Strut tower bolts

[JoshInAtlanta]

So I just tackled the strut bar install. I installed the drivers side, put the bolts back on finger tight, then jacked the drivers side up a little.

I then unbolted the passenger side (still on the ground) and slid it over. 2/3 were lined up, so I just tapped it a little and it fell into place. I was a little shocked to see the front-most of the 3 bolts was GONE.

I decided to bolt the other two down and look for a solution later. I bolt one down no problem. The second one snaps on me a few twists in. I'm not overtorquing it....

So... now I have one side completely bolted down and the other side only has 1/3 bolted, since one bolt is snapped off and the other one is gone.

Is my only option a new strut tower?

Thanks


PS- Is there an award at 5erFest for "Worst Participant to Work on an E28" ???? At this rate, the car doesn't look like it's gonna be in Chattanooga next week...

[Shawn D.]

Is my only option a new strut tower?

To be specific, it isn't a "strut tower bolt," but is actually a "strut mount bolt." The stud is attached the the strut mount (on top of the strut), not the tower (a part of the body). You could probably knock out the remainder of the stud and use a bolt as a replacement.

[JoshInAtlanta]

Is my only option a new strut tower?

To be specific, it isn't a "strut tower bolt," but is actually a "strut mount bolt." The stud is attached the the strut mount (on top of the strut), not the tower (a part of the body). You could probably knock out the remainder of the stud and use a bolt as a replacement.

So I would just stick the bolt through the bottom of the mount and it put a nut up top and it should work?

Thanks.

[Shawn D.]

So I would just stick the bolt through the bottom of the mount and it put a nut up top and it should work?

Yes.

[Mark 88/M5 Houston]

Real OEM lists this part number 31 33 1 092 886 for the "M8 X19 pin" for the strut mount bolt. Their price was less than a buck and a half apiece.

[JoshInAtlanta]

Real OEM lists this part number 31 33 1 092 886 for the "M8 X19 pin" for the strut mount bolt. Their price was less than a buck and a half apiece.

Cool. I see it now... so it's actually just a bolt that is separate from the platform?

[Mark 88/M5 Houston]

I think they are "splined" near the head and press in from the bottom so the nuts can be remove and the "pin" stays in place.

[LA]

If you have time to wait for the splined ,or knurled, bolts, which press in & stay in place (in theory) then that's the thing to do. I've done the regular bolt route but it took needle nose Vise-Grips and a very steady hand to put it up in place while starting the nut. I have also put a bolt in a vise & made my own knurling with a sharp chisle & heavy hammer with maybe 50% success.

Even if you get new knurled studs, put the mount on a flat steel surface & pound a hard blow to the hole with the ball end of a ball peen hammer before pressing the studs into place. This will result in a better interference fit.

Good luck...

[JoshInAtlanta]

Hopefully I will be picking up an entire replacement assembly in the morning.

[Shawn D.]

... Vise-Grips...

What kind of vice was doing the gripping? Liquor, drugs, wanton women, or something else?

[JoshInAtlanta]

I ended up sticking with the current setup, just pulling it out and replacing the missing and broken stud with equal size bolts.

It took 5.5 hours, but we got that and the strut bar taken care of.

[LA]

... Vise-Grips...

What kind of vice was doing the gripping? Liquor, drugs, wanton women, or something else?

OK I'll be honest ... gambling is the only vice that is not in the running here; it just never interested me much.

[alexdparsons]

If you have time to wait for the splined ,or knurled, bolts, which press in & stay in place (in theory) then that's the thing to do. I've done the regular bolt route but it took needle nose Vise-Grips and a very steady hand to put it up in place while starting the nut. I have also put a bolt in a vise & made my own knurling with a sharp chisle & heavy hammer with maybe 50% success.

Even if you get new knurled studs, put the mount on a flat steel surface & pound a hard blow to the hole with the ball end of a ball peen hammer before pressing the studs into place. This will result in a better interference fit.

Good luck...

Could anyone elaborate on how to press the knurled bolts (part # 31331092886 is NLA so I've got as the replacement # 31336765744) into the strut bearing plate?

I started to press them in with a very DIY technique using a ball joint separator tool, but the bearing plate itself started to deflect. Made me question whether the diameter of the knurled part of the replacement bolts was too large, or the BMW camber correction strut bearing I'm installing isn't designed for the knurled bolts.

Any advice would be much appreciated — really wanting to finish off my suspension redo and get driving again.

[Das_Prachtstrasse]

I've simply tapped them in the first little bit with a hammer, then packed some washers on the thread and seat them by tightening the nut. Remove washers, and install. Just don't over tighten the sucker.

