Steering Rack Mounting :Help Required

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alawrence10360
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Steering Rack Mounting :Help Required

Postby alawrence10360 » Wed Sep 25, 2019 10:11 pm

When looking from underneath the car and when the steering wheel is taken through its full travel I have noticed a slight flexing when the steering wheel changes direction from left to right
I see this at the point where the column meets the rack
No movement can be seen from inside the car
Its slight
All the bolts around the area are tight and all the bulkhead is solid and rust free
The wheels are on but are in free air
The bulk head is fitted with the later steering rack strengthening plate
Does anyone have a vehicle in the same state on axle stands who could look underneath while the steering wheel is moved to see if it flexes slightly as I'm hoping this is normal

Thanks in anticipation

philthehill
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Re: Steering Rack Mounting :Help Required

Postby philthehill » Thu Sep 26, 2019 7:53 am

If the rack has been disturbed on its mounts the rack to column pinch bolt must be tightened first before the rack mounting clamp bolts.
The rack must be free to rotate in its mounts so as to correctly align the rack pinion with the column.
If there is any mis-alignment between the rack and column the rack to column splines joint will move in an oscillating/eccentric way which may lead to flexing of the floor.
The pinch bolt which secures the rack to the column should be changed for a better fitting high tensile Allen headed bolt with self locking nut. The original bolt does not fit the groove of the rack pinion very well. Changing the bolt improves the fit between column and rack pinion.

Original pinch bolt on the right - new Allen headed bolt on the left in the picture below.
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100_2649.JPG (227.35 KiB) Viewed 383 times


alawrence10360
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Re: Steering Rack Mounting :Help Required

Postby alawrence10360 » Thu Sep 26, 2019 11:25 am

Thanks Phil

alawrence10360
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Re: Steering Rack Mounting :Help Required

Postby alawrence10360 » Thu Sep 26, 2019 9:32 pm

alawrence10360 wrote:
Wed Sep 25, 2019 10:11 pm
When looking from underneath the car and when the steering wheel is taken through its full travel I have noticed a slight flexing when the steering wheel changes direction from left to right
I see this at the point where the column meets the rack
No movement can be seen from inside the car
Its slight
All the bolts around the area are tight and all the bulkhead is solid and rust free
The wheels are on but are in free air
The bulk head is fitted with the later steering rack strengthening plate
Does anyone have a vehicle in the same state on axle stands who could look underneath while the steering wheel is moved to see if it flexes slightly as I'm hoping this is normal

Thanks in anticipation
bump

philthehill
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Posts: 6904
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Re: Steering Rack Mounting :Help Required

Postby philthehill » Thu Sep 26, 2019 10:30 pm

Here is a suggestion as you appear to have eliminated all other options.

The ball joints on the end of the rack can only articulate a maximum of 30 degrees. I have just checked the max articulation on my spare rack with an Moore and Wright angle gauge.

If the wheels are hanging free the ends of the rack may be under excessive strain from the tie rod between rack and ball joint which is causing the vehicle floor to flex. The free hanging suspension may be trying to exceed the 30 degrees allowed.

The strain could be made even worse if the bottom bump stops are removed or missing.

Whilst my own Minor is currently supported on axle stands I do not allow the suspension to hang free as it puts everything under excessive strain.

My front suspension is supported by wheel off supports bolted to the hubs and packed to remove a large portion of the torsion bar load.

I would suggest that you check the angle of the tie rod between the end of the rack and ball joint and see what reading you get.

If you release the ball joint from the steering arm and the suspension drops lower I think that you have found the cause of your flexing.

Phil


les
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Re: Steering Rack Mounting :Help Required

Postby les » Thu Sep 26, 2019 10:41 pm

I’m still not sure it’s been assembled and things tightened in the order you posted Phil. To be honest Ive lost track of where we’re at now! :D


philthehill
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Re: Steering Rack Mounting :Help Required

Postby philthehill » Thu Sep 26, 2019 10:48 pm

Les
I am not sure either but drawing on past experience the flexing can only be caused by the suggestions made in the above posts.

In addition to the above - when turning the steering wheel with the wheels hanging free the closer the track rod end gets to the end of the rack housing the angle of the tie rod between rack and track rod end increases putting even more strain on the rack mounts.

The ideal set up is when the rack and track rod end are on the same plane with no angle either upwards or downwards between them.

The torsion bar(s) still put a lot of loading on the suspension when the suspension is hanging free and that is why I will not allow my front suspension to hang free for sustained periods.

Phil


alawrence10360
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Re: Steering Rack Mounting :Help Required

Postby alawrence10360 » Fri Sep 27, 2019 7:49 pm

I have slackened everything off and carried out Phils installation method to the letter.
Unfortunately I now dont have a helper to operate the steering wheel whilst I'm underneath to check the flexing but I will report soon
Earlier in the post I suggested it may be down to the angle / wheels as Phil has suggested
Im going to get the tracking set up at a garage and whilst there they may be able to put the wheels on some gadget that allows the wheels to move with the weight fully on the suspension in its normal position and check if it still flexes.
I will let you know
Thanks


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