MGB Rack Alignment
Discussion
I am currently investigating very heavy steering on 'JimiGT's B. My first suspicion was seized kingpins but in fact they seem fine. With the track rod ends disconnected the hubs swivel freely but turning the steering wheel it still feels graunchy and tight. My immediate thought therefore was knackered rack. 'Easy job' I said. 'We'll order a new rack and that should sort it"
However, on checking the manual and varous other sources such as Moss, it appears that misalignment of the rack could be causing the problem. So a few questions for the PH experts.....
1) Is it worth trying to re-align it all before he spends his hard earned student cash buying a rack or do you think we will just end up doing the job twice!
2) Do you really need the column aligning tool (2 conical bits) and if so where do I get one?
3) Is it is a complicated as it sounds!
I really need to get it sorted this week if I can
Thanks in advance
Chris
However, on checking the manual and varous other sources such as Moss, it appears that misalignment of the rack could be causing the problem. So a few questions for the PH experts.....
1) Is it worth trying to re-align it all before he spends his hard earned student cash buying a rack or do you think we will just end up doing the job twice!
2) Do you really need the column aligning tool (2 conical bits) and if so where do I get one?
3) Is it is a complicated as it sounds!
I really need to get it sorted this week if I can
Thanks in advance
Chris
If the swivels feel fine, moving smoothly and without play, and you are still left with graunchiness and tightness when they are disconnected, then it narrows it down to the rack or the column. Be worth trying to work out first which one, without completely dismantling or replacing the rack and/or column first. Before doing so though, a few questions:
1) Starting with the simplest first, are there any signs or knowledge that the steering has taken a clout at some point, with a bent track rod or the like, or signs that the rack has been replaced?
2) Next up - is there sufficent oil in the rack? Sounds daft, but if it is dry....
3) Graunchiness implies that it makes a sort of grinding noise - if it does where does the noise the come from? Or do you mean a jerky motion as opposed to smoothness throughout the movement from lock to lock?
4) Is the tightness across the whole movement of the rack from lock to lock, or just in one or more places? If the latter, do those points occur when the steering wheel is in the same position, or the same position but 180 degrees opposed?
That should help you pin down whether the rack internals or a column bush might be the problem. If it appears to be the column from answering the above, then slacken the UJ (presuming that isn't the source of the problem!), mark against the body where the mounting plates line up, undo column mounting bolts, withdraw it to disengage it from the UJ, then see if the rack moves smoothly and quietly. If it does not, then the rack is the answer, as indeed it's the column if the problem is still there when twirling the steering wheel with the column disconnected from the rack. In terms of misalignment of the rack, when assembled and set up at the factory the MGB had any necessary shim plates (to set the rack alignment accurately for that shell) rivetted to to the top of one or both of the rack mounts as required. These may have disappeared if the car has been restored or the rack replaced at some time in the past, but equally some shells were accurate enough not to need shims....
Hope that helps, and good luck,
MG Mark
1) Starting with the simplest first, are there any signs or knowledge that the steering has taken a clout at some point, with a bent track rod or the like, or signs that the rack has been replaced?
2) Next up - is there sufficent oil in the rack? Sounds daft, but if it is dry....
3) Graunchiness implies that it makes a sort of grinding noise - if it does where does the noise the come from? Or do you mean a jerky motion as opposed to smoothness throughout the movement from lock to lock?
4) Is the tightness across the whole movement of the rack from lock to lock, or just in one or more places? If the latter, do those points occur when the steering wheel is in the same position, or the same position but 180 degrees opposed?
That should help you pin down whether the rack internals or a column bush might be the problem. If it appears to be the column from answering the above, then slacken the UJ (presuming that isn't the source of the problem!), mark against the body where the mounting plates line up, undo column mounting bolts, withdraw it to disengage it from the UJ, then see if the rack moves smoothly and quietly. If it does not, then the rack is the answer, as indeed it's the column if the problem is still there when twirling the steering wheel with the column disconnected from the rack. In terms of misalignment of the rack, when assembled and set up at the factory the MGB had any necessary shim plates (to set the rack alignment accurately for that shell) rivetted to to the top of one or both of the rack mounts as required. These may have disappeared if the car has been restored or the rack replaced at some time in the past, but equally some shells were accurate enough not to need shims....
Hope that helps, and good luck,
MG Mark
For a quick test loosen off the four bolts that secure the rack and then see if the steering turns freely, if it does look at the position of the rack as it sits on the mountings and if you can see or measure gaps then the rack requires shimming which is quite normal.
You may need different thicknes shims on each side to help with the side to side alignment so that the pinion shaft aligns correctly where th u/j joins the two pinion shaft and steering column.
it's also a good idea to lossen off the bolts that hold the cone where the steering column passes through the bulkhead as this may help the rack to align better, once aligned properly it should be fine unless the rack is badly worn.
Be aware that the replacement racks sourced in Argentina can be quite tight and prevent self centering.
You can take off the small cover and remove one or two of the shims.
Kevin.
You may need different thicknes shims on each side to help with the side to side alignment so that the pinion shaft aligns correctly where th u/j joins the two pinion shaft and steering column.
it's also a good idea to lossen off the bolts that hold the cone where the steering column passes through the bulkhead as this may help the rack to align better, once aligned properly it should be fine unless the rack is badly worn.
Be aware that the replacement racks sourced in Argentina can be quite tight and prevent self centering.
You can take off the small cover and remove one or two of the shims.
Kevin.
H6CJF said:
Thanks for the ideas chaps... I will have a go at it at the weekend and report back.
Currently trying some different ideas to make an alignment tool.....
Chris
http://www.mgb-stuff.org.uk/wn_suspensionframe.htm#alignCurrently trying some different ideas to make an alignment tool.....
Chris
Never had the need, real faff to use... the column should find its own location.
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