Saginaw Input Shaft Help (FAQ) (1 Viewer)

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Joined
Dec 27, 2005
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Location
Tucson / Vail, AZ
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kartchcustoms.com
Hey! I'm replacing the Saginaw steering box on my FJ40. The conversion was done by a PO. My old box was a 3 bolt even though a four bolt bracket was intalled. Anyway, I ordered the 27-6529 four bolt box that seems to be the popular choice. The problem is that the input shaft on the new box is larger in diameter than the input shaft on the old box.

I don't want to reinvent the steering shaft so to speak. Does anybody know what Saginaw box has the smaller input shaft and four bolts?

Thanks in advance!
 
After digging deeper into the FAQ it appears that the new box has the larger 13/16" - 36 spline shaft and my old box has the smaller 3/4" - 30 spline shaft.

Soooooo, does anybody know what used a four bolt, 3/4" - 30 spline box. I'm still looking, will post if I find out.
 
Please post up a picture of your steering shaft....

Do you have a spud shaft coupling the steering shaft to the gear?


There may be a pretty inexpensive piece that you could use to make that 13/16"-36 spline steering gear work in your truck...
 
Don't have my camera right now. I don't have a spud shaft. Right after the input shaft is a coupling that has a U-joint. The part closest to the input shaft has a set screw, the other end is the slip joint. That end is held on the shaft with a hollow pin that keeps the shaft from slipping all the way off.

Make sense?
 
Well, I found half of the equation. Here is a list of vehicles with 3 bolt and 3/4" shaft as far as I can tell.


"1977 thru 1982 Chevrolet and GMC C/K (2 wheel and 4 wheel drive) Pickup Trucks
1977 and 1978 Camaro, Firebird, and Nova
1979 Nova
1983 thru 1986 Chevrolet and GMC C (2 wheel drive only) Pickup Trucks

Pre-1980 used standard inverted flare fittings on the box. 1980 and up boxes (maybe 81 up) use a special fitting with an O ring seal. Adapters are available from Lee Manufacturing, call 818 / 768 / 0371"

Here is a link to the page with a wealth of information on steering gear boxes where I got the above information.

http://www.pozziracing.com/camaro_steering.htm
 
Here is the infromation on the 3 bolt, 3/4" box.

Part number 276507 at both NAPA and Checker.

Line Thread Size:11/16x18; 5/8x18
# of Mounting Holes:3
Input Shaft Diameter:3/4"
Output Shaft Diameter:1.25"
# of Turns Lock to Lock:3 1/8 - 4
Type of Hose Ports:Tube Seat (flare fittings)
 
FOUND IT!! YeeeHaaa!

Anyway, here's the one.

Part #: 276505

Attributes:
Line Thread Size:11/16x18; 5/8x18
# of Mounting Holes:4
Input Shaft Diameter:3/4"
Output Shaft Diameter:1.25"
# of Turns Lock to Lock:3 1/2
Type of Hose Ports:Tube Seat
 
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Here's the information for those who are in my situation. Again, this is a 4 bolt mount with the smaller 3/4" input shaft.

For ordering or looking in a junkyard here's the vehicles that should have the box.

American Motors:
1978-79 AMX
1978-79 Concord
1977-78 Gremlin
197 Hornet
1977-78 Matador
1977-79 Pacer (with or without licorice dispensor)
1979 Spirit

Cadillac:
1977-79 Commercial Chassis
1977-78 Eldorado
1977-79 Seville

J**P:
1977-79 Cherokee
1977-79 J10
1977-79 J20
1977-79 Wagoneer

Oldsmobile:
1977-78 Toronado


For everybody else looking for the box with the larger 13/16" input shaft order the part number 27-6529 box.
 
I feel like a heel. Just a warning I guess. My input shaft is a 13/16 36 spline. No problem right? Well no. I hve been unable to find a 13/16-36 with a 1" Double D. I am considering coring my PS box but that will cost me $between $150 and $300 at Autozone.
 
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Here's the information for those who are in my situation. Again, this is a 4 bolt mount with the smaller 3/4" input shaft.

For ordering or looking in a junkyard here's the vehicles that should have the box.

American Motors:
1978-79 AMX
1978-79 Concord
1977-78 Gremlin
197 Hornet
1977-78 Matador
1977-79 Pacer (with or without licorice dispensor)
1979 Spirit

Cadillac:
1977-79 Commercial Chassis
1977-78 Eldorado
1977-79 Seville

J**P:
1977-79 Cherokee
1977-79 J10
1977-79 J20
1977-79 Wagoneer

Oldsmobile:
1977-78 Toronado


For everybody else looking for the box with the larger 13/16" input shaft order the part number 27-6529 box.

