HOW TO REPLACE A STEERING RACK TIE ROD
This is a common wear and tear fault often picked up at MOT or if you find your car wandering, tramlining, or the occasional knock in the steering on application of power on a tight turn, or just play.
You can test for it by jacking up a wheel, grabbing both sides and rocking left ot right. Feel the outer ball joint to tell if it's inner or outer joint and test the other side to see if it might be steering rack play. Hopefully it's just the tie rod or outer track rod end ball joint.
8N0 422 804 C - tie rod (inc outer rod end ball joint) Right £72.60+VAT
[Alternative Firstline FTR4954 (offside tie rod only) @ £26.50 ask at a good motor factor]
[Alternative Firstline FTR4953 (offside outer rod end only) ask at a good motor factor]
8N0 422 803 D - tie rod (inc outer rod end ball joint) Left £72.60+VAT
N 908 349 01 - Clamp for boot (inner) Â£0.85+VAT
N 101 976 01 - Clamp for boot (outer) Â£0.40+VAT
One problem is that the tie rod is specified to be tightened to a torque of 75Nm but you can't use a socket. You need what's called a Crow's foot Spanner extension for your torque wrench.
After asking around for a 34mm crows foot spanner head and finding that they cost anything form £15 to £30 depending on which manufacturer, I decided to make my own. I looked at 34mm spanners to cut up but at that size they're expensive too and I wouldn't like spoiling a good tool. I found however that cheap and cheerful Draper Value have an adjustable spanner at £4.30 that goes to ~36mm. This would be ideal and would be useful for other sizes in future. So, I cut off the handle and made a 1/2" hole to work with a torque wrench.
Here's the assembled tool (click to enlarge):
When using this extension piece to torque a bolt (in this case tie rod joint) you need to carefully measure the distance between the centre of the bolt (tie rod) and the pivot (1/2" drive) point of your torque wrench. Also measure the pivot point to handle distance and then apply a correction factor according to the formula:
M1 = M2 x L1 / L2
M1 is the torque setting of the wrench.
M2 is the actual torque applied to the nut
L1 is the normal length of the wrench (from square drive to hand pull position)
L2 is the extended length of the wrench
See this Norbar link for an applet calculator for this: Torque Extension Calculator
It's not essential to make this tool. You could buy a Crows Foot spanner of the correct size, or estimate the correct torque. If the latter, it would be advisable to use some threadlock to ensure it doesn't come loose.
Now for the job....
Jack up the front wheel concerned, supplement the jack with an axle stand for safety and and remove the roadwheel. Turn the steering wheel to extend the end of the steering rack. Now prize apart the larger and smaller band clips on the steering boot and pull the boot away from the rack.
There are two flats on the rack end behind the joint, which you need to counterhold with a spanner. It's important not to strain the rack and pinion! Here you can see the adjustable Crows foot applied along with a spanner to undo the tie rod joint. you can also see some rust due to moisture getting into the joint which may have caused it's demise. Also shown are the official special tools but room for clearance is not quite as easy as sugested.
Now with the inner ball joint removed, measure the distance between the flat rear of the ball joint nut (ball joint held straight) and the interface between the lock nut and the outer ball joint. Be careful not to strain the outer ball joint boot. My distance was exactly 290mm.
Now undo the locknut with opposing spanners (there are flats on the outer ball joint) and unscrew the tie rod.
Remove the locknut and remove the boot.
Here are the two tie rods. The suppliers (Firstline) said they were OE parts. There are slight differences in design but this may be a revision by the OEM. The new one is certainly better than the old one!
If you are keeping the old boot, give it a clean with hot soapy water and brush inside and out and dry thoroughly.
Apply some lithium grease to the tie rod arm and slide the new (or re-used) boot over the arm. Apply some CopperEase or CopperSlip to the threads on the outer end of the tie rod and screw on the locknut. Measure the distance between the rear face of the ball joint nut and the outer face of the locknut and adjust to the previous measurement.
Without disturbing the locknut, screw the inner ball joint into the rack and torque to 75Nm (at rack - 62Nm on my torque wrench according to the formula). Some thread-lock compound will do no harm (although unnecessary if correctly torqued). Make sure you don't strain the rack - use the opposing spanner on the rack end.
Next, screw the outer end of the tie rod into the outer ball joint, up to the locknut, then lock the locknut securely (spec = 50Nm).
Now cover the ball joint, rack end and rack casing/boot mounting in grease (more for rust protection/sealing), connect boot securely to rack casing end and tighten larger boot clip in place. Nail pincers will do if you don't have the correct tool. Space is limited - make sure the boot and clip are tight enough not to rotate - you don't want them coming off and allow water and dirt to get in.
Next apply outer clip so boot is retained in recess on tie rod arm. Degrease the exposed portion of the arm and paint with black Hammerite paint.
Finally, test drive and note the position of your steering wheel in a straight line forward direction. Correct the tie rod accordingly to bring the steering wheel back in line but get the tracking checked properly before too many miles.