4L60E Vibration at Higher RPM's

I would like to know the outcome of the bad balance, is it fixed?

 

Yeah, what MartyK said. What happened? Or do you now drive around with an egg under the pedal?

 

I plan on putting a washer under one of the three bolt heads holding the torque converter to the flex plate. I'll check to see if the problem got better or worse. If worse, remove the washer and put it under the next bolt head. Repeat. Then try the last bolt head if necessary. I've been putting that off since the last post. I will report on results as soon as I try this.

 

If you do that, you risk not only putting the flexplate/TC coupling out of natural balance, you also risk putting undue stress on the flexplate, which could lead to cracking. Has a qualified mechanic inspected the drivetrain? some things to look for are an incomplete bolt-up between block and bellhousing, lost flexplate weights, flexplate damage (such as from a rock, not every car has its lower cover in place), crank damper damage/slipped annulus, bent CV axles, bad wheel bearings, etc. I don't believe this is a bad engine necessarily, as you describe the vibration only 'at speed.'

 

Andrew,
Please tell me how putting a washer under one of the three bolts holding the torque converter to the flexplate will put stress on the flexplate? The washer goes under the bolt head, not between the converter and flexplate--no stress possible.

The shop that rebuilt the transmission (which is when the vibration began) offered to change the torque converter. If it fixed the problem, no charge. If the vibration persisted, $500 charged to me. He said the problem is the SBC, which always vibrates under power. That's absolutely not true!!

I've spoken with several "car nuts" and they agree the risk free way to troubleshoot this is with adding washer(s) for balance weights. I do not see a downside except for the effort (minimal) to remove the inspection cover and install the washer, checking for improvement or worse vibration.

 

So, after reading through this thread my thoughts are this; If the vibration is engine rpm related, regardless of gear selected or road speed that pretty much rules out the driveshaft and MOST of the transmission.
The engine would make sense if it were not for the fact that the vibration wasn't present before.
This leaves everything turning at engine speed, the flywheel/flex plate, torque converter, transmission pump, etc.
The flex plate was most likely not disturbed during the overhaul, this leaves the TC, pump and whatever else is spinning at engine speed inside the box.
The trans guy who stated all SBCs vibrate is either an idiot, thinks you are or knows what's wrong and ain't saying. I suspect the former as he's willing to gamble on the TC.
If it were me I'd just demand they make it right. It's not the engine if this wasn't there before, unless they disturbed something else of course. I have had personal experience with O2 sensors wires being swapped bank for bank by a trans shop on a Jaguar that caused all sorts of running issues. It's possible they did disturb something engine related.
First Eliminator's suggestion about checking the TC seating into the crank snout makes sense

 

I reread your post about the washers and saw that, in fact, you did say it would go under the bolt head, so, my apologies. I read it as putting the washer between the flexplate and TC mount pad. So, as long as the flexplate was damaged in any way, I concur with the possibility of a problem with the TC's snout and the rear of the crankshaft.

 

Any resolution to this problem?

 

I'm having the same issue with my BMW 535i. The dealer charged me $165 to tell me it was the motor mounts. I had the motor mounts replaced and the problem is still there. 1400 rpm vibration no matter what gear it's in. I'm thru throwing money at it and will live with problem, I like the car.

 

What year is that Bavarian? I'm pretty well acquainted with some of the older E28,34 & 39 chassis.

 

2011 535i.

 

No experience with those, sorry.
BMW club or one of the BMW forums might have some insight if this is a common issue.

 

yeah, not really. The odd thing is if it were a bad harmonic balancer issue, wouldn't the vibration be evident when the car is in park and the engine is revved to 1500 rpms? This just happens when the car is in motion. If I were a better mechanic, I might think it was an issue involving the marriage of the engine and tranny

 

try posing your question here https://www.bimmerforums.com/forum/forumdisplay.php?322-2011-(F10)
There are also a few very knowledgeable pros that hang out in the general mechanical sub forum on the main page.
The knowledge seems to trickle down into the chassis specific(yours is F10) sub-forums as the cars age, yours is bit new for enthusiasts and DIYers that are the bulk of most of the sub-forums.

 

thanks, I'll give it a shot