"Tighten in Normal Position"

[rzm3]

I was looking at the torque specifications for the rear suspension arms, and I noticed under many torque values, there is "tighten in normal position".

I believe this means that you have to jack up the particular suspension arm you are working on to lift it into its normal steady state position, and then tighten to the specified torque value.

Clarification: see post #22.

[sparkyg]

So you mean unloaded?

Normal seems to mean at rest sitting on the ground, not on the jack.

[Gearhead999s]

Originally Posted by sparkyg

So you mean unloaded?

Normal seems to mean at rest sitting on the ground, not on the jack.

It means as sitting with the wheels loaded.BMW and a lot of other manufactures have had those instructions for a long time.

[rzm3]

So do most people/shops actually follow this instruction?

[Gearhead999s]

Originally Posted by rldzhao

So do most people/shops actually follow this instruction?

Good ones yes!But the thing to remember that you need a ramp type hoist to have access to do this.If you dont do this the bushings can be bound up in normal suspension movement.

[Malek@MRF]

This should be normal understood procedure from any competent technician or installer. Doing it any other way is completely wrong.

I would hope most do it this way.

Either a ramp, or hydraulic loader from underneath should be used if the car is on a lift with the wheels off the ground.

Not doing it this way will cause the car to perform poorly and destroy the bushings much quicker.

[JAJ]

Originally Posted by rldzhao

I was looking at the torque specifications for the rear suspension arms, and I noticed under many torque values, there is "tighten in normal position".

I believe this means that you have to jack up the particular suspension arm you are working on to lift it into its normal steady state position, and then tighten to the specified torque value.

This is correct for everyone but you. For you, it actually means "whilst phoning Moton customer service".

[montreal red]

hmm... what kind of work would require the disassembly and re-assembly of these parts? would you need to do this for a coilover install? sorry i am not very knowledgeable when it comes to suspension components.

[JAJ]

Originally Posted by montreal red

hmm... what kind of work would require the disassembly and re-assembly of these parts? would you need to do this for a coilover install? sorry i am not very knowledgeable when it comes to suspension components.

Changing the rear suspension (damper, spring, or both) involves removing the bottom bolt on the damper and the bolt that ties the Camber Link to the Wheel Carrier. Both have to be reinstalled "in normal position". There are no bolts in the front suspension that have to be done this way.

[montreal red]

^^^^
interesting.
my coilover install was done at a shop that didnt have a hydraulic platform lift to do work like that. it was hoisted on a regular lift and tightened while there was no load on the suspension components.

i've been driving the car with KWs installed for the whole summer. anyone knows what kind of damage could i be facing?

[rzm3]

~they must have jacked up the lower camber some what to align it with the wheel carrier. I would not worry to much about it. Just inspect it every couple months.

[montreal red]

Originally Posted by rldzhao

~they must have jacked up the lower camber some what to align it with the wheel carrier. I would not worry to much about it. Just inspect it every couple months.

thanks for the reassurance. i believe they did use something to push some of the links up so that they can bolt everything together but the wheels were definitely off the ground and there was not much of a load on it.

i've seen people do coilover installs in their own garage and they dont put any load on the suspension when bolting everything together so i didnt think it was much of an issue.

but this is nevertheless interesting to take note of.

[Gearhead999s]

Originally Posted by montreal red

thanks for the reassurance. i believe they did use something to push some of the links up so that they can bolt everything together but the wheels were definitely off the ground and there was not much of a load on it.

i've seen people do coilover installs in their own garage and they dont put any load on the suspension when bolting everything together so i didnt think it was much of an issue.

but this is nevertheless interesting to take note of.

Then they did not follow the proper procedure as specified by the manual.Whether that makes any difference in life or performance of the bushing is another issue.

[JAJ]

I've done my rears a few times now, and here's what I experienced:

First, to align the bolt holes for the 14mm bolt that holds the Camber Link onto the Wheel Carrier, you have to lift the Camber Link up to almost the fully loaded position. Just tighten it then. My opinion is that this instruction only applies to the regular 3-series in any case. On the M3, the connection in question is a ball joint; it's free to rotate, relieving any tension from the bolting process.

Second, for the rear damper, KW or OEM, the lower bolt passes through a sleeve locked in a rubber bushing. It needs to be bolted at the appropriate height or the bushing will be twisted at static ride height.

As for doing it at home, the rear Camber Link is a breeze to lift with a jack - you just have to remember to do it.

[montreal red]

Originally Posted by JAJ

I've done my rears a few times now, and here's what I experienced:

First, to align the bolt holes for the 14mm bolt that holds the Camber Link onto the Wheel Carrier, you have to lift the Camber Link up to almost the fully loaded position. Just tighten it then. My opinion is that this instruction only applies to the regular 3-series in any case. On the M3, the connection in question is a ball joint; it's free to rotate, relieving any tension from the bolting process.

