Hi there, I have a CPP power steering box in my truck. I have Coker radial tyres running good pressures. On the open roads at 60-70 mph it has a tendency to wander, so you’re correcting constantly as you are driving. I wondered if anyone in the community knows the correct factory steering settings for these trucks? Toe in Camber and Caster. I have a feeling that once that’s set correctly any steering issues should be closer to resolving. Thank you
Camber 13/32" or 1 1/2 degrees Caster 1 degree Toe In 1/16 - 3/16 http://chevy.oldcarmanualproject.com/chevyresto/56136.htm
Prior to worrying about alignment specs, make sure ALL front end ans suspension components are tight and within spec
Exactly, beginning with the gear box. A pal of mine said that shop's truck, same as that one, where he worked was tough to keep in line. Past the warranty period.
what happens if you don't constantly correct? Just hold the steering wheel still, move it gradually as needed, instead of constantly? But yeah, first thing is to check everything to make sure it's tight....at both ends of the truck. All the spring bushings and shackles, U bolts an alignment pins where the axles meet the springs, kingpins, all the steering linkage, etc. And some pictures of the underside of the truck, where the steering linkage is, might be more helpful than pictures that don't show us anything on the steering or suspension systems.
I wonder what the original truck drove like at 70mph on bias plies.... Just saying; that we've gotten used to a certain "feel" with newer cars and forget what the OEM drove like, even new
The other day we were watching some episodes of Highway Patrol and my son commented on how people were always sawing back and forth on the steering wheel as they were driving in a straight line. Maybe that was just the TV filming, but I remember doing the same in some of my old cars.
They were new cars at the time, so they tracked ok. The filming thing...they sat people in a car without a windshield, played a background movie behind them, and told them to move the steering wheel all the time to make it look like they were driving. At least that's what it looks like, to me
Toe in and caster seem to be the most critical settings to prevent what you describe. Those front ends were not designed with radial tires in mind and sometimes require a lot of trial and error. The toe in settings are a little different for radial tires. They tend to spread more at the front at speed. A little more positive caster can help keep it in a straight line. You will have a hard time finding alignment shops that can (or will) adjust the camber on a straight axle pickup. They don't even know what caster shims are for. Weak and sagging springs are a problem. Spring eye bushings allow the axle to move around if worn out, thus making it hard to stay in line. Tie rod and drag link ends must be tight. Spring mount bolts, too. Well balanced tires with proper inflation. All these things are critical and a very little change can make a big difference.
also these trucks came with a caster shim as original equipment, if it's missing, you won't have enough caster.
I didn't look at the picture very well. That model has independent front suspension, yes? If so, everything is adjustable via shims and elongated bolt holes, making things very easy to adjust. Check the rubber bushings on the control arms for deterioration and check for proper wheel bearing adjustment. That's pretty critical on some vehicles. If you have ball joints check them by placing a jack under the control arm and try to shake the wheels up and down and sideways. There should be no play. Sorry for the misinformation in my previous post. It is correct, however for earlier models with a straight front axle. I've also found that new steering boxes are often not in very good adjustment. You might check that. You want no more than an inch of free play at the steering wheel with the wheel centered on the high spot on the worm.
As others have said, be sure to confirm the other parts in the system are good and that your alignment is correct. I rebuilt or replaced all of my frontend pieces, along with adding a CPP power steering box. Everything from the tires to the steering wheel was new or rebuilt. But, I had serious issues with wander and the truck having a mind of its own. I went through everything making checks multiple times, always stopping before I got to the steering box, "because it was new and certainly wouldn't have any issues." I ended up watching the drag link closely and could see that all of the motion of the link was not translating into pitman arm movement. The result was that the new CPP box was junk. Hopefully you don't have a similar issue as CPP didn't stand behind their product in my case even thought I only had 25 miles on their $500 box.
This. My shoebox with plys doesn't do what I would call wandering, but it definitely needs constant adjustnwbt to go straight. And the wheels don't turn until the steering wheel goes 2-3 inches, lol, and I've driven other old cars wayyyyy worse than mine...
Looking at my old motors manual the numbers are a little different than X28s caster 1 1/2 camber 1/2-1 1/2 toe 1/8-7/32. The biggest thing make sure every thing is tight spring shackles king pins and tie rod ends . With loose parts the alignment is good only sitting on the machine once the truck moves it can be can be where
You need to ensure all the components are good shape and not worn. But I also think adding some caster shims between the leaf springs and the axle is a good idea. With power steering you can overcome the additional effort that the extra caster causes, but the result of additional caster is to provide better self centering (which also means less tendency to wander).
Unless the axle has been bent you do not adjust caster and camber on those old trucks. You can shim the axle at he spring to add caster. I have seen that done and they actually sell shims just to do that with. Usually all that gets adjusted is the toe. 1/8" out is the general rule of thumb but you can google the specs and find out if its different. The suspension components being up to par is good advice. There is one other thing that comes to mind. I started driving farm equipment when I was 7 years old. I never tried to drive anything with power steering until I was in high school. For me there was a learning curve, non-power was easy but not power. My uncle said that I was gripping the wheel too tight and had me drive with my finger tips. Try relaxing your grip a little bit. Remember it is an old truck and not a late model car.
I rebuilt the front end on an AD truck once and it wouldn't track straight. Looked into it and determined the lack of castor shims/wedges on the axle wasn't creating enough castor and was causing the problem.
Gentlemen ( and gentle ladies ) many thanks for your responses. I hope the steering box from CPP is in good shape. It’s new, well fitted a few years ago now actually. I’m always tinkering with the truck to get it to run just a little better, most of you will know what I mean. I fitted sway bars back and front from CPP, replaced all the bed fasteners, I also fitted a new steering column from Summit and a new draglink from LMC. I have LMC heavy duty shocks. It rides so much better now, I wouldn’t call it tight as such, after all it’s a 50s truck on buggy springs, but all in all it’s tons better. I used Borgeson joints between the box and Column. The CPP box has new hydraulic hoses and all fresh power steering/trans fluid. There is some adjustment in the box which I played with and that made the “feel” much better. The 292 I’ve fitted has a stock power steering pump on board. It groans a little when cold on lock to lock. Once your away it’s fine. It’s a long way from the manual steering, my arms thank me but my muscles miss the work out. I’ve not touched the bushings in the leafs front or back so I’m just considering having a tinker with those. There is a commercial truck garage a few miles from me that I’ve visited. They deal in 10 litre + Diesel V8s for coaches and trucks so I’m considering letting them have a look. I was thinking my starting point might be where am I right now. Try to check the current settings to see if it way off factory settings then tweak to suit. I’ve never had to adjust camber caster toe in on anything like this so it’s all a little “ black arts “ to me. If I took pictures of the steering setup you would just see stock 3100 components, with the exception of the CPP box.
Thank you sir. My flatulent intestinal issues are kind of ok today. I’ll keep you posted on any updates !!
Thank you for your comments. Like most folks I guess I only hold the wheel lightly when at highway speeds at say 60-70. I don’t think I’ve ever gone over 80 knowingly. If I leave it untouched it will wander from lane to lane so you have to correct it. I had a 70s Volkswagen camper van, if I drove much over 60 it would behave the same way. I learned that 50-65 was a safe sweet spot to stick with. With a modern car or van there is much greater precision. I understand that. I have a feeling that it needs a good alignment as I’ve changed major components. It’s a continuous improvement process I suppose.
That’s such a funny clip because when he delivers the line the other guy looks dead straight without a hint of acknowledgment
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