The Raven e9 project

[jjs2800cs]

I went through this years ago.

Control arm bushing replacement-HELP something not right

We are updating all the suspension bushings on our 1970 2800CS. Look at the attached photo which shows quite a difference between the old and new bushings. New inner bushing 31122614100 and new outer bushing 31121112902 look significantly different than the removed old ones. The are the...

e9coupe.com

At that time we did a refresh of the front suspension. The ball joints were ok at that time so we just replaced the bushings. Was a fun project!!!

Now car is apart for total restoration, so we are replacing the entire units with new ones from W&N.

jjs2800cs

 

[Gary Knox]

Stephen,

A renowned BMW mechanic whom I contacted privately said 'no one can get the bushings in dry - just buy new arms with the bushings installed' I did that!! ha.

 

[autokunst]

Joking aside, I feel I should clarify my position/perspective. Not saying it is right or wrong, nor the only way. But I did have reasons.

Anyone who has pressed these bushings in knows that the fit is tight. Very tight. The size of the original BMW bushings (not sure about aftermarket versions) are considerably larger than the metal race into which they fit. And the rubber is reasonably hard/stiff. The amount of energy to get the bushings into the race at all (lubed or otherwise) is significant. And once in there, the space left between the rubber and the metal can only be measured at a molecular level (I am postulating here). Which is to say, if you put anything on the bushing to help it press in, there is no way any rinsing agent (water or otherwise) is going to wash it away. There is either nothing left within the race, or maybe a tiny amount within the groove of the rubber. If it is soap, that soap is in there touching your rubber and metal for years to come.

I don't know what kind of soap the Bavarians had in mind when they wrote the blue books, but almost all soap has an active ingredient that is salt or acid based. And we all know what salt and acid do to metal if left unchecked. Whereas, the silicone grease is inert to both the rubber and the metal.

By the way, Gary, I have a set of replacement wishbones on the shelf. But they are OCAP and I couldn't bear to look at their subtle differences over the original Lemforder pieces. I know, it is obsessive. But I was fortunate enough that someone had replaced these parts previously on my car, so the ball joints were in great shape. I just refreshed the rubber and paint finish, and I am sure I'll get many years of service out of them before I have to put those OCAPs on.

If we had access to another wishbone (perhaps the OCAPs on the shelf), I'd be tempted to set up a jig and actually measure how much force/rotation it might take before any slippage between rubber and metal. But again, the bushings I pressed in are so tight, I would be concerned that the inner metal sleeve will break free before the outer race, which has a lot more surface area. So the experiment itself might just ruin the parts.

That's my philosophy, anyway.

 

[autokunst]

Error in Blue Book

Before pressing the fluid block back into the refurbished steering idler arm, I checked it against the specs listed in the blue book. Well, either my part is wildly off, or the blue book has an error in it. I think they are listing the measurement from the wrong location.

The book suggests that the out-to-out dimension should be 42mm + 0.5. But my part measures 72.1mm at this location. The .1 likely represents the paint coating.

Here you can see that the thickness of the machined part represents 30.1mm.

Doing the math, the book should read 72 + 0.5 mm. I think they forgot to add the thickness of the machined piece.

 

[HB Chris]

Not the first time they made an error!

 

[bluecoupe30!]

Wow, that is way off. Was it Friday or the Monday or every day, that they allowed beers on the workbench?

 

[autokunst]

Wow, that is way off. Was it Friday or the Monday or every day, that they allowed beers on the workbench?

One of the people that works in my studio studied in Germany. He tells me that it is normal for Germans to have two beers per day while at work. Something tells me he is just trying to get me to let him drink beer at work.

 

[Jon B]

Error in Blue Book

I think they are listing the measurement from the wrong location.

The book suggests that the out-to-out dimension should be 42mm + 0.5. But my part measures 72.1mm at this location. The .1 likely represents the paint coating.
Doing the math, the book should read 72 + 0.5 mm. I think they forgot to add the thickness of the machined piece View attachment 119472

As you said initially, I think it's more likely that the illustration is mistaken, and not the dimension.
The upper point of dimension A should have been under the machined piece, not above it.

 

[mulberryworks]

One of the people that works in my studio studied in Germany. He tells me that it is normal for Germans to have two beers per day while at work. Something tells me he is just trying to get me to let him drink beer at work.

When I worked at Apple we were told during orientation that while it was perfectly fine for us to have a drink or two at lunch, we should always be careful to not be or appear to be drunk when returning to work.

 

[Gary Knox]

Stephen,

Yes - Lemfoerder is essentially the only aftermarket supplier I'll buy for German cars. I think they are OE on most of the items as well.

