Yes, if you have hub-centric rings fitted they can cause all sorts of problems if of poor quality or worn out - more info here:
http://www.meeknet.co.uk/e31/wheel/F...he_BMW_E31.htm
...but really severe shaking is usually brake calipers....
Last edited by Timm; 03-05-2018 at 09:18 AM.
Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i
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Could you please elaborate on why you think it would be the calipers? My mechanic is adamant that it cannot be them... He says they are sealed and the flood would not have damaged them.
Is there anyway to check if it is them without replacing them?
You can try dragging the caliper at speed. Get into highway speed and hold the brake for a short period as you continue to hold a constant speed to get the brakes nice and hot, which can help retract the pistons fully and reduce stickiness. Then release and get back into the trouble speed zone and see if the shaking has been altered at all.
A caliper rebuild is fairly cheap insurance and if original, your car would benefit from it anyway.
Last edited by adamnur; 03-08-2018 at 10:47 PM.
I notice no listing for part#31121136607, why not?
Your mechanic replaces UCA without also replacing bushings?
^^ This, and cheap suspension parts cause problems..
^^ Thrust bushings = control arm bushings / control arms
Bad rotors trash Control Arms, bad control arms trash rotors!
Often overlooked, especially with aftermarket/larger wheels
The bottom line with shakes/vibrations: Suspension, brakes and wheels are all related. Welcome to E31/E32/E34 McPherson Strut vehicle ownership! It's amazing when it all works, but when shit goes awry, it can be a PITA. If any of them are screwed up, mechanics will first suspect the most obvious (brake rotors). When that doesn't work, things turn to suspension.. Folks try to save money and only replace a few parts, or buy cheap parts.. 30K miles, they're doing it all over again. Plus, extended vibrations are sometimes absorbed by suspension parts, and cause premature failure..
Prescription (E31/E32/E34): Every 100K miles, replace front end. :-) $1000
But then again, I'm the electrical guru not a mechanical person, all these folks have far more experience than I in this department!
Good luck!
Last edited by EEDegreeToDrive; 03-10-2018 at 10:01 PM.
'89 735i, '91 850i, '81 MB 380SLC (For Sale), Tesla Model 3, and VW Passat TDI -- Yes, I still repair General Modules, DM for info!
Hey guys, thank you for the replies. Sorry to bump this, I somehow missed you guys replies.
I was thinking it was the calipers because of what you guys were saying and because it happened right after the flood. There was no water inside the car but I thought maybe it sat in a few inches... he says it didn't and, on second thought, the calipers are pretty high up... If they were submerged, I think water would've gotten inside...
He has replaced the front rotors and that didn't fix it. He said it helps until the car warms up. When I told him it was doing that before, he said he thought it was the steering box. He's said this before but now he is adamant this is it. He says all the suspension is new and he's checked over his work. That, the way it's acting, it could be the rotors but it could not be the calipers. He said it could not be the back rotors the way it was transferring to the wheel... is that right? The article Timm posted seemed to suggest, depending on the speed, issues at the back wheels could cause vibrations at the front.
He thinks it maybe from an old injury? I used to do a lot of drugs and wrecked the car and almost broke a wheel off... I did 360s across like 4 lanes and 3 curbs. It cost like 11k to fix... just almost got totalled.
When the issue started, it started very mildly in both frequency and intensity. It used to barely shake and it would go away very quickly... it got worse over a couple of weeks. Even now, it seems okay for the first 5 minutes when the car is cold and then it starts and gradually gets worse over a couple minutes.
I'm not sure if I should let him do it or take it to another shop...
Take it to a frame shop that has lasers and have it checked.
Then take it to somebody that knows 8 series and have them investigate the condition of every bushing in the rear sub-frame AND the condition (correct shape) of each of the 3 links and 2 supports that connect each rear hub to the sub-frame.
I go with servicing/checking the brakes due to the flood just for grins anyway, but I think I agree to not rule out control arms. My experience of shaking was when exiting the interstate and going thru the 60 to 45mph range while braking. 4 cars. Lucky if you get 30-40k miles out of a set imo.
