DeTomaso Mailing List: October 99, Message #71

Landis wrote:

>I've noticed during all the work on my car that the steering rack has leaked 
all
its oil out.  

>>>From where?

>Also when I swing the wheels the rack feels like the pinion gear
has a bad tooth.  

>>>Aack.

>Is it possible to rebuild the rack?  If so can someone tell me
what is required tools and effort as well as where to get parts. 

>>>You can take it apart, look at it, and replace the parts that are leaking 
oil, but as for getting new individual components (i.e. just a new rack, or 
just a new pinion), you can forget about it. :<(  The only service components 
available are the pinion seal and the aftermarket bronze bushing.

> Also it is only
a week until the hot rod power tour east.  SO I'll be making a 3000 mi trek in
the car.  Is it all right to drive it like it is or will the rack seize up?

>>>Dunno about seizing up, but why not fix it, or at least try to make it 
better?

I didn't really plan on getting smart on steering racks, but at an earlier 
PCNC tech session this spring, I wound up rebuilding three of them in one 
day!  Actually, two of them received the bronze bushing modification, while 
the third one was totally dismantled to the smallest piece, then carefully 
put back together.  I also got to R&R two of them from Panteras--the third 
got the bushing with the rack still in place.

Okay, so here's what you need to do:

1)  Remove the rack from the car.  This isn't terribly difficult; check your 
factory shop manual for the how-to (you DO have one, right?  No excuse for 
not having one!)  Just in case you don't, removal is child's play.  First, 
jack the car up, support the front end with jackstands and remove both front 
wheels.

If you have The Touch, you can pop the tie rod ends out from the spindles.  
Since they cost $130 each, you want to be VERY careful with this maneuver.  
Since my alignment was out of whack anyway, I decided to take the easy way 
out and simply unthreaded the tie rods from each tie rod end, keeping the rod 
ends attached to the spindles.

The rack is secured to the underside of the car with two massivly heavy-duty 
clamps, each held in place by two long bolts which thread up into the chassis 
of the car.  The steering column also locates the rack in the left-right 
plane, and slides over the pinion and is held in place with a big cast clamp 
with a pinch bolt going through it.

Step one is to remove the column from the pinion.  You must remove the pinch 
bolt entirely; there's a cast-in indentation in the pinion, which prevents 
the column from sliding off if the bolt is still in place.  You can beat on 
it until doomsday and it won't move until you pull the bolt out.  Don't ask 
me how I know this.

Then, remove the four bolts that hold the (two-piece) clamps in place.  If 
you're directly underneath the car, the (heavy) clamp will drop straight down 
and smack you in the forehead (don't ask me how I know this either.)

Once that's done, the rack will now rest in the two holes in the chassis 
through which the tie rods pass.  Simply slide the rack out the driver's side 
(it's best to have somebody on the passenger side helping you feed it 
through; or you can do it from underneath until it's most of the way out, 
then crawl out to the driver's side and finishing removing it.)

This exercise will normally take 30-40 minutes (less if you remove the pinch 
bolt immediately!)

2)  Undo the clamps holding the tie rod boots to the rack.  BLEAH and the 
remaining fluid will pour out, so plan ahead.  If you forget this little 
detail, you will wind up with 80-90 wt oil all over the place.  Don't ask me 
how I know this.

3)  Place the rack housing in a padded vice.  Careful--it's aluminum so don't 
get too nutty when you clamp it down.  The tie rods are secured in a clever 
way.  The outside of the housing is threaded, and there's a fairly wide 
threaded collar that acts like a jam nut, and the tie rod has its own 
threaded collar.  There is an indentation in the surface of the housing into 
which the jam nut is peened, and there's another peening between the jam nut 
and the collar of the tie rod end.  You have to use a home-made tool (I used 
a flat-edge screwdriver that was heated up and the tip bent 90 degrees) to 
carefully pry the peened-in portions of the jam nut up, enabling it to turn.

Screw the jam nut towards the center of the rack.  This will take tension off 
the collar on the tie rod, and you can then unthread it and remove it.  There 
is a spring and ball bearing hiding between the inside of the tie rod and the 
end of the steering rack itself (tension of the tie rod is adjusted by 
threading the collar in or out to control the degree to which the spring 
presses the bearing into cups cast into the end of the tie rod and the rack.) 
 If you forget about the presence of this spring and ball bearing, when you 
remove the tie rod, the spring will go SPROING and the ball bearing will 
shoot across the garage floor and wedge itself underneath your 2,000 lb tool 
chest.  Do not ask me how I know this.