Regarding the 'beer' in assembly. Absolutely true - I toured the BMW plant in 1980, and at every station, including the engine build benches, there were at least as many locations for one or two bottles as there were workers in that particular task. A 'production error' on that car? Let's toast to it!!

Gary

 

[autokunst]

One Year Anniversary of the Raven Restoration
Day 365
270.00 hours

Today marks the one year anniversary of the day I started to take my car apart. I’ve always maintained that I don’t have a timeline and I’m not in a hurry. But I’d be remiss if I didn’t say I’d hoped to have more done by this first year’s end. Here’s an outline of where I’m at.

The project began with disassembly. Taking the car apart, fabricating the chassis dolly, and bringing the chassis to the stripper took 85 days.

While waiting for the chemical strip, I rebuilt some hydraulics including the brake and clutch master cylinders, and also the brake proportioning valve.

When the car came back clean and bare, I was able to assess. This led to a large sheet metal order, and I started to peel the onion, so to speak, by beginning to remove some metal and accessing the inner layers. The plan was to continue with chassis metal work, but I found the need to “tool up” the nest a bit. This brief delay worm holed into a sidetrack of disassembling and restoring/rebuilding the front subframe and suspension. I would probably be done with that work were it not for a part I am waiting on. Here’s a gratuitous photo of most of that progress. Missing from this photo are the Carl Nelson springs, the rotors and calipers that are not yet refurbished, and the power steering pump which I will go through the next time I have down time on the chassis. Oh, also the front subframe which all of these parts will be assembled to - again, when I take another break on the chassis.

The exciting news is that, perhaps due to the pressure of this anniversary looming, I jumped back into the chassis metal work. This past week I leveled the chassis on my rack, fabricated the first two parts from scratch and have them tacked in. I am tickled that I am welding new metal into this old girl. The Raven seems really happy, too!

Not knowing the true history of this car, the right side frame rail appears to have sat on the ground for a while (just a theory) and corroded the bottom portion pretty badly. But the top half or more of the frame is solid and pristine. I’ve cut out the pitted metal portion and am replacing with new 14 gauge (roughly 2mm) steel. It will be as good as new, or maybe slightly better.

This morning I started the last small piece of this frame rail. Once I have that fitted, I will finish welding in these pieces and move on to the next cancerous area.

 

[Stevehose]

Amazing!

 

[GolfBavaria]

Amazing!

Way above my pay grade.......

 

[Bmachine]

Super impressive work, Stephen!

 

[Stan]

Love the Bavarian flag!

 

[Dick Steinkamp]

Congrats on your first year. You've done more than you give yourself credit for. Excellent photo essay!

I also find the need to switch off between subprojects during a restoration. It starts to feel too much like actual work if I don't. It is probably not the most efficient thing but it keeps it interesting and it's satisfying to be able to tick off some lesser milestones every now and then.

Your car will be like new!

 

[Gary Knox]

Outstanding work Stephen. The progress is also much greater than you may appreciate at this point. Keep up the good work, you are going to have a fabulous result when it is completed.

Gary

 

[autokunst]

Thanks for the encouragement! It is the members of this forum that motivate and inspire me.

Went out this morning to work on the third/last part of the right frame rail, when my shrinker die snapped. I hate when I pay up for the better tool and it still breaks. Hardly used, but it snapped the die in two. Another setback - will have to switch gears again while I wait to see what the seller will do to replace it.

 

[mulberryworks]

How did you manage to so masterfully bend that thick steel? Do you have a large sheet metal brake or did you use a hydraulic press and some forms?

Nice work, regardless of how you managed it.

 

[autokunst]

How did you manage to so masterfully bend that thick steel? Do you have a large sheet metal brake or did you use a hydraulic press and some forms?

Nice work, regardless of how you managed it.

Hey Ian, thank you! I have an 18" press brake that I used for the long bends. Once the straight bends were formed, I shrunk portions of the vertical segments to create the soft bend in the length of the pieces. Then there is some hammering and forming to get everything precise for fit up. The front section - my last piece needed for this rail - is pretty short. The bends are made, and I am now doing a lot of shrinking to get the radius as it heads up to the engine bay. I like this method (shrinking the sides) because it makes the metal thicker on the sides. This can only add strength.

That said, I am debating adding some stiffener ribs inside the frame rail simply to support where the eventual jack lift will occur. These rails are so beautiful now - I can't stand to see them dinged up by a jack. I saw a thread where someone created jack pads. But I don't want to see them, per se. Still debating this...