Steering issues...

[nickvig]

Hey guys. My '87 R1500 GMC has been under minor repairs the last few weeks. After replacing the front springs to get it back to stock height and the shocks all the way around I've noticed that the truck tends to wander on the freeway. The only way I can describe it is that it tracks straight but there's a lot of side to side play. I find myself overcorrecting on the freeway quite a bit.

So...in talking to my cousin he said I probably need a new pitman arm and need to look at all the steering components that might need to be replaced. In looking for the pitman arm it's listed as GM Part 14013038

http://www.gmpartshouse.com/gmc/r150...ame=pitman-arm

But...when you look at Rock Auto it shows:

ACDELCO 45C0007 {#88911192} Professional Info
Power steering; Except Variable Ratio

45C0007 and 14013038 are supposedly interchangeable but the Rock Auto site specifically states not for variable ratio. My truck has RPO code N41 -- Steering Power, Variable Ratio. So now that you've read this novella....what's the right part number for the pitman arm? Keith? Hatzie?

[nickvig]

I don't usually bump my own threads but....anyone??

[cadillac_al]

It sounds like one of the models that came without a front sway bar. That's a common delete in farm country, not so sure about Cali. It could also be a worn steering box. I have only had 2 bad ones in my life but they do wear out.

['68 Newtricks]

Since you dropped the truck back down, what steering modifications were in place before lowering it? You may have a raise axle steering arm or dropped pitman arm and that would mess things up once lowered. If all things are back to stock spec, you could just have some parts that are worn.

Pic of the steering?
Lets get more info before you start buying stuff.

[nickvig]

Originally Posted by '68 Newtricks

Since you dropped the truck back down, what steering modifications were in place before lowering it? You may have a raise axle steering arm or dropped pitman arm and that would mess things up once lowered. If all things are back to stock spec, you could just have some parts that are worn.

Pic of the steering?
Lets get more info before you start buying stuff.

Thanks for the help, gentlemen!

I'm sorry if this wasn't clear. I bought the truck with it being lowered. After I had it for a couple of weeks I realized it was not lowered correctly and they had only cut the front springs and reinstalled them. I ordered a set of OEM front springs and shocks and had a suspension shop install the springs and shocks and do a complete alignment.

As far as I know there isn't anything changed in the front but I'll shoot some pics tomorrow morning once it gets light and hopefully we can do some internet diagnostic work.

[Dead Parrot]

Take it to a shop that does a lot of front end work. Tell them you want a good estimate on bringing it back to new new condition. Tell them it is a daily driver that you plan on keeping many years. Otherwise they may assume you just want a 'minimal make it safe repair.' Even if you decide to do the repairs yourself, you will have a good list of things to fix rather then replacing random parts.

My 75 was behaving similarly to yours and I was told I had a couple of worn ball joints, bad tie rod end, a broken sway bar bracket, and a couple of other things I don't remember. $700 later it drove like a new truck. That was about ten years ago. It still handles good today.

Don't overlook the screws at the base of the inside of the steering column. If they are loose, you will have a lot of slop.

[tommy217xxx]

Originally Posted by Dead Parrot

Take it to a shop that does a lot of front end work. Tell them you want a good estimate on bringing it back to new new condition. Tell them it is a daily driver that you plan on keeping many years. Otherwise they may assume you just want a 'minimal make it safe repair.' Even if you decide to do the repairs yourself, you will have a good list of things to fix rather then replacing random parts.

My 75 was behaving similarly to yours and I was told I had a couple of worn ball joints, bad tie rod end, a broken sway bar bracket, and a couple of other things I don't remember. $700 later it drove like a new truck. That was about ten years ago. It still handles good today.

Don't overlook the screws at the base of the inside of the steering column. If they are loose, you will have a lot of slop.

I've got some steering issues also. When u say at the base of the inside, are u talking about the screws for the plate at the fire wall or the screw that hold the column to the dash?

['68 Newtricks]

ah gezz, it's a 2wd
just say C10 next time please
I can't deal with GM's dumb labeling lol


if you are willing to go through the motions yourself, jack the front end up, grab a tire, and try to find slop in the ball joints by rocking it vertically. Do that to both, it will take a little effort to do so. If you get any, check the wheel bearings first. If they are tight, you have ball joint issues.

If you wanna check steering tightness. With the truck on the ground, have someone saw the wheel back and forth while you look underneath for any joints that aren't transferring the motion (aka sloppy). Also check steering box, the bolts that hold it to the frame, the steering shaft, and the lower part of the steering column that mounts to the firewall.