Quite a thorough and expensive set of replies you have going! I say strip it down to the frame and start over!! This "shake" subject always gets very deep when its really simple. Cheers!
edit: Thinking about this, if the water got high enough to reach the calipers- would that be above door level? If so, I would sure check the footwell electronics.
Last edited by TTTXGreg; 04-05-2018 at 11:57 PM.
Hey guys, I still have not got this problem figured out
We rebuilt the steering box like my mechanic wanted to do but it didn't work. He says hes taken apart the calipers and that there is no visible corrosion... could they still be not working correctly?
I remember the brake rotors, which were new, having a layer of rust on them after the flood... even if the water level didn't get high enough to cover the calipers, maybe the constant rain for 2-3 days could've still caused issues? I remember the calipers being noisy... at a low speed with the windows down, you could hear them closing and opening on one side.
I've finally convinced him to do the calipers and, although I previously felt very certain it was them, now, I'm having second thoughts. He says he got a quote for $2200 to get the parts (all 4) from BMW. If I'm wrong and this does not fix the issue, I will have to foot the entire bill. If I'm right, he says he will help. Hes still adamant that they look fine to him... what do you guys think? Should I do it?
Also, I remember reading that there was a BMW dealership that offered forum members discounts on parts... I think it was called Gault BMW? Does anyone know about that and how that works?
Thanks for all the help guys... hopefully I'll have a working car soon!
Replace the master cylinder before you do all that.
Sorry I can't help but 10K in repairs? WOW! That's what I paid for my '97 840ci four months ago.
If you do not feel vibrations on the pedal during braking, it is not brakes related. Swap front wheels with known good ones (that do not need hub-centric rings).Originally Posted by Guts1200
Rims & tires are the main source of all vibrations.
WBR, Tony
Discounted prices and lifetime warranty on parts:https://www.fcpeuro.com/BMW-parts/85...996&m=20&e=191
Last edited by MIKYZZ4; 08-29-2018 at 09:59 PM.
Cartoon - he was suggesting we do this next... unfortunately, the part has to come from Germany. Could you please elaborate a little on why this could be it?
Idfotou - yeah... it was more of a refresh than strictly repair but I wanted a solid, new suspension system. Unfortunately, after all that money, I still have a broken car.
Mr1173 - it's been a while since I drove the car and I do not remember if that happened or not... the vibration only happened at highway speeds and only when I was braking. If it was the front wheels, wouldn't it do it when accelerating as well?
Mikyzz4 - thank you, I'll check it out
The master cylinder in our cars does weird things when it goes bad... instead of no brakes, it likes to keep the front brakes engaged for some reason. Typical symptoms are not noticeable right off, but if you take it for a drive at speed down the highway the front rotors heat up and it will really shake and stutter when brakes are applied. Counter intuitive, I know, but it is common.
The fix is to replace the master. But, the master for our cars is absurdly pricey if you can even find one... so use one from an E32 735i. 1mm smaller bore, but works perfectly... and costs way less.
Before you go spending $2k on caliper rebuilding (which is ridiculous, as you can buy new ones for less), I'd suggest replacing the master. As I described, it can be the culprit for sticky calipers.
Also, the posts above about proper wheels and hubcentric rings are something to pay attention to, but that's not only under braking.
And that would be that the ABS system is misbehaving, cyclically enabling braking and then completely releasing, but only on one side up front.
The way to test that suspicion is A/B testing.
On a car that exhibits the symptom reliably (shaking violently under braking), take the ABS offline via its fuse or connector.
Note that in theory a misbehaving ABS might continue doing so regardless of sensors getting pulled, so that's not a reliable way to defeat the system.
Hmmm... that could be it. If it was that, would it kind of fail slowly? Like stop working slightly one time and get worse over time? Also, even at its worst, the car seemed to work fine when cold and would start showing issues only after the first few miles.
