'56 Cadillac steering box

[Dan Reed]

Hello - I have a leak at the output shaft of my '56 Cadillac's steering box. I've been keeping a pan below the pitman shaft to capture the fluid, but its about time I repared it. Has anyone performed this task? Is there a vendor for the required seals? Is it possible to remove the old seals and match them in size/diameter with a similar product?

Dan

[Mike Josephic CLC #3877]

Hello - I have a leak at the output shaft of my '56 Cadillac's steering box. I've been keeping a pan below the pitman shaft to capture the fluid, but its about time I repared it. Has anyone performed this task? Is there a vendor for the required seals? Is it possible to remove the old seals and match them in size/diameter with a similar product?

Dan

Dan:

What type of fluid are you using in your steering box?  I'm not talking about the hydraulic
reservoir (uses ATF).  The gearbox itself uses 90 weight MP (80W-90 is the modern equivalent).
The wrong fluid could be part of the problem.  Mike

[Dan Reed]

Thanks Mike,

I never thought of that, nor have I ever given any thought to the fluid in the steering box itself. Where would you even check and fill the steering box with the 80W-90?

Dan

[J. Gomez]

Dan,

Unless you have a different arrangement on your '56 the repair manual shows that the steering gear box was all hydraulic type of gear boxes.

The question is does your steering gear box have two hoses (pressure and return) connected to the pump driving by the main pulley (pump and reservoir are all in one unit picture attached)? If yes, you have a hydraulic type.

I have rebuilt my gear box (Saginaw) and pump (cleaning and replace the bearing, seals, and “O” rings) and I was able to cross reference and use the following seal kit from SKF 12392 for the pitman shaft. The individual pitman shaft seals are inner as SKF 12371 (were applicable), outer seal SKF 12355, I’ve used the kit. The worm shaft seal is SKF 8648.

If your system is hydraulic and you take the task in replacing the seals and bearing for the pump I could provide you with the part numbers, I have not add them to my database, I would need to grab the boxes and add the part numbers to my list.

Regards,

Jose Gomez CLC #23082

[Roger Zimmermann]

Dan:

What type of fluid are you using in your steering box?  I'm not talking about the hydraulic
reservoir (uses ATF).  The gearbox itself uses 90 weight MP (80W-90 is the modern equivalent).
The wrong fluid could be part of the problem.  Mike
[/quote]
Mike, it would be correct on a Corvette or Studebaker with the separate hydraulic piston. The Cadillac steering box don't have 90 oil inside, not even your '55!

[Dan Reed]

Thanks Jose - Yes, there are two lines from the pump to the steering box (one line out the back of the pump to the gear box and one  from the gear box up to the side of the reservoir). The only leakage is coming from the bottom of the gear box at the pitman shaft. According to my '56 shop manual there are two seals at the output end of the pitman shaft. My assumption is that one or both of those seals have gone bad. I've had the car for almost ten years and the leak appeared within the last year or two. Other than the leak the steering is tight and in good condition.

I just like to ask around before I tackle a job I'm not familiar with. Maybe avoid some mistakes

Dan

[J. Gomez]

Dan,

If the pitman shaft outer seal is the culprit you could be lucky by removing and replacing it without removing the complete unit from the car (this will be tricky), warning you have to removed the snap ring first. However if the inner seal is bad the process get a bit more complicated.

I could only offer my personal suggestion after tackling both the gear box and pump at the same time, maybe other member could offer alternatives for your dilemma.

Best luck to you..!

Jose Gomez CLC # 23082

[Mike Josephic CLC #3877]

Dan:

What type of fluid are you using in your steering box?  I'm not talking about the hydraulic
reservoir (uses ATF).  The gearbox itself uses 90 weight MP (80W-90 is the modern equivalent).
The wrong fluid could be part of the problem.  Mike

Mike, it would be correct on a Corvette or Studebaker with the separate hydraulic piston. The Cadillac steering box don't have 90 oil inside, not even your '55!

Roger:

I don't want to debate this matter -- but your incorrect.  If you read the shop manual
for 1954 / 55 you see that it clearly states "the gearbox requires G.M. Special lubricant
meeting Specification 4673-M."  That special lube is 90 MP gear lube.  See page 2-6 in the
1955 Cadillac Shop Manual Supplement for more detail on this.  It was the same in '53, '54.

