e-C4 wheel alignment data

[JT99]

Please forgive me if this information is in a sticky, but I can't find it using the search.

What is the wheel alignment front & rear for a 2021 MY e-C4?


My tyres are more worn on the outside, so I blew the dust off my ancient Dunlop track gauges and measured the front at 1/8" = 3mm toe-in.

That seems reasonable, except modern EPS cars use the motor to self centre, so they tend to run nearly parallel at the front and get slightly better economy.


I forgot that it doesn't have a live axle at the back and I'm now kicking myself for not checking the rear before I buried the gauges in the garage again!

The rears usually toe-in to keep the back nicely behind the front, but sometimes (I'm looking at you, Renault-Nissan!) they can be way over spec from the factory and need shimming.

[GiveMeABreak]

I believe the e-C4 axle data is the same as the non-electric version, translated here:

Legend:
"R1": Front wheel radius
"R2": Rear wheel radius
"H1": Measurement between the measuring area under the front cradle and the ground
"H2": Measurement between the measuring area under the rear spar and the ground
"K1": Distance between the wheel axle and the measuring area under the front cradle
"K2": Distance between the wheel axle and the measuring area under the rear side member


Checking the vehicle's front axle trim

NOTE: This trim measurement allows the front wheel alignment to be checked and adjusted without setting the reference trim.

Measure the front wheel radius "R1" using appropriate tools. Measure the front height "Z1" between the ground and the "Z1" zone using appropriate tools.
Calculate "K1" = "R1" - "H1" for the front.

Checking and adjusting: Front toe
The front toe is checked and adjusted by checking 2 different values:

• The front/rear thrust angle difference (0° ± 0°04’)
• The axle parallelism

NOTE: Adjusting the front and rear thrust angle difference ensures that the vehicle’s trajectory is maintained correctly, and adjusting the axle toe prevents excessive wear of the tyres.

Checking and adjusting values ​​(Technical solution 01).

"K1" Parallélisme à l’essieu (± 0° 08’)

48 mm 1° 19’

58 mm 1° 11’

68 mm 1° 02’

78 mm 0° 54’

88 mm 0° 43’

98 mm 0° 34’

108 mm 0° 24’

118 mm 0° 12’

128 mm 0° 01’

138 mm -0° 10’

148 mm -0° 22’

158 mm -0° 35’

168 mm -0° 48’

Reference plate: Geometry of the running gear

NOTE: To perform a complete geometry check, place the vehicle at reference height

Front Axle
Measure the radius of the front wheel "R1" using appropriate tools.
Calculate "H1" = "R1" - "K1" for the front
Measure the front height “H1” between the ground and the “Z1” area under the front cradle using appropriate tools.
Compress the front suspension until the calculated H1 value is obtained.
The height difference between the two sides of the front axle must be less than 10 mm

K1	Technical Solution
01	118mm

Rear Axle

Measure the radius of the rear wheel "R2" using appropriate tools.
Calculate "H2" = "R2" - "K2" for the rear.
Measure the rear height “H2” between the ground and the area “Z2” under the rear side member using appropriate tools.
Compress the rear suspension until the calculated H2 value is obtained.
The height difference between the two sides of the rear axle crossmember must be less than 10 mm.

K2	Technical Solution
01	-98mm

Front Axle Geometry

Reference	Tolerance	Technical Solution
Axle Toe (adjustable)	± 0° 08'	0° 12
Camber Angle (non-adjustable)	± 0° 30’	-0° 33’
Pivot Angle (not adjustable)	± 0° 30’	14° 30’
Caster Angle (not adjustable)	± 0° 30’	5° 30’

Reference	Tolerance
Forward / Reverse Thrust Angle Deviation	± 0° 04’
Camber Asymmetry	± 0° 30’
Pivot angle Asymmetry	± 0° 30’
Hunting Asymmetry	± 0° 30’

Rear Axle Geometry

Reference	Tolerance	Technical Solution
Back Thrust Angle (not adjustable)	± 0° 30’	0° 00’
Axle Toe-in (non-adjustable)	± 0° 08’	0° 45’
Camber Angle (non-adjustable)	± 0° 30’	-1° 42’

Camber Asymmetry

Value: less than n 0° 30'

[JT99]

Thank you very much!

The chances of anyone ever doing all that outside of the factory are somewhat less than my chances of winning the Euromillions, and I haven't even bought a ticket!

Just how poor is the suspension design if you have to compress the suspension to a known datum to check the toe? I always knew independent suspension was dodgy as you get such peculiar tyre wear compared to the flat wear of a beam axle.


So I need to crawl around on the ground and measure the hub centre to the ground {(upper edge of rim to ground+lower edge of rim to ground)/2}, and then subtract the subframe to ground clearance, to give a K1 value, and then convert the K1 value to toe using the Parallélisme à l’essieu table.

As I measured 7.5' toe-in I need to check that k1 is currently between 120 and 130mm

I hope it doesn't rain tomorrow!

Is there a Parallélisme à l’essieu table for the back? I measured 15' which looks in the right ballpark compared to the reference 12' with a K value of -98mm

[JT99]

I've hit a snag-

Measure the front height “H1” between the ground and the “Z1” area under the front cradle using appropriate tools.

Where is the "Z1" area?

It looks like a dog's back leg under there! It isn't even flat, the flange on the subframe is above the lower surface.

A 10mm error in measuring H1 is the entire tolerance on the alignment, and I have 3 measurements to make....


EDIT: taking measurements under the flange immediately beneath the lower control arm, I get 123mm for K1, which is as close as I am going to get to the reference value of 118mm, so my tracking is spot-on. (Subject to all the errors in distances, flatness of my surface and not checking for wheel run-out when I had the track gauges out.)

The reference value is probably the normal ride height of the car, you'd think the e-C4 would sit lower with the weight of the batteries and Z1 would be larger.

[GiveMeABreak]

This is all I have. I assume there are no values for the rear as they are not adjustable. This is combined info for checking the suspension height too, but as you elude to - not really a DIY job to be honest...

Legend
"Z1": Measuring area under front cradle
Z2": Measuring area under the rear spar

[JT99]

Thanks, you replied whilst I was editing my post.

That red area is above the splash shield!

I measured from the thick flange right where there is a letter A, and my ride height is "near enough" the reference value.

DIY would be the way I think, I can't imagine that a tyre fitter is ever going to bother measuring and calculating the ride height, especially if you have to take the splash shield off.

I imagine they have one value- probably the reference value, and set it to that.

I'll ask when I get the new tyres, I just wanted to check myself that the tracking is ok before I go and they try to charge me a fortune for "laser alignment" if I don't need it.

[GiveMeABreak]

Yes, be very wary of some places as they have all this hi-tech kit and no clue as how to use it properly or it's been wrongly calibrated - ATS caused my new tyres to run to the wires in 3 weeks because they didn't know how to properly track a C5 MK II (engine should be running while on the laser tracking post lift machine) and they put it out of commission when I complained, replaced replaced my tyres and it was out of service for months. Seems the machine was also badly calibrated.

Not so bad now that I don't have a Hydractive vehicle, so would hope that any numb nuts with some training could do the Aircross!