Steering Rack Install/Setup Procedure

[karlos]

The FFR build manual is a little short on detail regarding how to properly install and set up the Mk4 steering rack. There is interaction between the rack, the front end alignment, the steering wheel alignment, the steering shaft position, and the number of turns center to full-lock-left and full-lock-right that isn’t immediately obvious. After struggling for a couple weeks to set mine up properly I wanted to write down what I learned in the hopes that it saves someone else some time and trouble. My particular build uses the manual steering rack but the install procedure should be common to both manual and power racks. I acknowledge that there are multiple ways to do this. This is intended to be a somewhat systematic approach that should get all the important parameters in the box.

The single most important thing to get right is the concept of what is meant by ‘centering the rack’. Note particularly that this does not mean centering the housing of the rack in the chassis, nor does it mean centering the gap between the housing and the rack internals, nor does it mean centering the steering wheel at the midpoint between full-lock-left and full-lock-right. What it refers to is centering the position of the rack’s inner tie rod ends in the suspension. This is best illustrated with a few pictures.

A properly centered rack will center up the distance to the inner tie rod ends as shown below. Note that you’ll have to slide the boots back in order to measure this. The threaded connection between the inner tie rod ends and the moving part of the rack itself is a convenient place to take a measurement. You’ll also need a reference point on the chassis to which to measure. In the photo below the reference point is the outside wall of the vertical frame member. There are a couple of paint sticks clamped to the frame as a way to extend the surface in order to take a measurement.


46690

46691

46692

Set up in this manner you’ll notice that there is unequal extension as measured to either side of the rack housing. This is normal (and a reflection of the fact that the rack housing is not perfectly centered in the FFR chassis).


46693

46694


With the rack centered the outer tie rod ends can now be threaded on. You should end up with very close to the same number of threads showing on both sides with the wheels pointed straight ahead. Here’s a convenient way to get the wheels close to straight: tie a string to a spoke on the rear wheel and pass it through the wheel, around the back of the tire, and then extend it to the front wheel as shown. Adjust the outer tie rod ends as required to get the string to just touch the sidewall at the back of the front tire.

So at this point we have the rack centered, the front wheels are straight with respect to the rear wheels, and we have (mostly) equal thread engagement on both outer tie rod ends.


46695


Unless you’re very lucky, you’ll most likely find that that the steering wheel is now off center (crooked). There are a couple ways to fix this. One way is to remove the steering wheel from the hub it’s attached to, center it up, and then redrill the hole pattern in the hub as required. Another way is to take advantage of the fact that the steering shaft is splined where it attaches to the steering rack. The splines are fairly small and therefore provide for relatively fine adjustment. The problem with this approach is that the shaft on the rack has a flat that is intended to match up with a set screw on the steering column. And most likely the flat and the set screw won’t line up with the shaft rotated as necessary to center the steering wheel. So what you need to do is to mark the location where the set screw ends up and grind a small indentation on the shaft to provide purchase for the set screw. No need to remove a lot of material; the splines resist the torque (not the set screw), so all you need is a small indentation to help the set screw resist the fore/aft motion. I added the indentation shown with the help of a Dremel plus a carbide tungsten bit.


46696

46697


So we now have the rack centered, the front wheels straight with respect to the rear wheels, equal thread engagement on both outer tie rod ends, and the steering wheel is centered. At this point you can go ahead and set toe-in to specification (typically 1/32” per side, 1/16” total) per any of the techniques described in the FFR FAQ. Finally, we need to verify a roughly equal number of turns on the steering wheel from center to full-lock-left and center to full-lock-right.

Part of the reason it took me a couple weeks to complete the steering rack install/setup was because I was under the mistaken impression that an equal number of turns both ways was the starting point for the overall installation. This is not the case. In fact, equalizing the number of turns left and right is the final step in the sequence and is accomplished using the specialized set of spacers shown below.


46698


Ford “steering travel restrictors” part number N804842-S (about $15 for a package of 4). The rack as supplied by FFR most likely already has travel restrictors installed. On my particular sample, there were actually two of them on each side as shown below. The separately available Ford parts are a split design and can be easily installed with no disassembly of the rack required (other than moving the boot back to expose the innards). Simply install however many spacers are required to even out the travel on both sides. In my case I needed one additional restrictor on the passenger side, at which point I had about 1-1/4 turns from center to full lock on both sides.


46699


So at the end of all this we now have the rack centered, toe-in set properly, equal thread engagement on both outer tie rod ends, a centered steering wheel, and approximately equal travel from center to full-lock-left and full-lock-right. Whew!


Hope this helps someone else out there save some time and frustration.


