Steering rack play - How much is normal?

[DennisMenace]

Hi guys!

In the process of rebuilding my suspension, I removed the steering rack in order to replace the coupler. I have noticed a slight play when moving the shaft from the steering rack to the column. I am wondering if a very slight play is normal or if this means that I have to replace for example the puck that pushes the steering rack to the pinion.

On the video, you can hear a very slide knock when I rotate from left to right - this is the play I mean.

Any experience on this is much appreciated!

https://youtube.com/shorts/MFXXPscYvK4?si=LPgL5F6Gv60jR05q


Best regards and thanks
Dennis

[85RedCarrera]

Your video won't play. The "puck" inside your rack might be worn out. Since you have the rack out, why not change the two bearings & sealing o-ring inside, clean it out and re-grease? You can get a new composite puck from joe engineer.

Lots of threads on this. I'm in the middle of my rack rebuild right now- just waiting on the bearings.

[85RedCarrera]

This is the puck I'm talking about...it is supposed to be flat on top- mine is very worn...not uncommon.

[proporsche]

Originally Posted by 85RedCarrera

This is the puck I'm talking about...it is supposed to be flat on top- mine is very worn...not uncommon.

dear that is well used puck..i had mine(same year of 911 as yours) this summer and still flat as a ice rink

Ivan

[85RedCarrera]

Originally Posted by proporsche

dear that is well used puck... had mine(same year of 911 as yours) this summer and still flat as a ice rink

Ivan

Mine is a high mileage car- odometer broke at 215K over a decade ago (before I bought it). I was surprised by the amount of crud I found in the grease that the puck was sitting in- no gasket or other sealing material under the cover plate. Really glad I decided to open it up. It seems that some dust made its way into that area of the rack, and contributed to accelerated wear of the puck and the bottom of the rack.

In addition to ZF, 914rubber.com overhauls these racks, and they apparently replace the end bushings during the process, as well. They don't list the bushings on their site, however, I am going to ask them if they are manufacturing replacements.

[Otter74]

If you need to replace the end bushings in the rack housing, there is a McMaster-Carr part number that works when doubled up, and another for the star ring that holds it in.

The ring:
Square-Profile Oil-Resistant Buna-N O-Ring
1/8 Fractional Width, Dash Number 219
4061T241

The retaining ring:
Push-on Internal Retaining Rings
for 40 mm ID, Black-Phosphate 1060-1090 Spring Steel
90635A415

The O-ring is very slightly larger in OD than the original one, so it requires patience to insert. Use two per side, though I think in practice one will do.

[proporsche]

Originally Posted by 85RedCarrera

Mine is a high mileage car- odometer broke at 215K over a decade ago (before I bought it). I was surprised by the amount of crud I found in the grease that the puck was sitting in- no gasket or other sealing material under the cover plate. Really glad I decided to open it up. It seems that some dust made its way into that area of the rack, and contributed to accelerated wear of the puck and the bottom of the rack.

In addition to ZF, 914rubber.com overhauls these racks, and they apparently replace the end bushings during the process, as well. They don't list the bushings on their site, however, I am going to ask them if they are manufacturing replacements.

Dave i believe you with your mileage but you most likely overlooked miles on mine;-)
here is when i turned 500K
https://www.youtube.com/watch?v=YVE61n681bw

Ivan

[nickelplated5s]

There's 500K and 215K+. It all depends on how and where it's been driven. It's on my bucket list due to age more than anything.

[proporsche]

Originally Posted by nickelplated5s

There's 500K and 215K+. It all depends on how and where it's been driven. It's on my bucket list due to age more than anything.

yup , that is true.My 911 has been driven on 2 continents.. .it is all about the maintenance of it..which i do in my 29 years owning the 911;-)

Ivan

[85RedCarrera]

Originally Posted by proporsche

Dave i believe you with your mileage but you most likely overlooked miles on mine;-)
here is when i turned 500K
https://www.youtube.com/watch?v=YVE61n681bw

Ivan

Dang…I’m sure you’ve outdone me by at least 250k. Impressive. So nice to see others who drive their cars, rather then fearing breaking them.

[85RedCarrera]

Originally Posted by Otter74

If you need to replace the end bushings in the rack housing, there is a McMaster-Carr part number that works when doubled up, and another for the star ring that holds it in.

