metaruss

One particular part has always been a problem in the after market for these: power steering racks.  Parts stores have always done a poor job of keeping track of the different types and their applications (Rock Auto is no exception).  For the mid-late 80’s and early 90’s L and K-based stuff, this has been my understanding: there were two main manufacturers: Saginaw and TRW, each having a few variants (different turn ratios, valving, and stops).  These are some that I personally know about for K-based cars:

• Saginaw
  • 3.18 turns, standard feel
  • 2.50 turns, firm feel
• TRW
  • 3.25 turns, standard feel
  • 2.50 turns, firm feel
  • 2.06 turns, firm feel with larger turn radius to prevent wheels from hitting fenders

There are other variants as well (standard feel for larger wheels, L-body, etc).  The key difference between the two manufacturers is the routing of the hydraulic lines between the rack and the pump: the fittings at the rack valve body are reversed and offset.  So it is not straight-forward to switch between Saginaw and TRW racks unless you also change the lines (though the recent aftermarket situation seems to ignore this routing difference in some applications).  If you intend to swap both the rack and the lines, then you can choose whichever is available.  Note that this difference has no relation to the pump itself.  Earlier models all came with Saginaw pumps (larger, tear-drop shaped metal reservoir), with later models (circa ’88) switching to ZF pumps (plastic reservoir, different tensioner).  ZF pumps have their own, unique line set.

So how do you tell if you have a Saginaw or TRW rack?  There are various ways mentioned on the Internet, but the best way I’ve found is to look at how the lines enter and exit the valve body and main body of the rack.

Saginaw racks have the upper pump line fitting (A) towards the front of the vehicle with the lower fitting (B) more towards the center of the valve body.  The lines between the valve body and rack run parallel to each other (C and D).

TRW racks have the lower pump line fitting (B) towards the front of the vehicle with the upper fitting (A) more to the center of the valve body.  The lines from the valve body to the rack are not parallel, with the shorter line (C) on top and the longer line (D) facing more forward.

That brings us to the aftermarket.  Information is becoming scarce and confusing and rebuilders often pay little attention to the various differences above.  That said, I was able to uncover the following part numbers for Terrepower (now BBB Industries) racks:

• 102-0101: Saginaw, standard feel, 3.18 turns, for 14″ wheels
• 102-0102: TRW, standard feel, 3.25 turns, for 14″ wheels
• 102-0103: Saginaw, standard feel, 3.25 turns, L-body
• 102-0104: Saginaw, standard feel, 3.18 turns, L-body
• 102-0105: Saginaw, firm feel, 2.94 turns, L-body
• 102-0106: Saginaw, firm feel, 2.50 turns, 14″ wheels
• 102-0107: TRW, firm feel, 2.50 turns, 14″ wheels
• 102-0108: TRW, standard feel, 3 turns, minivan
• 102-0109: Saginaw, firm feel, 2.38 turns, L-body, 15″ wheels?
• 102-0110: TRW, firm feel, 2.06 turns, 15″wheels

Some models are available “new” rather than remanufactured, which have an “N” prepended to the part number (i.e. N102-0101).  Whether these parts are still available is a different issue.  As of this writing, the 0101 and 0102 variants are not difficult to find (both new and reman).  However, the firm feel racks are harder to find and may be special order only (if at all).

An alternative to replacement are the rebuild kits, which are available for both Saginaw and TRW.  These are universal across the subtypes.  If the issue is mainly with leaking or sticking, a better route may be to clean and rebuild the rack rather than to take a risk on an expensive reman replacement of questionable quality.  Reman racks are usually exactly that.  I will likely go this route on the CSX.