Mike

Mike
[/quote]

[George 23923]

If the box is a 56 it should be a Saginaw in line gear.
It's not hard to rebuild, but get the tool for removing the balls.
You may have to make one. thats not difficult either.
get the manual and follow the steps, It comes apart quite easily. You don't need to touch the valve body. thats the complicated bit.

[Dan Reed]

Thanks for the tip George.

I took another look at the shop manual for '56 and still can't find any lube data regarding the steering box itself (the 90W which has been mentioned here in the thread). There is, in section 2-6,  a "steering box" heading, but it only mentions the hydraulic fluid recommendations. No other mention of anything else.

Dan

[Roger Zimmermann]

Roger:

I don't want to debate this matter -- but your incorrect.  If you read the shop manual
for 1954 / 55 you see that it clearly states "the gearbox requires G.M. Special lubricant
meeting Specification 4673-M."  That special lube is 90 MP gear lube.  See page 2-6 in the
1955 Cadillac Shop Manual Supplement for more detail on this.  It was the same in '53, '54.



Mike

Oups! Sorry Mike, you are right. the steering box of the '54 & '55 models are an hybrid construction. The room for the Pitman shaft has heavy oil; the power piston and upper part of the steering box are lubed with power steering oil.
The '56 steering box is a different construction: the power piston is not an ad-on like '54 & '55, but is incorporated to the construction. The oil for the '56 box is power steering oil only. After all, I have 2 '56 cars; I know how they are constructed.
By the way, the seal on the pitman shaft on the '56 steering box is to be repaced completely if it's leaking. The first seal (or the outer one) will not hold pressure; it's just a small seal to avoid that the dirt is coming in. The seal holding the pressure is the inner one. The shop manual does not say that the pistman seals can be replaced with the steering box on car. Once the pitman arm is removed, the removal of the steering box from the car is not a big deal. It's just a mess with the oil and the box is heavy.

Good luck!

[J. Gomez]

Roger,

You are correct; the outer seal is just to keep the dust/debris out from the pitman shaft, the inner seal is considered as the pressure seal, there is also an intermediate leather dust seal (original unit, composite material with the new kit) between the inner and outer seal between two washers.

Unfortunately the 1956 Cadillac manual is not explicit on the steps or what can or not be done with the unit installed or removed. I was able to obtain a copy of the Service Manual for a 1956 Buick power steering system (long neck Saginaw) that includes the gear and pump (similar unit as the 1956 Cadillac) which contains a detailed step by step rebuilt process, which indicates the outer seal can be replace with the gear in the car.

My overhaul consisted is just the main seals, “O” rings and minor adjustments. I did not wanted to get deeper into the removing the special nut, the balls from the worm, etc since I did not have the special seal (Teflon type) for the wormshaft. I was able to get the “O” rings (large) for the end cover and the side cover, the ones for the control valve, and linkage cover from a hydraulic part shop.

One issue I had after installing the unit somehow the small “O” rings on the bottom of the cover valve were the wrong size and after pressurizing the line I’ve notice a leak. So I had to removed the gear again, lucky I already have done my bench-pressing exercise before removing the gear for a second time. 

Dan,

Best luck to you..!

[Dan Reed]

Thanks guys,

I've completed the project, so now I can speak from experience.

I was able to remove the pitman arm easy enough with a little PB Blaster. Removing the snap ring and the first steel washer allowed access to the dust seal, second washer and main pressure seal. I was surprised that the pressure seal still showed a part number in which my local auto parts supplier was able to cross reference and match to a modern replacement seal.  After getting everything back together I took the car out on the road for about a half hour. As of this morning - no leaks. I placed a white piece of cardboard on the garage floor under the gearbox over night to easily visualize any potential leaking. I'll leave it there for a week or so just to make sure, but what I normally had to do was to place a pan below the gearbox to collect all the ATF that would leak out over night - so this is a hell of an improvement.

Dan

[Musiclady]

What was the part number on the seal?

[Roger Zimmermann]

Mike, did you see that the message was from 2007?

[cadman56]

I guess I took the easy way out.  When I was down to the bare frame on my 56 convertible, I just sent in the whole PS gear box in to Lares Manufacturing.  Worked great & cost then was less than $250 incl. freight.
Larry