4) With both tie rod ends removed, turn the housing so that the bolts 
securing the pinion are accessible, and loosen them.  Also loosen the bolts 
that hold the tensioning cover down.  Note that the bolts are NOT metric!!!  
Then CAREFULLY remove the covers and associated equipment.  There are a few 
shims, springs, balls, etc. hiding here, so pay VERY careful attention to 
their orientation.  The shims are a critical part of the rack's adjustment 
and control the rack/pinion interface.  If you have a sloppy rack, I GUESS 
that you might improve matters by removing one of the shims.  Heck, at that 
point you probably have nothing to lose.

During the course of the disassembly, you will wind up removing the pinion 
seal (a speciality gasket which fits around the pinion where it joins up with 
the steering column.)  This gasket is a very, very special part, not 
obtainable anywhere.  This is also a common source for oil leaks.  Don't take 
short cuts here--obtain a new replacement (available from Larry Stock and I 
presume others for the princely sum of about $10.)

Once the pinion and associated hardware are removed, you can now withdraw the 
rack from the housing, out the driver's side.  Now the assembly has been 
reduced to the last possible part.

On the one that I performed this operation on, there was serious corrosion on 
the rack itself, due to it being exposed to moisture and not properly 
lubricated.  To fix it, we chucked it up in a lathe and hit it with emory 
cloth (or whatever that stuff is called) and cleaned it all up.

Take a look at your pinion and the teeth in the rack.  Place the rack 
teeth-down on a known flat surface and look for excessive wear (normally 
found towards the center.)  If there is a pronounced dip near the center, you 
should probably plan on pitching the thing. :<(  Hopefully things will look 
halfway decent and you can continue.

5)  Now it's time to put it back together.  Carefully re-insert the rack into 
the housing, and then slide the pinion in and secure it (and the associated 
tensioning shims.)  Then slide the new pinion seal over the pinion and drive 
it into position in the  rack housing using a deep-set socket.  Note:  If you 
install the seal first and then attempt to inert the pinion through it, you 
will pop the seal out, tweak it, and possibly ruin it.  Don't ask me how I 
know this.

6)  Carefully torque the bolts securing the pinion and shims.  Remember that 
the housing is aluminum.  You're in a difficult position here, since you're 
attempting to sandwich several thin sheet-metal shims under a cover with no 
gasket material; not enough torque and it will seep fluid; too much torque 
and you'll strip the housing.  (I tightened mine as much as I felt was 
prudent, then after it was all assembled and filled I put it in the back of 
the Scirocco of Doom for 24 hours.  Smelling oil the next day, I found a 
fairly large pool of oil underneath the pinion on the floor of the trunk.  
Gritting my teeth I set it back in the vice and let it know who's boss with a 
slightly longer 3/8 inch drive breaker bar.  No more leaks!)

7)  Now is the time to install the bronze steering rack upgrade.  I don't 
care if your rack feels good or not--if it's out of the car and doesn't have 
this bushing, you're wrong.  Just put it in.  I installed one in my rack, 
which was brand-new.

They come with full instructions from the vendors, but basically at this 
point you merely slide it over the passenger end of the rack until it bottoms 
out against the existing (and trashed) plastic bushing.  You mark its 
location, remove it, drill a small hole in the housing right over the 
bushing, tap it for the included set screw, slide the bushing back in (after 
cleaning out the metal shavings of course), use a slightly smaller drill to 
make a small indentation in the bushing without screwing up the threads in 
the housing, then install the set screw (using Loctite.)

Note:  The bushing is supposed to be a tight fit against the housing, but the 
rack is supposed to pass smoothly and freely through it.  The 
above-referenced rack rebuild was caused by a corroded rack which would NOT 
pass through the bushing; after we'd installed it, we discovered that the 
rack was bound up solid!  This is NOT what you want!

8)  With the bushing installed, re-install the tie rod ends.  You want to 
tighten the collar down far enough so that the tie rod will move smoothly, 
but will remain in any position that you place it (i.e. doesn't flop around.) 
 Once it's there, tighten the jam nuts back against the collars, then 
carefully re-peen the nut in the appropriate places.  If you're lucky, you'll 
probably wind up peening it right back where you had un-peened it before.

9)  If the tie rod boots are even slightly suspect, toss them.  New boots can 
be had from DeTomaso for big $$$, but they're a fairly generic piece; any 
auto parts store should have appropriate substitutes, or you can buy low-cost 
substitues from the vendors at the same time as you buy the bushing and 
pinion seal.

Slide the boots over the tie rods and secure the passenger side tightly.  
There is an indentation in the rack housing and another slight indentation on 
the tie rod which marks where the hose clamps need to go.  Do yourself a 
favor at this point and use the boots as a visual aid to center the rack 
(i.e. have about equal boot length on both sides.)  This will make it easier 
to ensure the steering wheel points straight ahead when the rack is centered 
when you install it back in the car.

