Rack & Pinion Service Tools & tips

Overview ​

This write-up should be considered as a supplement to the FSM and many things in it I will not repeat. The FSM is a very good but sometimes confusing tutorial, it just needs a little help. Improvised and home fabricated special tools along with their use will be most of the discussion along with associated tips and lessons learned.


Why attempt this and things to consider first
Each person will have to make the decision based on their situation. Some examples for "do it" would be a leaking control valve seal or rack end seal on an otherwise well-functioning rack (with good rack shaft), as life extending PM or part of the recovery from fluid contamination (H2O, bad PS pump, wrong fluid).
This job requires a fair bit of meticulous, super clean and careful, careful work. I say this in part because in the information age, folks can get lured into a technical repair without enough previous work experience or understanding of working with this type of hydraulic device. One slip of the hand or nicked surface and it's over. Additionally many of the parts are not available or have prohibitively high costs.

The original racks, up to around 2001 had a poorly designed "rack guide" known as the "roller style". I recommend a thorough inspection first before purchasing parts or planning to do much work on these units. Many of them were used for quite a time with the bad guide, causing other terminal damage. I think this collateral damage is why there is such a bad rep on rebuilds as the majority of the racks produced and rebuilt were the roller style. A rack that passed a rebuilders pressure test may not last with use. The racks with the newer guide seem to last significantly longer and as such make a much better candidate for service.
Don't be deterred if you have an early rack with the roller guide. Even if the rack shaft has been damaged by a roller guide (see below, "divots"), as long as there is no other damage to the shaft in the form of deep scoring or rust pitting, the successful upgrade to the new guide is completely realistic.
The guide combined with the pinion gear is all that stabilizes the driver side of the rack shaft. They would get loose in as little as 15-20K miles. This short life was exaggerated by lifts, large tires and hard use. The increased angle of tie rods to rack due to lifts is IMO the single worst offender. Stock geometry allows for more of a straight line for the push pull steering action. The higher the lift, the greater the angle, the faster the wear. The new guide is interchangeable with the old and is a worthy upgrade, assuming no other serious damage was caused. All rebuilds listed as "95-01" should be assumed to be the old type. All the 1st gen 4wd racks are the same aside from the guide.

Changing out guide only
http://www.yotatech.com/f2/how-replace-steering-rack-guide-pictures-215931/

Rack with new style guide. Preload adjuster cap has Allen type socket.


Rack with old style guide. Adjuster has an external hex head. Happens to be on a rebuilt rack.



Below is the roller style guide compared to the newer style and lastly the area that wears in the blink of an eye. You can see the PTFE (or something like it) mushed away from the thrust surface of the roller. Years ago I would shim up the play in the roller style with circular "washer" shaped shims from McMaster Carr. It worked pretty good but the new style guide is better.





Take it apart before ordering any parts. Internal damage can't be detected till it's apart. You can always put it back together and use/sell it as a core. One the subject of cores, should you go with a rebuild, for whatever reason, I would avoid any that come with the old style roller. The old style will have an external hex head on the preload adjuster located below the control valve (looks like a giant drain plug). The new style looks like a big Allen socket.

Before you start
I will just mention this once at the start, it applies to the entire process. Grease on gears, ATF on seals, o-rings, Teflon rings and sealing surfaces.
Initial Inspection
Turn the steering wheel all the way to the right. Pull back the driver side boot and inspect the extended portion of the rack shaft for damage from an old style roller and/or rust. See the first pic. I will talk about rust pitting later, it could very well be a deal breaker, particularly on the pass side. Turn the steering to the left and repeat for the passenger side. Rust pitting on the pass side is very bad, maybe fatal.

The fun begins, control valve tools
With the rack on the bench keep in mind that no matter how well you think the unit is drained it will spit at you when you cycle things back and forth, the voice of experience here.
I like to index the control valve shaft/pinion gear teeth to the rack teeth. They have already gotten to know each other so why break the relationship. Extend the driver side rack shaft (RS) out till it stops (boots off). Mark the control valve shaft (CVS) and control valve body (CVB) so they can be reassembled in the same relationship.
The divot seen below on the RS is where a worn/loose roller guide was rubbing the rack in the "steering straight" position. Close inspection actually reveals 2 side by side divots, before and after a lift/alignment/poly bushing install.



Remove the CVB and the hard lines. The union seats will fall out and the driver side is different than the pass. The only really special tool for the CV is an octagonal hollow socket of sorts, the "octOsocket". This one was made from brass round stock I had laying around. It is 1.27" from flat to flat with a 1" hole. Below are a few of the steps I took, layout, cutting etc.
An easier method would be to grind/cut flats on a 1" shaft collar (the hole is already there).







Shots of the lower seal carrier and using the octOsocket. When installing the carrier tighten it to the "stake", it just needs to be snug, don't worry about the torque spec. Then re-stake lightly at another spot.




The three improvised drivers for r+r of the 2 CV seals and the upper bearing. A piece of 1" ODx1/8" wall brass pipe and 2 sockets. Anything that fits can be used. The pipe presses out the top seal and bearing while the sockets do the install of the seal then the bearing.



