Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Bojan on 02 February 2017, 09:27:18

Title: Subframe alignement
Post by: Bojan on 02 February 2017, 09:27:18

Some time ago I have removed the front subframe, and it seems I didn't manage to align it properly when refitting (I did make align markings on frame and chassis, but ones on subframe were almost entirely washed out while cleanging with jet-washer  :-[ ).

At first, it seemed OK, but over time I've notticed a bit of understeer in itght left turns, and sometimes it doesn't return the steering wheel from almost-full-lock -> so I suspect not enough castor. Did some preliminary measurements:
- measured wheelbase, left and right side - right side is ~5 mm shorter (yes, I know that it could be that rear axle is not aligned, but I'll go with this ATM) .
- measured (compared) camber - they are approximately the same.

So, this is what I plan to do:
- move the subframe in front-back direction, until I get a correct castor values
- check camber angle, check front-to back axle vertical plane alignement
- if vertical palne alignement not OK - move front subframe in left-right direction.
- if vertical plane aligment is OK - check and adjust camber at hub-to-shock absorber connection
- at the end, adjust toe

Does this seem like a good procedure?

Title: Re: Subframe alignement
Post by: Doctor Gollum on 02 February 2017, 19:06:27

As good as any ;) camber should be last adjustment  :y

Title: Re: Subframe alignement
Post by: Kevin Wood on 03 February 2017, 10:48:19

Quote from: Doctor Gollum on 02 February 2017, 19:06:27

As good as any ;) camber should be last adjustment  :y

The last adjustment before you adjust the toe. ;)

Title: Re: Subframe alignement
Post by: Marks DTM Calib on 03 February 2017, 11:02:33

Yep, camber is second adjustment.

You can get a reasonable setup on the caster by measuring the strut angle with the suspension loaded.

Title: Re: Subframe alignement
Post by: Bojan on 03 February 2017, 18:43:55

Great. Just a question or two more:
- left-right alignement - I'll check the camber -> If equal on both sides, I'll try to check the SAI (steering axle inclination, or stut angle), and if that is OK, that means that frame is in correct left-right position. If camber is not equal on both sides, correct it, and then check the SAI - if not equal, I'll know on what side frame needs to be moved. Of course, camer needs to be set one more time after that.

- will I be able to move the frame with vehicle on ground. I will be doing this in my driveway, and I have a jack and stands. If I will have to get it on and of the stands for several times, it will be a very tedious task.

- any tips on calculating thrust angle? I'll be using strings, tape measure and spirit measure (try to guess why  8) ).