wheel's toe keeping the steering wheel centered (assuming LHD) 3. measure the length of left tie rod 4. adjust the right tie rod to that length minus a specified amount (5mm? - don't quote me on that) finally - 5. adjust the center tie rod to give the right wheel the proper toe.

I don't recall where the toe measurement is taken - off the edge of the wheel would be my assumption but, again, don't quite me on that.

If a search doesn't find a post with the procedure I'll try to remember to post it later.
 

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Discussion Starter #10
I see where you are comming from alfaloco, but the answer is no, no crash damage beyond a repair that I uncovered (during paint prep) on the RH (passenger side US) ding on the rear quarter pannel that is pretty minor (bit of bondo between rear wheel and bumper).
Axle to Axle measurements on both sides yeild the same results - but no, it has not been on a frame rack during my ownership. I have also not done an extensive X type inventory of where the wheels lie in relation to each other either. It is unlikely (IMHO) that the car can handle/track so well (and I have watched it on the road) if there are major issues with the frame geometry.
I think this is more of a wear/alignment issue so far. If a relatively minor "tweak" on toe in has improved the issue, then I think that is the place to direct my efforts.


For those interested here is a distilled version of what I found on alignment and the 'string' method of checking (the only thing fuzzy in this is where the 3mm toe in is checked at, any help on that is greatly appreciated) :
*********************************************
For LHD cars;
Left tierod length = 264-280mm (adjust 1st)
Right tierod length = left tierod length MINUS 5mm (adjust 2nd)

For RHD cars;
Right tierod length = 259-275mm (adjust 1st)
Left tierod length = right tierod length PLUS 5mm (adjust 2nd)

Center trackrod = 530-550mm (adjust 3rd)

Toe-in = 3mm total (1.5mm per wheel)
__________________


The 'special' tools required for a string toe alignment are about 12 feet (4 meters) of string or twine and since the front track of 105/115 cars is 2 inches (50mm) wider than the rear, you'll also need a one inch (25mm) spacer (a piece of wood for example).
Before starting, ensure there is no free play in the steering system. Adjust, repair or replace as necessary. The car needs to be on level ground and tires inflated to specs.

1) Center and lock the steering wheel

2) Refering to figure 1, have a helper hold the spacer, at axle height, against the rear portion of the left rear tire and the string against the spacer (location A) while you at the front, pull the string tight and move it in the direction of the arrow toward the left front tire also at axle height. If the string touches the rear portion of the front tire first, as in fig. 2, the wheel is toed in so the left tierod needs to be shortened. If, however, the string touches the front of the tire first, fig. 3, the wheel is toed out requiring the tierod be lengthened.

3) Adjust the length of the left tierod so that the string touches the front and rear portions of the front tire at the same time (fig. 4). The toe of the left wheel is now zero.

4) Measure the length of the left tierod from stud center to stud center. If the length isn't between 264-280mm, somethings bent.

5) subtract 5mm from the dimension obtained in step 4.

6) adjust the length of the right tierod to the dimension obtained in step 5.

7) Move the spacer and string to the right side of the car and using the same technique as on the left, see what the toe of the right front wheel is.

8) If the right front wheel is toed in, shorten the long center track rod. DO NOT adjust the right tierod. If the wheel is toed out, lengthen the track rod.

9) After adjusting the right wheel toe, measure the length of the center track rod. If the length isn't 530-550mm, somethings bent.
**********************************************************

Cheers!
Dave G.
 
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