Rear insert alignment in top metal mount & axle position
Posted: Sun Jun 21, 2009 9:43 am
I just got back to working on the rear of my track S4. It is 26 R type unused (NOS) black chassis with TTR "A" frames and all metal back end (top spherical mounts and inner and outer "A" frame bearing etc). I am having a trial build up of it all as you have to when you go metal.
It is all new kit!
I have question regards ligning up the lot.
I imagine that you dont want any forward or aft' stess on the shocker insert piston ????? Will wear out seal etc! I.e. the pistion should slide into the top metal mount hole in the middle and not under stress. Not requiring flexing to enter! The adjustment you have for this is the small top hat bushing for locating the rod end bearing in the inner "A" frame part. Lathe job! Also there is some scope for movement with the chapman strut and the washers that locate it in the spherical bearing on the outer part of the "A" frame.
Or am I wrong as this throws out your axle position????
It is good to do the same to each side, if the chassis and all the bits were identical, but I dont think they are.
I understand that the Chassis's can be out and also the "A" frames could have a very small natural twist (from heat of build) causing the strut to kick at a very slight angle giving top misalignment.
I am in a bit of a muddle. I have even had the camber gauge on the shocker tube (and the chassis leg uprights to see if the are perpendicular).
Have we any advice or is it best compromise because it is Lotus chassis. Should I be less concerned about a small amount of tension giving misalignment at the top of the shocker tube as it enters the top mount and more about the wheel/axlel position.
With all the tolerance's of the bits it is hard to decide what is a reference point. Should I be measuring rear axle postion in relation to the the front chassis leg wish bone pins as a reference for correct distance between front wheels and rear wheels. Then using the adjustment mentioned to give right whee/axle positions.
And I thought it was going to be quite easy. I have end up with one "A" frame set back ref' the other in trying to get a straight entry into the top mounts. This can not be right. I may have answered my own question. Perhaps the Chapman strut (and shocker insert) do not give a perfect 90 degree when bolted into the TTR "A" frame. Do they need a flex to assemble? We are only talking about 2 -3 mm here.
Any advice welcome. I have kind of got lost in tolerances. I may be over estimating the small amount of strain I may put on the spherical bearing.
PS I hope this is clear.
This is what happens when electrians start doing mechanical bits, they get all worried about stressing things. Nothing lost, as it can all be altered. Only washers and metal bushings etc.
Mike
It is all new kit!
I have question regards ligning up the lot.
I imagine that you dont want any forward or aft' stess on the shocker insert piston ????? Will wear out seal etc! I.e. the pistion should slide into the top metal mount hole in the middle and not under stress. Not requiring flexing to enter! The adjustment you have for this is the small top hat bushing for locating the rod end bearing in the inner "A" frame part. Lathe job! Also there is some scope for movement with the chapman strut and the washers that locate it in the spherical bearing on the outer part of the "A" frame.
Or am I wrong as this throws out your axle position????
It is good to do the same to each side, if the chassis and all the bits were identical, but I dont think they are.
I understand that the Chassis's can be out and also the "A" frames could have a very small natural twist (from heat of build) causing the strut to kick at a very slight angle giving top misalignment.
I am in a bit of a muddle. I have even had the camber gauge on the shocker tube (and the chassis leg uprights to see if the are perpendicular).
Have we any advice or is it best compromise because it is Lotus chassis. Should I be less concerned about a small amount of tension giving misalignment at the top of the shocker tube as it enters the top mount and more about the wheel/axlel position.
With all the tolerance's of the bits it is hard to decide what is a reference point. Should I be measuring rear axle postion in relation to the the front chassis leg wish bone pins as a reference for correct distance between front wheels and rear wheels. Then using the adjustment mentioned to give right whee/axle positions.
And I thought it was going to be quite easy. I have end up with one "A" frame set back ref' the other in trying to get a straight entry into the top mounts. This can not be right. I may have answered my own question. Perhaps the Chapman strut (and shocker insert) do not give a perfect 90 degree when bolted into the TTR "A" frame. Do they need a flex to assemble? We are only talking about 2 -3 mm here.
Any advice welcome. I have kind of got lost in tolerances. I may be over estimating the small amount of strain I may put on the spherical bearing.
PS I hope this is clear.
This is what happens when electrians start doing mechanical bits, they get all worried about stressing things. Nothing lost, as it can all be altered. Only washers and metal bushings etc.
Mike