Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   Porsche 911 Technical Forum (http://forums.pelicanparts.com/porsche-911-technical-forum/)
-   -   SC Steering Rack DIY Bearing Replace (http://forums.pelicanparts.com/porsche-911-technical-forum/224112-sc-steering-rack-diy-bearing-replace.html)

kcf7z 06-22-2017 12:00 PM

Thanks
Everything is apart and the bearings are in the mail...I just started mentally preparing for the reinstallation

That all makes perfect sense.

I always try to overthink things

javadog 06-22-2017 12:15 PM

When installing bearings, it's usually good practice to lightly heat whichever part needs to be expanded to allow for a looser fit. You can also cool the other part. You don't want to use so much heat that it affects the grease or temper of any of the metals but a little bit does help.

If a bearing fit is so loose that it slips into/on the housing/shaft, that's not a good thing. For that reason, I generally will not use anything abrasive to clean either a shaft or housing.

JR

kcf7z 06-22-2017 12:23 PM

Thanks

That all makes sense.

A trip to the freezer then seems to be the easiest thing to do to allow freedom of motion without needing to fire up a torch. Just requires a few steps.

javadog 06-22-2017 12:42 PM

I would probably never use a torch to heat something like that, but I use a heat gun all the time.

JR

kcf7z 06-22-2017 05:14 PM

The heat gun is a better plan for sure. I don't even own a torch. will just use the reverse plan of the freezer.

bugstrider 10-03-2017 09:37 PM

SC Steering Rack DIY Bearing Replace
 
Quote:

Originally Posted by casor (Post 9635875)
Kc - no need for a press or any other giant tools to reinstall the bearings. The needle bearing should simply slip on the pinion with almost a feeler gauge amount of drag. The larger ball bearing can be tapped in using a socket of the appropriate o/s diameter of the bearing.



For the latter, make sure the bearing seating area in the rack housing is free and clear of crap and corrosion. Fine emery cloth and WD will clean this area up, but feel around for burrs that may prevent the bearing from going in level. You don't want to cock it going it - you will mung the alum housing.

Rob



Like Rob stated, make sure the socket is the proper size and NO larger than is needed to clear the post..... ask me how I know. After ruining my first $18 sealed bearing, I learned the frustrating lesson in proper vs improper installation techniques. Not too worried about the cost of the bearing but more on just being careless and going about it with the "Ramming Speed! Captain" mentality.

First failed attempt.
https://uploads.tapatalk-cdn.com/201...a382622ca3.jpg

https://uploads.tapatalk-cdn.com/201...9b2ec55190.jpg
Damaged due to a slightly oversized socket.[emoji35]
https://uploads.tapatalk-cdn.com/201...bb17135421.jpg

Second attempt was done with a press, for better control of direction and pressure.
https://uploads.tapatalk-cdn.com/201...3e7b284b1c.jpg

https://uploads.tapatalk-cdn.com/201...aaa92a953c.jpg

Cheers


Sent from my iPhone using Tapatalk

casor 10-03-2017 10:18 PM

No sweat man, bearings are cheap and there is probably a bearing house close enough that can be hit by swinging a dead cat. Just take the bearing with you or the number.

Pay no attn. to the "sky is falling naysayers" that say you cannot use a torch on aluminum. You can, just not an oxy/acetylene torch. A propane job is fine - just get it hot enough to evap water. Nevertheless, I did not find it necessary to use one. But I have never shot the pooch with a PP torch. Ever.

ClickClickBoom 10-04-2017 08:54 AM

Quote:

Originally Posted by casor (Post 9762381)
No sweat man, bearings are cheap and there is probably a bearing house close enough that can be hit by swinging a dead cat. Just take the bearing with you or the number.

Pay no attn. to the "sky is falling naysayers" that say you cannot use a torch on aluminum. You can, just not an oxy/acetylene torch. A propane job is fine - just get it hot enough to evap water. Nevertheless, I did not find it necessary to use one. But I have never shot the pooch with a PP torch. Ever.

Having rebuilt 3 racks, I can say, everything was a hand remove/install affair. Nothing was tight or difficult to do with bare hands. If you gotta heat or freeze something is amiss.

bugstrider 10-04-2017 01:29 PM

Quote:

Originally Posted by ClickClickBoom (Post 9762855)
Having rebuilt 3 racks, I can say, everything was a hand remove/install affair. Nothing was tight or difficult to do with bare hands. If you gotta heat or freeze something is amiss.


Interesting,
My main rack gear bearing was pretty snug and needed some pressure to push on. Nothing crazy but some pressure. I haven't completed this step but by doing a pre-fit of the gear and bearing into the aluminum housing, I see it will also need some pressure to get the bearing into its collar.

Thoughts on that install?


Sent from my iPhone using Tapatalk

ClickClickBoom 10-04-2017 02:04 PM

Quote:

Originally Posted by bugstrider (Post 9763236)
Interesting,
My main rack gear bearing was pretty snug and needed some pressure to push on. Nothing crazy but some pressure. I haven't completed this step but by doing a pre-fit of the gear and bearing into the aluminum housing, I see it will also need some pressure to get the bearing into its collar.

Thoughts on that install?


