'91 M5 #06091 resto thread

[Shock(/\)ave]

Well, I got hit in the mouth yesterday. Before I even touched the driver side KW, I poked around with a strong light at the spring perch and saw what sure looked like metal threads sandwiched between the interlocking perches. These are old enough to use two opposing perches, and not set screws (I like this older setup better, honestly), but likely from being on an East Coast car/owned by someone about whom I've since heard sketchy things, the opposing perches that are supposed to be impossible to strip, are stripped

I spent 30 minutes spinning the perches to be sure, but yep. Owned

I'm praying (and honestly expecting) that the strut body threads are fine, being steel, and have ordered replacement KW spring perch parts. They no longer sell the interlocking perches AFAIK, but we'll see. I don't even know if these parts will fit, but I'm not driving the car until I get the perches in (I bought a second set for the pass side, in case that perch is stripped--haven't looked yet).

Reason #2 this coil-over guy needs to go to confession: the passenger coil over is absolutely bent. I can't tell how much, and I can't tell from driving, but it's the only reason I can think of that the inner sidewall of that tire (obviously same wheels, tires, spacers side to side) is contacting the spring perch. Since the valving and rebound feel excellent still, I'm not going to address this for now, aside from trying a little more spacer to hopefully clear the 255 section width. I likely can't fit a wider tire on that side (read: both front sides) until I fix that, which is a bummer, too.

Some people really shouldn't be working on cars; sometimes this hobby feels like a game of snakes and ladders.

[AHenry014]

Reason #2 this coil-over guy needs to go to confession: the passenger coil over is absolutely bent. I can't tell how much, and I can't tell from driving, but it's the only reason I can think of that the inner sidewall of that tire (obviously same wheels, tires, spacers side to side) is contacting the spring perch. Since the valving and rebound feel excellent still, I'm not going to address this for now, aside from trying a little more spacer to hopefully clear the 255 section width. I likely can't fit a wider tire on that side (read: both front sides) until I fix that, which is a bummer, too.

I cant say for sure since i haven't seen the car in person and don't know that coil design, but i wouldn't be so sure its bent. There is a lot to that stack up of tire to strut clearance. Relationship of tube to spindle, wheel bearing, rotor hat thickness, wheel offset, spacer thickness, actual tire width, etc. If it were my car, i would be comparing it to the "good" side to get an idea of how far off they are from each other.

LOVE the 9"ers with turbines. Ugh would love to have that setup. Trade for my mille's? ;-)

[BleedsBlue]

Some people really shouldn't be working on cars; sometimes this hobby feels like a game of snakes and ladders.

To be clear, and public about this: the interim owner of BK was not to blame for this. He got a pretty bum deal from someone he thought was a friend, and has offered to cover any of my costs during this fix--which I am not accepting, but I appreciate

Snakes and ladders have been the absolute name of my game lately, Paul-o. Ladders leading to deadly snake pits, that is.

I cant say for sure since i haven't seen the car in person and don't know that coil design, but i wouldn't be so sure its bent. There is a lot to that stack up of tire to strut clearance. Relationship of tube to spindle, wheel bearing, rotor hat thickness, wheel offset, spacer thickness, actual tire width, etc. If it were my car, i would be comparing it to the "good" side to get an idea of how far off they are from each other.

LOVE the 9"ers with turbines. Ugh would love to have that setup. Trade for my mille's? ;-)

Man, I'm glad you said something! Last night I started questioning all of the other potential wheel offset imbalances from side to side. Initially I was wondering about wheel bearings, but I'm also not familiar with these coils or spindles in general, since both came off of a different car.

I think I was looking at this the wrong way. I figured something was bringing the passenger side wheel too far inboard (this was the BNIB ET22 forged wheel from my buddy), but I think maybe the driver side wheel is further outboard instead. It's been shoddily refinished, so the paint on the center is too thick to read the stamping, but now I think it's maybe an ET19 E31 wheel, which would explain the ~3mm extra inboard clearance. I have 3mm spacers in the mail and will try that on ET22 wheel--if things are even stevens, I'll then get an 18mm spacer and just run asymmetric spacers. These wheels are too hard to find to worry about 3mm.

