Steering box interchange?

[Muswagon]

Been checking out a companies website that rebuilds everything. They show the steering box on the 71-73 Mustang as being the same as a million different cars, including the 77-79 Thunderbird.

I found a 79 tbird power box in stock, but, do these specs line up with our cars? I have looked everywhere and cannot get the technical info for our steering boxes.

Steering Box Type

Power Steering

Input Shaft Type

Splined

Input Shaft Diameter

0.725

Input Shaft Spline Count

34

Output Shaft Diameter

1.312

Output Shaft Spline Count

32

Pitman Arm Included

No

Inlet Size

1/2'' X 20

Outlet Size

5/8'' X 18

Total Turns Lock To Lock

4

 

[72HCODE]

No and that is the problem, the box will interchange but the ratio is different.

I forgot the spec but off the top of my head the mustang has a faster ratio then the thunderbird.

So the thunderbird box is going to make your steering much less responsive.

 

[Muswagon]

I dont care about the ratio, its a death machine now and for the cost of the T-bird box at least I can drive it/sell it. I can send mine in for a proper rebuild if I keep it.

 

[nailpounder]

check out o'rillys auto parts for a box

 

[Muswagon]

I am in Canada and they won't even consider shipping when I called

 

[rocket366]

I beleive these interchange;

72-73 Torino

72-73 Ranchero

77-79 T-Bird

Saginaw Box with 4 bolt cover

You need a Lares 806 or 807 (one is QR) or Atsco 6539 or A1 Cardone 27-6539 (Reg Ratio 4 turns L to L)

Verify my research by rockauto part # listing for cars

Personally I gave up and rebuilt the box myself with a $25 kit. (see my thread)

http://www.7173mustangs.com/thread-i-ve-had-enough-i-m-going-in-boys

Good Luck Paul

 

[Ron Tanzi]

Been checking out a companies website that rebuilds everything. They show the steering box on the 71-73 Mustang as being the same as a million different cars, including the 77-79 Thunderbird.

I found a 79 tbird power box in stock, but, do these specs line up with our cars? I have looked everywhere and cannot get the technical info for our steering boxes.

Steering Box Type

Power Steering

The steering box on our 71-73 Mustangs is unique in the fact that the power steering units are General Motors Saginaw units. There are 2 varieties : variable ratio that came with the competition suspension package and constant ratio with non competition suspension (base models and Grandes) this can be determined by the tag on the box SPA-T= Variable and SPA-S= constant ratio. The manual boxes were manufactured by Ford. No other Ford models to my knowledge other than the 71-73 Mustangs used this power steering box. If your box is leaking have it can be easily resealed as most parts store rebuilds are junk. Ron

Input Shaft Type

Splined

Input Shaft Diameter

0.725

Input Shaft Spline Count

34

Output Shaft Diameter

1.312

Output Shaft Spline Count

32

Pitman Arm Included

No

Inlet Size

1/2'' X 20

Outlet Size

5/8'' X 18

Total Turns Lock To Lock

4

 

[Muswagon]

Weird twist... The one I ordered was the atsco 6541 for 79 tbird....they had one remaining at rockauto. Two days later I get an email from them that its out of stock. I check back under 73 Mustang and 79 Tbird and they are now showing one Atsco 6539, so I grabbed it. I think its the same physical box they had, was just mislabeled.

The 6539 is 4 turns? I am gonna have a look to see what my current one is.

 

[rocket366]

You Got LUCKY! The 6541 is a Ford box not a Saginaw.

Yea the 6539 is Saginaw and not QR

4 turns L to L

Paul

 

[Muswagon]

I am not too concerned, just happy its the right box. Where can I send my original to rebuild and get a faster ratio? Or should I try this myself with the 70-82 Saginaw Vette parts winters are long up here, so could be a neat project

 

[rocket366]

QR thread:

http://www.7173mustangs.com/thread-higher-ratio-steering-box

Try to find somebody in your area that can do the conversion the

shipping is expensive.

Paul

 

[mustang7173]

Muswagon,

I had mine converted to the corvette quick steer.

http://www.powersteering.com/

mustang7173