Pressing out the top seal/bearing. A note on pressing. All the press work on the entire rack could be done with a hammer but the chances of damage will increase dramatically. In either case be careful, these are small delicate parts. Hammer blows could easily damage the top bearing during removal and I have not been able to find that bearing separately. It is a KOYO DG1935A. (Correction, Toyota does sell the bearing.) Good luck



Semi exploded view. The chamfer helps settle the 4 Teflon rings during assembly.



Installing the seal and bearing. Same operation with 2 different sockets and an extension.



The 4 Teflon rings on the CVS get stretched when they are put on and must be squeezed back to shape with this improvised "ring compressor". It is just thin plastic from blister packaging with the burrs wet sanded off. Try to save a few of the old rings to practice the stretch with.

New Teflon ring "stretching" procedure.





Ring compressor in operation.


When it's time to install the re-ringed CVS into the CVB, first feel the ports inside the CVB with your finger, OUCH! To avoid cutting the rings, slightly twist the CVS CW when looking into the bottom. This way the rings are rotating off the razor sharp edge of the ports instead of into them.
The CV is now done and the rest of the rack is really straight forward.

Rack housing end seal tools Obviously, work on the rack housing is done with the control valve removed.
ITR removal, typical, 41 and 30mm or what ever you got.



Remove the "end stopper" (Toyota's word not mine) with a giant wrench or a big chain wrench/pipe wrench. Note the hole in the flat at the end of the shaft. It connects to a hole on the other end to allow air pressure within the boots to equalize as they expand and contract. Don't let it get plugged with excess grease.



Press out the pass side end seal along with the rack shaft. Hold the shaft or it will fall to the ground.



Pass side seal pushed out with/by the rack shaft/divider piston. Do not remove the Teflon ring from the divider yet. It will be used as part of an install operation later. Note the paper towel "spit guard" on the hard line fitting.



The setup to press out the driver side seal/spacer (toward the pass side) with a socket and a piece of fence pipe. I was able to just push this seal out by hand after getting it started with a few taps from a rubber mallet. The tape is to guard against scratching the inside of the rack body. I used an 1-1/16" socket. It should be just under 1.43" OD.



Inspection and putting it back together
Take a good look at the rack shaft and look for the "swept" area where the seals ride. It's only the last 14" or so of the pass side. Total rack travel is only around 7-1/2". At this point it should be obvious where any pitting or shaft damage would cause trauma to the seals or the Teflon ring. Try to polish any nicks or scratches. With a good light inspect the inside of the rack body for damage. I found a worn area dead center where the divider piston resides when driving straight. This was due to the loose roller guide allowing the shaft to flop up and down. It was pretty smooth and the previous steering effort was smooth so I let it go.
To install the driver side seal/spacer, use a taped socket and extension or the passenger end of the rack shaft itself. The driver side of the divider piston has a weld bead that could cause trauma to the seal. Remember, the lip goes toward the fluid. A taped 36mm socket fit for me but the rack shaft itself is the perfect tool to use, just make sure there are no burrs on the end. The old Teflon ring on the divider prevents scratches.
Stand the rack shaft on the bench with the pass side up. Slide the seal and spacer up against the divider then Lower the rack body over it. Tap the body down with a rubber mallet till the seal seats. Be aware that the end of the rack shaft must align with the reduced diameter hole in the rack body towards the driver side, keep it straight.



Next comes installing the rack shaft. First install the new Teflon ring and o-ring with the same technique as the control valve rings.
The SST for the final shaft install is tape. After double checking and removing any burrs (on the teeth) clean the rack tooth zone with solvent. Then wind tape nice and evenly around the gear end of the shaft. Start right at the inside end of the teeth (no further in) and wind towards the end. The (wet with ATF) seal will be sliding over this tape and "off" the sharp edge of the tape. Do not push the shaft into the body any more than flush with the pass end as the driver side of the divider piston has a ridge (weld?) that will damage the seal. Familiarize yourself with what is going on with that first. The shaft will not be removed after this and the tape can be unwound off the rack teeth from the driver side. ATF will cause the tape to leave black adhesive on the shaft but it can wiped off.
Nicely taped teeth.




Important
Finally, installing the pass side rack seal, the last one. This one is simple, use the "end stopper". Pry out the plastic bushing from the stopper and slip in the new one, add a light smear of grease to the bushing. Start the seal by hand and gently tap it home with the stopper and a rubber mallet or your hand. Go easy when the stopper threads are about to engage. At this point start twisting the stopper to start the threads. Once started just screw that baby home. The book says to stake it but the factory didn't so I didn't. Install both ITRs at this time to prevent any seal destroying over travel of the rack shaft.

Pass side "end stopper" with plastic shaft bushing, a new bushing comes in a seal kit.




Slide the control valve into place. This will take a few tries to get your marks to line up. It is a twist and push motion due to the spiral pinion gear teeth.
Follow the FSM technique for setting preload on the control valve shaft. It is way less precise than the book makes it out to be. They call for a final preload on the (turning) control valve shaft to be 4.1-14.9 in/lbs (both guide types). Another way to look at that spec is 4.1 to 3 and a half times that! I have found that that the "back off 19 degrees after bottoming the spring" puts things in the sweet spot.
If you want to get technical, a few wraps of tape will allow a 17mm 12pt socket to act as an adapter for a torque wrench. Install the union seats, hard lines and boots finished.



