Alignment of rear beam

[ArthurH 7]

Having done a bit of research, we have decided to go for the BBM 'Group' A mounting kit for our rear beam (Aluminium blocks / Poly bushes) - it is a pure circuit car, a little extra harshness will not be noticeable.  We lifted the rear beam into position with a pair of trolly jacks.  Even although the holes are slotted, the 6 studs needed to be positioned quite precisely to pass through the floor, there seems to be extremely little 'float' on the beam now that it is up.  Although the side of a plastic fuel tank is hardly an ideal datum, the front torsion bar is noticeably closer to the tank on the one side of the car (about 1mm away!).  I started to wonder what was the correct way of aligning the beam.  Ultimately, it could be the measuring of equal Toe in/out, but prior to fitting the brakes, are there any chassis points that should I measure from?

 

TiA

 

 

[petert 588]

Pop it in, run some string lines and adjust as necessary?

[ArthurH 7]

I just wondered if Peugeot had ever published any alignment data, perhaps from a chassis tooling hole.

 

However, it could be a moot point, as there is so little float on the beam.  Probably due to the chassis having had a few knocks over the years.

[welshpug 1,657]

they have, however just the standard wheel alignment data will get you sorted.

[PhilNW 44]

23 hours ago, ArthurH said:

I just wondered if Peugeot had ever published any alignment data, perhaps from a chassis tooling hole.

 

However, it could be a moot point, as there is so little float on the beam.  Probably due to the chassis having had a few knocks over the years.

 

[ArthurH 7]

Thanks Phil, even although some of the links in the post no longer work, it is still a useful step.  I know now the dimensions to the chassis rail that the beam is fitted to, although because they are from near the front of the car, I can see measuring them accurately without the body jig would be a challenge.  Having thought about it further, I guess the beam would have been fitted on the assembly line using a jig that would hold it in the nominally correct position within the slotted holes.  From that point forward, if it needed adjustment, it would be using the wheel alignment data as Mei suggested.

[PhilNW 44]

In the first instance try measuring wheel centres front to back to see if there is a difference 

[ArthurH 7]

Thanks Phil.  I have now tried as you suggest, but the result wasn't what I expected.  The nearside wheel centre measurement was shorter by about 3mm, but that is the side where the rear beam is 4mm further from the petrol tank 

[welshpug 1,657]

the front subframe probably has more wiggle than the beam, I wouldn't go off a squishy plastic thing for measuring!

 

how are the castor angles looking on the front?   that may give you an indication whether the subframe is on square.