spr993

97 993 C4S Can't remove eccentric bolt which connects toe arm to cross member because of heat exchanger interference. Suggestion on Rennlist to jack up engine doesn't increase space by needed few mm - jacking the engine raises the entire car. Any other suggestion?

AOW162435

spr993

Andreas - Thanks for replying. I have the car on a lift and experimented with a floor jack at various points on the engine trying to raise the engine relative to the rear cross member - the cross member and the engine seem to lift together in tandem with no additional space created for the head of the bolt. which is obviously turned to the best eccentric position to pass the heat exchanger. Whacking the heat exchanger is the obvious shortcut but not an option for me - I don't think I'd sleep at night ! Is there a critical spot at which to lift the engine ? Should the car be on wheels on the ground when lifting the engine and not on the lift ? If nothing works I may resort to disassembling the four bolts that hold the rear crossmember - one is blocked by the same toe arm which I'm trying to lower, but loosening the bolts may provide some wiggle room.

AOW162435

spr993

Following your advice that unbolting the shock on top would influence the lower shock eye, I unbolted the top of the shock. Yes, it does influence the bottom eye but not nearly enough to remove the ball head at the end of the toe arm without first removing the eccentric and lowering the toe arm from the cross member. Understand from your working with the car on jack stands that taking the car off the lift, putting wheels back on and floor jacking the engine under the engine or the body at the jack point won't make a difference.

Dplus

loosen the motor mounts and then jack up the engine.

Darell

AOW162435

spr993

Darrel thanks for your input. Is loosening the motor mounts preferable to loosening the rear cross member ?

Richard

spr993

Andreas - Given your question to Darrel on loosening the motor mounts, do you see a problem with loosening the cross member?
Richard

Luftd993

With a jack under the engine and the mounts slackened off, I used a metal flat bar to push the engine over to the right side, Only needed a very small movement but it made the difference.

samurai_k

Curious were you having problems with removing the eccentric or putting it back in? I flipped mine around where bolt head is point to front and nut is point to back to avoid jacking engine.

spr993

Thanks everybody for your help and advice. My problem was removing the Driver side eccentric because of the heat exchanger interference. Preferring to dismantle rather than apply force, I chose to remove the rear croiss member (4 bolts M12 x 1.5 x 50) The fourth (lower driver side bolt is also obstructed by the toe arm but loosening it and removing the other three allows the rear cross member to rotate down and the eccentric easily clears the heat exchanger. If you want to remove the fourth bolt completely, compress the driver side strut with a floor jack and the toe arm moves up and clears the head of the fourth bolt. Problem solved - thanks everybody for your help.

samurai_k

Great to hear you were able to remove it. I got lucky too. When I refurbished my rear suspension with new bushings, I noticed the "jack the engine" technique worked when I had the stock motor mounts to move the heat exchanger just enough to remove the toe control arm eccentric bolt. However, when I replaced the motor mounts to solid RS ones, the "jack the engine" technique did not work as the motor did not lift or sag due to the solid motor mounts. Luckily I had already removed my toe arms before replacing the RS motor mounts so it was not a big deal to just flip the eccentric bolt around to get it in. I remember the lower cross member subframe being a big PIA to get the cross member bolts to line up correctly.

spr993

samurai_k - The manufacturing tolerances, although better on the 993 than on earlier 911s, clearly left something to be desired. Designing a car which calls for disassembly of various items to replace suspension components is one thing but having a heat exchanger block the removal of a bolt because of a few mm clearance is ridiculous. The fact that some people have the problem and others don't indicates that Porsche never intended it to be a problem but poor tolerances in production resulted in what is technically referred to as a Fubar setup. I suspect that my >20 year old original engine mounts are now almost as hard as solid mounts and that is why jacking the engine didn't help. Ultimately I was lucky - removing that rear cross member was very easy and provided plenty of space to remove the eccentric. Nevertheless, I am tempted to copy your idea and reverse the eccentrics, inserting the bolt from front (of the car) toward the rear - it's an elegant solution which will make the next suspension job somewhat easier. Thanks again for your advice. Richard

SpeedyC2

I was lucky (?) enough when I replaced the shocks/struts/springs on my car a while back the eccentrics had already been installed in the reverse direction. In fact, at the time, I did not know this was the case. When I read about this situation some time after I went back and looked and I'm sure the bolt removal would have been very difficult in the original orientation.