Sent from my iPhone using Tapatalk

My stuff on all 3 rebuilds took nothing more than a few very light taps with a plastic hammer. I guess if you gotta use what you gotta use, so be it. The issue is getting it all back together with new bearings, and the new grease. If a flame is needed that's a lot of expansion.

bugstrider 10-04-2017 02:17 PM

SC Steering Rack DIY Bearing Replace
 
Thanks,

I haven't had to use a flame on anything. Light taps using a plastic hammer sounds right on the amount of pressure I think it will take. I just know in our case, it won't just drop in. Just making sure I'm not doing something stupid.


Sent from my iPhone using Tapatalk

ClickClickBoom 10-04-2017 07:45 PM

Quote:

Originally Posted by bugstrider (Post 9763278)
Thanks,

I haven't had to use a flame on anything. Light taps using a plastic hammer sounds right on the amount of pressure I think it will take. I just know in our case, it won't just drop in. Just making sure I'm not doing something stupid.


Sent from my iPhone using Tapatalk

Sounds like you got it!

evan9eleven 01-12-2018 07:24 AM

This awesome and helpful thread deserves to be kept alive!

in 2015 I did the full Elephant Racing upgrade to my 911SC. However the steering linkage and rack wasn't touched. I had the turbo tie rods from before. Previous to the suspension refresh the car wandered a bit, requiring constant small steering inputs. After the upgrade, new tires, and alignment this condition is exactly the same. (Other then that the new suspension transformed the car!)

Chuck at Elephant tells me that the alignment could be to blame. It was setup by a Porsche gold tech, so I would like to think he got it right, but I will check the specs with him when I can.

However, the steering rack has always concerned me as being suspect, and having read this whole thread I decided to do some checking. As a test I put the car on my lift and 2 vice grips on the steering linkage at the smugglers box on each side of the u-joint. No play in that joint. I then left the lower vice grip in place and by wiggling it I get a clunking/clicking sound. I had a helper wiggle the vice grip while I was under the car, and it seems the noise is inside the steering rack. I verified this with a stethoscope.

I think it is high time for a rack refresh... video below, turn up the volume as the sound isn't that loud on the video.

<iframe width="560" height="315" src="https://www.youtube.com/embed/bk56578qJcU" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

KTL 01-12-2018 07:36 AM

I bet you have some considerable backlash in the rack-to-pinion gear mesh, on account of the wear that occurs between the smooth/back side of the rack and the pressure puck that contacts the rack. Basically it's because the grease breaks down and leaves that interface with no lubrication. W/out lubrication the steel rack slowly wears a groove in the aluminum puck and reduces the applied pressure.

Here's a re-post of bugstrider's puck to show what i'm talking about

http://uploads.tapatalk-cdn.com/2016...b514a72aab.jpg

evan9eleven 01-12-2018 10:33 AM

Quote:

Originally Posted by KTL (Post 9882572)
I bet you have some considerable backlash in the rack-to-pinion gear mesh, on account of the wear that occurs between the smooth/back side of the rack and the pressure puck that contacts the rack. Basically it's because the grease breaks down and leaves that interface with no lubrication. W/out lubrication the steel rack slowly wears a groove in the aluminum puck and reduces the applied pressure.

Here's a re-post of bugstrider's puck to show what i'm talking about

Thanks Kevin!

Yeah, I've seen the pictures of the worn out pucks and expect that mine is properly thrashed too. Has anyone found a source for these or do I just need to lathe one up? And did we ever determine the correct material? You mentioned aluminum but others say a magnet will stick to it so I'm guessing mild steel.

Pazuzu 01-12-2018 01:37 PM

So, I guess I'll jump in and do my rack as well...

Concerning the puck, was there ever a consensus concerning turning it 90 degrees? There was one shown that looked like it was nearly molten it was so distorted, but the others looked better.

Maybe dress the top smooth, and then add something *underneath* between the puck and the spring to give it a bit more pressure? I'd be concerned with just turning 90 degrees, you'd now have contact just along the tips of the ridges that were carved into the surface, and the stiction will be quite different, not to mention an accelerate dwear on the much smaller contact points.

evan9eleven 01-12-2018 02:45 PM

I can't imagine that turning the puck 90 degrees is a good idea if it is really worn. If the groove is slight then maybe a resurfacing would work, but if its like bugstrider's above with a deep trough in it then I can't see any option other then replacing it. Someone should sell these but of course no one wants the liability. My steering rack gets removed this weekend, then we'll see what I have to work with!

chrismorse 01-12-2018 04:09 PM

Puck source - ChrisSeven
 
Chris seven on this board manufacturers an epoxy bonded nylon steel replacement puck for our racks, it cost me 35.00
He also manufacturers one of the lightest flywheels for both the 6 and 9 bolt cranks.

Can't wait to get back to assembly.

Could someone list the sealed bearing part numbers?

I also picked up a Quaife manufactured quick ratio, 2.5 lock to lock rack and pinion gear set. Patrick Motorsports.

Chris

Pazuzu 01-13-2018 07:03 AM

Quote:

Originally Posted by chrismorse (Post 9883365)
Could someone list the sealed bearing part numbers?

Chris

If you go to (for example) Amazon, you can put in the 6202 bearing number, and you'll see lots of options. Open bearings, sealed bearings, semi-sealed bearing...

6202 is a measurement, then you can add on depending on the manufacturer to specify open or sealed or whatever.

Harpo 01-13-2018 07:48 AM

I have an email in to Chris seven about purchasing the puck but have not yet heard back.

David


All times are GMT -8. The time now is 09:15 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.