power steering reseal
04-20-2010, 09:43 PM
#1
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power steering reseal
I've done some searching here and not much info, just wondering if anyone has done a steering rack reseal and if so any tips. I have some help from a mechanic who rebuilds Toyota racks, hopefully not to much difference. Thanks, Jack
04-21-2010, 12:12 AM
#2
Rennlist Member
We just had a rack rebuild party up at Colin's place in BC, Can. Colin has done a number of racks so he knows the drill. With his guidance it was relatively straight forward.
I can't give you a step by step, but we used the rennbay kit with success. Kept track of all the seals, made sure everything was spotless, and most importantly, made sure the inner bore of the rack and the shafts were in good shape.
Any pitting or damage to those and the reseal effort will fail.
And of course cleaning everything thoroughly before reassembly is key as well.
Hopefully those with more experience will chime in with more details. And with your buddies experience with rebuilding racks you should be fine.
I can't give you a step by step, but we used the rennbay kit with success. Kept track of all the seals, made sure everything was spotless, and most importantly, made sure the inner bore of the rack and the shafts were in good shape.
Any pitting or damage to those and the reseal effort will fail.
And of course cleaning everything thoroughly before reassembly is key as well.
Hopefully those with more experience will chime in with more details. And with your buddies experience with rebuilding racks you should be fine.
04-21-2010, 01:52 AM
#4
Caveats: I am not expert in rebuilding steering racks; I have no idea if any Toyota rack is similar to a 928 rack; and my only experience is rebuilding my own (and I made most of it up as I went along….).
Consider getting a rebuilt unit before you rebuild your own as many people have had problems, particularly if there is excessive radial play in the passenger side. The driver’s side has some adjustment allowance for radial play, but the passenger side does not. The passenger side of the rack has an internal bushing that controls the radial play at that end.
This bushing is a wear item that is not included in any of the rebuild kits that I have found and does not seem to be available otherwise. Also, if the steel ram has been polished to remove corrosion, then a stock bushing won’t help anyway. You could always have a bushing machined to fit. (FWIW, there is a plastic bearing on the saddle block under the pinion gear on the driver’s side that is not included in the normal kits also, but I suspect that it is not usually needed)
If you get a rebuilt rack, I suggest that you get one rebuilt in Germany by ZF. They are expensive ($1200 at last check), but they will be built to new specifications, unlike the two rebuilt racks that I ordered and sent back.
I was not happy with either of the two rebuilt racks that I ordered from two separate sources: both had far more radial play than my old rack; both had been “rebuilt” with improper tools (apparently a hammer and punch is considered to be an acceptable substitute for the correct spanner required for the threaded sleeves that secure the end castings to the central tube, and beating those sleeve rings into deformed submission is not considered a QA problem by either of the two rebuilders…); both had been clamped in vises when they were worked on with large stippled areas to show for it; one had the end castings improperly aligned with each other; and one had various minor dings and damage.
In all events, I suggest caution: inspect any rebuilt rack carefully, measure the radial play, etc. A warranty is nice, but they will not be sending a mechanic out to replace a rebuilt rack should it fail.
OK, I am done ranting, but if you choose to have your Toyota mechanic do the work, make certain that he has the proper tools: correct spanner, seal drivers, fixture to hold the rack assembly while tightening the threaded sleeves, etc. Also make certain that the radial play of your rack is acceptable or that you can get or make a proper bushing as well as properly grind/polish the steel ram if needed (and this is not done by hand with a strip of crocus cloth as if polishing shoes….). Note that if you grind and polish the ram, you will definitely need to make an internal bushing; also, I do not know what the undersize limit for the steel ram is, so if it is too small, even with a custom bushing, the seal might not work….
After having sent back the two racks, and deciding that I did not want to spend $1200 for the genuine ZF rebuild just yet, I ordered a seal set from Roger at 928sRus along with boots, tie rods and other miscellaneous bits, removed the rack from my ‘89GT, cobbled up a nice sturdy looking spanner, clamped the rack to the table of my milling machine, broke my POS home made spanner without budging the first threaded sleeve (it took a LOT more torque than I expected…); ordered and received a BMW steering rack spanner from Sir Tools, modified it to fit the 928 rack, disassembled the rack, cleaned everything, lathe turned seal drivers as needed from delrin rods and replaced all of the seals, polished steel ram in lathe with 1500 and 2000 grit, cleaned everything again, lubricated the parts and reassembled the rack on the mill table, used the about the same amount of torque to hold things together as it took to take it apart, and made a centering bolt…..
The job is really pretty simple: use the right tools; keep everything clean; and put the seals in the right places facing the correct direction.
Getting the rack back into the car took about as long as the rebuild process. The universal joint on the steering shaft is a tight fit onto the input shaft of the rack and the Devek level 2 headers severely limit access. It was no fun at all.
The rack originally started leaking on the passenger side due to corrosion of the steel ram; the boot on that side had a crack that was not visible from below that allowed water to get in, and once in, it stayed there and formed light speckled corrosion that destroyed the seal. This rack was a German ZF rebuild that the PO had installed, so it had few miles on it and almost no radial play on the passenger side, so it seemed worth the gamble to rebuild it.
