KevinC
02-04-2016, 01:21 PM
So I'm turning to my ZHP brethren and their expertise, hoping for some help. The car: my E39 M5, purchased last July from EAG - fresh off an $8300 (!) work order to bring it up to snuff. 59k miles at the time, 64.5k miles now. The car had new thrust arm bushings installed during that service, no other suspension work deemed necessary.
The car comes home and has a minor shake in the front end, at 53-55 mph. It's not severe, seems to just be a run-of-the-mill tire balance issue, so I don't alert EAG nor even address it right away. It's not a common cruising speed so it's just a minor annoyance. So I thought.
I finally have the wheels rebalanced. No change. I then have them done a second time. Again no change. So I haul it off to my local indy, a grizzled veteran BMW guy with plenty of E39 experience. He examines it and deems all the suspension components to be in excellent health. He's convinced that the wheels just need to be balanced properly, suggests letting him sub it out to the wheel shop across from him and have them road force balanced on the Hunter GSP9700 machine. So that gets done - and again, no change. Shake still there. I start to communicate with EAG and their head mechanic jumps in, wants to know how the readings were from the road force rebalance. Unfortunately the shop did not supply the report and nobody will return a call, so I don't have the answer to that question. I wind up deciding to replace the front tires, which are half-shot anyways, with fresh Michelin PSS's (which the car already had all-around). No change. It's then suggested from various sources to have the car aligned. Had that done, turns out it was considerably out of alignment, particularly in the rear. It now tracks much better (was a bit of a wanderer before), and SOMETIMES the shake is gone - but not always! I can take it out for a run, and not experience it at all. I can take it out the following day, over the same roads and general route, and it's there in spades. I was beginning to think it only happens when the car is "cold" but that turns out to not be a factor.
Other notes: when the car was aligned, the new tires were a few days old. The alignment tech claims that both fronts have excessive run-out, and spun the wheels to show me that you can see that they aren't perfectly round. No idea if that's a tire or wheel issue - though a bent wheel should have turned up during the balance process, no? I will probably return to Discount Tire and have them check for run-out, because if the tires are not right, then I want them replaced. But the problem existed before and is no different with these, so I don't think this is the ultimate resolution anyways.
What else could be to blame here? Some of suggested LCABs but my guy (whom I trust implicitly) claims they're fine. But can an eyeball judgement be 100% reliable? Anywhere else to look/try? I hate to keep throwing $$ at the problem, but it's now driving me completely insane and MUST be quashed ASAP!
Thanks for any pointers.
The car comes home and has a minor shake in the front end, at 53-55 mph. It's not severe, seems to just be a run-of-the-mill tire balance issue, so I don't alert EAG nor even address it right away. It's not a common cruising speed so it's just a minor annoyance. So I thought.
I finally have the wheels rebalanced. No change. I then have them done a second time. Again no change. So I haul it off to my local indy, a grizzled veteran BMW guy with plenty of E39 experience. He examines it and deems all the suspension components to be in excellent health. He's convinced that the wheels just need to be balanced properly, suggests letting him sub it out to the wheel shop across from him and have them road force balanced on the Hunter GSP9700 machine. So that gets done - and again, no change. Shake still there. I start to communicate with EAG and their head mechanic jumps in, wants to know how the readings were from the road force rebalance. Unfortunately the shop did not supply the report and nobody will return a call, so I don't have the answer to that question. I wind up deciding to replace the front tires, which are half-shot anyways, with fresh Michelin PSS's (which the car already had all-around). No change. It's then suggested from various sources to have the car aligned. Had that done, turns out it was considerably out of alignment, particularly in the rear. It now tracks much better (was a bit of a wanderer before), and SOMETIMES the shake is gone - but not always! I can take it out for a run, and not experience it at all. I can take it out the following day, over the same roads and general route, and it's there in spades. I was beginning to think it only happens when the car is "cold" but that turns out to not be a factor.
Other notes: when the car was aligned, the new tires were a few days old. The alignment tech claims that both fronts have excessive run-out, and spun the wheels to show me that you can see that they aren't perfectly round. No idea if that's a tire or wheel issue - though a bent wheel should have turned up during the balance process, no? I will probably return to Discount Tire and have them check for run-out, because if the tires are not right, then I want them replaced. But the problem existed before and is no different with these, so I don't think this is the ultimate resolution anyways.
What else could be to blame here? Some of suggested LCABs but my guy (whom I trust implicitly) claims they're fine. But can an eyeball judgement be 100% reliable? Anywhere else to look/try? I hate to keep throwing $$ at the problem, but it's now driving me completely insane and MUST be quashed ASAP!
Thanks for any pointers.