Second, for the rear damper, KW or OEM, the lower bolt passes through a sleeve locked in a rubber bushing. It needs to be bolted at the appropriate height or the bushing will be twisted at static ride height.

As for doing it at home, the rear Camber Link is a breeze to lift with a jack - you just have to remember to do it.

anyway i can check to see if my bushings are twisted or deformed? i just dont know which part i should be checking or looking at.

[rzm3]

Check for grease leaks and if there is excessive play.

[montreal red]

Originally Posted by rldzhao

Check for grease leaks and if there is excessive play.

thanks, i'll jack the car up and take a look at the bushings when i change to my winter wheels and tires.

[Malek@MRF]

Originally Posted by rldzhao

~they must have jacked up the lower camber some what to align it with the wheel carrier. I would not worry to much about it. Just inspect it every couple months.

Jacking up the arms high enough to align the arms for reassembly is no where close to being in "normal position" as it has to pushed up much further.

For the front suspension, this applies to all fellow M3posters who have modified their suspension:

-Tighten your top hat bolts (the 3 13mm bolts) with the wheel hub under load. This will ensure trouble free and noise free operation and will not strain the upper hat stud threads.

-For the front damper, tighten the center bolt while the system is compressed, it will ensure the bolt fully tightens. If this bolt isn't fully tightened, you may experience noise immediately or eventually down the line.

-Anti-roll bar end link.. Suspension must be aligned correctly, then tightened. Do not barely align it and expect the bolt the pull the suspension into its proper position, you must put it there first.

-Malek

[JAJ]

Originally Posted by montreal red

thanks for the reassurance. i believe they did use something to push some of the links up so that they can bolt everything together but the wheels were definitely off the ground and there was not much of a load on it.

i've seen people do coilover installs in their own garage and they dont put any load on the suspension when bolting everything together so i didnt think it was much of an issue.

but this is nevertheless interesting to take note of.

Loading isn't an issue - it's all about position. When the car's in it's static loaded position on the ground, the suspension arms are at an certain angle relative to the bolts that hold them. If there's a rubber bushing in the bolt hole, then you want that bushing to be "relaxed" in that position with no twist applied by the arm.

If you tighten the bolts in the same position as they will be when the car is standing on it's wheels, then they're in the right place, loaded or otherwise.

While many purists will argue the only way is to put the tires on and lower the car onto its suspension before tightening, frankly you can measure the position of the hub relative to the fender opening with a tape measure and tighten the bolts while you support the control arm on a hydraulic jack. If you do one side at a time, the car never rises off the lift holding the body when the arm is at the correct height.

[JAJ]

Originally Posted by Malekreza11

Jacking up the arms high enough to align the arms for reassembly is no where close to being in "normal position" as it has to pushed up much further.

For the front suspension, this applies to all fellow M3posters who have modified their suspension:

-Tighten your top hat bolts (the 3 13mm bolts) with the wheel hub under load. This will ensure trouble free and noise free operation and will not strain the upper hat stud threads.

-For the front damper, tighten the center bolt while the system is compressed, it will ensure the bolt fully tightens. If this bolt isn't fully tightened, you may experience noise immediately or eventually down the line.

-Anti-roll bar end link.. Suspension must be aligned correctly, then tightened. Do not barely align it and expect the bolt the pull the suspension into its proper position, you must put it there first.

-Malek

I think rldzhao was talking about the rear suspension.

You are correct with respect to the front suspension, although that particular set of cats can be skinned other ways. It's about getting everything firmly in place before tightening. The anti-roll bar end links are ball joints, so they have no rotation orientation to worry about. As for getting all this stuff correctly in place, if someone's doing a DIY and they don't know what "correct" looks like and how to get it all there, they'd best get a pro to do the work.

[rzm3]

After much thought I still don't understand why "tighten in normal position" is needed.

My thinking is, most of these joints are just ball joints, which is allowed to rotate about the bolt axis freely. This is what allows it to articulate when installed. The only issue I can think of are the lubrication boots, as they may be strapped to a non-moving part.

Please correct me if I am wrong.

[rzm3]

I think I finally get it.

For ball joints (left side of each arm in picture below), tightening in normal position probably does not matter because it is free to rotate.

But for actual bushings (right side of each arm), tightening in normal position will matter because the rubber will be loaded when not in normal position.

When we do a rear spring/shock replacement, the lower camber arm outer joint is a ball joint, that's why it is OK to tighten that joint when NOT in normal position.