47-55.1 Front End Alignment

[Zippi]

On my 49 Chevy pickup the front clip is a 92 S10 with IFS and disc brakes. When I bought this truck 2 1/2 years ago I had the inner & outer tie rods and upper ball joints replaced along with a front end alignment. The truck had been slowly pulling more and more to the right. I just rotated my tires and noticed the passengers side front tire wearing pretty good on the outside. After rotating the tires, the truck tracks straight down the road. What should a look at for a possible cause?

[mr48chev]

There is "pull" and there is "drift", I know that sounds a bit crazy but pull is usually due to a tire issue while drift is an alignment issue unless the alignment is way off.

Without seeing and reading the tread on the tire I would have a hard time saying exactly what the issue is.

When you slide your hand sideways across the tread of that tire does it feel if it is feathered towards one direction or the other? Your hand slides smooth one way but you catch the feathered edge of the treads sliding the other way. Excess toe in could cause the tire to wear on the outside and show up on the rest of the tread as feathering.

did you happen to check and correct tire pressure when you rotated the tires? A low tire would wear on the edges and cause the truck to pull.

Excess Camber would cause the car to drift to one side and cause the tire to wear on the outside edge.

Normally to have a car drive straight down the road hands off I set the driver's side Camber at 1/4 degree more than the passenger side. Setting the drivers side at factory specs and setting the passenger side 1/4 degree less. That compensates for the camber in the road surface on most roads in the US and helps the rig drive right while keeping tire wear down. Toe in and Caster I usually set at factory specs. I did front end work in tire stores and Pontiac Dealerships for a number of years before I started teaching high school autoshop.

If it were me I'd make sure my tire pressure is correct on all four tires and think seriously about having the alignment checked again. You might have hit a pothole or curb or ?? and knocked it off a bit.

[MARTINSR]

Post the alignment results. Honestly, if the alignment shop knows what they are doing they can correct it. So often they don't. It blows me away how limited the knowledge is on this subject at shops.

Brian

[mr48chev]

Too many "techs" now don't understand the ins and outs of what they see when they are looking a car over that is in for the alignment to be checked. Along with checking the bushings, ball joints, rod ends and what not you have to read the tires that it came with to tell what was going on.

I took a car back to a shop a couple of years ago after having it aligned because it drifted to one side and the steering wheel wasn't centered. Tech looked up the paper work and says "It was in specs". Blank stare about the wheel not being centered. I asked if he had test driven it after he aligned it and got another blank stare. A bit of questioning and it came to light that the guy had been doing alignments there for two years and had never test driven a car after he did the alignment. I asked how would he know if he fixed it if he hadn't test driven it on his test route. Basically I got "what's a test route?" I had to explain that that was the stretch of straight smooth street close to the shot that didn't have much traffic on it an the route to and from that street. For years my test route was less than 3/4 of a mile but that street helped me have the reputation of doing it right the first time including making sure that the steering wheel was centered. I had spoiled picky customers when I was in Texas and if you didn't do it right it came back.

As I said, tires that have tread feathered in one direction or the other shows toe in or out.

More but even wear on one side of the tread or the other often means that the camber was excessive. You really see this with bagged rides or ones with hydraulics.

Tires that have cupped wear spots that are usually on the outside edge usually means bad shocks, it can also mean a tire that is way out of balance. I've driven down the highway beside cars that actually had the front tire coming several inches off the road surface while it was going down the road because the balance was so bad. On one the driver was totally oblivious.

[MARTINSR]

Originally Posted by mr48chev

Too many "techs" now don't understand the ins and outs of what they see when they are looking a car over that is in for the alignment to be checked. Along with checking the bushings, ball joints, rod ends and what not you have to read the tires that it came with to tell what was going on.

