The Checker Taxi Stand

bill_vail · Posted: Sun Jun 22, 2008 6:51 pm Post subject: Power steering

Does anyone know what power steering gearbox will work on a 76 a12 marathon. Mine has just started leaking like a sieve. Just imagine and only a few days from the trip. I don't know whether or not I'm going to make it . I thought about driving it anyway.

john_w · Posted: Sun Jun 22, 2008 9:14 pm Post subject:

Bill,

The 1976 cross reference list (in the manuals section) shows a Saginaw 7818124

here's a Direct link to the 1976 cross reference:

1976 Cross Reference List in downloadable PDF format

The 1977 cross reference shows a Saginaw 7826673

The 1973 cross reference shows a Saginaw 7810860

I didn't find any listings doing some quick searches on 7818124 but it should be one of the standard GM power steering boxes. Most likely it is one of the 3.5 or so turn lock to lock boxes ... which were the norm on almost all GM passenger cars except for sporty high performance models. I'm sure the box has some numbers cast into it on the top side of it ... should match the 7818124 number but check to be sure. Get your local NAPA parts store to cross the number over. A rebuilt one will run you about $175 or so plus labor. Also, I believe there are rebuild seal kits since the seals are usually the problem when they leak.

I wouldn't drive it leaking if it is spraying fluid out ... that stuff is flammable when it gets on hot exhaust manifolds.

John W

bill_vail · Posted: Sun Jun 22, 2008 9:39 pm Post subject: power steering

John I've never changed a gear box what's involved? Thx Bill

john_w · Posted: Mon Jun 23, 2008 7:16 am Post subject:

Bill,

A lot of labor and frustration. It also took me about 3 days for what a good front end shop can do in a few hours.

Seriously, you will need some special tools (tubing wrenches, torque wrench, pitman arm puller at minimum) and the ability to get the front end of the car a ways off the ground.

Also, I've only done front steer Checkers and your's is a rear steering, so this may not be 100% exact.

You will need to disconnect the power steering lines and will probably need a pair of tubing wrenches. When you do so, all the power steering fluid will drain out of the pump so have a catch pan.

Then you will need to loosen the steering shaft to steering gear box coupling at the box.

You will, at minimum, need to remove the pitman arm from the steering box output shaft and will need a special puller for that. I had trouble getting mine off even with a puller and ended up disconnecting the arm on the other end using a tie rod separator (pickle fork) and taking it to my front end guy's shop where he pulled it off for me.

The box itself is attached to the frame with three bolts. It is heavy so don't drop it ... depending on the box, you could be out a core charge of $50 to $70 if you damage it. On my front steer, I had to pull the sway bar loose to get clearance (breaking a couple of bolts I had to then remove and replace, adding time & frustration).

Reverse the process to install and torque all bolts to specs. The 1978 shop manual shows the following specs for a rear steer car on page 7-57 (I'm including most of the torque specs even though you won't loosen some of them):

Pitman shaft nut - 160 to 210 ft/lbs

Center link to pitman or idler - 35 to 45 ft/lbs

Idler to frame - 35 - 45 ft/lbs

Tie rod to center link or steering arm - 40 to 45 ft/lbs

Steering arm to knuckle - 90 to 103 ft/lbs

Gear box to frame bolts - 50 to 60 ft/lbs

Both hoses (at box) - 30 to 40 ft/lbs

Coupling flange bolt - 25 - 30 ft/lbs

Coupling flange nuts - 15 to 20 ft/lbs

Sway bar to frame bolts - 30 to 35 ft/lbs

My advice, with your time limitations at this point would be to take it to a shop and have it done.

John W