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I'm replacing my PS box on the M as this summer late while off-roading with the M I experienced some times of no steering, both while driving and while setting still. The steering would suddenly start again after I stopped and/or moved.

I've had some problems for the past couple of years where the steering was much harder than it should be from time to time. Nothing consistent, but always at the wrong time. It seemed to act like I didn't have enough power in the PS, but some times I swear I could not turn as short as I think I should have been able to. I don't remember if the PS Pump would squall in those cases, but it seems like it might have.

This time while driving late this summer I just suddenly could no longer turn, left or right, it was like the steering wheel was locked. No I don't have a locking steering column, I'm using a stock M column.

While setting still once in a while the exact same, except no wheel movement. In both cases there was no typical PS Pump squall like I was trying to force the truck to turn turn further than it was supposed to.

As with no PS Pump squall, and the fact that the truck was moving in 4WD, my conclusion was that it was not related to the front axles tracts joints.

So now I've installed the new Box, and am also installing a NOS Pitman Arm as the one I had on since I broke the original one in May was a well used, but functional unit.

With the original Arm and PS Box I could only get about 2/3 of the splines to engage, and just barley had enough threads to install the lock washer and nut. Now with everything new, and the threads as clean as I can, I can only get about 1/5 spline engagement, and no room for the lock washer.

The splines are correctly aligned and inside the arm, you get some evidence of shaving metal out of the valleys of the splines. You see nothing on the PS Box.

What is/have everyone else who has done the PS conversion seen for spline engagement and did you have room for the lock washer?

Thanks,
Will

Here is a picture. I even used a file and cleaned the Pitman Arm splines of any burs from the previous install attempts, and warmed it up some and this is still as for as it will go on. I'm using a 1/2" breaker bar with a cheater pipe to tighten it as for as I dare (I'm stronger than my impact wrench even with out the cheater bar).

Hi Will,
It looks like you have a full nut, that should be fine. I ran into the same thing with my Power Wagon, and ended up with about the same results you show. Hasnt fallen off yet!
Tim

The weak physical link in that set up is the cast box bracket, too much flex for severe off roading, idler arm balls, pitman arm, steering knuckle arm ball, etc.

Spline engagement will vary from box to box. We never use the lock washer, thread engagement is far more important than the washer. Apply red lock-tite to the shaft threads and torque. We use a new grade 8 nut instead of the original, size is 7/8" X 14 TPI pitch. Most of the time I can get a full nut thread engagement.

The box / pump failure issues was most likely brought on by having a locker in the front end and trying to over come the natural tendency of the vehicle to go in a straight line with power steering. I have seen this be the death of a number of PS set ups, usually kills the pump first. People ask me; can't we install a good enough hydraulic system to over come this issue when using a locker? The answer, of course we can, but then you start breaking other components like the pitman arm, idler arm balls, steering box bracket, etc. I believe you also mentioned a pitman arm failure. Doing what you are doing, you will continue to have issues like this, it isn't safe is the truthful bottom line. Will the next breakage event causing steering loss be on the road? God forbid!! You need a much heavier system of components throughout to stand up to that V8 engine, severe off roading, big tires, and a front end locker.

Charles,

Thanks for the feedback. I've heard about others braking the cast bracket and have been watching it, so for so good. I have a spare idler arm, after watching Mark Y. break is when he hit a tree stump, felt I should have a spare on hand. As for my Pitman Arm, I know what caused it to break, a broken front left PS Box bolt, and a broken spring pack bolt. I now watch the PS Box bolt closely.

I figured there was some spline taper variance, and thanks for confining the you leave the lock washer off. I'll be keeping an eye on it for spline engagement play increase, but I know it's very tight right now.

I've experienced the locked front axle drive straight tendency, but usually no issue in turning the wheels, gust the trucks desire to go straight. I've experienced this on other 4WDd vehicles as well and am familiar with the feel. The ARB doesn't disengage as quick as most would expect, I often stop after having used it and needing to turn to help allow for disengagement. As I don't want to place undo stress on the parts I only engage the front locker when I absolutely need it.

I've replaced the pump once, but believed it to be heat related, as I don't have a lot of clearance between the exhaust manifold and the lines, and I do over spin the pump slightly as compared to stock. When I installed the new pump, I added a cooler.

Based on my fun experiences and now my wife's love of riding around the woods in the M, I will be looking to build a more extreme capable off road rig, and keep the M for some family fun and mild off roading. Now to just get the money and plans for a new vehicle, oh and aslo get the other three trucks done. Anyone want to buy a W500 Fire Truck?

Thanks,
Will

Will, mine looks just like yours. Just enough engagement for the nut to fully thread on. I added hydro ram assist for this very reason. Mine turns very nice, no effort at all in teh sttering wheel, even at idle. I recommend tapping your box and adding a ram as I did. This will take 70% of the load off the box and arms as well.

My nut doesnt quite go on as far as that but I can turn full lock in either direction with 1 finger when idling.

Thanks guys. I've not got it back on the ground yet, just pulled the hub to check the right tracta joint, and all was OK. Now rebuilding a newer front drive shaft to get rid of my slip yoke play. Once that's on I'll put the tires back on and be ready to roll again. I expect to be single finger turning power again soon.

W_A_Watson_II wrote:Thanks guys. I've not got it back on the ground yet, just pulled the hub to check the right tracta joint, and all was OK. Now rebuilding a newer front drive shaft to get rid of my slip yoke play. Once that's on I'll put the tires back on and be ready to roll again. I expect to be single finger turning power again soon.

Yep, power steering was the best mod I made to my truck, so far..........