I took a car back to a shop a couple of years ago after having it aligned because it drifted to one side and the steering wheel wasn't centered. Tech looked up the paper work and says "It was in specs". Blank stare about the wheel not being centered. I asked if he had test driven it after he aligned it and got another blank stare. A bit of questioning and it came to light that the guy had been doing alignments there for two years and had never test driven a car after he did the alignment. I asked how would he know if he fixed it if he hadn't test driven it on his test route. Basically I got "what's a test route?" I had to explain that that was the stretch of straight smooth street close to the shot that didn't have much traffic on it an the route to and from that street. For years my test route was less than 3/4 of a mile but that street helped me have the reputation of doing it right the first time including making sure that the steering wheel was centered. I had spoiled picky customers when I was in Texas and if you didn't do it right it came back.

As I said, tires that have tread feathered in one direction or the other shows toe in or out.

More but even wear on one side of the tread or the other often means that the camber was excessive. You really see this with bagged rides or ones with hydraulics.

Tires that have cupped wear spots that are usually on the outside edge usually means bad shocks, it can also mean a tire that is way out of balance. I've driven down the highway beside cars that actually had the front tire coming several inches off the road surface while it was going down the road because the balance was so bad. On one the driver was totally oblivious.

The other day at the shop we had a car come back from the alignment at the dealership with a neg camber and I called and asked the service righter for the more detailed specs being the regular camber,caster, toe told me nothing about what could be damaged. His head spun and he said he would get back with the tech. I then told my boss and the body tech that I had requested these advanced specs and they looked at me like I was a moron "What would you need that for, the camber is all we need." And I told them the "included angle and SAI will tell you WAY more." They had a glazed look on their face not having any idea what those specs were! These guys both have spent decades in the collision industry and didn't have a clue!

Brian

[Zippi]

I appreciate the response fellows. I have no way of checking things that were mentioned so I have to rely on a service center. Yeah....I don't trust anyone out there anymore so for me it's a toss up of where do I take it and did they do it right. Here is a pic of the tire that was on the passenger side front. It's now on the drivers side rear. I feel no feathering one way or the other.

[dsraven]

yup, same here. most of the time I need to tell the alignment guys that unless the vehicle has been road tested after the alignment, don't bother calling to say it is done. the first thing I check is the steering wheel center. if it isn't done then the rest is also questionable. I had one tech tell me it would only take a minute to pull the wheel off and center it. I asked if he had centered the steering box prior to alignment and he looked at me like I had 3 eyes. I usually get the eye roll when I ask for the alignment printout including the before and after specs. 1 guy told me the camber couldn't be adjusted. I asked if the lower ball joint was still the bolt on style, he had the "I dunno" look. I answered with a yup, and said the holes are slotted for a reason, it's for adjustment. and that was at a shop who "specialized" in the brand of car that was in for the alignment.
anyway, it makes sense to always ask for the specs when you get an alignment. maybe they will be more on their toes then. and, there are still guys at shops out there who know what they are doing and check the tire wear, compare tire size and wheel offset to the stock specs and check all components properly before they start the alignment. then road test after to ensure it's right.

[MARTINSR]

I did all the alignments at a bodyshop I worked at and I can't imagine not test driving it. That blows my mind when I heard they didn't do it where I work now. I WILL be taking it for a drive before I call the customer telling them it's done now.

Brian

[dsraven]

oh man. I had a little write up done and when I went to post it disappeared.
things to check yourself with home shop tools.
set the truck on stands under the axle out back and under the lower control arms out front. then jump it up and down a few times to get the suspension settled. be aware that the stands under the control arms may tend to move when you do this so ensure they are placed well and then check them before getting under it. basically what youy want to do is set the truck on stands but do it so the weight of the truck is sitting on the springs to simulate the truck sitting on the ground. some guys will do this with the suspension "hung" as well. basically what we will do is get some good dimensions of the axles in relation to each other. to do this drop a plumb bob to the floor under each axle at the wheel mounting flange and put an X on that spot on the floor. drop the plumb from the same spot on each axle so it is the same side to side. then getthe dimension from front to rear each side and also do a corner to corner dimension. they should be the same front to rear and from the corner to corner perspective.
do you run wheel spacers?
do you run wheels with a different offset than a stock S10?
do you run tires with a different outside diameter than the stock S10?
is your wheel base different than the stock S10 the front end came from?
these differences can affect how the steering angles work so setting the alignment to a stock S10 setting may not be enough to sort it out.
google ackerman angle, scrub radius, independent front suspension angles. youtibe will show you how it all works.
here is a link to some of it
https://www.motor.com/magazine-summa...november-2019/

