Hi Scott,
If you're subscribed to the mailing list then just sending an email to
tigers@autox.team.net will post your message to the list. I've CC'ed the
list on this reply.
Unless your Tiger has serious bodywork modifications (rear fender
flares, specifically) then the rear track pretty much has to be narrower
than the front. You can easily measure the track by measuring from the
inside of the tire sidewall on one side, to the outside of the tire
sidewall on the other side.
What tires and wheels are on the car? Tom Hall mentioned to make sure
you don't have bias ply tires on the rear and radials on the front (or
vice versa) because that can seriously affect the stability of the car.
It should have either bias-ply tires all the way around or radials, but
not a mix.
To learn a lot about alignment and suspensions, go to your local speed
shop and buy the book 'How to make your car handle' by Fred Puhn. I'll
give you a quick explanation of the basics but it's harder without
pictures and diagrams.
The toe-in is the amount that the front tires point towards each other
front-to-back. You can measure it in the following way, using a jack,
some tire chalk or other white marker, and a tape measure:
1. Jack up the front of the car so the tires are free to rotate.
2. You need to make a reference line around the circumference of the
tire tread (the tread itself is not always straight on the tire
carcass). Spin the tire by hand and then hold the tire chalk up against
the tire tread so it puts a line on the tread. A steady hand is
necessary here. Do it on both front tires.
3. Lower the car again, then roll it backwards about ten feet, and
forwards the same amount. This settles the suspension.
4. Get a helper to hold the end of the tape measure against the mark on
the front of the right front tire, while you take the tape reading at
the mark on the left front tire. Measure as high up on the tread as you
can without bending the tape measure. Write down the reading, to the
nearest 1/16 inch.
5. Take another reading from the rear of the front tires. The toe-in is
the difference between these two measurements. The rear reading should
be equal to the front, or up to 1/8" greater. If the front measurement
is larger than the rear, then you've got toe-out, and this will be part
of the handling problem.
The steering caster is the front-to-back angle of the front spindles,
and it's hard to describe how you can easily measure that, but one way
to get an approximate measurement is to slightly loosen the lug nuts on
the left front, then
jack up the left lower control arm (as close to the balljoint as
possible) to just get the tire off the ground, then remove the left
front wheel. Hang a plumb bob just outside the fenderwell, so it's in
line with the lower balljoint. Measure how far the upper balljoint is
rearward of the string when viewed from the side (this is hard to do),
then work out the angle using this measurement, the distance between the
upper and lower balljoints, and some trigonometry. You should have about
four degrees caster. If you have substantially less than that, then that
would be part of the problem.
Hopefully this wlll give you some ideas. To get better explanations you
can buy Puhn's book, or find a copy of Carroll Smith's books 'Prepare to
Win' and 'Tune to Win'. Some Web searching might also turn up pictures
and alternate methods of doing front end alignment at home.
Best regards,
Theo Smit
-----Original Message-----
From: Jen/Scott [mailto:jsloan798@earthlink.net]
Sent: September 11, 2003 10:09 PM
To: 'Theo Smit'
Subject: RE: Possibly Dangerous Handling posted on Forum
Thanks for the info. I am trying to digest all this data I have gotten
and it is kinda tough since I know very little about alignment and
suspension. So, I am replying to your email with a few questions. I
signed up for the mailing list, but I am unsure of how to post to there,
so if you have any tips, I would appeciate it.
Ok, I do know that the rear end it around 3 inches wider than the front
is, but I am not sure how much that affects the steering. I think the
Dana 44 was shortened in the past.
1. How do I get a rough measure of the toe in/out? What is that? I think
I know but I need clarification.
2. Same as above with the caster.
3. I think I got this part, but where might I find a good diagram of a
suspension setup so I am sure I know what to look for.
As for the spacers, I have no idea. I will have to check that out.
Also, what kind of specs would I want an alignment shop to set the car
to? Not sure what settings or measurements they might need. Thanks a lot
for your help. I hope I can find time to take a look this weekend.
Thanks again
Scott
-----Original Message-----
From: Theo Smit [mailto:theo.smit@dynastream.com]
Sent: Thursday, September 11, 2003 10:56 AM
To: Steve Laifman; Tiger's Den
Cc: NewTigerGuy (Scott Sloan)
Subject: RE: Possibly Dangerous Handling posted on Forum
Scott,
The stock Tiger rear track is a couple of inches narrower than the
front, so unless someone has made some significant changes (oddball
wheel combination or spacers?) the front is wider than the rear, not the
other way around. This arrangement in general does make the car less
prone to understeer, but shouldn't by itself make the car track
erratically. You can (and probably should, eventually) take the car to a
good alignment shop, but there are a bunch of things you can do yourself
to assess the situation:
1. Check the toe-in - you can do this with a tape measure and a helper.
Sensitive steering can be caused by having toe-out on the front wheels.
2. Check the caster, either using a caster gauge or by eyeballing it.
Having too little caster will definitely make the steering very twitchy.
3. Jack up the front end, put the frame on jackstands, and first inspect
the inboard mounts for the lower control arms (on the crossmember) very
carefully. Verify that the nuts on the fulcrum pins are tight, and that
the fulcrum pins aren't cracked. If there's anything funny going on
there it's a very serious problem. Then jack it up again and put the
jackstands on the outer ends of the lower control arms so the suspension
is loaded as it would normally be. Grab the wheel/tire and try to move
it inboard and outboard (at the top of the tire), and wiggle the tire
side to side to see if there's any play in the steering or the upper
control arm pivots or balljoints. On my Tiger the upper balljoints were
no longer a press-fit in the upper control arm when I got it from the
PO.
Other thoughts: If the aluminum spacers for the crossmember were left
out or installed backwards (was the crossmember rebuilt?), it would
definitely reduce the caster significantly.
Good luck,
Theo Smit
|