This Saginaw manual steering box fits many GM applications from 1965-1991 and probably many more. It accepts either our universal pitman arm (702-2940) or your stock GM arm (small style, like our 910-32552). Box has a 25:1 ratio (6.25 turns lock-to-lock) with a 3-13/16" long input shaft with 3/4" 30-splines.
- Input shaft is 3/4"-30 spline
- 6.25 turns lock to lock
- 25:1 ratio
- If you turn the input clockwise, the output also turns clockwise.
- Stock specifications on this gear refer to it as 6 rounds lock to lock for a 24:1 ratio.
- 36 Spline
- 1.058 Diameter Top of Splines
- 1.100 Diameter Middle of Splines
- 1.124 Diameter Bottom of Splines
Note: Steering box is not adjusted at the facotry and therefore, it is necessary that the steering box be adjusted upon installation per the instructions as provided on the PDF instruction sheet.
1965-1991 GM Manual Steering Box Installation Instructions (PDF)
- This box can fit a lot of GM cars, plus it can work in a variety of street rod applications. When mounted behind the axle with the pitman arm forward, it steers like a Vega box. In many GM cars, it is mounted in front of the front suspension, with the pitman arm to the rear. Works well on vehicles weighing over 2500 lbs.
18 questions : 19 answers
September 11, 2014
Do you know if this is a direct bolt in on a 1991 S10?
Truck currently has an OE power gearbox.
January 31, 2015
Fits most Chevys but need there pitman arm to make it work!
September 11, 2014
No this manual steering box is not a direct bolt on for an S10.
It will actually bolt to the frame but the output shaft on this steering box has a smaller diameter spline than your stock power steering box has. A different pitman arm would be needed. Sorry we do not offer the correct pitman arm to install this on your S10
May 22, 2014
manual steer conversion 1966 Impala
I have a 1966 Impala with P/steering & would like to convert to manual steering, is the 525 steering box a bolt on for this application ?
If not, please advise if you have product to make this conversion.
May 22, 2014
The 525 box fits almost all the 65-91 applications but there were some variables. The input shaft is ¾” x 30 spline and the output is 36 spline. Spline count is computed by counting half of the shaft without the master spline or flat and multiplying times 2. There were some with 36 spline and if your joint from your column is 36 spline then replacement of the joint would be needed.
May 06, 2013
Do you carry the rag joint for this steering box ? or location and part No.
May 06, 2013
The GM 525 manual steering box has a 3/4"-30 input shaft. Speedway offers GM style rag joint part #91032410 or 1967-68 Camaro style rag joint part #4464331.
Las Vegas Nv
April 05, 2012
Hi, what is the ratio ? Thank you
April 06, 2012
This box has a 25 to 1 ratio
Grand Rapids, MN
July 23, 2012
What ratio is this steering box?
July 27, 2012
This 525 box has a 25 to 1 ratio and features 6.25 turns lock to lock
May 13, 2011
I like to install this box in a 1977 z 28. Is their a manual pit man arm avaiable to do this. Any help
May 18, 2011
This p/n is a GM 525 manual steering box and works on many applications from 1965-1991and several other hot rod applications. This box has a 25:1 ratio and available for order. You questioned the availability of a manual pitman arm for your 1977 Z28 and currently we do not have these in stock. GM used a couple of different lengths to achieve different steering ratio compatibility and the pitman arm and idler arm need to be in sync for proper steering geometry. We do offer the standard 91032552 pitman arm which is 6 ¼” from center to center for comparison to your idler arm. If a custom application is in the works we also have a universal under part number 7022940 which is 7” from center to center of the holes.
March 20, 2011
I have a 46 ford that i would like to use this box in. Could you give me the dimensions of the box? I need this information to be sure it will fit my application before I order it.
March 24, 2011
This box from end of impute shaft is approx 11” and from the pitman arm shaft to opposite end is approx 8 ½ “ the box itself is approx 7”x6” FYI:This box can fit a lot of GM cars, plus it can work in a variety of street rod applications. When mounted behind the axle, with the pitman arm forward, it steers like a Vega box. In many GM cars, it is mounted in front of the front suspension, with the pitman arm to the rear. Here are a few more measurements for this box. The input shaft is 3/4"-30 spline, lock-to-lock is 6.25 turns. This box can use our street-rod pitman arm 702 2940 or OEM style 910 32552. The output shaft on this box measures 1.058" at the bottom end, 1.100" in the middle of the splines, and 1.124 at the top end of the splines.
June 26, 2015
Can this replace the power steering box in my 1989 Trans Am? Do I need a different idler/pitman for this? Just want a good manual box and get rid of the power steering.
June 29, 2015
This will bolt onto your frame but the output shaft spline is a smaller OD than your power steering box has. Sorry we do not have the correct pitman arm for your application. That might be a tough to find item since a manual steering box was never used on a 1989 Trans Am or similar vehicle.
The input shaft of this manual steering box is 3/4" - 30 spline and your rag joint could be changed if your current box is a 13/16" - 36 spline, however many of the later model power steering boxes were 3/4" - 30 spline as well.
September 22, 2015
I have a 1968 Olds 442 with factory manual steering. Will this be a direct replacement or will I need to do some modifications and/or other parts to do the job?
September 23, 2015
This would be a direct replacement as long as your 442 has a Saginaw 525 steering box.
September 22, 2015
Could I Fit this to a 1955 Chevy Hardtop ?
September 28, 2015
If you still have the original column and steering gear the 525 box will require modifications to the column and the box is wider at 4.50" which may create clearance issues with the exhaust or other components. This box would set beside the frame on the inside whereas the original was above the frame and the housing extended down on the inside along with the pitman shaft. The input shaft would be lower than it currently is and with the limited space would be difficult to hook up to the column and if raising up would be difficult for hook up to your center link.