10)  With the driver's side boot NOT yet attached to the rack housing, stand 
the rack up so that the passenger side points down, and pour exactly 1/3 pint 
of 80/90 wt gear oil (same as you use in your transmission and rear end of 
conventional cars) into the housing.  Do NOT attempt to substitute motor oil, 
grease or wishful thinking.  Just pour in the 80/90 and be done with it.

11)  Secure the driver's side boot hose clamps, and now you're ready to 
re-install the rack into the car.

12)  Rack installation is the reverse as un-installation, with a few 
cautions.  Slide the rack assembly in from the driver's side, then crawl 
underneath and position the clamps and slide the bolts through and thread 
them into the holes in the chassis.  This might take some doing if you're 
working by yourself, and you can pretty well count on getting at least one 
(heavy) clamp right between the eyes.  Don't ask me how I know this.

You can go ahead and tighten the mounting bolts fully at this point, but if 
you do, I can virtually guarantee that you'll discover that during the course 
of your wrestling, the rack housing shifted to the side and the pinion 
doesn't line up with the steering shaft.  After you loosen it and slide it 
into place and tighten it up again, you'll then find that the housing pivoted 
and the pinion will no longer be pointing back towards the steering column, 
but will instead be pointing straight up.  As there is a bit of chassis 
between here and there, even loosening the clamps somewhat won't give you 
enough clearance to simply rotate the housing to put the pinion in the proper 
orientation--you'll have to remove the clamps fully, drop the rack about 2 
inches, rotate, then re-install.  Don't ask me how I know this.

13)  Getting the steering column back over the pinion can be quite a 
challenge.  The technique that worked for me was to use a big screwdriver as 
a wedge, and hammer it into the split in the steering column clamp, which 
enabled the column shaft to (barely) slide over the pinion (both are 
splined.)  An assistant is quite a bonus at this point.  Using a long punch 
and a small hammer, have the assistant lightly tap the steering shaft from 
inside the driver's compartment, above the pedals.  As he/she taps the shaft 
down, look carefully through the hole in the shaft where the pinch bolt 
passes through and mates with the indentation on the pinion.  As soon as it's 
lined up, have the assistant stop tapping.

You might want to shout something like "STOP!!!" or your assistant might not 
hear you and continue tapping, which will then require you to use another 
hammer and punch and tap the shaft back off the pinion until the holes line 
up.  Don't ask me how I know this.

Once the holes are more or less lined up, attempt to insert the pinch bolt.  
A little tugging or tapping and or out on the shaft may be required before it 
goes home.  Once it does, tighten that sucker down to the max.

14)  With the pinch bolt tight, you can now safely get underneath the car and 
tighten the rack housing clamps down.

15)  Center the steering wheel and ensure there is equal travel to the left 
and right.  Be VERY careful when you turn the wheel left and right, the limit 
should be approached with caution.  With no externally-provided resistance, 
the rack can travel far enough so the pinion suddenly encounters a non-geared 
portion of the rack, causing damage.

16)  Now thread the tie rod ends back onto the tie rods.  Give your best shot 
towards ensuring that equal threads appear on each side, the steering wheel 
and the two front discs are all pointed straight ahead.


Congratulations!  Now all you have to do is to install the front wheels and 
get the front end re-aligned!

Note that even if you popped the tie rod ends from the spindles and left them 
attached to the tie rods, you will probably need to re-align the front, 
because you might not have tightened the tie rods back onto the housing in 
exactly the same place.  

Truthfully, if you're concerned with steering feel, you might as well take 
the time to perform another steering system modification which is to tighten 
and/or bolt or weld the male and female slider portions of the steering 
shafts.  Look underneath the dashboard, up above the pedals, and you'll see 
that the steering shaft coming down from the wheel has a male fitting which 
slides into a female fitting on another shaft, which then leads (via a 
u-joint and still another shaft) to the steering rack.  Very often this 
slip-fit is very sloppy and imparts tremendous slop in the steering.

With the steering system completely assembled (to position things properly in 
the in/out plane), either weld the two-piece slider assembly together, or 
(cheaper and easier, although not quite as effective), drill a hole 
completely through both parts and run a bolt and nut through.

The overpriced Pantera I checked out last week had absolutely awful fitting 
here--there was a bunch of slop in the wheel and virtually 100% of the slop 
was visible right at this slip joint.

Well, I hope this little primer will give you what you know to tackle the 
job.  I had a lot of fun (and learned a few too many painful lessons) during 
the course of my job.  With all my buffoonery, the entire job from start to 
finish took about three hours.  If you learn from my mistakes you should be 
able to shave quite a bit of time from that.

Good luck, and let us know how it turned out!

Mike