Jump to content

Recommended Posts

Ok guys I'm needing to change my steering gear box on my 73, my doesn't have the tag on it. Is there another way of telling which gear box I have? Fixed or variable. "73" 351c 2v power steering

Thanks

Share this post


Link to post
Share on other sites

First my guess is fixed. Not really sure how you tell for sure though.

 

Next, how bad is your box that it needs changed? Do you have a spare? I am having mine rebuilt by powersteering.com and converted over to a quick ratio box at the same time. I just sent it off so I cannot give a review on their work but several other members on here have used them and were pleased. The rebuild and conversion together came to $398. I think just a rebuild is cheaper.


73 Grande H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

 

- Jason

 

 

082-hot-rod-power-tour-2017-1970-1970s.jpg

 

Share this post


Link to post
Share on other sites

I replaced mine with a lares 807. It is listed as 10:1 but it is really 12:1. I checked they are currently around $200 w/ a pretty hefty $200 core deposit. I believe the stock ratio box is a lares 806 and they are $175. (same $200 core deposit). It looks like these come with a new coupler as well

 

I would also check the pitman arm. Mine was pretty worn and had a significant amount of play in the socket.

Share this post


Link to post
Share on other sites

If you are willing to pull the box apart a bit you can identify it.  Someone who knows what box they have might also be able to give you a lock to lock amount of turns and you could use that too.  I don't have a stock steering box anymore, mine is 12.7:1 with stock steering stops and mine is about 2 2/3rds of a turn lock to lock.   If you do decide to take it apart for identification I would be sure to keep everything squeaky clean and clean off the end of the sector shaft before you start.  The last thing you would want to do is damage a seal or introduce dirt into your steering system.

 

1) Remove pitman arm.

2) Center the input shaft (turn it to full lock left and right and split the difference.

3) Remove the 4 bolts on the sector shaft cap.

4) Tap the end of the sector shaft with a soft mallet to remove it.

 

Once the sector shaft is removed you just look at the teeth on the piston inside.  If all three teeth are the same depth it is a fixed ratio box.  If the center tooth has a deeper root it is a variable ratio box.  They look quite a bit different.  See post number 1 in the linked  thread for photos...  https://www.7173mustangs.com/thread-playing-with-steering-boxes-spa-s-fixed-ratio-spa-af-variable-ratio-firebird-12-7

Share this post


Link to post
Share on other sites

Ok guys I'm needing to change my steering gear box on my 73, my doesn't have the tag on it. Is there another way of telling which gear box I have? Fixed or variable. "73" 351c 2v power steering

Thanks

 

can you take a picture of it? i have  73 and a 72 they are both the same.. but with a picture i will be able to see if it's original


73 Stang totally restored with a 351 cleveland cobra jet Q code motor ,Owned car since new. 

IMG_0291.jpg

 

upload facebook picture

 

 

Share this post


Link to post
Share on other sites

Thanks guys I'll have to wait and take a picture when I get home, also I'm changing cause I have a large amount of slop.i would consider a rebuild but I would really like to just swap it out instead of waiting for it to come back, lol

Share this post


Link to post
Share on other sites

The slop could be the pitman arm and or the rag joint. Both of mine were worn out. I thought at first it was the steering box also. Wow, what a difference after I replaced them. The steering box was fine.


John - 72 Q Code

Share this post


Link to post
Share on other sites

toastintx,

 

I agree with 73pony. Most Saginaw variable ratio power steering was typical with the competition suspension option.

 

 

A new variable-ratio (15.7:1) power steering system was standard on the Boss 351, while a conventional fixed-ratio system could be had on other Mustangs.

 

Source: https://www.hemmings.com/magazine/hmn/2011/11/1971-1973-Ford-Mustang/3704941.html

 

Another Source:

 

71 -72 Mustangs without the Competition Suspension used a Constant Ratio P/S gearbox listed as SPA-S and SPA-U.

 

http://429mustangcougarinfo.50megs.com/steering.htm

 

mustang7173


Thanks,

mustang7173 🇺🇸

"Courage is being scared to death but saddling up anyway" -- John Wayne

Share this post


Link to post
Share on other sites

Anybody feel like posting their lock to lock amount of turns and what box they have?

Share this post


Link to post
Share on other sites

Went out to my parts car today, 73' with a SPA AE fixed ratio box. From hard lock to hard lock (lots of effort into the steering wheel, no engine) it was right at 4 turns.

 

Hope that helps identify what you have. The variable ratio boxes also have a sharper pitch on the lead screw, so I would guess that a variable box would be somewhere between the 2 2/3rds turn custom 12.7:1 box and the 4 turns lock to lock of the stock fixed ratio box that is somewhere up there in the 18+:1 range.

Share this post


Link to post
Share on other sites

For future people...

 

Don C & Stanglover both have variable ratio boxes and confirmed them to be about 3.6 turns lock to lock.  Paul113 also has a variable box, and his was about 3.4 turns lock to lock.

 

My parts car with a fixed ratio box is 4 turns lock to lock.

 

My 12.7:1 quick ratio box is about 2.67 turns lock to lock.

 

So it looks like....

4 turns = fixed ratio

3.5 ish turns = variable ratio

2.67 turns = true 12.7:1 conversion

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

About Us

7173Mustangs.com is a community forum designed especially for fans and owners of the 1971, 1972 and 1973 Ford Mustang! We are not affiliated with Ford Motor Company in any way.

Site Navigation

Forums
Gallery
7173 Wiki
Blogs
Clubs

7173logo_small.png

Site Info

Founded:
July 2010

By:
Webfinity Design

From:
Latrobe, PA

×
×
  • Create New...

Important Information

We have placed cookies on your device to help customize your user experience here on 7173Mustangs.com. You can adjust your cookie settings to your preferences if you like, otherwise we'll assume that you're okay to continue.