Steering rack issue resolved!
11-15-2003, 09:23 PM
#1
Cottage Industry Sponsor
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Steering rack issue resolved!
This is a follow-up for the thread at https://rennlist.com/forums/showthre...threadid=95033
I have good news: Today we installed a rebuilt Porsche steering rack - the correct version for the 91 and newer models. And the difference felt like day and night: Now the steering is back to how it used to be - I can park without getting a workout, and it's just perfect at speed. I'm so glad we went through this exercise again!
So, what do we learn from this? If you have a 928 that is a '91 or newer model, don't get a reuilt rack that says "84-95" -- becaue very likely you are going to experience the same as I did. Do it right and get the original Porsche rebuilt rack. It costs a little more (about $75 difference to the ZF), but it is the right part that won't change the characteristics of your car.
Unless, of course, you want to save the expense for the gymn...
I now strongly believe that it is possible to upgrade older 928 models to the new power steering setup. If your rack leaks, inquire about getting a '91+ part as an exchange (the rack has the same dimensions), and the lighter, higher pressure power steering pump from the newer models. Maybe you can even find a used pump. Especially if you are running wider front tires, you will benefit tremendously from this setup.
Unless, of course, you want to save the expense for the gymn...
I have good news: Today we installed a rebuilt Porsche steering rack - the correct version for the 91 and newer models. And the difference felt like day and night: Now the steering is back to how it used to be - I can park without getting a workout, and it's just perfect at speed. I'm so glad we went through this exercise again!
So, what do we learn from this? If you have a 928 that is a '91 or newer model, don't get a reuilt rack that says "84-95" -- becaue very likely you are going to experience the same as I did. Do it right and get the original Porsche rebuilt rack. It costs a little more (about $75 difference to the ZF), but it is the right part that won't change the characteristics of your car.
Unless, of course, you want to save the expense for the gymn...
I now strongly believe that it is possible to upgrade older 928 models to the new power steering setup. If your rack leaks, inquire about getting a '91+ part as an exchange (the rack has the same dimensions), and the lighter, higher pressure power steering pump from the newer models. Maybe you can even find a used pump. Especially if you are running wider front tires, you will benefit tremendously from this setup.
Unless, of course, you want to save the expense for the gymn...
11-15-2003, 10:18 PM
#2
Drifting
Nicole,
The high pressure hoses have different part numbers too. So it's not just pump/rack swap. Just by letting the car roll ever so slowly makes a huge difference in the steering effort.
Where did you buy your Porsche rebuilt rack from? Thanks!
The high pressure hoses have different part numbers too. So it's not just pump/rack swap. Just by letting the car roll ever so slowly makes a huge difference in the steering effort.
Where did you buy your Porsche rebuilt rack from? Thanks!
11-15-2003, 10:33 PM
#3
Drifting
Also noticed in PET, that the part numbers for the pump support bracket are different in 91' and later. Another gotcha.
At least the console and pully are the same.
At least the console and pully are the same.
11-15-2003, 10:42 PM
#4
Nordschleife Master
If you think it's bad with the older style rack, and wide frount tires, try it with no power.
Been there done that. That is a workout!
Once I got used to that, haveing power stearing again made my car almost feel jumpy!
Been there done that. That is a workout!
Once I got used to that, haveing power stearing again made my car almost feel jumpy!
11-15-2003, 11:44 PM
#5
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Hi Nicole:
Glad you got that sorted out. Where did you get the replacement rack? Same place you got the first one?
More than a few folks have commented about the heavy steering at slow speeds. I'd be sorely tempted top get the rack now you have if/when my original '89 unit needs replacement.
See ya!
Glad you got that sorted out. Where did you get the replacement rack? Same place you got the first one?
More than a few folks have commented about the heavy steering at slow speeds. I'd be sorely tempted top get the rack now you have if/when my original '89 unit needs replacement.
See ya!
11-16-2003, 03:04 PM
#7
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Good news!
Just as an FYI to those that don't enjoy the heavy steering characteristics of the stock setup - I replaced the pressurized power steering hose (runs along the driver's side of the engine) with a larger diameter hose, eliminating the integral constrictor orifice. I just brought the original hose to a hydraulic hose shop (it was leaking slightly), and they used the original fittings mated to new hose material.
This resulted in a significant reduction in the effort required to turn the wheel - even at a dead stop. Steering at speed is not compromised, due to the variable speed assist characteristics of the original pump (higher engine speed results in a decrease in power assist).
Just as an FYI to those that don't enjoy the heavy steering characteristics of the stock setup - I replaced the pressurized power steering hose (runs along the driver's side of the engine) with a larger diameter hose, eliminating the integral constrictor orifice. I just brought the original hose to a hydraulic hose shop (it was leaking slightly), and they used the original fittings mated to new hose material.