Some listed are three point mounts some have four.

I do have a question though, of the boxes listed, which use flare fittings and which (if any) use the worse o-ring fittings?
 
Last edited:
Nice thread revival.

It does not specify if they are the 3 turn or the 4.5 turn.

Be careful. Some listed are three point mounts.

These cars really had power steering?

1978-79 AMX
1978-79 Concord
1977-78 Gremlin
197 Hornet
1977-78 Matador
1977-79 Pacer (with or without licorice dispensor)
1979 Spirit
 
Well check it out.
I have been doing a bunch of research as the box I have is a four bolt mount with 13/16-36 input shaft.
The universal I have is 3/4-36 and the slip-shaft I have is 1" double D.

Obviously, the 4 bolt mounts are stronger than three - if I have to further explain why, maybe you should go elsewhere.

I discovered in my internet search that the 4 bolt 3/4-36 boxes are difficult to come by remanufactured or at a reasonable price. I found where the 1977 J20 was a 4 bolt mount but a dude ordered a replacement and received a three bolt. He intern called the reman (Cardone) and was told about a change in the casting and to just mount the 3 bolt as it is the direct replacement.

Sounds hokey to me.

Anyway, I started searching some of the options. and I think I have the Advance/Kruger/Autozone/Oreilly's part numbers right I just can't tell you what all the vehicle are that used what application and as we all know, the turn ratios can be different even for the same part number for some reason. I assume it is something that happens at Cardone.

27-6529 - 4 Bolt 13/16-36 input flare fittings
27-6528 - 4 Bolt 3/4 input (dunno the spline count) O-Ring fittings; application was an 80-86 Jeep J10 and J20
27-6537 - 4 Bolt 13/16-36 input flare fittings (often received in 4.25 turn ratio)
27-6507 - 3 Bolt 3/4 input (unk splines) flare fittings; application was 1977-1979 Jeep J20 and many others. I believe the Jeeps originally had a 4 bolt mount.
27-6530 - 3 Bolt 3/4 input (unk splines) O-rings; turns very 3 thru 4.25; 1980 Chevy application
27-6550 - 3 bolt

And as mentioned elsewhere, in 1980 the boxes switched from flare fittings to o-rings.

Well, I ended up going to Summit and buying the correct Flaming River U-Joint. FR1758 which is 13/16 -36 by 1" DD.
 
Interesting info.
Seems that 27-6537 is the only box with 4 holes and 4-1/4 turn.
 
K, need to bump this. Going through the same thing as the op and need options...



Please post up a picture of your steering shaft....

Do you have a spud shaft coupling the steering shaft to the gear?


There may be a pretty inexpensive piece that you could use to make that 13/16"-36 spline steering gear work in your truck...

Mines not a spud shaft, it appears to be welded to the steering shaft. Any thoughts on how I can ditch the 3/4 yoke and convert this to the 13/16? I'd prefer not to replace from the column down if I don't have to.

Here's what mine looks like...


Column end...

7CAF3D56-385C-4712-A0B9-F0295BC37406-3275-000005364940D78C-1.jpg



Box end, sorry for the crappy pic.

22C2B4F6-9C64-41EA-A8C8-B206E544BBFB-3275-00000536810C93B9-1-1.jpg




Yoke that needs to be replaced for new box.

7C31815C-573D-42D2-9E83-F55AFE86D498-3275-000005366D521077.jpg



Any thoughts or recommendations, would be greatly appreciated!
 
I got my U joints for my conversion from Summit. They had a decent selection. I would guess you might be able to find something that would work for you from them...
 
If one has the old box as well as a new box, swapping the input shafts would be a reasonable solution and is a straightforward process.
 
Looking at the joint, it appears to me to be a Flaming River forged:

tn250_product_FR2631.jpg

I can't find it on their site, but I believe the joints are serviceable (they just have mini needle bearing u-joints in them. the allen screws are there to secure the caps). Couldn't you buy a joint with the splines you need, take them both apart, and swap out the end you want with what you have? That would leave your steering shaft as is. I think the trick would be verifying what joint you have, and then email their tech folks about the procedure / feasibility.

Obviously it would be a bit of a delicate operation, but it's not unthinkable.

Good luck,

Lefty b
tn250_product_FR2631.jpg
 

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