Front end hardware 101 please..

[ChrisB]

http://www.napaonline.com/Search/Detail ... 28+2028028#


I've got a big one piece arm from knuckle to knuckle then a single arm with adjustment sleeve to the pitman arm. I am swapping a 69 F250 disc brake setup to my 72 F250. So far the pitman arm is different with larger splined shaft coming of the steering box. The angle of the arm is also slightly different with the center to center length being the same or close to it. I plan to continue using the 72 pitman as the balljoint end appears to accept the same.

When I search the above 'tie rod' or 'drag link' for 73,72 or 69 F250 I get big apparently one piece arms like I have on both trucks but also short threaded ends like I'd expect to find. One NAPA I went to in person told be no drag links are available for a 69 F250.....then I go online and find all sorts of stuff.

1. Why is my tie rod, center link, whatever it's called one piece? How does one set the toe alignment? Is it assumed to be fixed and correct with this single piece?

2. Can I swap to an adjustable setup without reinventing the wheel?

3. The link from the pitman arm to this full width piece has an adjustable sleeve on it, one presumes so the steering wheel can be centered.

subject change....

4. I was told 67-72 F250 drum and disc spindles accept the same backing plate or caliper mount bracket bolt pattern. If I understand correctly 68-72 calipers were all dual piston calipers. The bolt pattern is not the same. I needed to get disc spindles. Have I also read (where the confusion may have come from) that 68-72 and 73+ DISC spindles have the same caliper mount bracket rectangular four bolt pattern?

5. Can I buy 73+ dual piston bearings/hubs/discs for my pre-73 project? IIRC I've read the 73+ stuff becomes a 3500 lb axle rating up from 3000 lb for 67-72. Are the spindles bearing surfaces any different, in other words, the inner diameter of the bearings the same? Are 73+ bearing outside diameters larger?

[fordman]

in mid 1971 Ford changed the steering on our trucks. at serial number M00,000. the change was suppose to have been made to the steering linkages and the pitman arm. the pitman arm was change to part number D2TA-3590-BA. from C9TA-3590-A. Also the drag link was changed to fit and work with the pitam arm. it had a slight crook put in it so that it would work with the pitman arm. This was done to make way for the new disc brakes they would be using in all of the 73 and up trucks. http://www.fordification.com/tech/images/71tsb.jpg
the front end alignment is done on the adjustable sleve. it moves the long arm and the outer tie rod on the other side of the sleve. no need to mess with makign a new adjuster it is already there.

[ChrisB]

OK, I see I have two different drag links and pitman arms due to 69 and 72. I'd like to use the pitman for the 72 since I have it and the splined end is larger than the 69 donor. My guess is the splines are larger due to the 72 probably originally having power steering vs. the 69 donor being non-power steering. Or was there a steering box/box splined shaft change along with teh other steering hardware at serial M00,000?

To me it appears the 72 pitman will work with the straighter 69 still drag link, but I don't see any reason why I can't just get all 72 replacement drag link and tie rod. Believe it or not, NAPA (doesn't get much more well known and wide spread than that) told me they don't have a 69 drag link available anywhere. I wonder if I ask for a 71 or 72+ if all of a sudden they have those? We'll see. There's almost no way I'll be putting these old pieces in for this swap. Everything, kingpins, bushings, down to blasting and powder coating everything is being done.

How does the single sleeve on the tie rod change toe if it moves the drag link ends the same distance. The drag link is solid...the ball joints that attach to the knuckles' steering arms remain constant distance appart....am I missing something?

[fordman]

the manual steerign pitman arm wont fit or work with the saginaw power steering box.

as far as getting a 67- early 71 drag link that is good i have several of them.

i am not an alignment expert. so i cant explain it. but that is how ford made them. and they work as far as i know. all it does is push or pull the tires in or out so they line up straight.

[ChrisB]

I straightened myself out as far as the alignment goes. I had each end of the drag link going to a knuckle in my mind. They are more or less 40" balljoint to balljoint center. One end goes to the pitman and one goes to a knuckle. Then the tie rod goes from the offset (from center of draglink) to the other knuckle.

I'm going to go ahead and drop some coin for Dana or Moog drag link and tie rods. The drag is 3+X $$ as the quotes for Chinese stuff, but I'm pretty sure they're a sturdier unit and a lifetime warranty, so I need to make sure and use this truck. I'm going to get these new steering pieces powder coated along with everything else down there.

It looks like I gain some bearing size along with stopping precision and capacity. This truck has an 1100 lb. dry weight diesel engine in it and was rolling on 2.0 wide drums which have smaller bearings/spindle stub diameter IIRC than the 2.5 wide drum stuff or disc setup which appear to have identical inner and outer wheel bearings in 68-72 trucks.

For anyone interested the disc/hub stays the same part number from 68-74, then the disc goes from 12.5 wide like the 68-72 to 12.5 by 1.25 thick, instead of just 1.0 thick. The only change in disc wheel bearing dimensions between 68-74 and 75-79 is the inner bearing inside diameter goes up to 1.781" from 1.625" which tells me the spindle stub ought to be slightly different as well, which tells me I shouldn't be able to put the thicker/larger bearing combination 75+ disc on my 69 spindle. Oh well, but not a big deal.