Suspension torquing in the air or on the ground?

Hi all,

So first off, I'm not asking for torque specs; I've got all those, but I've read here and there that a lot of the suspension components need to be torqued while loaded (ie. on the ground or with a jack applying pressure to suspension), but I don't see anything about this in the ebahn version of Bentley and a lot of shop videos torque everything while on the lift. I'm just trying to figure out which components need to be torqued while loaded, so I'm making a list with blank spaces that hopefully people can fill in on what can be done while up in the air and what needs to be torqued on the ground or if someone can point me in the right direction if this has been posted in the past. Thanks

Front
Top nut on front strut assembly to chassis:
Pinch bolt:
LCA (control arm) bolts:
Ball joint to knuckle: (I assume this one should be torqued before even installing axle since there is no room to even counter hold the stud after).
Ball joint to LCA:
Sway bar bushing bolts:
Sway bar link bolts:
Tie rod nut:
Inner CV joint Triple square bolts:
12 point axle nut:

REAR
Top shock bolts:
Bottom shock bolt:
Large, rear bushing bolts:

One of the professionals will likely come along and correct me on this, but I'd figure that the rough rule of thumb would be to pre-load anything that pivots (those points have bushings). I don't want to discuss the sway bar bushing bolts! (I HATE those things! Don't ask!)

CV joint bolts can be tightened by placing a breaker bar (w/socket) on the axle nut. Axle nuts are high torque, which requires the wheel on the ground, but that's not necessarily a "loading" thing in the sense we're talking about here.

UhOh said:

One of the professionals will likely come along and correct me on this, but I'd figure that the rough rule of thumb would be to pre-load anything that pivots (those points have bushings). I don't want to discuss the sway bar bushing bolts! (I HATE those things! Don't ask!)

CV joint bolts can be tightened by placing a breaker bar (w/socket) on the axle nut. Axle nuts are high torque, which requires the wheel on the ground, but that's not necessarily a "loading" thing in the sense we're talking about here.

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I know what you mean with the sway bar bushing bolt. Used the old brackets because the new Meyle ones had a different hook and could not screw bolt back on, even when using welder vise grips!

The funny thing about the axle nuts is I've read some posts that state the wheel should barely be touching the ground or else the wheel bearing life will be shortened. Again, ebahn reader says nothing about this and I've seen other stick large screw drivers in rotor and torquing while on the lift

When you are putting 140+ ft.lbs. of torque on a bearing in an axial plane, it really can't make much difference whether the tire is loaded (on the ground) or in the air. One of the best TDI shops I know applies the torque while on the lift.

I agree with Tony. Moreover, when the factory built the car I highly doubt the suspension was loaded.

FWIW - when I rebuilt my suspension I didn't load mine and I'm not have any issues or noises.

I only load up for the rear axle bushes bolt and the front lca ones, just in case it adds any sort of twist pressure and shortens their life.

There is a significant difference in handling of the car and life of the bushings, if installed, at "ground height". I have found it is best to emulate the height with the car up on the lift, and using an engine and gearbox jack to raise the suspension to the listed " normal height".

Apart from the front LCA bolts and rear axle beam bolts, the rear shock absorber bolts should also be done on the ground, if the rear shocks have bushings at the bottom, at least.

You should check out the official VW service manual for your car, off VW Erwin using a few bucks an hour subscription.

It should have everything listed in there.

Let's look at the reason some bolts should be torqued on the ground.

When in the air some bushings are hanging down from the loaded position. If you torque them in that position the rubber wants to be in that position so when you load that bushing by lowering the car, you have twisted that bushing to a new position. Now, as the suspension moves while driving, the bushing will relax as the car bounces up, but it will twist farther as the car bounces down.

The bushings are designed to operate within a certain range and now, it is reaching or has exceeded that design limit. This is what causes premature wear. Your pinch bolts and ball joint fasteners are holding things that dont move even though they may be part of something that moves. You ball joint to LCA nut holds the taper in the hole, so that doesn't move even though the ball joint itself moves. Same thing with the three ball joint nuts and bolts. And the pinch bolts.

Hopefully this will give you a lesson on fishing rather than giving you a fish.

whitedog said:

Let's look at the reason some bolts should be torqued on the ground.

When in the air some bushings are hanging down from the loaded position. If you torque them in that position the rubber wants to be in that position so when you load that bushing by lowering the car, you have twisted that bushing to a new position. Now, as the suspension moves while driving, the bushing will relax as the car bounces up, but it will twist farther as the car bounces down.

The bushings are designed to operate within a certain range and now, it is reaching or has exceeded that design limit. This is what causes premature wear. Your pinch bolts and ball joint fasteners are holding things that dont move even though they may be part of something that moves. You ball joint to LCA nut holds the taper in the hole, so that doesn't move even though the ball joint itself moves. Same thing with the three ball joint nuts and bolts. And the pinch bolts.

Hopefully this will give you a lesson on fishing rather than giving you a fish.

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Alright, so basically anything with a bushing, torque loaded (front and rear LCA bushing, rear axle bushing and rear, lower shock bolt).

Everything else can be done before. After thinking about it, I may torque top front strut and pinch bolt when loaded as well so that both are completely seated in chassis and knuckle respectively.

Metal Slug said:

Alright, so basically anything with a bushing, torque loaded (front and rear LCA bushing, rear axle bushing and rear, lower shock bolt).

Everything else can be done before. After thinking about it, I may torque top front strut and pinch bolt when loaded as well so that both are completely seated in chassis and knuckle respectively.

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I'd hope that your strut is seated when you have things basically snugged: the pinch bolt aligns the strut in the knuckle, not likely to move any. These things aren't really going anywhere. But, just as it likely won't be of any benefit, it probably can't hurt either. I'm thinking that I might be tightening the strut bolt pre-loaded as I'm tightening up the other things requiring pre-loading. Top strut nut is just easier to tighten when the car is down on the ground (I'm short!).

If I sound like the voice of authority, it's because I AM! I've done THREE suspension refreshes!