The ring:
Square-Profile Oil-Resistant Buna-N O-Ring
1/8 Fractional Width, Dash Number 219
4061T241

The retaining ring:
Push-on Internal Retaining Rings
for 40 mm ID, Black-Phosphate 1060-1090 Spring Steel
90635A415

The O-ring is very slightly larger in OD than the original one, so it requires patience to insert. Use two per side, though I think in practice one will do.

Thanks for the info. Are the original ones rubber?

I watched a 914rubber.com video today where he was rebuilding a rack and mentioned that they used to sell a kit with brass end bushings, but people didn’t understand the they had to custom hone the ID due to the fact that the rack isn’t always square from end to end.

[GH85Carrera]

To answer the OP question, almost no play.

My 911 steers like a laser beam. Any movement of the steering at all cause a direction change.

Upgrade to Turbo tie rods. and rebuild that rack.

[DennisMenace]

Thanks for all the responses so far. Super helpful!

I did not open the rack yet but will. Car has only 100,000 miles so the puck shouldn’t be worn too much I hope so that I can reuse it. To compensate for the wear, can I add additional shims between the puck and the spring? Does anyone have the exact dimensions for those ? Thanks!

[proporsche]

Originally Posted by DennisMenace

Thanks for all the responses so far. Super helpful!

I did not open the rack yet but will. Car has only 100,000 miles so the puck shouldn’t be worn too much I hope so that I can reuse it. To compensate for the wear, can I add additional shims between the puck and the spring? Does anyone have the exact dimensions for those ? Thanks!

If i remember correct 3 shims..
Little off topic .Seeing your name i can offer you free T shirt ...have it for 17 years never used;-)hope it fits you?
Ivan

[dennisO]

Who sells the replacement pucks?

[85RedCarrera]

Originally Posted by dennisO

Who sells the replacement pucks?

Google "joe engineer"

[85RedCarrera]

Here's some older threads on the steering rack:

https://forums.pelicanparts.com/porsche-911-technical-forum/224112-sc-steering-rack-diy-bearing-replace.html

https://forums.pelicanparts.com/porsche-911-technical-forum/85404-steering-rack-rebuild-procedure.html

https://forums.pelicanparts.com/porsche-911-technical-forum/1082293-steering-rack-grease.html

[dennisO]

Thanks Dave!

[Otter74]

Originally Posted by 85RedCarrera

Thanks for the info. Are the original ones rubber?

I watched a 914rubber.com video today where he was rebuilding a rack and mentioned that they used to sell a kit with brass end bushings, but people didn’t understand the they had to custom hone the ID due to the fact that the rack isn’t always square from end to end.

I don't know what they are, but the material appears to be similar to the Buna-N o-rings. Mine had broken on one side, giving me play between the rack rod and rack housing. The ID is a perfect-enough match to the rack rod, which is the important part. The clearance on the OD is tight enough that I had to tap them in using a screwdriver tip. Twice the thickness would be ideal but that isn't available from McMaster-Carr.

I have lots of both, so if you end up needing a few, let me know and I can send you some in an envelope.

As someone else mentioned, there should be no perceptible play at all in your steering.

[85RedCarrera]

Originally Posted by Otter74

I don't know what they are, but the material appears to be similar to the Buna-N o-rings. Mine had broken on one side, giving me play between the rack rod and rack housing. The ID is a perfect-enough match to the rack rod, which is the important part. The clearance on the OD is tight enough that I had to tap them in using a screwdriver tip. Twice the thickness would be ideal but that isn't available from McMaster-Carr.

I have lots of both, so if you end up needing a few, let me know and I can send you some in an envelope.

As someone else mentioned, there should be no perceptible play at all in your steering.

I appreciate the offer- I will let you know.

Hard to believe it’s just a square rubber o-ring. An O-ring with steel sliding back and forth through it would require constant lubrication, which means the rack should probably be re-greased maybe every other year? I wonder if it is on the factory maintenance schedule?

I guess you could re-grease it in situ, provided it had been completely disassembled and cleaned somewhat recently. I know that I will be paying more attention to the rack in the coming years, after seeing how bad it can get.
Then again, new ones are only about $4k, right?