What have you done to your E70 today?

[SF2000x5]

Trying out Cerakotes headlight restoration that uses a ceramic coat as the final step. Hope it lasts!

[andrewwynn]

Looks pretty good too start hope you're right on lasts.

I'm considering doing mine but I like the smooth beam I get from the slightly frosted lens

[andrewwynn]

Originally Posted by josiahg52

For the clunk, check the sway bar end links.

Sway links will usually tap at every road ripple when they go. Sounds like morse code.

Fortunately very easy to diagnose: wrap as tight as you can about 15 layers of electrical tape around the ball joint in question it'll stop tapping immediately. It'll also last long enough to order up a proper set from FCP vs. china copy from Amazon.

If more of a clunk than a tap, see if you can reproduce by hitting the brakes firmly. Especially noticable when going slow. The wheel will even move backwards like 1/2 to 3/4"! That would be the tension strut bushing.

If it's the sideways control arm what bmw usually calls the wishbone, the main symptom when it fails is a shudder in the steering wheel when soft braking from about 50>40 mpg. (also a jiggle in the steering when crossing over 12:00 straight ahead).

[Zulu95]

New plugs and both front drive shaft seals to cure a small leak.

[SF2000x5]

Originally Posted by andrewwynn

Sway links will usually tap at every road ripple when they go. Sounds like morse code.

Fortunately very easy to diagnose: wrap as tight as you can about 15 layers of electrical tape around the ball joint in question it'll stop tapping immediately. It'll also last long enough to order up a proper set from FCP vs. china copy from Amazon.

If more of a clunk than a tap, see if you can reproduce by hitting the brakes firmly. Especially noticable when going slow. The wheel will even move backwards like 1/2 to 3/4"! That would be the tension strut bushing.

If it's the sideways control arm what bmw usually calls the wishbone, the main symptom when it fails is a shudder in the steering wheel when soft braking from about 50>40 mpg. (also a jiggle in the steering when crossing over 12:00 straight ahead).

thanks!

I've recently replaced the sway bar endlinks along with the thrust arm since I was feeling the play when hitting the brakes firmly like you've mentioned. Haven't replaced the Lower control arm though..

[andrewwynn]

I've never seen that one cause clunk. Loose bolts on the bolts holding the sway bar or the bushing holding can do it or the ball joint are the prime suspects


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[SF2000x5]

Will check torque. Happen to have the specs handy? I think these are stretch bolts so I’ll likely do initial torque, loaded, without the 90 degree or so rotation.

[13brian]

Originally Posted by SF2000x5

Trying out Cerakotes headlight restoration that uses a ceramic coat as the final step. Hope it lasts!

Looks great, update us at 3 month intervals?

[13brian]

Originally Posted by andrewwynn

I've never seen that one cause clunk. Loose bolts on the bolts holding the sway bar or the bushing holding can do it or the ball joint are the prime suspects


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Recently had noticed a hard thump from potholes, harder than it should have. Replaced both Thrust Struts (rather than just bushings), like driving new vehicle. FWIW

[andrewwynn]

Originally Posted by SF2000x5

Will check torque. Happen to have the specs handy? I think these are stretch bolts so I’ll likely do initial torque, loaded, without the 90 degree or so rotation.

From memory but I think it's 65 N·m+90°

Doing destructive testing on about 3 bolts, every one took the full punishment 3x before they couldn't get to the design torque. One member on xo does 65+45° which I consider a pretty ok comprise but I haven't done the math to determine what's the loss in clamping force.

At 66+90°, each bolt will have 12,000# of force.

At 65+0°, each bolt will have 7500 ±1000 # of force.

72000 spec

39000 to 51000 at 65 N·m variance. I am confident the reason BMW chose TTY is because you get consistent result oily or dry

45.8 – 70.8% of spec; a crazy wide variance!

Adding the 45° will get you much closer to spec and get the plate tight enough to do it's primary job of reducing the body twist.

In the destructive testing, yield wasn't hit before 45° until after the 3rd test at 90°, so it is likely you could use that method dozens of times.

Or you could do what I did: switch to 12.9 bolts which are at proof load right at the TTY of 10.9.

You can use lubricated torque values to get a fairly consistent clamping force maybe 11000 ± 500.

I bought nylock washers to keep the bolts from working loose and keep the bolts tight.