[joedoh]

that tire is definitely worn on the outside corner.

Originally Posted by dsraven

most of the time I need to tell the alignment guys that unless the vehicle has been road tested after the alignment, don't bother calling to say it is done.

yep, a static alignment does nothing. what i bet is happening is the alignment checks ok on the rig, but underway the suspension is pulling backward under road forces because a component is worn out, maybe the upper control arm bushings. you said you replaced the tie rods and upper balljoint, but there are upper and lower control arm bushings and lower balljoints in that system too. are you getting any head shake under braking? thats a sure sign of upper bushings going bad. if you poke your head in the engine bay you can usually see the one side of the upper arm, take a look at the condition of the rubber for cracking and missing pieces.

[dsraven]

how about some pics and/or explanation of what you have for front end stuff. wheels and offsets, tires and sizes, spacers if any, new stuff replaced, pics of the old stuff, pics of the alignment printout etc.

[mr48chev]

To me that looks like camber wear. I don't see any sign of excess toe in or out but when you look across the tread you see that the whole tread is worn on and even angle meaning that the top of the tire was leaning out too much.

If you measure tread groove depth across the tire it most likely changes in even increments. Each groove to the inside being a few thousandths deeper than the one outside of it. When you expand the photo and study the edges of the tread bars there is no feathering or signs of the tire having been pushed sideways from the wrong toe in or out as they are sharp crisp edges.

It looks like it may have 3/4 to 1 degree positive camber in the front wheel where it was and that should be 1/2 or less and maybe 1/4 in the left and 0 in the right wheel with that tire width.

[Zippi]

Thanks for all the help fellows. Here's a little run down of my chassis setup. The front clip is a 92 S10 with ifs and disk brakes, the rest of the chassis is the stock frame that has been boxed, Camero Big 10 rearend, 18" Ridler wheels that are 8" wide, Fuzion 235/45R18 low profile tires. I'm running g 3" spacers on the front and 1/2" spacers on the back. I think everyone's input has some valid points. I think its going to hard to get a good alignment as mentioned due to my setup. I may set a square on the floor and push it up to the tire and take a measurement at the bottom and top of the wheel. I'm thinking the passenger side will have a smalller reading at the top vs the drivers side.

[mr48chev]

It can be aligned but you have to go to someone who knows what they are doing and doesn't panic because they don't have a 49 Chevy pickup with an S-10 stub in their alignment machines computer.

Still with the alteration to the scrub radius with the spacers and the wide tires on offset rims you are going to go through front tires faster than rear tires and that is just hazards of playing the game. I have 205-60 14 on the front of my 49 on 7 inch rims and 255-60-15 tires on the back on 15x8 rims and there is no way I can rotate tires so the norm was replace three pair of front tires for every pair of rear tires I replaced. I think the rears that are on the rims now have 50K on them and outside of being unsafe because they are 20 years and maybe more old they still don't have that much wear. A wimpy six cylinder helped with that though because the truck wouldn't do a burn out out in a puddle.

The only real cure for your rig is longer control arms so you can toss the spacers. That would cut down on the scrub radius.

[mr48chev]

The actual fix might be http://michiganmetalworks.com/store/...product_id=144 Not inexpensive but a vast improvement over spacers on a too narrow to begin with chassis.