Other variables ruled out:

• Both tires are exact same model/production/inflation
• Spacers are same size
• Rotor hats look identical
• Wheel bearings are an unknown; they are quiet and causing no vibration of any sort

Either way, raising the height of the coils will also buy me more tire clearance. I don't consider a 255 to be that wide for the front of an E34 and I had more tire clearance with H&Rs, since the stock perch was safely above a 25.3" tire.

Side note: funny you mention Milles, I've been eyeing Milles and Racing Dynamics 5 spokes both lately. I spent a long time assembling the square 9s (at least forged ones) and it's tough to beat the 17x9 @ 21lb for a strong, forged wheel.

[AHenry014]

You could try swapping the two front wheels side to side to see if the clearance issue follows the wheel or the KW. Just a thought!

[BleedsBlue]

Deffo! Now that the wheels are my primary suspect, I will do so when I have that 3mm spacer on hand. Good call.

[BleedsBlue]

Alex's simple test proved one of my 9J M Systems is indeed an ET19 E31 wheel! That's a relief all things considered, since I would rather use asymmetrical spacers than deal with a bent strut tube, wheel bearing, or any other possibility. But I still had a stripped lower spring perch on the driver side KW, so out came the driver coil over once I had figured out the wheel rub thing.

I'd ordered a few spring perch parts somewhat blindly from KW, who do not have the best online interface or customer service, in the hopes that one would fit this old kit. Also a DSSR, which I will install later.



I have the E34 strut removal down to under 30 minutes including beer drinking and getting the car on stands, and was relieved the top nut on this guy was very removable with hand tools. This was also the side that required a replacement strut mount/camber plate bolt, and my patch job on that held up well. It just requires me to hold the bolt in the fender with an allen key while I wrench the nut off on the tower, not too bad.



Being older KWs, they use interlocking metal spring perches, not the later plastic single ring with set screws. I like this interlocking setup better! Except when they strip, which I chalk up to East Coast and being aluminum. You can see the threads that fell out on disassembly. The strut threads (steel) cleaned up nicely at least.



Unfortunately, none of the KW replacement perches would thread on. The spares all had bigger thread pitch than these strut bodies. I ruined one KW spare part but will try and return the other 3 ($100 there), and after much Google-fu, measuring, and asking around, have ordered some interlocking spring perches that should fit (not KW parts, funny enough). If these parts work, then basically any BMW coil over spring perch will work on these old KWs, except for modern KW spring perches. Hmm.

They arrive tomorrow by EOB, and I will hopefully get the car back on it's feet tomorrow night after a softball game.

Side note is that 72.6mm hub bore is pretty ideal for burr... that's a 3mm spacer (now that I know I need 18mm total, I will get an 18mm solid spacer to avoid running two on one hub) and then I'm throwing 25mm on the rear axle

[AHenry014]

Nice job Brent, glad you are able to salvage the KW's! Glad you figured out your wheel fitment issue as well. You will LOVE the DSSR. Had one in my car when it was b40/6spd and it was spectacular. What are you running for the shift itself?

[BleedsBlue]

The KWs are totes worth saving, they ride well and are valved ideally (in my amateur opinion) for this chassis.

I haven't decided if I'll do the E60 lever or leave it stock with all fresh bushings and rubber, honestly. I've done the OEM SSK route before, and don't really mind the longer throw of these cars.

[AHenry014]

Many people like it, but I felt the e60 shifter to be too short for the b40/6spd combo. Made the combo feel too notchy for me. Cant speak to the M5 shifter though, since its all relative from factory to e60 shifter, and the 540i shifter may be different than the M5 shifter.

I happened into an e34 parts lot once, which came with a "short shifter". I was told it was an early UUC shifter, but cant confirm. It looked to be a factory bmw shifter, though i do not know which one, where the plastic lower bushings were replaced with ball bearings. The ID of the bearing matched that of the pin that goes through them, leaving no slop at that joint. It was shorter than the factory 540i shifter, though not as short as the e60 shifter, which i thought was perfect.

