1939 Plymouth P7 Roadking Steering Box

[Richard Coney]

Hi!

The steering on my '39 P7 business coupe is getting "notchy" and it appears that all of the adjustment slack has been taken up. Can anyone advise me if it's possible to obtain a reconditioned (or even an NOS) steering box? I've seen that Andy Bernbaum lists a rebuild kit for about about $85.00. Is this perhaps the best alternative to a new box, and is it a job I should be able to accomplish myself with normal hand tools? It seems quite a cost effective option.

Thanks for your time.

Richard

[Andydodge]

As far as I know the rebuild kits include the upper/lower bearings & races, gaskets & Pitman arm bushes & seal. I have also seen listed on US ebay NOS pitman shafts that also include the roller. I have never seen a NOS steering worm, tho' as the are a separate piece on the steering shaft they should exist somewhere. I try the rbuild kit or at least pull your steering box apart & check the worm/roller for general wear. If they seem o/k get the kit & try that, if nothing else a new pitman shaft seal would be a worthwhile install as then at least it would be lubed..........andyd

[greg g]

I guessing "notchy" might british for something other that maybe notchy means over here. But if you mean difficult to operate or not smooth in operation, could it be lubrication related? If so then folks here have been using an agricultural lubricant that is designed for the corn picking heads of harvesting machines. John Deere calls it Corn head grease. You might try filling the box with that.

If notchy means loose, or with lots of dead feel withthe wheel centered, you might want to check the rubber isolater that goes between the box and the frame. They will get gooey from age and exposure. They will aloow the box to move quite abit befor the steering arms move. Replacing the pad goes a long way toward regaiing a more precise system.

Edited April 27, 2011 by greg g

[Fluid drive]

Hi Richard!

Rebuilding your steering box isn't a difficult or expensive job if the worm gear at the bottom of your steering tube and the rollers on the shaft are in serviceable condition. Usually the majority of the problem will be worn bushings in the steering box that support the shaft and roller assembly. The bearings that support the tube are standard bearings that should be available by using the numbers that are visible on the bearings and races and ordering them from an auto parts or bearing supply house. That is with the exception of the upper steering tube bushing - it will have to be obtained from a supplier of N.O.S. Mopar. The brass ( don't use oilite!) bushings in the bore in the steering box can be ordered, turned to press into the box, and line reamed to fit the steering shaft. I use a set of Crichely angle blade reamers with a piloted end for that job. They allow adjustment to assure a perfect fit. If the steering shaft has been worn it can be chucked in a lathe and cleaned up unless it has been worn past serviceable limits. The seal at the lower end of the box is also obtainable by seal number or by measuring the diameter of the shaft it seals and the hole it drives in to and its thickness and giving those dimensions to a parts man.

I would be glad to help you if you need further assistance.

Fluid Drive

[Richard Coney]

Hi Guys,

Thanks for the rapid responses. I'd forgotten just how friendly this forum is.

By "notchy" (a word I confess I made up. It has no other meaning that I am aware of in the UK) I meant that when you turn the wheel it isn't a smooth, continuous flow, but seemingly clicks around, rather as if it was turning a cog wheel with smoothed off teeth. Difficult to describe and certainly not so noticeable that I wouldn't want to drive the car, but my more knowledgeable friend who was helping me with a problem I had with the carb the other day reckoned the less than smooth rotation was indicative of excessive wear in the box. I suggested loosening the lock nut on the adjuster on top of the box, but he suggested that if it wa s clicking in this way there was no more adjustment left.

Two questions occur to me. Is the insulator pad between the steering box and the frame rail available from somewhere? How best do you remove the box? Presumably by removing the box & column complete through from below the car, which you elevate as high as possible?

The sticking throttle problem turned out to be a missing brass screw which attaches the throttle butterfly to it's shaft, so the disc was slightly out of alignment in the carb's bore. Easliy sorted once we had found a suitable screw. I wonder what happened to the original.? Good job it was brass!

Regards,

Richard

[austinsailor]

chances are your gears are gouged from most likely running with no or wrong grease. pull the pitman arm, take the bolts out of the top cover and push the sector gear/shaft up through the top. not a big job, easy to put back, and you can tell exactly what shape they are in.

new worm and sector gears are around, but might be pricey. it's possible the bearings are at fault, but the 5 or so I've taken apart that met your description all had good bearings and bad gears.

[Andydodge]

Richard, the insulator pad is in 2 pieces, on the outside of the chassis and between the chassis & steering box, I got both of mine from "moparkenen" a seller from Turkey, he generally lists under 1948 plymouth parts on ebay, whenever I find a listing from him I then search to see whatelse he has. From what I understand Turkey was where Chrysler had their Middle East distributorship based and there is a lot of mopar stuff there........I've bought the isolator rubbers, valves,valve springs, oil pump, cam, rod , big end & main bearings and other bits all from there, prices are usually 1/3 of what they are here in Oz even with postage, supply is quick and easy. All parts so far have been USA made parts in the boxes.........works for me.........andyd

[wkristick]

I have been told that my '34 Ford hot rod has a '37-39 Plymouth steering box. Trying to confirm. It has casting number 667210-15.  I can't find any information on it.  Does anyone know if its Mopar?

Thanks,

Walt

[keithb7]

Mopar did not make their own steering gear boxes. Neither did Ford. They were both sourcing them from Gemmer. My ‘38 Plymouth Gemmer made steering box, had all interchangeable internal parts from a Ford.  You just need to take it apart and look at it. Go to an old Ford parts website and match up the parts. Buy them and rebuild your steering box. That is exactly what I did. A perfect fit. 

[wkristick]

Hi Keith, Thanks for the information. Walt