You do all this and you are miles ahead of what a shop will do. If the steering shaft is bad, look into an XJ shaft. Don't know what I'm talking about, search

[Gregski]

Originally Posted by cadillac_al

It sounds like one of the models that came without a front sway bar. That's a common delete in farm country, not so sure about Cali. It could also be a worn steering box. I have only had 2 bad ones in my life but they do wear out.

my '74 was doing the same thing when it had no sway bar so I went and installed one with brand new bushings and guess what it still does it still wonders, I don't think that's what the sway bars job is, so I am just commenting on this comment, ha ha trying to help as I need help myself

[Gregski]

Originally Posted by '68 Newtricks

ah gezz, it's a 2wd
just say C10 next time please
I can't deal with GM's dumb labeling lol


if you are willing to go through the motions yourself, jack the front end up, grab a tire, and try to find slop in the ball joints by rocking it vertically. Do that to both, it will take a little effort to do so. If you get any, check the wheel bearings first. If they are tight, you have ball joint issues.

If you wanna check steering tightness. With the truck on the ground, have someone saw the wheel back and forth while you look underneath for any joints that aren't transferring the motion (aka sloppy). Also check steering box, the bolts that hold it to the frame, the steering shaft, and the lower part of the steering column that mounts to the firewall.

You do all this and you are miles ahead of what a shop will do. If the steering shaft is bad, look into an XJ shaft. Don't know what I'm talking about, search

I second this persons comments, it's most likely a combination of warn out parts, (even the imfamous rag joint) so its probably both suspension and steering and not just a steering issue

[Dead Parrot]

Originally Posted by tommy217xxx

I've got some steering issues also. When u say at the base of the inside, are u talking about the screws for the plate at the fire wall or the screw that hold the column to the dash?

Neither. Inside the column after you have removed most of the guts are 3(4?) screws that tie two of the actual turning parts together. If they work loose, you will get a lot of slop in your steering. This is on a tilt column.

['68 Newtricks]

4 torqs head bolts, below the tilt pivot
but those tend to be obvious

what do you mean by "side to side play"? Check the toe if you feel like you are "correcting" constantly. It should be a tiny bit in. (1/16" just to make sure it's not out)

also, after you have checked everything on the front and replaced all the worn out, tired parts........ make sure you check the rear.

[lilpoindexter]

Is it possible your alignment is now off?

[cadillac_al]

Originally Posted by Gregski

my '74 was doing the same thing when it had no sway bar so I went and installed one with brand new bushings and guess what it still does it still wonders, I don't think that's what the sway bars job is, so I am just commenting on this comment, ha ha trying to help as I need help myself

The sway bar must have made a big improvement didn't it? They handle kinda weird without them if you aren't used to it. I always noticed a big difference in handling between trucks with a bar and without them. If it's wandering with a sway bar then It's time to move to alignment.

[hatzie]

Vague steering can be a lot of things.

AC Delco 45C0007 states not for variable rate steering boxes. It will probably fit but there's a reason for the note about the variable ratio box... caveat emptor.

When folks slam em they tend to put wider than stock tires on too. This puts stress on the frame where the box mounts just like a lift and big tires on a 4x4. Check the frame for cracks around the steering box mounting bolts. ORD makes braces and weld-on repair plates.

Check the rag joint and steering shaft in general between the column and the steering box. This is a good time to put on a U-Joint shaft out of a Jeep YJ or build one from Borgeson parts.

Slamming and wide tires puts stress on the recirculating ball screw in the steering box too. Check the steering box for play. Have an assistant turn the wheel and observe the amount of play between the input shaft and the pitman arm.
If the steering box has a lot of play you can re-build it yourself or find a used box that isn't clapped out. Considering the quality level of recent so called rebuilds I've seen I'd seriously consider this option.

Check the joint at the end of the pitman arm for play. #11
Check the Idler arm joints for play. #12
Check that bubba didn't loosen up the idler arm support from the frame. #13
Check all four tie rod ends for play. #s 1 & 4.
Check the top and bottom A-Arm ball joints for play.
Check the A-Arm bushings for play.

Replace or repair the worn out broken stuff, grease with your favorite EP chassis grease, and get a full alignment. Many shops complain about how "hard" it is to adjust the camber and caster with shims. If they do go somewhere else. Demand a full printout of the alignment before and after numbers... the alignment machine will provide one that should show actual and optimal numbers.

