Front LCA Rear bush by Bilstein/Febi

[Rattnalle]

Tightening the bolts with the control arm pointing too far down compared to it's operational level could easily be bad for bushing life since it means they'll have to move a lot to reach the top, compressed, position.

[mrbrian200]

I think jonesg is working on a different MY/model and may not be familiar with the P2 LCA design where preloading the front lower LCA bush for the proper ride height isn't a consideration (this is preset by the angle that the bushes are pressed into the LCA), Leaving any of the bolts loose while attempting to connect the ball joint doesn't accomplish anything. In effect if you were to install lowering springs you'd need to press the forward bush out of the LCA and rotate it a little before pressing it back in. In the P2 design there is no way to address preloading of the rear bushing for the purpose of raising/lowering the vehicle. Anything other than OE ride height is going to load that rear bush and there's nothing you can do about it.

This may be partly my fault for not expressly defining what MY/Chassis the thread is about in either the title or first post. Picture of the Febi bush shows it sitting up on end which might be confusing (mistaken as a flange type bushing where the bolt goes through and until tightened can rotate around the bolt as you raise/lower the LCA).

[Rattnalle]

Yeah nvm I too forgot for a moment what the rod connecting to the frame looks like and why it doesn't matter.

[dlundblad]

Tightening the bolts with the control arm pointing too far down compared to it's operational level could easily be bad for bushing life since it means they'll have to move a lot to reach the top, compressed, position.

So what do you do if you get a flat tire? The suspension will have to be fully relaxed to remove the tire.

[Rattnalle]

Tightening the bolts with the control arm pointing too far down compared to it's operational level could easily be bad for bushing life since it means they'll have to move a lot to reach the top, compressed, position.

So what do you do if you get a flat tire? The suspension will have to be fully relaxed to remove the tire.

As above I had some bad luck while thinking.

But for other styles of bushings I don't see how removing the wheel could possibly be an issue regardless.

[mrbrian200]

Tightening the bolts with the control arm pointing too far down compared to it's operational level could easily be bad for bushing life since it means they'll have to move a lot to reach the top, compressed, position.

So what do you do if you get a flat tire? The suspension will have to be fully relaxed to remove the tire.

Unless you also change to a different/shorter strut the longest extension of suspension travel would be the same as it would be with the standard spring. You get a narrower distance of suspension travel until you hit the stop as you roll over a speed bump, more room as you roll over a hole. When placing a jack under the car you start lower but end up at the same point where the wheel starts to lift off the ground where you can remove it (the end stop of the strut at it's furthest extension limit).

[jonesg]

Hmm. Might part of the issue with LCA bushes not lasting very long on these vehicles be that the procedure for installing the LCAs could be damaging the bushes? Hear me out:

In most cases we disconnect the ball joint by loosening the large bolt at the bottom, then force the LCA down which I believe is the Volvo procedure. This requires that the LCA be pulled several inches below where the strut would normally limit suspension travel/lower extension.

Getting an old LCA off isn't generally the issue.

I recall from installing the (currently on vehicle) LCAs that came preloaded with new bushes: After the LCA is bolted to the subframe, the bushes would flex fairly easily out to about where the normal end of suspension travel would be. But to get the ball joint into the LCA, we must press the LCA further down by several inches. The rubber really doesn't want to accommodate this extra few inches. So we force it using extra long pry bars with a lot of weight and/or attaching a winch strap to force it.

Is it possible that this damages the rubber bushes during installation right from the get go by forcing the bush past it's usable design limits thereby dramatically shortening service life?

Might a better method be to somehow devise a way to compress the strut/spring assembly a few inches rather than forcing the LCA down?

Alternate method would be to disconnect the ball joint at the bottom of the steering knuckle - in every case.

Thoughts, anyone?

Weather is becoming more hospitable. Pressed the Febi bushes I ordered back in January into the original LCAs that came off the car 2 years ago. They'll be back on the car once we get a reasonably warm day without rain, toward the end of next week maybe.

The control arm inboard bolts should be left loose to give enough play to get the balljoint inserted.
Then jack the balljoint end up to the normal wheels installed resting position to preload the bushings, then tighten all the inboard bolts.
An offset box end wrench worked for the bolts inside the frame.

I thought about installing the spring compressors but its time consuming and I didn't want to be wrenching in a highly sprung area.

Failure to preload the CA might be a cause for bushing failure.?

Having a hard time following this, but you're suggesting to install the ball joint (and I assume the strut as that's the main issue causer) with the control arm bolts loose?

Assuming we are talking about the P2 design mentioned in the OP, I don't see an issue with hyper extending the bushing during reassembly as I would be afraid of something not getting bolted up squared and torqued correctly with the strut's tension pushing everything down.

Yes, P2, at least mine is 2004 v70.
Leave the bolts slightly loose.
Put a jack under the ballpoint to compress the strut , set the correct road height, then tighten bolts.
Otherwise you have no preload. See video below.

Observe the normal road height before jacking the car up and removing the wheels.

[mrbrian200]

Rear suspension yes, preload is an issue. The bush being discussed is on the front LCA.

[mrbrian200]

Somewhat notable update on this.
In a moment of embarrassment (and a front seat passenger yelling 'step on it or you won't make the light!') I ran over a ~5 inch high curb while making a right hand turn at said stale yellow light. It was awful.
Amazingly I didn't bend or break anything. Checked my front end toe setting, it's exactly where I set it some time ago (very slight toe-in around +.02 degrees).
I jacked the car up yesterday after I got back home and did a thorough inspection on that side. Everything came through the event A-ok, including this bush. This car really is a tank. I've seen other cars get thrown completely out of whack or even disabled after rolling over a high curb like that... didn't seem to phase this car one bit.

[mrbrian200]

These febi bushes seem to be holding out fine. Somewhere around 10k miles now, when I raise the car there is no sign of rubber fatigue/tearing or failure to hold the LCA vertical alignment 'centered' in the subframe.

More recently the front bushes that I didn't replace are getting objectionably 'weaker'. Although fine on reasonably well maintained pavement, they're not holding the toe angle over larger pavement imperfections and uneven bumpy side roads. Tracking issues, wheel hop, and some occasional tramlining. Reinforced this bush by filling the airspace with a soft durometer (around 35), super stretchy poly based sealant I stumbled upon. It drives wonderful like this (good febi rear bush, front OE worn bush reinforced through unconventional means). Probably the first combination, including the LCAs from IPD, I've tried where handling and ride quality actually befits the vehicle. Longevity of this is stuff is in question as it's not it's intended use (Loctite PL polyurethane roof sealant).

My thought is that this probably somewhat approximates the mechanical properties of the relatively soft, stretchy **but solid** rubber bushes used on some of the P1s, P80s and before. Vehicles with handling/ride quality people still rave about to this day.

Technically just an experiment to confirm that these forward bushes were causing issues and not something else. Rides like a dream though. I'll leave it for as long as that goo holds up whether it be 10 days, 10 months, or 10 years...