-Karl

[DaleG]

Gee Karl, you should have posted this a year ago. Now I understand.

[Jazzman]

Great post Karl! Thank you!

[KDubU]

Agree, this is an excellent post.

[cgundermann]

Thank you for your time in sharing/very-very valuable info!

[6t8dart]

Good work! thanks

[hjoensy]

I followed this thread, but stuck in the beginning steps. I centered the wheel lock to lock. My drivers side tie rod end only has about 1/2" of thread. The pass side has over 1". I followed the part about centering the rack, but don't know how to adjust it.

101686
101687

I have the power rack from FFR.

[BadAsp427]

I followed this thread, but stuck in the beginning steps. I centered the wheel lock to lock. My drivers side tie rod end only has about 1/2" of thread. The pass side has over 1". I followed the part about centering the rack, but don't know how to adjust it.

101686
101687

I have the power rack from FFR.

You do not center by "lock to lock" you must center the rack with measurements and then if needed either add or remove steering stops on the rack ends. I can't tell for sure, but it looks like your photo #1 above shows it has a 1/4-1/2" steering stop on it where as photo 2 doesn't have one. I had one on both sides and had to remove one side to get things to work correctly. If you have the rack centered correctly, then you will have almost exactly the same amount of threads showing on your outer tie rod ends. You may not have the same amount of turning from left to right, this is what is adjusted by the steering stops. Example, after I had centered my rack and completed my alignment, I found that I could turn a very nice tight turn to the right, but not even close to as tight to the left. I found that once I removed my steering stop on the right side, I was then able to turn more to the left and in fact very close if not exactly the same as to the right. Of course yours could be a different fix, but the rack is not mounted center on the FFR roadster so it does take a little adjustment.

[karlos]

You can start with the steering well centered between full lock left and full lock right if you'd like. But centering the steering wheel is not the same as centering the rack. After centering the wheel, equalize the dimensions to the inner tie rod ends as shown above. This is done by simply turning the wheel (there is no adjustment capability at the rack). This of course means that once this step is complete, the steering wheel will no longer be centered. While making sure the rack doesn't move, disconnect the steering shaft at the coupler, rotate the steering wheel until it's pointed straight, and reconnect. If the flat on the rack matches the set screw location on the coupler, you're done. If not, just grind a small flat on the rack shaft to match the set screw location on the coupler and reassemble. That's it.

[Big Blocker]

Centering the rack shaft in the rack housing will ensure equal turns lock-to-lock . . . once the position of the rack shaft and the pinion are established (centered), now you can set the inner tie rod ball joints to be centered in relation to the frame - this might mean that you have to mount the rack housing either left or right to get this inner ball joint spec to be correct. Breeze makes a great set of [solid] rack bushings that have off-set center holes for accomplishing this task. If you don't want to run solid bushings, you might need to "clearance" the frame mounting holes a bit in whatever direction you need to move the rack housing.

Once you have everything set: centered rack housing, centered rack travel, toe-in, that's the time to set the steering wheel to center.

IF you find that you have tire interference at full lock, go ahead and install steering restriction bushings to limit steering angle.

Doc

[RJD]

Excellent post. So, now that I'm going back to center my rack, are there any precautions for removing the clip that holds the boot on. Looks like it's just a spring clamp? Is that a true statement? Reuseable right? Never removed one before, so wanted to ask before I create more issues. Thank you.
101798

Edit: I have the power steering rack. I just re-read the instructions for installing the power steering rack and there was no mention of centering the rack. An oversight, or not needed for the powersteering rack? Just trying to figure it out.

[BadAsp427]

as for the clamps, not sure if those metal ones are reusable.... Mine has large zip ties. I'm certain you could do the same if the metal ones can not be reused. And regardless if it is power or not, centering the rack should be completed.

[jrcuz]

Like BadAsp427 said use zip ties to replace them. Later on you may need to remove the zip ties if you need to add rack limiters inside the rubber boots.
JR

[dhuff]

Excellent post. So, now that I'm going back to center my rack, are there any precautions for removing the clip that holds the boot on. Looks like it's just a spring clamp? Is that a true statement? Reuseable right? Never removed one before, so wanted to ask before I create more issues. Thank you.

Yes reusable. use a screw driver to widen it out. to reinstall you can use fine needle nosed pliers. i usually us a pair of well worn and not very sharp wire cutters, very gently.

[RJD]

Like BadAsp427 said use zip ties to replace them. Later on you may need to remove the zip ties if you need to add rack limiters inside the rubber boots.
JR


Yes reusable. use a screw driver to widen it out. to reinstall you can use fine needle nosed pliers. i usually us a pair of well worn and not very sharp wire cutters, very gently.

