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"Thrust Angle Alignment" vs Regular Front-End Alignment
I've got Les Schwab telling me my 1997 4x4 Expedition needs a "Thrust Angle Alignment" for $89, instead of their Regular Front-End Alignment for $39. (Hey, at least they're not trying to sell me their Four-Wheel Alignment for $109).
As I understand it, the only reason to accept the $89 Thrust-Angle alignment, would be if I thought my back axle was bent. I can tell you, and am telling them, that if my back axle is bent, then it will just be staying that way.
If it makes a difference, said alignment is needed due to the replacement of both front upper control arms.
What am I missing? Is there any other value to the $89 job? Looking for some language I can use to respond to these guys. Also, would love to hear from any employee of Les Schwab who could explain it better.
This "thrust angle alignment" was first offered in the middle 80's, the phrase coined by Hunter Equipment trying to convince people every vehicle needed this and they had the only equipment that could do it. They must have forgotten NASCAR racers had been doing the same thing with actual strings long, long before they tried re-inventing the wheel, no pun intended.
Its mostly a money grab and I'd bet one in 10,000 vehicles would have rear axles needing any sort of "alignment".
The appropriate language dealing with this sort of BS is "No......." you can add anything you feel fitting after that.
Haha! Thanks. Your choice of language is much more gentlemanly than mine!
Well thank you but know this--what I thought to say first was completely "un-gentlemanly".
I don't completely doubt or discount that aligning the rear axle to the body's longitudinal axis isn't important in some instances. A factory stock vehicle that's never been heavily loaded or pulled large loads OR never in a collision where frame or unit-body repair was required typically wouldn't need what we in the body shop business once called "four wheel alignment".
Replacing the front control arms shouldn't affect anything other than the front end geometry which is why it should be aligned after that repair.
I do wonder how many people get suckered by Les Schwab's sales pitch? Here in the USA I can't remember the last time any chain store tire shop with their own "free alignment" deals has offered me this "thrust angle alignment".
I HAVE NEVER liked Les Swab since they pulled an expensive alignment scam on my elderly mother! Kind of like their "Road hazard warranty" anytime you go back with a flat you get, "Oh sorry that isn't covered." Big O is much better.
Lets back up here for a sec, and get our facts straight. I am a steering and suspension mechanic with 30 years under my belt. A four-wheel alignment and a thrust line alignment ARE NOT the same things. A four-wheel alignment is for cars that actually have an adjustable rear suspension, and all four wheels are aligned off the centerline of the vehicle. A thrust alignment is for vehicles, like trucks, that don't have adjustable rear ends. By adjustable, I mean by built-in cams or places to put shims. I have "Re-aligned" many rear axles, but that's not what we are talking about. So, the rear is not adjustable. The thrust line is the particular angle that the rear wheels are sitting at. Should be 0 could be up to a few degrees. the front alignment is set to the rear thrust to eliminate pulling and tire wear. In extreme cases the truck will "Dog track" and then you need to fix something in the rear. A thrust angle alignment however should not cost any more than a regular front end alignment. Thanks for reading.
Dan
^^^^ Well alrighty then---where were you two weeks ago when this topic first appeared here? I'm guessing OP has taken care of this or just let it go.
I was over at East County Alignment getting my twin I beams bent to correct the caster. Well worth the $500 to be able to take my hands off the wheel at 90 mph in my 65 F100 and go straight down the road! Shortly after I bought my slick.
Thunderkiss is absolutely correct in his description, I am also a suspension/alignment specialist with a few more years in 40+ When I was doing alignments at the Ford dealer I worked at for 11 years I didn't charge any extra for a thrust angle alignment, only extra for 4 wheel alignments which took extra time and parts (aka shims, cams)
I'm taken aback at the $500 he paid to have the I beams bent to correct caster as that's not possible, the only adjustment you can make to I beams is for camber. In order the change caster you have to manipulate the radius arms. (For older trucks where the beams can actually be bent) Pre camber cam I beams. The newer ones you can manipulate both camber and caster but there's no bending involved.
I make that last statement based on a typical I beam bender from the late 60's so it's possible they now have an I beam twister that can bend the beams between where the radius arm connects and the king pins?
I was working for Ford in Dearborn in the late 70's, and remember one time working on my car in one of the shops. The guy a couple stalls down from me had a a pickup truck on the hoist, a torch in one hand, and a 3 pound sledge hammer in the other. He would spend some time heating something on the front end, then pound at it with the hammer, sending sparks everywhere. I asked someone what he was doing, and the answer was "frontend alignment; bending the I-beams". I asked if he shouldn't be doing that on a rack? and the answer was that they come from the assembly line so far off that you can usually do a pretty good job just eye-balling it.