I considered “enhancing” the rebuild somewhat: hard chroming the ram, and a beefier passenger side bushing, but the cost and delay of the hard chrome and grinding ($750 and three weeks), and the potential for screwing things up due to my lack of understanding or skill dictated otherwise…
So far, so good. However, if this rack starts to decorate the street and driveway again with ATF, I intend to replace it with a ZF rebuild.
Good luck, whatever you decide to do.
Bob
Consider getting a rebuilt unit before you rebuild your own as many people have had problems, particularly if there is excessive radial play in the passenger side. The driver’s side has some adjustment allowance for radial play, but the passenger side does not. The passenger side of the rack has an internal bushing that controls the radial play at that end.
This bushing is a wear item that is not included in any of the rebuild kits that I have found and does not seem to be available otherwise. Also, if the steel ram has been polished to remove corrosion, then a stock bushing won’t help anyway. You could always have a bushing machined to fit. (FWIW, there is a plastic bearing on the saddle block under the pinion gear on the driver’s side that is not included in the normal kits also, but I suspect that it is not usually needed)
If you get a rebuilt rack, I suggest that you get one rebuilt in Germany by ZF. They are expensive ($1200 at last check), but they will be built to new specifications, unlike the two rebuilt racks that I ordered and sent back.
I was not happy with either of the two rebuilt racks that I ordered from two separate sources: both had far more radial play than my old rack; both had been “rebuilt” with improper tools (apparently a hammer and punch is considered to be an acceptable substitute for the correct spanner required for the threaded sleeves that secure the end castings to the central tube, and beating those sleeve rings into deformed submission is not considered a QA problem by either of the two rebuilders…); both had been clamped in vises when they were worked on with large stippled areas to show for it; one had the end castings improperly aligned with each other; and one had various minor dings and damage.
In all events, I suggest caution: inspect any rebuilt rack carefully, measure the radial play, etc. A warranty is nice, but they will not be sending a mechanic out to replace a rebuilt rack should it fail.
OK, I am done ranting, but if you choose to have your Toyota mechanic do the work, make certain that he has the proper tools: correct spanner, seal drivers, fixture to hold the rack assembly while tightening the threaded sleeves, etc. Also make certain that the radial play of your rack is acceptable or that you can get or make a proper bushing as well as properly grind/polish the steel ram if needed (and this is not done by hand with a strip of crocus cloth as if polishing shoes….). Note that if you grind and polish the ram, you will definitely need to make an internal bushing; also, I do not know what the undersize limit for the steel ram is, so if it is too small, even with a custom bushing, the seal might not work….
After having sent back the two racks, and deciding that I did not want to spend $1200 for the genuine ZF rebuild just yet, I ordered a seal set from Roger at 928sRus along with boots, tie rods and other miscellaneous bits, removed the rack from my ‘89GT, cobbled up a nice sturdy looking spanner, clamped the rack to the table of my milling machine, broke my POS home made spanner without budging the first threaded sleeve (it took a LOT more torque than I expected…); ordered and received a BMW steering rack spanner from Sir Tools, modified it to fit the 928 rack, disassembled the rack, cleaned everything, lathe turned seal drivers as needed from delrin rods and replaced all of the seals, polished steel ram in lathe with 1500 and 2000 grit, cleaned everything again, lubricated the parts and reassembled the rack on the mill table, used the about the same amount of torque to hold things together as it took to take it apart, and made a centering bolt…..
The job is really pretty simple: use the right tools; keep everything clean; and put the seals in the right places facing the correct direction.
Getting the rack back into the car took about as long as the rebuild process. The universal joint on the steering shaft is a tight fit onto the input shaft of the rack and the Devek level 2 headers severely limit access. It was no fun at all.
The rack originally started leaking on the passenger side due to corrosion of the steel ram; the boot on that side had a crack that was not visible from below that allowed water to get in, and once in, it stayed there and formed light speckled corrosion that destroyed the seal. This rack was a German ZF rebuild that the PO had installed, so it had few miles on it and almost no radial play on the passenger side, so it seemed worth the gamble to rebuild it.
I considered “enhancing” the rebuild somewhat: hard chroming the ram, and a beefier passenger side bushing, but the cost and delay of the hard chrome and grinding ($750 and three weeks), and the potential for screwing things up due to my lack of understanding or skill dictated otherwise…
So far, so good. However, if this rack starts to decorate the street and driveway again with ATF, I intend to replace it with a ZF rebuild.
Good luck, whatever you decide to do.
Bob
04-22-2010, 09:12 PM
#6
Here is a link to some pictures when I tried to reseal mine. I have rebuilt hydraulic cylinder many times but didn't have any luck with this and bought a rebuilt unit.
http://www.flickr.com/photos/3294140...7623788139925/
http://www.flickr.com/photos/3294140...7623788139925/
04-22-2010, 11:24 PM
#7
Rennlist Member
I am working on a less expensive way to repair a pitted shaft. Not sure it will work or be worth it or be enough to solve all problems anyway. Anyway, I'll post it here if I get it working.
