randii
4x4Wire.com Managing Editor Emeritus
Reged: 08/02/99
Posts: 9030
Loc: Fair Oaks, CA USA
|
Re: working with the Ford TRE (SAS steering)
07/29/03 02:09 PM
|
|
|
Quote:
...i'm considering switching my tie rod from SREs to TREs becuase i don't like the play that i believe is in the pitman from me drilling out the taper (rather than machining precise bolt size).
BTDT, Rob. That slop was what provoked me to first sit down with all the dimensional TRE cross-reference tables to come up with what fit. When I was first researching this, I used the measured angles and specifications from the Isuzu center link to identify a tie rod end that would bolt right up to the stock taper in the Isuzu pitman arm. I found a TRE with the same taper and pitch, but designed for a thicker pitman arm. This latter dimension is easier to work around -- you seat the tapered parts together (you get full engagement of the Isuzu pitman taper, there's just a bit more length to the Ford TRE taper) using a washer between the nut and the pitman arm. The washer is compressed when you pull the TRE into the matching taper of the pitman arm. Essentially, all steering loads are taken by the taper interface -- the castellated TRE nut and added washer just clamp that interface together.
Quote:
From what i gather, the Ford F250 TRE is a left hand 7/8-18 (fine thread).
Yup, but the taper dimensions varies across years, you need the left-hand threaded tie rod end off a 1967-72 F250 3/4 ton Ford 4WD.
LINK
Quote:
My question is, how do you guys attach this to your custom steering linkage?
I just had my drag link tapped to match those threads.... Marlin Czajkowski ( www.MarlinCrawler.com ) and Scott Ellinger ( www.Rockstomper.com ) both have that tap. Matt Brown ( www.Independent4x.com )also has weld-in threaded tube inserts. With a right-threaded end and a left-threaded end at opposite ends of the drag link, the drag link tube itself can be rotated for adjustment.
Quote:
... I know the isuzu taper is backward, causing the TRE to sit on top of the pitman arm. would there be anything to be gained by flipping the pitman arm on the box, now causing the arm to curve up instead of down but the TRE be underneath not on top?
I think that any gain in TRE position would be offset by the loss in position inherent in the curved arm (there's enough curve to make it almost the same net height). If you really need that taper flipped, consider drilling it and having a damn good welder burn in one of Front Range Offroad Fab ( www.FrontRangeOffroadFab.com ) or Rockstomper's (see above for URL) tapered inserts facing the way you want it. FWIW, this is not an uncommon part and more vendors stock it, but IMHO, few folks posess the welding skills and equipment to do this job right, and if at all possible, I'd avoid welding on the pitman arm.
Still another solution, if you want to weld the pitman, is to run a substantially larger TRE, and have your pitman arm retapered from the bottom. Get to a good auto parts store and ask for the Quay-Norris or Moog steering guide. In the back of it, you'll find a dimensional cross-reference guide. This is what I used to identify the Ford TRE in the first place -- you can do the same by leveraging the large dimension of the stock Isuzu taper as the small dimension of the taper you seek. You can back all of this out of the guide by starting with the Isuzu part and working backwards. Your goal will be to insure that the taper on the new TRE will be engaged for the full thickness of the pitman arm. 'Extra' taper protruding from either side of the TRE is acceptable, but you want to make sure not to have too much levering out the TRE side... the flip side, where the castle nut and cotter pin goes, that's where I put the washer (described above).
Randii
--------------------
Randy Burleson
4x4Wire Managing Editor Emeritus
Mongrel Isuzu Amigo
|
|
Previous
Index
Next
Flat
Edit
Reply
Quote
