E34 Subframe Reinforcement Plates - Review

[puppypilgrim]

I tried all weekend to put the Delrin insert plates in but couldn't get past the 22mm nut. The 13mm nuts were not big problem. But the 22mm wouldn't budge even after spraying liquid wrench and WD40. I tried attaching a long pipe to increase the leverage. I tried hammering the long lever to loosen the nut. No dice.

I tried heating the nut with heat. Loosen it barely. Enough to rotate the bracket but not enough to turn the nut any more. Finally snapped the socket extension right off the the wrench.

Very frustrating. I know what to do but the nut won't budge.

[bayviewsbb]

I would say they tighten up the rear, significantly reducing oversteer. I tracked my car with and without them, and existing corners with the delrin inserts made the car a lot more stable, is was noticably improved. The extra noise vechile harshness was minimal.

G'day BigKriss,
Thinking of getting a pair for my old bus...I'm a cuppla hours north of you, and need to know what to add for air exp post to NSW...
Cheers,
bayviewsbb

[BigKriss]

I did this exact same thing, I snapped the subframe bolt and had to purchase new items (bolt and nut). I used a braker bar and a long pipe. The other side was fine though.

I tried all weekend to put the Delrin insert plates in but couldn't get past the 22mm nut. The 13mm nuts were not big problem. But the 22mm wouldn't budge even after spraying liquid wrench and WD40. I tried attaching a long pipe to increase the leverage. I tried hammering the long lever to loosen the nut. No dice.

I tried heating the nut with heat. Loosen it barely. Enough to rotate the bracket but not enough to turn the nut any more. Finally snapped the socket extension right off the the wrench.

Very frustrating. I know what to do but the nut won't budge.

[puppypilgrim]

I did this exact same thing, I snapped the subframe bolt and had to purchase new items (bolt and nut). I used a braker bar and a long pipe. The other side was fine though.

OK, so I took it to my indie specialist in Vancouver this morning and he was kind enough to put me on the lift right away. One hit with the air pressured impact gun and the 22mm came off. Both Delrin inserts were mounted in about 8 minutes. I also had them replace the front and rear sway bar bushing while they were at it (I had purchased them and had them with me). 35 minutes later we took the car for a test drive. By the time we wrote up the paperwork, he asked permission to bill me for 45 minutes of time = $60 plus taxes. I felt it was fair.

Front sway bushings at 203,500 km were toast, gone, ovalized, cracked and finito. Don't know if the one previous owner had ever changed it. Rear sway bushings did not look visibly deformed, but looked aged. Still for the cheap price of the OEM rubber bushings, I thought it was worth it.


DRIVING IMPRESSIONS
This is just the initial drive from the service shop to the office (yes I got to work late as a result of going to the service shop first thing in the morning). Everything feels more planted and tight. Noticeably better hookup on acceleration although with the wet weather here and 245/45/17 winter tires, I can engage ASC in the first three gears so all out acceleration tests are not going to happen yet. Over washboard surfaces where the imperfections are one after another, there is more harshness felt in the car. If I had to put a number to this, I would say 5% not more than 8% greater harshness felt.

On normal roads, one would not be able to tell that the Delrin inserts have been installed. The car just feels more connected to the road. No highway driving yet so don't know about that yet. High speed cornering should feel a lot better.


NEXT THING ON THE LIST

Change to Valvoline synthetic 5W-50 at 205,000 km.

Am taking delivery of front and rear sway bar end links and will order the rear dogbones as well.

Install short shifter from BMW Z3 1.9M

[puppypilgrim]

I posted my installation of the Delrin inserts on the Alpina forum and received this post from someone called Stevie.

"Sigh.

If you would take out a subframebushing you would see that the center of the subframe bushing is a hollow aluminium tube that fits snugly into a 1/4 deep recess in the shell. The subframe bushing is about 4 inches long to make sure that all forces applied to that aluminium core are distributed so it doesn't BREAK. The delrin shim you just put in does exactly that, as it allows the subframe to move on the worn bush, the 1/4 inch edge of the shell to become a pivot, and the delrin shim to form a lever. Can you say S N A P ?

Exactly this happened on Nynkes e30 because some ignorant fool inserted a shim just like yours as a bodge instead of a proper replacement, and left me and my Dremel tool to get the remainder om the alloy core out of the shell. This is not a job you'll like..... If you want to tighten it up, use a harder material as supplied by Powerflex, Turner, and many others. Don't change the concept. That bush is 4 inches high, and PF even changes the inner core to steel FOR A REASON!"

This was my reply:

"nteresting. I will share your knowledge with others who have installed the insert and sample their feedback on the failure of insert.

"However, it should be noted that the insert is shaped like an O-ring and not a solid plate through the middle and does not transmit any direct force to the core bolt. It simply limits the amount of vertical compression on the rubber bushing by filling in the gap."

For those of you who have installed the Delrin inserts, have you experienced a failure of the aluminum core or the bolt yet? Am I correct in saying that since it is an O-ring, the insert will not snap the bolt?

[BigKriss]

Right, there have been no failures on here yet. The delrin insert will make the bushing last longer because there is less flex.

This was my reply:

"nteresting. I will share your knowledge with others who have installed the insert and sample their feedback on the failure of insert.

"However, it should be noted that the insert is shaped like an O-ring and not a solid plate through the middle and does not transmit any direct force to the core bolt. It simply limits the amount of vertical compression on the rubber bushing by filling in the gap."

For those of you who have installed the Delrin inserts, have you experienced a failure of the aluminum core or the bolt yet? Am I correct in saying that since it is an O-ring, the insert will not snap the bolt?

[Russell]

No failure on the rear inserts. My have been in two years. However, Bruno's red colored inserts for the thrust arms have failled on one side. I replace with new Lemforder arms and 750i bushings

[OneBeLow]

just ordered mine

[Bruno]

just ordered mine

I have been swamped at work (still working as I type) but I will ship tomorrow.

[OneBeLow]

I have been swamped at work (still working as I type) but I will ship tomorrow.

thanks man!