Thanks guys. I'll try to reuse them. If I screw them up, I'll replace them with zip ties. Much obliged.

[Mark Reynolds]

Here you go: https://www.breezeautomotive.com/shop/offset-rack-mounting-kit-for-ffr-roadster-and-coupe/

[FLPBFoot]

Here you go: https://www.breezeautomotive.com/shop/offset-rack-mounting-kit-for-ffr-roadster-and-coupe/

I used Mark's rack bushings and made the adjustments easy. I like the solid bushings as well. A recommendation from Build School.

Great product Mark!

Steve

[AutoShippingHUB]

My question isn't related to setup so I apologize. Anyone here have a manual rack? I think it will be fine because the car is light but need some input thanks

[mike223]

Anyone here have a manual rack? I think it will be fine because the car is light but need some input thanks




Drove one for several years with manual steering - they aren't too bad except slow moving in a parking lot.

On the other hand - I eventually decided it wasn't something I was likely going to want to (continue to) wrestle hand over hand in a few years - installed EPAS.


https://thefactoryfiveforum.com/showthread.php?28241-Mk-4-Pull-A-Part-EPAS&highlight=epas

[MSumners]

Thank you for the detailed explanation , this is clear now. Going to go back through and ensure I have this right.

[TMartinLVNV]

One more thanks for this post. Great instructions that go above and beyond the FFR manual.

[Jeff's First FFR]

The FFR build manual is a little short on detail regarding how to properly install and set up the Mk4 steering rack. There is interaction between the rack, the front end alignment, the steering wheel alignment, the steering shaft position, and the number of turns center to full-lock-left and full-lock-right that isn’t immediately obvious. After struggling for a couple weeks to set mine up properly I wanted to write down what I learned in the hopes that it saves someone else some time and trouble. My particular build uses the manual steering rack but the install procedure should be common to both manual and power racks. I acknowledge that there are multiple ways to do this. This is intended to be a somewhat systematic approach that should get all the important parameters in the box.

The single most important thing to get right is the concept of what is meant by ‘centering the rack’. Note particularly that this does not mean centering the housing of the rack in the chassis, nor does it mean centering the gap between the housing and the rack internals, nor does it mean centering the steering wheel at the midpoint between full-lock-left and full-lock-right. What it refers to is centering the position of the rack’s inner tie rod ends in the suspension. This is best illustrated with a few pictures.

A properly centered rack will center up the distance to the inner tie rod ends as shown below. Note that you’ll have to slide the boots back in order to measure this. The threaded connection between the inner tie rod ends and the moving part of the rack itself is a convenient place to take a measurement. You’ll also need a reference point on the chassis to which to measure. In the photo below the reference point is the outside wall of the vertical frame member. There are a couple of paint sticks clamped to the frame as a way to extend the surface in order to take a measurement.


46690

46691

46692

Set up in this manner you’ll notice that there is unequal extension as measured to either side of the rack housing. This is normal (and a reflection of the fact that the rack housing is not perfectly centered in the FFR chassis).


46693

46694


With the rack centered the outer tie rod ends can now be threaded on. You should end up with very close to the same number of threads showing on both sides with the wheels pointed straight ahead. Here’s a convenient way to get the wheels close to straight: tie a string to a spoke on the rear wheel and pass it through the wheel, around the back of the tire, and then extend it to the front wheel as shown. Adjust the outer tie rod ends as required to get the string to just touch the sidewall at the back of the front tire.

So at this point we have the rack centered, the front wheels are straight with respect to the rear wheels, and we have (mostly) equal thread engagement on both outer tie rod ends.


46695


Unless you’re very lucky, you’ll most likely find that that the steering wheel is now off center (crooked). There are a couple ways to fix this. One way is to remove the steering wheel from the hub it’s attached to, center it up, and then redrill the hole pattern in the hub as required. Another way is to take advantage of the fact that the steering shaft is splined where it attaches to the steering rack. The splines are fairly small and therefore provide for relatively fine adjustment. The problem with this approach is that the shaft on the rack has a flat that is intended to match up with a set screw on the steering column. And most likely the flat and the set screw won’t line up with the shaft rotated as necessary to center the steering wheel. So what you need to do is to mark the location where the set screw ends up and grind a small indentation on the shaft to provide purchase for the set screw. No need to remove a lot of material; the splines resist the torque (not the set screw), so all you need is a small indentation to help the set screw resist the fore/aft motion. I added the indentation shown with the help of a Dremel plus a carbide tungsten bit.