The reason i state this is that there is options for the lower bushing replacement should you want to ditch that sloppy factory bushing. I have seen people use bronze bushings before, though i do not know if they are a direct drop in or not. I too dont mind the factory throw, so a bushing replacement may be just right for you!

Also, dont forget to replace the coupling at the transmission! The one that came on my 6spd was toast.
Example of bushings:
https://www.e9coupe.com/forum/thread...acement.20602/

[BleedsBlue]

I believe Jason has the E60 shifter in his with the DSSR, and was very complementary of that setup. But as you say, it's very subjective and even chassis/sub-model dependent.

FWIW I believe many early short shift kits, including UUC's, were at one point lightly modified factory shift levers, so that makes sense.

That's a good link! I think there are now aftermarket suppliers of that type of stuff, and I will want to remove all the slop at once certainly. With at least 200k on this transmission, it needs all the help it can get.

Thank you (not just for me, but for others!) for the input again, Alex! I toasted to you with a nice can of IPA after I swapped wheels on the front axle to determine it was wheel offset, not strut tube bends, that were my issue

[BleedsBlue]

Thank. The. Lord.

So I've learned that modern KW coils use some proprietary shock body size and that their modern collars/perches etc won't thread onto their own older shock tubes. That pair of silver locking beauties is the standard M52x1.5 coil over spring perch and locking ring, from Bilstein, which will fit Bilstein, H&R, Moton, you name it (and apparently older KW!).

I spent a solid hour rectifying the issue on the strut tube threads that caused the old perches (they are all aluminum, basically) to fail: a million bent and damaged threads. I hand-chased all 19 feet of them with a small, strong screwdriver, making sure to clean the threads up if the spring perch encountered any resistance whatsoever. I have no idea how the strut threads were so beat up (honestly, most of the damage would be inside the springs, so... wut?), but someone had just forced the old spring perches over the damaged threads and each point of damage stripped a little more aluminum thread off the spring perches. It just takes time to do things correctly, most of the time.

I'll get the front end back together and check if I raised the front ride height enough, which was why this entire struggle even happened

[Butler]

Damn, nice work man!

[sugaki]

I think my fav short shifter is the stock E36 M3--was thinking of going the E60 route too, but also heard that the E60 is too short. Glad I went for this and love the feel of this setup--not too long, not short where you're not sure if it's engaged.

How do the KWs feel compared to Bilsteins?

[UnrulyGrace]

I have the e60 shifter + a dssr and it's incredible. Definitely not too short or notchy, in my opinion it's close to perfect for these boats.

[BleedsBlue]

How do the KWs feel compared to Bilsteins?

Whoops, missed this a few months back. Somehow the ride is better; I guess these spring rates are more street-oriented than I had assumed. I still need to take the car in for a pro alignment, C/B, and tune, and then I'll get a sense of where in the adjustment range these are sitting. For our terribad roads (and now 18" wheels), it's a good balance. Even the fiance thinks so.

No news is good news!
Nothing to report. As in, the car is running great, just having rolled over 247k miles. I have had time for exactly zero projects on it, but have accumulated lots of parts for a big install party/week/month.

-Full black interior swap (I think I'm just lacking the rear carpet and black door seals)
-Most of what I need for a TSX projector retrofit (just need to pick bulbs and ballasts, and solder some LKM connections)
-DSSR and bushings, as discussed
-Greg BBK for the front axle
-Volve 850 e-fan assembly
-Fresh A/C compressor (also from Greg, ha)
-Blower motor resistor
-Couple body panels to replace unsaveable pieces (see electrical tape in photos below )

These things need to happen before I embark on the inevitable, which is selling the Touring to pay for the M5 resto (paint), and house projects.

I'll probably take the M5 off the road once we're moved into the new place, so I can send some critical parts out (driveshaft, injectors) for refurbishing while I work on the other stuff.

