I've spent my Sat replacing the shocks (Bilstein HDs) and during those strenuous 12 (yes, twelve, as in double the norm) I've hit a few issues I'd like to share with you fine gentlemen. I won't get into the procedure, many have done so before and a copious amount of details can be found searching the archives. I'll just enumerate a number of issues/tips that hit me like a cold (very cold) shower and gave my confidence an exaggerated thrashing.
- spring compressors - when you rent them, make sure you know the size of those bolts and that you have the appropriate wrench/socket. It is _NO_ fun at all to turn them with a heavy adjustable wrench. Is is _MAJOR_ fun to twist the mothers with an air gun 8-) (big big grin);
When you mount them, be mindful of the most advantageous position to allow you to insert the not so thin 15/16ths socket. Sometimes the bolt is too close to the strut/spring assy and there is not enough clearance. In my case, for the rears it would have been better to mount them bottom-up (the direction of the bolt); for the fronts, one top-bottom and the other bottom-up. Have I said that 'air rules' ? That option was available to me for only one spring.
- you definitely need antiseize
- if you go aftermarket with the shocks, you can skip the trip to the dealeship for the self locking nuts; Boges don't match with Bilsteins and the latter come with the associated nuts. Should I have taken a close look in the package when the shocks arrived, I would have saved 2h worth of running all over the place looking for self-locking M14 1.5 nuts that are nowhere to be found. (actually I did find them, on the top of the strut, in its box..)
- if the moron at the service parts tells you 'your model doesn't have paper gaskets for the rears' - don't believe him. Better yet, cut off his tongue so he'll never lie/mislead another naive creature. He said all other years but 92 (production, not model) have those gaskets. And yes, 92 has them,too.
- make sure you have a flat 3/4 SAE wrench. Those strut-to-steering arm bolts (front) are tight mothers and a ratchet won't beat them. Apparently there was a shortage of anti-seize in Deutschland when they manufactured my car.
- if you buy a floor jack, pay close attention to the lift spec - I got the cheapest 2 tonne good for nothing jack and I could only use the first tooth of my jack stands. Anyway, not a significant problem - there's more than plenty space to work underneath. I'm also fairly sure a lift wouldn't have made my life much easier. On the contrary - on a lift you can't climb in the car to change that tune and leave dirty marks on your interior and you can't reach the trunk easily when you need the band-aid.
- you will need a large adjustable wrench - the original shocks (fronts) have that seal ring screwed on to the strut housing and you need a large one to grab it.
(enough prep work, let's delve into it..)
Oh, and by the way - by all means start early. If you start around noon and plan to be done by 8pm you'll probably be in for a bitter disappointment.
They say you should start with the rears for they're easier. Hah, I say. I lost already 1 lb before I got the seat back out of the way. But the real problem began when it was the time to install the new shocks. Apparently the Bs are a bit longer and that by more than 2 cms. Good luck trying to compress against the springs or to lower the wheel assy. Dark thoughts of unbolting the trailing arm (RR) crossed my CPU, but I had a brilliant idea. I installed first the LR one and somehow the independent suspension wasn't so indep any more, for it helped bring the right assy up. 2 grey hairs so far.
It could well be that my springs were unevenly stressed, for it looked like the left was weaker than the right or I have had serious hallucinations. It was some 4pm already (4h 1/2 since start) and not eating at all didn't help that much.
- the stabilizer bar link is a tight mother and the most annoying thing. The nut is a 17 and the other one behind it is a 16. It's better to counter the 17 and work the 16 - you have a lot more clearance/travel to use. It took me one side to find that out. Sockets don't work that well there. Be mindful of the rubber boot, it looks thin.
- the strut-to-steering bolts are tight, have I said that before ? Nothing a few groans and shouts won't fix, but still - they're tight. And after you undo everything and wonder why the hell won't the bloody thing get out of the way, don't pick a larger hammer. The strut stays fixed on the arm with the help of some matching fins (improper term) that are transversal (to the axle of the car), so move the assy sideways and it will come out. Sometime.
- be mindful of how you support/handle the assy - the tiny annoying tin dust cover is easily deformable. For Bilsteins, don't reuse the bump stops - they'll be broken anyway and they're not needed. Also pay attention to the hooks/rings that hold the various cables attached to the strut housing - you can bend them in the process and discover the damage after you've installed it, when it's much more difficult to undo the deformations. It's tight in there and you can barely fit a plier in a position that would fit you.
A few more thoughts at the end (yeah, I know you - those who made it so far - were wondering) :
- big kudos to Don Udel for this most awesome tip - untie just a tiny bit the strut top nut before taking the assy out. It was so easy after that.
- set your Bentley on fire - it will keep you warm and it will be more useful that way. They simply say unbolt/bolt on back. Which skips close to one hundred steps and leaves out ten thousand details.
- eat something, for when you'll be done and drinking the appropriate beverages, the headache doesn't go away.
- if you have help (and it is a two man job, at least for the fronts), don't let her/him rush you. Don't assume - double check everything is in place before you uncompress those springs. It's no fun at all to compress/uncompress them several times because you've forgotten the top cup that acts like a washer to the top nut. I only had help occasionally (read - when most needed) and it made a huge difference. Try to fit the front assy top and down by yourself, after a good number of hours of wrenching and staying slightly bended.
The outcome - simply awesome. Diving/squatting is eliminated but the ride is basically untouched. I kept the stock springs and I still feel what's going underneath but ever so gently. Bumps do not affect my teeth. The rebound is firmer and it helps to eliminate that sailing feeling. The turn in is just a bit sharper (it was pretty sharp before, even compared to E36/E46s). The rear suspension seems to have been modified the most, which makes me think the original shocks are differently valved. Meaning - considering the Bilsteins as equally stiff all around, the increase in stiffness of the rear susp is more pronounced than that of the front susp.
Stiffer means also less forgiving - I took an off camber tight left hander and it oscillated three times before I caught it. Granted, I entered it faster than I used to do but it seemed less predictable to me. I'm going out to the track this fall to sort it out. It's not fair to compare them - the original shocks were the originals - as in 98k miles of abuse. Going over small bumps rendered the suspension unusable, they didn't offer any rebound at all.
Some words of caution - some people (on the UUCGarage list) have had problems with the bilsteins shortly after installing them - clunking noises indicating defective shocks.
So - me doing this is huge - my mechanical skills match those of a tree trunk. The boost in confidence I received from accomplishing this made me think I should tear the engine apart next week. In two months I'll start reprogramming the ecu. What ?!?
what a perfect weekend - I come back to discover my own fan club !
please contact GhassanS for membership details