46696

46697


So we now have the rack centered, the front wheels straight with respect to the rear wheels, equal thread engagement on both outer tie rod ends, and the steering wheel is centered. At this point you can go ahead and set toe-in to specification (typically 1/32” per side, 1/16” total) per any of the techniques described in the FFR FAQ. Finally, we need to verify a roughly equal number of turns on the steering wheel from center to full-lock-left and center to full-lock-right.

Part of the reason it took me a couple weeks to complete the steering rack install/setup was because I was under the mistaken impression that an equal number of turns both ways was the starting point for the overall installation. This is not the case. In fact, equalizing the number of turns left and right is the final step in the sequence and is accomplished using the specialized set of spacers shown below.


46698


Ford “steering travel restrictors” part number N804842-S (about $15 for a package of 4). The rack as supplied by FFR most likely already has travel restrictors installed. On my particular sample, there were actually two of them on each side as shown below. The separately available Ford parts are a split design and can be easily installed with no disassembly of the rack required (other than moving the boot back to expose the innards). Simply install however many spacers are required to even out the travel on both sides. In my case I needed one additional restrictor on the passenger side, at which point I had about 1-1/4 turns from center to full lock on both sides.


46699


So at the end of all this we now have the rack centered, toe-in set properly, equal thread engagement on both outer tie rod ends, a centered steering wheel, and approximately equal travel from center to full-lock-left and full-lock-right. Whew!


Hope this helps someone else out there save some time and frustration.


-Karl

Great article.
Just spent a day aligning rack, tie rod ends and centering steering wheel.
Now, after rough camber and toe alignment i can't figure out how to measure or set the camber.
Any good posts for this?

Thanks for any help,

Jeff

[StewPididiot]

I used Mark's rack bushings and made the adjustments easy. I like the solid bushings as well. A recommendation from Build School.

Great product Mark!

Steve

Do the Breeze bushings allow installation of the rack without pulling the boots back?

[Big Blocker]

The Breeze solid bushings have nothing to do with the boot positions, they go in the two mounting holes that attach the rack housing to the frame.

You have to pull the boots back to "see" the outer ends of the rack shaft to inner tie-rod ends to center it to the frame for equal turning radius.

Doc

[StewPididiot]

The Breeze solid bushings have nothing to do with the boot positions, they go in the two mounting holes that attach the rack housing to the frame.

You have to pull the boots back to "see" the outer ends of the rack shaft to inner tie-rod ends to center it to the frame for equal turning radius.

Doc
Yep, that makes sense to me. But unless the Breeze bushings help us skip some step or greatly simplify the centering of the rack vs. the process described above the Breeze parts aren't worth the expense. If they allowed for centering the rack without pulling back the boots to peek at the inner tie-rod ends I might be interested in that.

[dhuff]

With the '04 rack splines are not variable to get the steering wheel rotation closer. I found that you can get fairly close by rotating the hub 180 degrees and then re drilling 2 of the steering wheel holes. See post 34 the the link.

https://www.ffcars.com/forums/17-factory-five-roadsters/618130-dean-s-mk4-9191-build.html

[MSumners]

Yep, that makes sense to me. But unless the Breeze bushings help us skip some step or greatly simplify the centering of the rack vs. the process described above the Breeze parts aren't worth the expense. If they allowed for centering the rack without pulling back the boots to peek at the inner tie-rod ends I might be interested in that.

Having just redone the rack centering, the bushings do simplify this process.

[karlos]

Changed over to power steering last winter and used the Breeze bushings when installing the new power rack. If you're bothered by having to clock the steering wheel to get it pointed straight ahead, or by having to grind a new flat in the rack shaft to accommodate the new position, then the offset bushings may allow you to skip that step. The offset bushings provide for some additional lateral adjustment capability that the standard rubber bushings don't.

During the installation of my new power rack with the Breeze bushings it was possible to shift the entire rack housing over nearly enough to get it centered. What little remained was then taken up by moving the rack internals. This left the steering wheel clocked at about a 10-degree angle rather than the 90-degree angle shown in the photo above. 10 degrees is a modest amount that can be corrected at the outer tie rods with no ill effects during the alignment process (left/right outer tie rod thread engagement will still be mostly equal).

Not sure if avoiding a new flat on the rack shaft warrants the $56 cost of the bushings, but I like them and would use them again. Note that either way you'll still need to pull the dust covers back to take your measurements.

Happy building!

-Karl

[StewPididiot]

Changed over to power steering last winter and used the Breeze bushings when installing the new power rack. If you're bothered by having to clock the steering wheel to get it pointed straight ahead, or by having to grind a new flat in the rack shaft to accommodate the new position, then the offset bushings may allow you to skip that step. The offset bushings provide for some additional lateral adjustment capability that the standard rubber bushings don't.

