Advice on a 1988 Fiero hydraulic rack and pinion unit (Page 1/2)
sspeedstreet DEC 13, 04:42 PM
I'm hoping someone here can give me advice on a 1988 Fiero hydraulic rack and pinion unit. I found this one in a junked car in Michigan. My question is about corrosion on the rack shaft. Both ends under the boots (bellows) have surface rust. Is that area critical to sealing the unit? Sadly, no info seems to be around any more for these. Any insight into how critical the finish needs to be at this location?

[This message has been edited by sspeedstreet (edited 12-13-2022).]

theogre DEC 13, 07:13 PM
No Fiero has PS. 88 was going to have PS but was Electric unit and deleted from final version.
Someone Mod'ed the car to have PS and you have to guess what PS rack was used.

Rust near the ends on the rack when can see car steered straight is maybe ok.
Depends exactly where the rust is and if it is in the "working zone" where rust hits hydro seals then the seals won't last long.
Even if rust removed first, any pitting or other damage can cause seal problems too.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

fierogt28 DEC 13, 07:54 PM
Could you post more pictures of the rack?
sspeedstreet DEC 13, 08:55 PM
Not visible from this angle, but the bracket that supported the electro-hydraulic pump still has the rubber bushing in it. Also, I noticed the hydraulic fittings to the ram are clocked to the horizontal. I wish I'd thought of that when I installed a C5 rack in my '88. In the stock Corvette vertical position they interfere with the spare tire bulkhead. I ended up using banjo fittings to get clearance.

sspeedstreet DEC 13, 08:56 PM
Bottom view. Placed side by side with the 1988 manual R & P the units are exactly the same length. All mounting points are the same. In fact, the aluminum sections appear to be the same part.

[This message has been edited by sspeedstreet (edited 12-13-2022).]

sspeedstreet DEC 13, 09:13 PM

quote
Originally posted by theogre:

No Fiero has PS. 88 was going to have PS but was Electric unit and deleted from final version.
Someone Mod'ed the car to have PS and you have to guess what PS rack was used.




And yet, here it is.
fieroguru DEC 13, 09:38 PM
That looks like an EHPS rack for the 88s. You might want to go back to that car to see what else if anything is left.

Based on the location of the hydraulic lines, the corrosion on the shaft is going to cause a hydraulic leak at the seal.


[This message has been edited by fieroguru (edited 12-14-2022).]

sspeedstreet DEC 13, 09:49 PM

quote
Originally posted by fieroguru:

You might want to go back to that car to see what else if anything is left.



I wish, but all the seller had was the front suspension out of the car.
FieroWannaBe DEC 14, 09:01 AM
Due to the rarity of this rack, I think it can be repaired.

The corrosion may be a problem for seals, but the shaft could be ground and polished by a competent machine/finish shop, an engine shop with a crank grinder could accomplish this as well. depending on the depths of corrosion the seal has the possibility to work, if it must be ground further than a few thousands of an inch, there my be a undersize seal available. But you will have to tear it all down to pull the rack gear out to see.

There are steering rack rebuilders that are US based still out there, but expect to pay dearly. Like Turn One (https://turnonesteering.com/rebuilding-services/rack-and-pinion-rebuilding/) , but for these older and rarer cars there really are few options.
sspeedstreet DEC 14, 02:15 PM
Update: Once I stopped thinking of this as a "power steering" problem and approached it as a hydraulic piston repair, a wealth of options appeared. Yes, regrind and/or rechrome but also several epoxy fillers formulated just for this purpose. After the first of the year I'll pull it apart for a better look.