Torque value for Powerflex Bushings

I was just wondering if the torque setting is the same on the OEM bushing. The forums procedure notes and Besian procedure... 110 Nn or 81 ft/lbs. Does anyone know if is the same or different. The powerflex procedure did not specify anything along these lines.

Same torque.
Do NOT forget to torque these bolts with the car weighed down (on ramps).

Ok - I read somewhere on this forum, that if you used the powerflex bushings you did not to put the car on ramps, load it up etc. etc. because the bushing is sandwiched between two washers and can moves on the stainless sleeve in the middle. I torqued them up on the jack stands and lowered it slowly. Seems fine.

You CAN do it both ways ... I weighted down the car and torqued to 81 ft lbs when it was on the ground. Yes, the bushings pivot on the inner metal sleeve and against the large end washers but why run the risk of pre-loading them, even if it is a slight possibility.

The only drawback with the PF bushings is having to re-lube them every so often (in my case about 18 months).

I also hand trimmed mine for a better fit (still wider than space they need to go into) but wouldn't recommend this unless you have access to a lathe or have done this sort of work before.

Good luck.

What's the impact of pre-loading? Thanks

Originally Posted by Jase007

You CAN do it both ways ... I weighted down the car and torqued to 81 ft lbs when it was on the ground. Yes, the bushings pivot on the inner metal sleeve and against the large end washers but why run the risk of pre-loading them, even if it is a slight possibility.

The only drawback with the PF bushings is having to re-lube them every so often (in my case about 18 months).

I also hand trimmed mine for a better fit (still wider than space they need to go into) but wouldn't recommend this unless you have access to a lathe or have done this sort of work before.

Good luck.

Jason, was this on the touring? I've been considering doing mine as the only piece left on the suspension to swap out.

Jase007--How do you like these bushings overall--I have a set that are sitting in my tool box --haven't taken the time to put on yet--been thinking about just replacing with the OEM part from EAC Tuning that has the heavy duty bushings--but that would be a waste of money since I already have the Power Flex---are they OK
better than stock --just value your recomendation

I have them on my touring.

I like them but they are "stiffer" than stock and increase steering effort a little. They are NOT a no maintenance item like the OEM or the Meyle solid HD aftermarket bushing. I just removed mine and re-lubed with copper based lubro-moly antiseize (good stuff) after about 18 months of daily use. The insides of the book-ended large metal washers had visible poly marks from the bushing rotating against it which may have been caused by my not applying enough lube at initial install or the rotating (up and down with suspension travel) of the bushings on the center metal sleeve (bolt passes through).

When you torque the bolts down to 81 ft lb (I did mine with car on the ground and weighted) the large washers on the outsides of the bushing halves compresses the poly bushings and eventually gets torqued tight to the center metal sleeve (through the bushing halves) that prevents further tightening.

Opinions on them seem to vary from absolute trash and use the Meyle non-fluid filled solid rubber ones or the OEM fluid filled ones to ... they are great.

[edit]

Michel (mmm635) posted that even after trimming his lower control arm bushings (there is a fitment interference issue inside the ears of the subframe on the 525 E39s apparently) his bump steer and other issues were never corrected. These are not the "thrust" arms or upper control arms or "bendy" arms.

Here is a pic of the trimmed to fit bushings for the lower control arms on his 525 E39 (not the thrust arms / upper control arm) :



[end edit]

I trimmed my bushings for my upper control arms / thrust arms (not shown) on a lathe and bench grinder taking off about 2-3 mm. 1/2 of the reduction was from each bushing half and half of THAT reduction was from two surfaces. 1. the surface of the outer part of the bushing that rests against the outside of the metal rim of the control arm and 2. from the inner stepped mating surface that can make contact with the other bushing half (not visible).

Like I said, mine fit within the subframe ears (were 2mm +/- oversize) with the included un-modified large metal washers with no problems. Even if you trim them, you should leave extra material on them to maintain a compression fit where you have to use a hammer, lever or jack to push them up and into the space between the subframe ears (tabs). This is by design from Powerflex.

Bottom line: I like the feel but they may be more suited to a 3 series performance / track oriented car than a heavy sport sedan. Not passing judgment just saying that their required maintenance and IMHO, necessary hand fitment raise the bar as far as potential to not be happy with them. As advertised, they also increase NVH (noise vibration harshness) and road feel so that small road surface imperfections get transmitted to the steering wheel.

YMMV and all that.

Thanks for getting back--on cutting the bushings down--al I have is a bench grinder and a belt sander--but I do have a set of Starret calipers--might be able (being real careful) to cut them down and watch my progress
as I whittle away on them--might give this a go--I have 186k miles on the ones on there-and no real trouble out of them as yet--but I know they should have been changed by now

My experience with them over the last week and change is they are as Jase007 notes. "increase NVH (noise vibration harshness) and road feel so that small road surface imperfections get transmitted to the steering wheel." The bonking is gone, the steering is firmer. Overall, happy with them.

I have 186k miles on the ones on there-and no real trouble out of them as yet--but I know they should have been changed by now

I'd be amazed (gladly) if these were the originals.

Fluid filled bushings in a high stressed application (4,000 lb car pushing and pulling them with every accel/decel) is, IMHO, 1. not a smart solution, and 2. a $$$ maker for the dealer's service department.

Originally Posted by morrisroad

Ok - I read somewhere on this forum, that if you used the powerflex bushings you did not to put the car on ramps, load it up etc. etc. because the bushing is sandwiched between two washers and can moves on the stainless sleeve in the middle. I torqued them up on the jack stands and lowered it slowly. Seems fine.

Likewise, I looked at the design of the bushing and didn't bother. A year later and no problems.

The bushes don't come with enough grease, buy a tub of copper grease if you don't have one. Many uses.

In case it's not clear to anyone, the thrust/traction arm bushings (i.e. on the big bendy arm, not the control arm) don't need trimming to fit, at least they did not on my car.

I'm very happy with the Powerflex bushings on the traction arm. Increased NVH but the car feels great. The only downside for me was that it made the rear feel noticeably loose.. Meaning more €€€ to spend on replacing things.

One thing to keep in mind. The picture referenced up there is for my lower control arm and not the upper control arm. The thrust arm bushing did not need to be trimmed to fit,. However, the upper control arm bushing was actually making contact with the subframe on the top and causing my car to have bump steer, as well as the metal washer that were binding and deformed.

I did use both washers on the install of the upper control arm bushings.

PF were awesome on my M3, but not on the E39.

Upper Control arm pics: http://picasaweb.google.com/mmm635/ControlArmPics#

Lower Control arm pics: http://picasaweb.google.com/mmm635/L...lJointInstall#