NEW PICS Rust, the rack's biggest enemy.

Rust and scoring on driver side. Could be cleaned up and used with new type guide.


Most likely terminal rust on driver side. Impossible to tell because the area swept by the end seal can not be seen without removing the rack shaft.


On the passenger side the seal sweeps nearly all the way out to the ITR so rust here is nearly always fatal.

 

Very nice write up!

Bump so others can see it

 

Awesome write up Dirty Pool! I ordered the newer style rack guide last week and I'm just waiting for them to come in so I convert it to a newer rack. I will have to check and see if I see the divot from the old bushing.

 

I love this write up, i got the old leaky rack out of the taco this makes me want to attempt a rebuild. Did you have to mark the control valve assy before you removed it, or can it just be taken out and put back in? I might have already taken it off before without marking it to get the pressure line out…..

 

Man, I'm the opposite of you guys. This is one awesome write up and I am now convinced that I DON'T want to do this myself! Great attention to detail and patience on the work and the write.

 

wow, excellent write up and attention to detail. love the "octo socket" and ring compressor! makes me bummed I have a rack from '99

 

Awesome Dirtypool. Thank you. Im going to give this a shot.

 

That is just one of those things I do because it only takes a few seconds, it can't hurt/only help and it's the type of "standard shop procedure" I was taught. You will be fine, just remember to check for and remove any burrs on the rack shaft and it's teeth.

I might have initially come down a little hard on the early racks so I just edited that section accordingly. Thanks
As long as there is no other damage to the rack shaft such as rust pitting or scoring in the sealing areas of the rack shaft, a guide upgrade is perfectly reasonable. See the "Initial Inspection" part.

 

Bravo, truely awesome writeup. It is good to finally see some technical info on this site beyond how to install an air freshener or how much lift do I need to fit XX" tires questions. Sadly I don't think the writeup will get the appreciation it deserves due to a lack of skill sets in a major portion of the forum members. If this offends anyone...I am probably referring to you.

Thanks for the tech info I will use it!

 

I'm offended.

how much "better" is the new guide? obviously it is better, but does it reduce clunking or improve response? my old rack is on it's way out if a bushing replacement doesn't work, so I might just do this write up.

 

The new guide was a noticeable improvement for me in my lifted 96 Taco. IMO the new style guide is a must have especially for a lifted Taco. The angle that the tie rod ends up being after a lift really exacerbates the sloppy tie rod issue. I went ahead and installed the new guide on my stock 3rd gen 4Runner as well to tighten up the steering response. It is worth it.

 

The new style guide just lasts significantly longer. The roller type develops play quickly and allows up and down slop in the rack shaft. Because the driver side of the rack shaft is twice as long as the passenger side and the pass side has its own 360 deg bushing, the slop is noticed on the driver side first. This allows the front wheels to have a mind of their own (more so on the driver side), makes accurate toe adjustment impossible and can cause a "clunk". It doesn't do the rack end seals any good either.
There is no improvement in response other than correcting the play and tightening up the steering.

 

you know now that you mention it, my driver side is significantly sloppier than my passenger. must be the old style worn out guide in there.

well sub'd for future work, I'll obviously need it.

 

I'm def going to be updated the rack guide soon. Sure beats buying a new OEM rack.

 

My 17 yr son took his Tacoma to get alignment done. He brought it home and said they could not do alignment because drivers side tie rod end needed replaced. On closer inspection we found it was actually play in the rack, due to the shaft guide wear (roller style). We have shimmed it but would like to replace with newer style. Would have replaced rack if I had not found this thread, thanks for posting this!

 

They are dealer parts. Try the online parts dealers such as Camelback Toyota for the best prices. Should be less than $65. The following thread has the part #'s. Use the numbers when ordering, if you give them your VIN# it is likely you will end up with the old style parts. If you are sourcing the parts at your local dealer, use the #'s or just tell them it is an 04.

 

Sub'd. Very well done and super helpful!

 

This needs a big ole bump. I'm not recommending everyone rebuild their rack, but I'm definitely recommending anyone with rack issues read this. It really helped me understand what is going on with the rack and why the issues that pop up actually happen. Stellar writeup, extremely informative. Thanks @Dirty Pool for taking the time to write this up and post it. Obviously the writeup and pics took effort. Very clear and concise. Actually makes me excited to rebuild mine, when it needs it. I guess that's one thing I can't complain about with my 3" body lift(don't start, was already on it when I bought it, lol), the steering and drivetrain geometry is still all stock. No wonder my drivelines and steering rack and rod ends all still perform okay....but that body lift has to come off sometime.

 

Now I know why I'm replacing my rack guide today. And where to grease it!

 

Just want to add my thanks to Dirty Pool for his OP. I'm new to the forum and am about to replace my old-style roller bearing/guide. Great write-up and tutorial with very usable pics. Thanks a lot.