I was working for Ford in Dearborn in the late 70's, and remember one time working on my car in one of the shops. The guy a couple stalls down from me had a a pickup truck on the hoist, a torch in one hand, and a 3 pound sledge hammer in the other. He would spend some time heating something on the front end, then pound at it with the hammer, sending sparks everywhere. I asked someone what he was doing, and the answer was "frontend alignment; bending the I-beams". I asked if he shouldn't be doing that on a rack? and the answer was that they come from the assembly line so far off that you can usually do a pretty good job just eye-balling it.
Sounds to me like he was replacing king pins and whom ever you asked didn't know or was pulling your leg. Blue wrench and a BFH are required tools to replace those things. Pulling of leg is optional.
The last part about alignment being off from the factory is nothing but truth. Sadly it's still true to this very day and it's not just Ford.
Thunderkiss is absolutely correct in his description, I am also a suspension/alignment specialist with a few more years in 40+ When I was doing alignments at the Ford dealer I worked at for 11 years I didn't charge any extra for a thrust angle alignment, only extra for 4 wheel alignments which took extra time and parts (aka shims, cams)
I'm taken aback at the $500 he paid to have the I beams bent to correct caster as that's not possible, the only adjustment you can make to I beams is for camber. In order the change caster you have to manipulate the radius arms. (For older trucks where the beams can actually be bent) Pre camber cam I beams. The newer ones you can manipulate both camber and caster but there's no bending involved.
I make that last statement based on a typical I beam bender from the late 60's so it's possible they now have an I beam twister that can bend the beams between where the radius arm connects and the king pins?
I searched all over San Diego, including the "Old School" alignment shops, big truck shops, and even the Ford dealerships looking for someone that could align my truck before I found Scotty @ East county alignment. I didn't watch him, but he def bent only the beams. He gave me NINE DEGREES of positive caster, which many of the guys in the 61-66 forum said was way too much. However that truck drives like a wet dream. The only time it is hard to steer is on big sweep[ing turns on the freeway. Just have to lean into it a little.
I searched all over San Diego, including the "Old School" alignment shops, big truck shops, and even the Ford dealerships looking for someone that could align my truck before I found Scotty @ East county alignment. I didn't watch him, but he def bent only the beams. He gave me NINE DEGREES of positive caster, which many of the guys in the 61-66 forum said was way too much. However that truck drives like a wet dream. The only time it is hard to steer is on big sweep[ing turns on the freeway. Just have to lean into it a little.
Doesn't your year model have the solid almost i beam like radius arms? If so I can see how he was able to do it. There's a very tiny amount of space between the king pin and where the radius arms connect, maybe 4" at most. I sure am curious if he bent those radius arms or has sort of i beam twister. Nine degrees, WOW that's insane. I bet it does track good lol.
I would have set it for 3.5 right and 3.0 left to account for road crown (power steering equipped only). The only car that I have aligned that has more caster than that is a Mercedes sedan from the late 80's early 90's perhaps even a wider year span, those suckers were 12º give or take half a degree. Funky front ends on those things, have to use a 25# spreader bar to set the toe.
Doesn't your year model have the solid almost i beam like radius arms? If so I can see how he was able to do it. There's a very tiny amount of space between the king pin and where the radius arms connect, maybe 4" at most. I sure am curious if he bent those radius arms or has sort of i beam twister. Nine degrees, WOW that's insane. I bet it does track good lol.
I would have set it for 3.5 right and 3.0 left to account for road crown (power steering equipped only). The only car that I have aligned that has more caster than that is a Mercedes sedan from the late 80's early 90's perhaps even a wider year span, those suckers were 12º give or take half a degree. Funky front ends on those things, have to use a 25# spreader bar to set the toe.
You are correct about the front end setup, and I'm sure he didn't bend the radius arms. It is a bunch of caster but I'm driving on 31's and hauling *** most of the time so stable is important.
You are correct about the front end setup, and I'm sure he didn't bend the radius arms. It is a bunch of caster but I'm driving on 31's and hauling *** most of the time so stable is important.
I'm not questioning the why, just curious in the how he was able to achieve caster correction bending I beams. Best I was ever able to get using radius arm shims was about 3/4º.
I've never even thought about changing caster bending I beams due to geometry and the rigid nature of the solid I beam.
Every beam I ever bent (many) did nothing for caster, only camber.
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