TCP power rack clearance issue

[BadTaste]

Hi all.
I have a installed a new TCP power rack & pinion in my '70 coupe. Everything looked fine when the car was on stands and the front suspension had no load. But with the car on the ground, a problem was revealed. By doing a full right turn, the outer tier rod are hitting the end housing on the rack (passenger side) before I can do a full turn. Anyone else experienced this problem?

Hans

 

[j69302]

There are 2 places to mount the inner tie rods to the racks "center link". The lower holes are for small block. The upper holes are for big block.

Refer to Pg 2 of http://www.totalcontrolproducts.com/download/instructions/7903-TIER-03.pdf

Did you install the spacers in between the center link and tie inner tie rod ball joints? Looking back through pics of my install on my 69, it looks like i would have your problem if the spacers were not there.


Do you have stock spindles?

Also make sure you not only have the correct inner/outer tie rods, but also that you have them mounted to the correct set of holes on the center link.


From TCPs FAQ page: http://www.totalcontrolproducts.com/faq.html#TurningRadiuses

Rack & Pinion - Uneven left and right turning radiuses

A tighter turning radius in one direction indicates that the rack & pinion was not at its center of travel when the toe alignment was set.

Visual Cues:

* Uneven number of turns at steering wheel from center to full left and full right lock.
* Tie rod assemblies are different lengths.
o Can be verified with a tape measure or by counting the number of exposed threads on each side of the adjuster sleeve.
* With vehicle at ride height, check both left and right steering arms to steering stop clearance at full lock and compare.

Solution:

* Find center of travel of rack and pinion.
o With tie rods disconnected from center link, use steering wheel to find center.
o Count number of turns from lock to lock. Should be a touch over three turns.
o Turn to full lock, and then back one-half the number of total turns. Just over one and one-half turn.
* Adjust tie rod assemblies to even lengths then reattach to center link.
* Set toe, making equal adjustments to the left and right assemblies.
* Steering wheel may have to be centered once the alignment is complete.
* Tighten all jam and castle nuts.
* Insert and bend all cotter pins.

 

[BadTaste]

Hi j69302, and thank you for your reply.

There are 2 places to mount the inner tie rods to the racks "center link". The lower holes are for small block. The upper holes are for big block.

My rack is for small block only, witch means I only have the lower holes you refer to.

Did you install the spacers in between the center link and tie inner tie rod ball joints? Looking back through pics of my install on my 69, it looks like i would have your problem if the spacers were not there.

Yes I have installed those spacers.

Do you have stock spindles?

No, I have forged spindles from TCP. I'm not sure if they are 100% identical to the original 1970-1973 disc brake spindle.
And it actually seems like my spindle is part of the problem. I decided to remove the tie rod from the spindle steering arm, and the steering arm is hitting the rack before the spindle hits the steering stops. Since the rack cannot be moved sideways, it seems like I have to modify the steering stops. Unless someone has a better idea...

Hans.

 

[j69302]

as far as I know the tcp spindles are just beefed up versions of the 70 spindles. I think they make other spindles though.. I would check the part numbers and verify that you have the correct spindles.

How far does the wheel turn before the spindle hits the rack? Does it hi on both sides?
When the one side hit the rack, was the other wheel turned at approximately the same angle as the other?


Are you sure the rack is in its center of travel?
Disconnect the tie rods to prevent the spindle from moving and hitting the rack. Turn the steering wheel all the way from one lock to the other lock and count the turns. Turn the wheel back to center by half the amount. The rack should now be centered. At this point adjust both the left and right tie rod so they are the same length. then attach them to the rack and spindle. See if the spindle still hits the rack.


Im over seas right now so I cant physically look at how close mine come to the rack till I get home.

I have granada style spindles on mine and I didnt run into any issues.

 

[BadTaste]

Hi.
I have studied the front suspension/rack and I cannot find anything at this point that would solve my problem. Everything appears to be mounted correctly. I don't know if the angle of the spindle steering arm on the TCP spindle is slightly different than the original spindle steering arm. BTW: "MBM 1521R" is cast into the backside of driver side spindle.
I have decided to modify the steering stops for now. But since I'm not happy with this solution, I'll try to find out why I'm having this problem while the majority of Mustang owners with this power rack don't have one.
If its not too much trouble it would be great if you could upload some pictures of your rack & spindle.

Hans.

 

[j69302]

I would email TCP.. they have always helped me out when I had questions.

I am not in the states right now so I can get any more pictures until I get back which will be the end of the year.

Take the casting number and check TCP's website and verify its the correct one.

some more pictures of your install might help, pics that show the whole rack in place and some of the mounting points. maybe a pic straight down the rack from the spindle in would be a good angle. The pics you posted above show the problem well but dont show a good angle on how its all installed.

 

[Psydwaze]

There are two solutions to the tie-rods contacting the end of the rack.

1. Modify the steering stops to contact the steering arm before the tie rods make contact.
2. Lengthen the passenger side tie rod until the steering arm has clearance at full right lock. A couple of turns will make a large different the amount of clearance. The driver-side tie rod will have to be shortened by the same amount and the steering wheel reindexed if you elect to go with this method.

Option one is the better of the two solutions with regards to suspension geometry. Running offset tie rods is not perfect, but the 1/8" difference in length will be unnoticeable.



This situation is also noted on page 9 of your rack and pinion instructions.
http://www.totalcontrolproducts.com/download/instructions/7903-RCKM-02.pdf?page=9



Lino
TCP/Chassisworks

 

[BadTaste]

There are two solutions to the tie-rods contacting the end of the rack.

1. Modify the steering stops to contact the steering arm before the tie rods make contact.
2. Lengthen the passenger side tie rod until the steering arm has clearance at full right lock. A couple of turns will make a large different the amount of clearance. The driver-side tie rod will have to be shortened by the same amount and the steering wheel reindexed if you elect to go with this method.

Option one is the better of the two solutions with regards to suspension geometry. Running offset tie rods is not perfect, but the 1/8" difference in length will be unnoticeable.



This situation is also noted on page 9 of your rack and pinion instructions.
http://www.totalcontrolproducts.com/download/instructions/7903-RCKM-02.pdf?page=9



Lino
TCP/Chassisworks

Lino, thank you for your reply.

Since the steering arm alone also is contacting the end of the rack, the only option would be the first one in this case.

Would certain ride heights/geometry make the steering arm to contact the rack more easily or is this problem only related to the 70-73 Mustang spindle?

Hans

 

[Psydwaze]

I would say it's a combination of things that cause the issue. Alignment, spindle, positioning of the rack, chassis variances, etc. We don't see it on all installations, but have seen this before.