During the installation of my new power rack with the Breeze bushings it was possible to shift the entire rack housing over nearly enough to get it centered. What little remained was then taken up by moving the rack internals. This left the steering wheel clocked at about a 10-degree angle rather than the 90-degree angle shown in the photo above. 10 degrees is a modest amount that can be corrected at the outer tie rods with no ill effects during the alignment process (left/right outer tie rod thread engagement will still be mostly equal).

Not sure if avoiding a new flat on the rack shaft warrants the $56 cost of the bushings, but I like them and would use them again. Note that either way you'll still need to pull the dust covers back to take your measurements.

Happy building!

-Karl
I ordered the Breeze bushings last night. Thanks for the advice!

[Smarstiller]

Power steering rack-MK4
How equal should the thread count on the outer tie rod ends be?

With the rack centered and equal threads on each outer tie rod, my passenger side is very short. Memory serves right 3/4 an inch off.

[mike223]

Power steering rack-MK4
How equal should the thread count on the outer tie rod ends be?

With the rack centered and equal threads on each outer tie rod, my passenger side is very short. Memory serves right 3/4 an inch off.


If "the rack" was centered, your passenger side would not be short - the driver + passenger side would be equal.

I suspect that you concentrated on centering "the rack" in the "the rack housing" - the rack housing does not matter - the rack housing is never going to be "center" because the steering shaft has to locate pretty much "right where it is".

Center "the rack" (the moving part).

[BradCraig]

Just went through this process, many thanks!

[crcarch]

I have a base kit and am using a Mustang PS rack, with the extensions added. Are travel limiters required to keep the tires from rubbing the inner fenders?

Also, is the difference in angles between the two tires at full lock significant? I haven't measured the angles, but the delta between the two seems too large.

Thanks, in advance for any advice.

[initiator]

The wheels will have different angles at all turning positions - this is needed because they're going around differently-sized circles as you turn. At full lock, it is a very obvious difference in angle. Look up Ackerman angle for more info.

[toadster]

how do i remove these clamps on the boot?

https://i.ibb.co/F0jgD9N/IMG-9460.jpg (https://ibb.co/vQKZjbg)

[JohnK]

I just used a screwdriver to pry up the end and unlock it off the tab. They're not reusable. I used a heavy duty plastic zip tie to put the boot back on but I'm sure you could find a replacement boot clamp at any auto parts store.

[nucjd19]

I just used a screwdriver to pry up the end and unlock it off the tab. They're not reusable. I used a heavy duty plastic zip tie to put the boot back on but I'm sure you could find a replacement boot clamp at any auto parts store.

Agree. I did go on Amazon and picked up a crimping tool for these types of clamps and recrimped mine after setting the c clips for stops on mine

[CraigS]

W/ a bit of patience you can re tighten them w/ a pair of cutters. If you have an old pair that don't cut well anymore they will be perfect.
https://www.amazon.com/iExcell-Diagonal-Cutting-Nippers-Chrome-Vanadium/dp/B076XYVS6Y/ref=asc_df_B076XYVS6Y?tag=bngsmtphsnus-20&linkCode=df0&hvadid=80333185695396&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4583932713300696&psc=1
A vice grip can come in handy also. If you enjoy an opportunity to buy another tool, end cutting pliers may have more other uses in the future.
https://www.homedepot.com/p/Husky-7-in-End-Nipper-Cutting-Pliers-48060/203287749

[JohnK]

These band clamps are just really large Oetiker (pinch clamps). I bought this tool, which has jaws on the top and the side, which comes in handy in tight spaces. Pinch clamps are a nice clean, reliable solution on hoses that you don't need to disassemble regularly. So much nicer than having worm gear clamps on all the small hoses. This is a worthwhile addition to the toolkit, beyond just the steering rack clamps.

https://www.amazon.com/Knipex-Tools-10-99-i220/dp/B01I3H6UIC/ref=sr_1_3?crid=3QSWTDCIFH2YK&keywords=oetiker%2Bclamp%2Bpliers&qid=1696602366&sprefix=oetiker%2Bclamp%2Bpliers%2Caps%2C145&sr=8-3&th=1

[toadster]

I assume you all did this recommendation first? was it that far off from this basic setup?

https://i.ibb.co/Fxdqfq5/Screenshot-2023-10-06-095529.png (https://ibb.co/YRVTKTc)

btw - I also have the Breeze offset rack kit

https://breezeautomotive.com/shop/offset-rack-mounting-kit-for-ffr-roadster-and-coupe/