He said he's already taken apart the calipers and "rebuilt" them (I think he means he just put them back together though... rebuilding means they are kind of refurbished though, right? ). The 2k quote was for parts for new calipers on all fours.
Hyper - is there a more reliable way to test this theory?
It is not a light vibration though... it feels like a wheel is about to come off
To me the answer is staring you in the face-$10,000 in suspension refresh,
and WITHOUT replacing one of the most important bushings-CONTROL ARM BUSHINGS!!
Your own damn parts list omits that essential bushing!
Either your mechanic is a moron/milking you for $$$, or you're trolling us.
If it's the first - get rid of your mechanic ,
if it's the second - I'm out!
Last edited by MIKYZZ4; 08-30-2018 at 11:29 AM.
I dunno why you would think I'm trolling you... what would be the motivation? Well, either way, I'm not... in the last 2 years, my car has been in the shop for about 3/4 of the time. I'm really quite frustrated and am trying to figure this out... I'm almost ready to just sell the damn thing as is and take my losses. I've almost (if not have) spent more on repairs than I paid for the car.
I'm sorry that I didn't catch the issue with the bushing, I'm not very mechanically inclined... that's why I posted the list... thank you for pointing it out. Could this cause the car to shake when braking? It worked fine for a while after the suspension upgrades. The suspension stuff was finished around February of last year and the shaking issue showed up after Harvey which was in August.
Edit: I asked him and he said he changed the complete control arm and that they came with bushings
Last edited by Guts1200; 08-30-2018 at 11:52 AM.
They did not come with bushings, as it states it right on the parts list-w/o bushing,
read the description for part#311239999 and part#31121140000
Part #31121136607 is not included in that description or ANYWHERE ELSE on that list!
Last edited by MIKYZZ4; 08-30-2018 at 12:23 PM.
I see... that's weird, I dont know why he wouldn't change them. I'll ask him again and see what he says... I imagine it shouldn't be too hard to tell if they are new or not by looking at them?
I could be wrong, but I don't think that is what's causing the shake, even if they weren't changed. It doesn't seem to make sense... it definitely seems like it's related to braking.
On a test I did with him to reproduce the issue, I remember the brakes felt like they stopped working after some hard use. The brake pedal felt really spongy and went further into the floor than usual (I think). When I told him i felt the brakes weren't working right, he thought it was probably due to brake fade. Even though I did accelerate and stop rapidly a few times, I did not think it was nearly enough to cause that level of failure... I mean they went from working normal to feeling like they weren't working at all from one moment to the next. Plus, we had stopped testing and were in traffic when it happened.
I say all that to say maybe cartoonz is right about the master cylinder... that could cause both issues, right? Something wrong with the calipers wouldn't cause a spongy brake pedal, would it? I would love to hear another opinion or two but I was thinking about trying the master cylinder next. My mechanic had actually recommended to try that next but I wanted to do the calipers. Now, after cartoonz suggested it as well, I think that might be a better fit.
Last edited by Guts1200; 08-31-2018 at 09:38 PM.
How qualified is that mechanic?
If several hard stops cause that level of brake fade,there's something wrong.
Severe brake fade leads me to suspect contaminated fluid,
possibly very old-if the brake system has never been flushed.
Your mechanic did flush the system when he rebuilt your calipers,right?
Sorry for the late reply but I believe hes qualified... I was referred to him from someone on here. I've seen him working on other 8s and exotics.
Previously, I misspoke... he wasn't actually with me when we did the test, it was one of his employees. I was explaining what was happening to the brakes to him but I think I didn't do a good job... I just kinda said they weren't working. It didn't really connect in my head until cartoonz suggested the master cylinder and I googled the symptoms of it. I read it could lead to "spongey" brake feel that travels too far and that is exactly what it felt like.
And yes, the brake system was flushed. I was thinking the master cylinder could be the culprit because it is one thing that could cause both problems. When the shake first started, it was very minor. It would happen once or twice every like 50 miles and go away... it also wouldn't shake that much at first. It progressively got worse. Would the master cylinder fail in such a way?
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