2/3 steering knuckle bolts broken--impact damage or monkey mechanic?

[ryan roopnarine]

right now, the broken strut assembly is sitting in the trunk of the ford taurus--which i'm driving right now (because the alignment is too far off on the e34, with the repairs and all). ill take pics of the broken bolts in the daylight.

i bought two strut assemblies from vines because i suspect that both the wheel bearings and strut mounts are dying, and this replaces both in one fell swoop. i did these repairs with others on friday and sunday.

first of all, i believe the bolt damage to be from a mechanic with a impact gun. the two easy to access bolts (the 19mm ones) were torqued to between 200 and 300 lb ft. the hard to access one was about 90 lb ft, ie, what it should be. both broken bolts did not absorb any pb blaster or wd40, it simply pooled up. if i had been doing this repair without having the whole assembly on hand, i'd have been fubar'd. BTW, for anyone else ever in this situation, the plate will come off after all three bolts are removed or broken off. the extremely difficult task of how you get the studs out is up to you. the more disturbing part of this repair occured when i attempted to remove the tie rod on the breaking side. the nut turned very hard, and eventually sheared the tie rod stud, coming off with the nut attached (its a lemforder, before you ask)

background about this particular strut/wheel/side. about a year ago, i ran over a large piece of concrete on the highway at about 50 mph (i couldn't swerve in time, and that's all of the velocity i was able to kill before hitting it). the impact occured on front wheel on the side referred to above. the impact was enough to cause the srs light to start flashing, as well as make my glovebox open (bending wheel, as well). i only hit it with one wheel, not both on the impacted side.

my reason for the post (other than to post a pic of the assembly tomorrow) is to ask, what should i start checking/measuring down in the area to make sure that everything is OK with the car? the tie rod issue was disturbing (thankfully autozone now sells tierod ends for the e34 for $25 each). for safety purposes, i'll be getting around to replacing all of the front links, as well as my dead steering box. i have the two SRS sensors, which i will be replacing when i get a chance. anything else anyone can think of? xmission mounts that were killed during the incident were replaced by me last year. thanks.


ps, before i forget. the other side strut assembly came out easily, only eating tools for 2 hours before it came out with relatively easy effort.

pps...i don't think that dealers carry the 19mm bolts. i had to stay on the phone with the dealer for 30 mins for them to finally ask me "what happened to the car?" in the vein that an e34 doesn't have e 19mm strut bolts. they finally faxed over a pic of the bolts with the quotation "are these them? no stock---3 to 4 days to arrive" thankfully a junkyard on HO-TOWN has two 34's and an e32 in stock, and was able to get bolts off of them.

ppps--does a 89 535i have that different a steering ratio that i wouldn't want to use its box in my 1992 525i?

[Anthony (M5 in Calgary)]

Those bolts are supposed to have Loctite 270 which will make them tough to remove and will seal against PB Blaster etc. Sometimes it feels like 200lb/ft though.

If they really were torqued that high I'd fear for the integrity of the internal threads on the end of the strut knuckle.

[ryan roopnarine]

i can see the other side possibly having something like loctite on it, but those bolts eventually "broke" and spun out far easier than it was to break them free. the side in question, though, don't believe that was the case. it was a "hard" effort until the bolt snapped off, and the most indicative part...the hard to reach bolt came out (relatively) easily--like the other side, like someone was unable to fit a impact gun on it or such.

[winfred]

i use nothing but a impact on those and have not seen a broken/stripped knuckle bolt yet, theres no way you'd get 2-300 pounds of torque on a bolt that size and grade, id guess someone assed them down with a good sized breaker bar and streched them

[632 Regal]

id agree with Win, you can probably have a muffler shop burn the stud or "threaded" part of the bolt out and clean the threads with a tap. They were probably loctited and over torqued by someone with a bad attitude on steroids going through a divorce. worse comes to worse and they overburn the knuckle, if you can index them in a press you can helicoil them...but at that point id get a new knuckle.

now the dumb question, why did you get new strut assemblies OR was it because of the broken bolts on your old ones?

[Kalevera]

Ditto. The only way I've ever stripped (rather, began to strip) one was when using hand tools in my driveway last February.

Seems like a lot of work to replace bearings and mounts with used parts -- and risk having bashed dust shields or other accident damage. Vines?!? :|

best, whit

[ryan roopnarine]

jeff--i got the used assemblies because it would be faster/easier to swap out the whole unit than have to change a wheel bearing+hunt down a strut bearing to troubleshoot a possible vibration caused by the pair. the shock absorbers on both sides look mint, too. it'll let me hold off on buying new front ones for a month or two so i can put in the new boge shocks i bought into the back of the car. no, they weren't bought because i broke off the bolts, their presence was handy when the things did break off into the originals, however.

[ryan roopnarine]

Vines?!? :|

best, whit

i'm not that worried 'bout vines. i usually get better from vines than what i can pull with my own hands from the junkyard. the bastiges just don't leave feedback, though.