Steering gear backlash adjustment? *UPDATED*

[DaveO]

Hi all,

What does that adjustment do exactly? I have a lot of sector/worrm play, will that take any of that up, or just make the steering stiffer?

Thanks!

[Lifer]

It should take some of it up. If you have a LOT of slop in your steering wheel, though, look for worn linkage components. If those are good and snug, and you've adjusted the backlash but still have excessive free play, there's a very good chance that you have worn bushings/bearings in the box and should rebuild it. Mind you, of course, they were designed with a certain amount of "slop" built in. This was intended to allow the truck to find its own way over rough terrain without jerking the driver's arms to death. Modern steering systems are much "tighter" in this respect, which is great for highway cruising. Off-road, however, everyt little rut or crevice between rocks will jerk the wheel this way and that and make you wonder if the "fun" is worth the "effort."

[DaveO]

Hi Lifer!

Okay, I'll try the adjustment and see what I get. Everything but the box is pretty tight. I've replaced the tie rods ends recently (within the last 5K miles, anyway), and the drag link connections feel solid. I replaced the king pin bearings with rollers when I started getting the death wobble a couple of years back. However, when I turn the steering wheel from side to side I get about a tenth of a turn before the sector contacts the worm going the other way. More sporting that way, I suppose. I'm rather of used to it, and know not to get distracted whilst on the road, but I asked a buddy to move my truck for me and he didn't have anything good to say about it. I'm planning on rebuilding it this summer, but wanted see if that adjustment will give me any more life.

How's Georgia treating you?

Thanks for the response...

Dave

[Cal_Gary]

Those drag links are spring-loaded and will slop around if they aren't tight. I ended up replacing my box with a used one, compliments of Charles at M-Series Rebuild-don't know if he has any more.
Gary

[Lifer]

Roughly 36 degrees of "slop" isn't too terribly much, really, and should be expected in a truck as old as ours. I used to have a '55 Pontiac that had more than 100 degrees of free play in the wheel, but I was used to it and it never bothered me. My son-in-law has it now, and is beginning a frame-off resto which will include a rebuilt box. My current daily driver is a '92 Dodge Dakota that I bought 10 years ago. I had to wait an extra day for delivery while the dealer put a new power steering rack in it. Guess what! After 10 years, I have about 36 degrees of "slop" in the wheel. Doesn't bother me, but the wife hates to drive it.

[MSeriesRebuild]

One may think the slop doesn't bother, and in general it may not be a huge deal to some; but when you have to make the split second maneaver at a moments notice in an attempt to avoid some incident, who knows what may happen then. It can very easily cause you to over or under steer. The loose box may suddenly become a huge deal. The smart thing to do without question is fix it RIGHT; just not smart to cut corners on components like steering and brakes. I do have some used boxes around, quite a few in fact as we have replaced many with power steering, so if you need one, I think I could come up with a good one.

To shed some light on how your original box should function; with front wheels clear the ground, you can tighten the adjustment screw until you feel a defined tight spot at the exact center of steering wheel travel. Loosen it a little until you barely feel the high spot at the center when turning the wheel. As you spin the wheel either direction away from center, it should get slightly looser. The very slight tighter spot at the center of travel is the defining factor of correct box adjustment. If the pitman shaft (ouput shaft) is loose in its bushing; you will be unable to achieve a correct set up because the shaft will not be held in a centered true rotating position. This will require a complete tear down and rebuild of the box. If you notice any type of movement other than rotational when turning the wheel back and forth at center; you have a problem that needs correction. If you see up or down pitman shaft motion or shaft end play after adjustment; you have done all you can with adjustment, it needs a rebuild.

Another typical spot for loose motion problems is the intermediate arm. Check for wear at the pin and bushing. Also check the end play of the arm on the pin. This is a huge issue that most folks overlook. If the arm has end play, it causes the truck to wander all over the road. End play can only be corrected by building up the edge of the arm pin bore, then refitting it into the bracket that mounts on the frame rail. This issue is paid no attention by most and pin / bushing replacement has no effect on end play whatever. Pin / bushing wear and arm end play are 2 totally different issues that must be handled separately. End play will create far worse handling issues than pin / bushing wear.

The best way to troubleshoot the system is to jack up the front end off the ground completely. Have some one turn the wheel while you look at every component for any loose motion. Even the slightest will make a difference. You mentioned replacing knuckle bearings a while back. Did you set up the knuckles with a proper bearing preload at that time? This is extremely critical if using tapered rollers on top. We use tapered rollers top and bottom on all our builds. No question it is the better way to go, but it must be done correctly in relation to set up to achieve a long lasting good result. Feel free to give me a call if you have questions or if I can help you any with that.