This resulted in a significant reduction in the effort required to turn the wheel - even at a dead stop. Steering at speed is not compromised, due to the variable speed assist characteristics of the original pump (higher engine speed results in a decrease in power assist).
Trending Topics
11-16-2003, 03:20 PM
#8
Racer
Join Date: Jan 2003
Location: Berkshire. 'Old' England. U.K.
Posts: 465
Received 0 Likes
on
0 Posts
Randy
Were abouts is that ?. I've replaced my main hose as you have, just replacing the hose & reusing the ends but did not come across the constrictor ?
may be diferent on an '87 ?
the integral constrictor orifice.
may be diferent on an '87 ?
04-12-2006, 06:33 AM
#10
Racer
Join Date: Feb 2006
Location: Madrid, Spain
Posts: 320
Likes: 0
Received 0 Likes
on
0 Posts
Hi.
I recover this old thread because it almost took me where I want to go! I'm also a bit tired of the heavy steering of my 87 s4. I can easily take out the hi-pressure hose, measure it and order a bigger diameter one from goodridge with the proper fits and lenght. We do it often (we build racers). I will make a test and if it's really and improvement you could make a group buy using the code nº I'll generate. It will be cheaper than rebuilding non-leaking parts and replacing the whole system with the 91'.
To start, I just need:
1) List of things to do to have a perfect original system. I don't want to tell you it's an improvement, when I just improve because I changed the fluid at the same time. Tell me all the things that improved your power steer, and how much effect each one had. So far I know of new fluid, new reservoir, rebuilt pump, rebuilt rack, proper bleeding and proper joints.
2) Confirmation (Randy V) a bigger diameter made a difference over the time, and with no side effects. Which diameter did you used?
Let me know what do you all think.
I recover this old thread because it almost took me where I want to go! I'm also a bit tired of the heavy steering of my 87 s4. I can easily take out the hi-pressure hose, measure it and order a bigger diameter one from goodridge with the proper fits and lenght. We do it often (we build racers). I will make a test and if it's really and improvement you could make a group buy using the code nº I'll generate. It will be cheaper than rebuilding non-leaking parts and replacing the whole system with the 91'.
To start, I just need:
1) List of things to do to have a perfect original system. I don't want to tell you it's an improvement, when I just improve because I changed the fluid at the same time. Tell me all the things that improved your power steer, and how much effect each one had. So far I know of new fluid, new reservoir, rebuilt pump, rebuilt rack, proper bleeding and proper joints.
2) Confirmation (Randy V) a bigger diameter made a difference over the time, and with no side effects. Which diameter did you used?
Let me know what do you all think.
04-14-2006, 02:39 PM
#12
Inventor
Rennlist Member
Rennlist Member
The steering effort in my car increased significantly after putting 8" rims/245 tires on the front.
It's the odd fitting in the middle of the hose, with a rubber doughnut around it, at the top of the shock tower. I've read that removing it causes the pump to whine with older US pumps. It doesn't seem to effect Randy's pump.
I plan to replace all the hoses with Aeroquip, but run them in a more direct path under the car, and include a cooler. The early cars have no cooler at all, and the later cars have just a tubing loop.
I've also wanted to try installing a bypass valve that would dump most of the pressure to the return line at freeway speeds. The control could be as simple as a button to engage the bypass, and brake light and/or idle switch to disengage.
Hmmm...The unused (in my car) cruise control stalk could be reused for a range of controls...
Sorry, I've had a bad cold the past few days, and am feverishly rambling...
Originally Posted by martin D
I've replaced my main hose as you have, just replacing the hose & reusing the ends but did not come across the constrictor?
I plan to replace all the hoses with Aeroquip, but run them in a more direct path under the car, and include a cooler. The early cars have no cooler at all, and the later cars have just a tubing loop.
I've also wanted to try installing a bypass valve that would dump most of the pressure to the return line at freeway speeds. The control could be as simple as a button to engage the bypass, and brake light and/or idle switch to disengage.
Hmmm...The unused (in my car) cruise control stalk could be reused for a range of controls...
Sorry, I've had a bad cold the past few days, and am feverishly rambling...
04-14-2006, 04:38 PM
#13
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Wow - here's a thread outta the tar pits!
It's been a few years since I did that on my previous car (a '79), so not real sure about the hose size. If I recall, I requested that a hose with an increased inside diameter of 25% be used when I had it rebuilt.
Between the larger hose and removal of the constricter, the improvement in steering ease was significant.
There were no adverse effects such as pump noise.
It's been a few years since I did that on my previous car (a '79), so not real sure about the hose size. If I recall, I requested that a hose with an increased inside diameter of 25% be used when I had it rebuilt.
Between the larger hose and removal of the constricter, the improvement in steering ease was significant.
There were no adverse effects such as pump noise.