[528elover]

Is there a way to install longer bolts? I have a strut brace (from jakeb) between the towers, and I am only able to get a few threads of an E34 deep seat nut onto the bar. I would like to remove the stock bolts and replaced with a longer knurled (splined) bolt. Does such a bolt exist? Perhaps on a different BMW application?

[tn535i]

No offense to the OP but this story makes me wonder how many times people install a strut brace with no idea what the condition the rest of the suspension is or it's age or how it's been abused. I would spend my time and $ first upgrading the rest of the factory suspension before adding the brace if you haven't already. If the suspension is sloppy will a brace do much good anyway? Again no offense intended.

It also makes me think those three bolts may only be engineered to keep the mount in place since gravity does most of the work while a strut brace has a whole other function for which upgraded bolts in a large size might actually be a good idea. IDK though.

[Devinder]

Is there a way to install longer bolts? I have a strut brace (from jakeb) between the towers, and I am only able to get a few threads of an E34 deep seat nut onto the bar. I would like to remove the stock bolts and replaced with a longer knurled (splined) bolt. Does such a bolt exist? Perhaps on a different BMW application?

Many US E9 E3 and E12 came with longer pins/studs/bolts. Those cars had a 1" spacer between the strut mount and the body.

[wkohler]

I have a full set of those out of the car after I removed the spacers from my '75 E12. One concern I had with leaving the longer studs was the possibility of hoodal contact, though I did no extensive testing.

[528elover]

Many US E9 E3 and E12 came with longer pins/studs/bolts. Those cars had a 1" spacer between the strut mount and the body.

Realoem has the following diagram for an E12 528 from 1977. The schematic shows the following setup:

01 Upper spring plate 2 08/1976 31331117664 $11.65
02 Washer 2 08/1976 31332750139 $0.57
03 Gasket ring 2 08/1976 31331108927 $2.50
04 Pin M8X18 ZNS 6 08/1976 31331092886 ENDED
04 Pin M8X18 ZNS3 6 08/1976 31336765744 $1.17
04 Pin 6 08/1976 31331124547 ENDED
04 Pin 6 08/1976 31331138102 ENDED
05 Guide support 2 08/1976 31331101663 $137.89
06 Washer 8,4 6 08/1976 07119936441 ENDED
07 WAVE WASHER B8 6 08/1976 07119932095 $0.09
08 Hex nut M8-ZNS 6 08/1976 07119922856 ENDED
08 Hex nut M8-8-ZNS3 6 08/1976 07119904032 $0.16
09 Washer 2 08/1976 31331110301 $0.91
10 SELF-LOCKING HEX NUT M18X1,5 2 08/1976 07129922475 $1.46
11 Cap 2 08/1976 31331101662 $32.18
12 Washer 2 08/1976 31331118694 $1.93
13 Absorber 2 31331117662 $15.08
14 Protection tube 2 08/1976 31331117663 $6.61

I'm assuming you are referring to part #4 in the diagram as the PIN. Is the 1" spacer you are referring to the "WAVE WASHER" listed as part #7? If so, that appears to still be available. The idea is to use the longer bolts from the E12 and put it into the E28. Would this work, assuming of course, as Chris mentioned, there are no hood-fitment issues?

[John in VA]

Is the 1" spacer you are referring to the "WAVE WASHER" listed as part #7? If so, that appears to still be available. The idea is to use the longer bolts from the E12 and put it into the E28. Would this work, assuming of course, as Chris mentioned, there are no hood-fitment issues?

That washer is not 1" thick. The aluminum spacers were supposedly used to raise the front of the cars for new bumper height standards. These spacers (two different sizes - 12mm spacers #31.33.1.113.721, and the 'thicker' 20mm spacer # 31.33.1.106.059) were fitted to all '02s, Euro & USA, and 74-on Australian delivered cars. Also fitted to E3 & E9 cars, as mentioned above.

You can see the spacer surrounding the strut mount in the picture (moved from below the body):


Anther shot:

[528elover]

You can see the spacer surrounding the strut mount in the picture (moved from below the body):

John,

Thanks for the pictures. That makes more sense now. I understand how those spacers work. Anyway, I've been trying to source a longer strut mount bolt but can't seem to find the write part #. The original bolt is a M8x18, which is too short. I want to put the original splined/knurled type bolt in. However, realoem shows that earlier cars such as E12s used a similar-sized M8x18 bolt (see #4 in list above). ????! I thought these were longer-sized bolts?

Anyone know the correct part # for a longer bolt?

Chris, would you be so kind as to sell me the set you have?

Thanks in advance.