It is a good idea to disassemble the drag links, remove the ball seats, spacers, and springs for cleaning. Lots of times they get full of crud that will block or seize spring motion. Even when the plugs are tight, the springs must remain "LIVE" in order for things to function and feel correct. You cannot diagnose whether this is a factor without tear down and visual inspection of drag link internals. They may indeed feel solid, but the reason could well be because there is no live spring movement. It is a relatively simple system, yet quite complex when all factors are considered.

The correct oil for the box is worm gear lube, ISO 460. If the box is completely dry, such as after a rebuild; it holds exactly 12 ounces of oil, no more, no less. This does not come up to plug opening level with the box installed on the frame. Many boxes leak after seal repairs simply because they are over filled with oil. Pay close attention; measure out 12 ounces, pour it in and install the plug, with good thread sealant.

[DaveO]

Thanks to all for your excellent input!

Our roads here have some pretty deep tire ruts in the pavement. I have to ride the ridges while going down the road while in town. Sometimes the truck will just take off in one direction, or the other, if I fall off the ridge. It can be entertaining. This is with STAs, I'd hate to think what would happen on NDTs...

I'll do the adjustment now, then look toward rebuilding it all this summer when I don't need the truck every day.

Charles: Do I need to pull the drag link to do the adjustment? I'm pretty sure I got the roller gouge from you when I swapped it over. Thanks for your thorough answer. I'm going to e-mail you on a separate issue this morning.

Lifer: 100°!?! You are a man among men! Thanks for your input.

Cal_Gary: Roger, I'll rebuild the links "while I'm in there" (four words that send a shudder down my spine).

Dave

[Lifer]

Thanks to all for your excellent input!

Lifer: 100°!?! You are a man among men! Thanks for your input.

Dave

Naw!! Just dumber (and broker) than most. Keeping it in my own lane was not a problem, but I will agree with Charles about the unexpected split-second maneuvering. I have always been a defensive driver and allowed plenty of room for just such exigencies. The older I get, the more room I allow, 'cuz I know that my reflexes ain't what they used to be. At least I can afford proper maintenance now...if I can keep my son's hands out of my pockets!

[MSeriesRebuild]

You will need to pull the drag links in order to remove the ball seats and springs for cleaning and lube. It is not necessary to remove then for other adjustments.

[DaveO]

I finally had a chance to get at the gearbox this past Sunday. I took three full turns on the adjusting screw to get most of the slop out (I left a couple of degrees in there; thanks Lifer). I never did feel a high spot, but the truck sure behaves a lot better! I reckon it will hold until I can get the system rebuilt this summer. While it was on the stands I found that the idler arm has some side-play.

Thanks to you all for for your help.

Charles: Uncle Sugar is done with me for the year, and the eagle craps tomorrow...

[Tuko]

It is a good idea to disassemble the drag links, remove the ball seats, spacers, and springs for cleaning. Lots of times they get full of crud that will block or seize spring motion. Even when the plugs are tight, the springs must remain "LIVE" in order for things to function and feel correct. You cannot diagnose whether this is a factor without tear down and visual inspection of drag link internals. They may indeed feel solid, but the reason could well be because there is no live spring movement. It is a relatively simple system, yet quite complex when all factors are considered.

I was looking over my steering last night because its sloppy going down the road. there appeared to be some play in the drag link joints. I have never messed with this style steering component before. So I did a search and found this thread. From what I understand from the quote above these joints can be tightened if they exhibit play? I saw what looked like a plug in the end of the link that was slotted if I tighten that inward would it take up slack?

[MSeriesRebuild]

Tighten each of the plugs until it bottoms out;. Back off only enough to insert the cotter keys that secure the plug and leave it there. Be sure they are greased well.

What this won't tell you is if there are any other issues going on; such as cracked ball shanks, or worn seats and whether the balls may be worn out of round.

[Tuko]

I was going to take them apart, clean, inspect then adjust. Are individual internal replacement parts available if I find something that is bad?

[m15256]

Everything is available

[jordankjcm]

This is extremely critical if using tapered rollers on top. We use tapered rollers top and bottom on all our builds. No question it is the better way to go, but it must be done correctly in relation to set up to achieve a long lasting good result.

This post came at the perfect time as I am in the process of doing a knuckle rebuild. I am now at the stage of adjusting the "pre-load" on the knuckle bearings. I have used NOS bronze cones on top and the proper Timkens on the bottom (all with new Timken cups). Yes I know know that the best fix was to use the tapered roller bearings on the top as well.....I'll do that next time. I have the type/style of torque wrench that the manual spells out in testing the preload (looks like that old kind of torque wrench that bends to provide a reading). So what it the proper procedure to set the preload? Mine is set now about 15 ft/lbs and the seems REAL tight.

Thanks!

Jeff