Even with the sh!t interior, bad lights, rough exterior, etc, I've been driving it way more and loving it. 300k miles is the goal in the next few years!

Fifteen52 diversion
Last year, I jumped on a Fifteen52 sale (buy three in-stock wheels, get one fo free) and ran 17x8 ET35 (+ big spacer) front, 18x9.5 ET22 rear Tarmacs on the Touring. The double stagger was cool, but the front wheel just needed too much spacer. With BBKs on the horizon for potentially both of my E34s, I ended up selling the 17s and then had Fifteen52 build a pair of custom-offset 18x8.5s in ET15, 20mm lower than their off the shelf model. Now the stagger is in width only, 8.5J and 9.5J, and I run 235/40 and 265/35 Michelin PSS on these.

For kicks, I threw them on BK06091, knowing I would soon install a 345mm rotor and large Brembo caliper under them. Particularly with the camber on this car, the lower offset was key--and I can still run a 20mm spacer under them!

I was going for a DTM look, but I'm not sold; the white wheels contrasted well with the Oxford touring, but they are just enough off of my faded Alpine white that it clashes. I've still received a share of looks and thumbs, but we'll see. These may end up another color or back on the wagon. The wheels are fun and a great design, but heavy: one day I'll commission a forged set of Fifteen52s and not use a wheel like the Tarmac for anything but snow tires.

[BleedsBlue]

I let this thread die right as Angry Ass ramped up! But, time for an update, and this one is semi-final.

In May this year, at a rural intersection with a somewhat blind corner, I struck another car that appeared in the intersection I was passing through (T-bone situation, other driver coming from the blind corner). I had only enough time to divert slightly, and avoid a true 90 degree head-on. I was not distracted, and I do not feel I could have avoided this entirely - but I am focused on being grateful that all parties involved were ok. Cars are replaceable things.

The M5 held up its end of the bargain, considering I was traveling just under 50mph, and hit an SUV right at the rear wheel/hub (where there is not much give). There was zero intrusion into the cabin, and even the windshield (a brand new OEM BMW unit ) only cracked later! The body is quite tweaked, but the power plant is salvageable, and the durability was admirable.

The carnage:







I'm keeping a few pieces, like the hood, for sentimentality's sake, but the car has gone to a friend and local fellow gearhead. The S38 has but 30k miles on the fresh, stock head rebuild/head gasket, and will be united with another Alpine '91 M5 with near 200k miles, which is complete save for a beating six cylinder heart.

The car was in fine fettle, almost to 258k miles and due to take my wife and I to The Vintage the week after (very bummed to have missed out on that trip). I had just installed bright TSX-retrofitted headlights (ex-UnrulyGrace), our Angry Ass SAP-replacement tensioner (pumping ice cold A/C through a fresh motor blower), our Angry Ass Street front BBK, and many interior upgrades on the horizon. The car still had a ratty overall interior, crusty surfaces, and lots of previous-owner niggles, but I was ready to blow past 300k miles without pause. That is something I will always feel I missed out on, because at 220k this car was a quick decision away from being parted out with a 535 interior, shot suspension, and blown HG. Every mile we put on it after it was mechanically sorted, was a sort of blessing - not to get too cheesy

Anyway, I've moved onto something better and am content that no one was hurt. It brings me solace that the engine will live on to bring another of these special cars back on the road. And with any luck, content in this thread will help some Google searcher on a regular basis. If not, I'll go back and read through it from time to time

I'll close with one of the last photos I took of the old thing, my 4x season daily since 2014:

[a777fan]

Sad to see the end, but glad everyone was ok. Thanks for sharing your journey here, and I’m lookin forward to the next adventure you choose to document. Hope its in an e34.


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[E38740iMD]

im sad to hear this news. but glad everyone is ok.

cant wait to find out what you decided to get your hands into.

[T444E]

Have you thought about selling the engine to PorscheH6? It's possible he will just blow it like his original S38 but

[PorscheH6]

I will buy it for $1

[T444E]

I will buy it for $1

Pretty much market value

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