Download both the 1985-1991 GM 52R Parts and the GM 52R Illustration books from the manuals link in my signature. There's a wealth of information in them.
Page 740 of the 1985-1991 GM Illustration book

[nickvig]

I really appreciate all the responses. I'm glad I bumped the thread.

'68 Newtricks:

Thanks for the help. I feel you on the nomenclature but I was hoping Hatzie would jump in here because I really was curious to find out the correct part number. That's why I had to refer to the model and year specifically.

I'm going to have to have my cousin come over and walk me through this stuff. Honestly I'd rather just replace everything because the truck is close to thirty years old and I don't think much has been done to it.

Hatzie:

Thanks for the link. I had already downloaded the shop manual but I didn't realize you had a Parts and Illustration list there as well. I'll go get those now.

So here's what's interesting. I pulled the truck out and shot a picture of the pitman arm. The number on the arm is 6272424. This shows as a 63-66 pitman arm. So I'm wondering if it was changed at some point with whatever was laying around.

So...here's what the truck looked like when I bought it:



Here's what the truck looks like now:



The front end had the springs cut down by about 3-4 inches. I went to an alignment shop and they replaced the springs and aligned the truck. Hatzie is spot on. The original wheels were 15x8 smoothies with 275/60/15 tires. The truck drove like it didn't even have power steering. I replaced the wheels with OEM Factory Aluminum 15x7 and OEM size 235/75/15 tires. When I did this it made a world of difference. The truck steered much better, it wasn't difficult to steer but I noticed the wandering issue quite a bit. The truck still has the 2" drop shackles in the rear which I'm going to change back to stock but I realize this won't impact my steering issues.

So here's some suspension/steering pics:

Pitman Arm:



Driver's side control arm/steering:



Passenger side control arm/steering:



BTW -- I was wondering after reading Hatzie response about the shims but I can see that the alignment shop I took it to did shim the truck correctly and gave me all the computer print out information. So they're good on that one...

[hatzie]

The drop in the back may affect things more than you'd think. But it's probably not what is causing this.

If you find that the alignment shop did a decent job of verifying the condition of the steering and suspension then it could be as simple as your tread design, tire width, sidewall flex, and the tire pressure you're running.

As you say the suspension parts are 30 plus years old. They may be good enough for a cruise in queen but not really that good for a daily driver. Worn A-Arm bushings will directly affect both Toe and Camber/Caster angles.

The phenomenon of following ruts in the road is called Tramlining... The tires make a huge difference in Tramlining. Folks tend to notice it when moving from narrower softer Winter tires to wider stiffer Summer tires.

This is an article from Tire Rack on what tramlining is and possibilities on how to mitigate it. http://www.tirerack.com/tires/tirete....jsp?techid=47

Alignment can be used to lessen tramlining. This is a Motor article on custom alignments to mitigate things like tramlining. http://www.motor.com/magazine-summar...eel-alignment/

I'd be interested to see the printout from the Hunter or Bear or ... machine. The articles seem to say that 1/32 to 1/16 Toe IN and mild changes to Camber angle can reduce tramlining somewhat.

[hatzie]

6272424 is indeed a 63-66 part...

What's the part number on the steering box?

[nickvig]

Originally Posted by hatzie

6272424 is indeed a 63-66 part...

What's the part number on the steering box?

Not sure. I'll have to get under there tomorrow and look at it.

My plan is to raise the rear back up, so I'll see how much that helps before I go spending a bunch of money on parts. Although at this point I'm tempted just to get everything and replace it. Buy once, cry once, the saying goes.

Thanks for the other links, I'll go check them out. I don't drive the truck every day but when I do it's to work once or twice a week which means about 25 miles of freeway driving. I don't expect it to drive like a car with rack and pinion steering but I do expect it to only move left or right if I'm actually steering it in that direction.

Here's the alignment print out. Let me know what you think.

IMG_20160725_224244_result by nickvig, on Flickr

[nickvig]

Originally Posted by hatzie

6272424 is indeed a 63-66 part...

What's the part number on the steering box?

Steering box is PN 7802644L

IMG_20160727_162700_result by nickvig, on Flickr

However, according to the PN Listing I downloaded from you....

RPO Code N41 - Power Steering, Variable ratio is PN 7846958

And there's an eBay seller who states that the part number above is actually the casting number.

Screen Shot 2016-07-27 at 5.12.02 PM by nickvig, on Flickr

['68 Newtricks]

no castle nut or cotter pin on the pitman arm