Shimming the steering gearbox

So, I have my steering gearbox apart. (Ford 640, mechanical steering). When I took it apart, there were a number of shims of varying thickness between the gearbox and the steering column.

I assume that this shimming may need to be adjusted for wear? How do I determine the proper amount of shimming?

shims are used to set preload on the thrust bearings.

I prefer a HAIR of preload.

too much and you stress the ebarings, too little and you have slop.

cowboy.......unless you replace yer steering gearbox bearings, use the same shim stack you removed. Simple, eh? ......Dell

I am replacing the bearings. This is my friend's tractor. He ran the steering box dry (oil leaked out). It then went through a phase where turning one direction was easy and the other direction tried to thread the steering shaft up out of the column (as opposed to moving the sector gears). It finally broke and wouldn't steer either direction.

The sector gears are still good, I'm going to take everything out, put in new seals, install all new bearings and retainers on the steering column, put it back together and lubricate it with corn head grease.

I kept the original shims, but I was wondering how to know if the shimming was still correct..or if I would have to adjust it.

I'm somewhat stuck doing this, as I called the local Ford dealer, and they said that their "old guy" retired, and the new guys don't really know their way around this gearbox.

They did give me a number for a private guy who works on old Fords.

I also see complete new gearboxes online for a little over 500 bucks.

It cost 246 bucks for the bearings, retainers and such. By the time I get done, I may have more money and "time-money" into this gearbox than 500 for the new box...

what!!!!

246$ for bearings? sorry... you are shopping in the wrooooong place!

thrust bearings are 10.35 a piece, 2 needed cups are 10.12 each, 2 needed. ( needed if yours are not smooth ).

sector seals are 8.52 each, 2 needed

not sure how far you are going, spring under steer wheel is 5.42

felts and springs and upper column bearing kits are available 16-32 $

acorn nuts are 6$

6 piece shim kit 15$

orings for sector covers are in the 16$ kit.


most boxes get by with 2 thrust bearings and 2 seals, if the top column bearing is ok as well as all the cups and sector orings.

IE. 40$ plus lube does the average box...

shims i make from gasket papers or tin cans or roofing metal or roof flashing, just rub or tap out a pattern on the open top of the box, trace or cut out... EZ to make.

These boxes are EZ to work on,.. if your dealer says he has no mechanics that can work on the box, RUN AWAY FAST... find a better parts seller.

parts I quoted come from the steering parts here on YT. all the non power steering parts are kinda mixed for the late 8n thru hundred series, so if you dont see seals int he 600 section, look in 640, or 641 or 840.. etc. some sections list more than others... but the listing shows what it fits, as said.. the boxes have lots of interchangeable parts thru a wide range of years.

cowboy.........$500 ain't nuttin', I just got quoted $1200 fer steering gear box fer my 1994 3/4T Dodge Cummins Diesel, I can gitt brand new by mail order fer $500. Guess what I'm doin' tomorrow??? Meanwhile, I'll be pouring more power steering fluid down a LOOOooonnng funnel. (it hazzta be long to gitt past all the injector tubes) .......oily Dell

Ouch! That is indeed a steep price tag.

So this is how my shimming went, I first assembled with the retainer on the bottom of the shaft upside down. Way too much slop. I then posted on here and did some figuring and put the retainer on the right way.

Less slop.

I then disassembled and tried removing the very thin shims that were already being used before I started the job.

Less slop, but I thought too much.

I then disassembled and tried with only the two thickest shims (there were like 7 of varying thicknesses originally).

Less slop, but maybe too much.

I took it apart one more time and tried with no shims.

I think that this is where one of the replies above mentions "preload"...that is, the column didn't set right down on the gearbox. I put a couple of bolts in to hold it in place with just a little gap where the shims would go...

steered OK

tightened the bolts a little

too friggin tight!

So, I figured that one thick shim would be best.

I disassembled, put on the shim and went to reassemble

The friggin eye popped out and dropped the retainer and bearing, so when I test steered....CRUNCH!

I'm getting a new eye, retainer and bearing. Next time, I'm putting some locktite on the eye and letting it set so that it holds the retainer and bearing on the bottom of the shaft with a little more strength.

Close, so close....My wife said that I should have left well enough alone.