Hot Rod Forum banner

TCI mustang II IFS caster adjustment

19K views 10 replies 2 participants last post by  Rick4070 
#1 ·
Hello there, all.

I just purchased one of TCI's mustang II IFS front ends and have a couple of questions for those who know front ends.

I have mocked up the front end, installing the crossmember on the frame and tacking the upper spring mounts onto the frame, and am putting together the rest of the parts so I can mount the fenders to check that the wheels are centered in the wheel wells before welding everthing permanently.

I have figured out how to check camber and toe-in, but how do you adjust caster??

I know that the car has to be at ride height, but unless you "cant" the upper control arm in the slots, I don't see any other adjustment.

By cant, I mean to offset the arm so it is not parallel with the frame, but has more slot showing at the front or rear of the upper spring support.

There is no fore and aft adjustment that I can see, unless the arm is moved in this way.

Here is an exploded view of the front end:

http://www.totalcostinvolved.com/instruction_det.cfm?ManualID=290

Any help with how and where the caster is adjusted, and how to measure it, would be greatly appreciated.

Also, the arm on the upper control arm that bolts to the upper spring mount,(the arm with the two holes in it,) seems to have a lot of play in it between the two ends of the "yoke" part.

Will this go away after tightening the nuts on the ends??

Thanks for any help.

Rick
 
See less See more
#2 · (Edited)
but unless you "cant" the upper control arm in the slots, I don't see any other adjustment
That is how you do it....

To measure caster in each wheel, we use a caster/camber gauge and turn plates. This tool (caster/camber gauge) attaches to the wheel hub. To check the amount of caster, you need to follow these instructions:

1. Attach the caster/camber gauge to the RF wheel hub first,with the wheels pointed straight ahead and the turn plates zeroed.

2. Turn the steering wheel to the right so the RF wheel has turned exactly 20 degrees.

3. Level the gauge and set the adjustable caster bubble vial so the bubble is at the zero mark on the caster side of the tool.

4. Turn the steering wheel to the left so the RF wheel is turned past straight ahead and ending up at left from straight ahead by 20 degrees.

5. Again, level the gauge, note the location of the bubble on the scale, and record the amount of caster in the RF wheel.

6. While the wheels are still turned left 20 degrees, remove the caster/camber gauge and place it onto the LF wheel hub. Adjust steering so left wheel is at 20 degrees.

7. Level the gauge and set the bubble on the caster gauge to zero.

8. Turn the steering wheel to the right past straight ahead until the LF wheel is turned 20 degrees to the right of straight ahead.

9. Level the gauge and read the caster gauge to see how much caster is in the LF wheel.
 
#3 ·
Thanks for the help.
I called TCI, and talked to the tech guy, and he said that the play in the upper control arm is how you adjust caster, by tightening the nuts differently on either end of the two holed mounting shaft, this moves the arm fore and aft, keeping the arm mount parallel to the frame.
There is about 3/8" of play between the inside of the "yoke" bushings and the two holed mounting part.(See my link to exploded view, above.)
You say that canting the upper control arm is the correct way, now I wonder if I should just tighten down the nuts on either end of the shaft, removing the play,and cant the upper arms in the slots...
 
#6 ·
Turn plates are an alignment tool used to indicate the angle you have the wheels turned to. You set the front wheels on the turn plates and the rear wheels on a spacer the same thickness as the plates. Center your steering, zero the turn plates.....Now you can check/adjust caster....
They look like THIS
 
#7 · (Edited)
Well, I went out and took some measurements (with calipers) did some math....It looks like if you are able to adjust caster that way you would get about 1.3 degrees total movement from end to end. I don't think it's enough range for proper adjustment, but it would also depend on cross member and spring mount installation.....
 
#8 ·
Thanks for checking the adjustment range using the turn plates, and correcting me on the terminology.
I still don't know what the two holed shaft in the upper control arm is called.
Kind of reminds me of when I went to the plumbing supply store and asked for an outside faucet, and the guy said:"Oh, you mean an anti-siphon exterior hose bib." :D
Thanks for taking the time to help, it is much appreciated!
 
#10 ·
Alright, I got the turn plates and set everything up. I took initial caster readings then tried to adjust it with the nuts on the ends of the cross shaft.....I could get no movement of the a-arm in relation to the cross shaft. My front end is from TCI and I do not see this as a way to adjust caster, not even a fine adjustment. So the person at TCI who told you to adjust this way must be smoking crack..... :pain:
 
#11 ·
ceh383 said:
Alright, I got the turn plates and set everything up. I took initial caster readings then tried to adjust it with the nuts on the ends of the cross shaft.....I could get no movement of the a-arm in relation to the cross shaft. My front end is from TCI and I do not see this as a way to adjust caster, not even a fine adjustment. So the person at TCI who told you to adjust this way must be smoking crack..... :pain:
Yeah, pretty much the way I feel, too.
I couldn't see what 1/4" one way or the other would do, that is about all the slop between the cross shaft and the arm.
I think that I'll just tighten up the two nuts, and cant the arms to adjust.

Thanks for taking the time to check things out for me!!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top