Car is eating pressure plates what gives? E36 M3 1995

[Brad @ evosport]

Pricey and not legal for stock or prepared classes.

cheaper then the alternative of breaking strap designs over and over.

The rules may be a changing, so I would not rule out the OSG Super Single.

Thanks
Brad

[S.Lang]

OK, I have been watching this thread for a while and biting my tongue. I'm sorry, but if you go through 3 pressure plates and all is true with the OP's post about driving style, etc....then you have another problem that needs to be dealt with. There is a vibration that is killing your PP's!

Your PP is a canary in a coal mine. It is the symptom, not the disease. Regardless of manufacturer, all flywheels are just hunks of metal, and like anything else are subject to potential issues. But the reality is, the most logical place to start is the flywheel. Pull the tranny, put an accurate torque wrench on the flywheel bolts and check to make sure they have not been backing out. Then remove the flywheel, take it to a machine shop, and have it checked for both balance and runout. If the flywheel bolts have loosened at all, take a good look at the mating surface of the flywheel where it sits on the crank.

If there's anything out of spec, try a different flywheel.

I've been down this road, with an AASCO flywheel, and it's the definition of insanity to keep throwing new PP's at this car thinking "this one might solve it". Not only that, to throw another, "beefier" PP in the car that is going to withstand the real problem, is only asking for problems elsewhere later. Bearings, seals, and worst of all, oil pump keyways and crank hub bolts/vibration dampeners are all in danger.

[Brad @ evosport]

when Scott says he has been down this road - he means HE HAS BEEN DOWN THIS ROAD! lol

[ssburns]

OK, I have been watching this thread for a while and biting my tongue. I'm sorry, but if you go through 3 pressure plates and all is true with the OP's post about driving style, etc....then you have another problem that needs to be dealt with. There is a vibration that is killing your PP's!

Your PP is a canary in a coal mine. It is the symptom, not the disease. Regardless of manufacturer, all flywheels are just hunks of metal, and like anything else are subject to potential issues. But the reality is, the most logical place to start is the flywheel. Pull the tranny, put an accurate torque wrench on the flywheel bolts and check to make sure they have not been backing out. Then remove the flywheel, take it to a machine shop, and have it checked for both balance and runout. If the flywheel bolts have loosened at all, take a good look at the mating surface of the flywheel where it sits on the crank.

If there's anything out of spec, try a different flywheel.

I've been down this road, with an AASCO flywheel, and it's the definition of insanity to keep throwing new PP's at this car thinking "this one might solve it". Not only that, to throw another, "beefier" PP in the car that is going to withstand the real problem, is only asking for problems elsewhere later. Bearings, seals, and worst of all, oil pump keyways and crank hub bolts/vibration dampeners are all in danger.

Scott,

Do you mind sharing what you found wrong with the AASCO FW?

[S.Lang]

Sure, the flywheel bolts had backed out, even though they were tightened to spec and loctited. The vibration continued, thus killing 2 more PP's in one race weekend and eventually loosening the crank hub, which finally destroyed the crank nose. The issue really only reared it's ugly head at CA Speedway, with its long straight/high sustained RPM run. After that the flywheel was checked out and it was found to have too much runout, whether from the factory or from the problem with the flywheel bolts. Flywheel was replaced and all the problems went away. Eventually the oil pump failed but we feel that was residual from the original flywheel issues, since the motor had low oil pressure literally from the moment it was re-started after the crank replacement/bearing freshening. Turns out one of the keyways in the oil pump failed. The primary pump rotor was still pumping, but the secondary pump rotor was stationary on the pump shaft - even though the shaft was spinning away happliy.

Vibrations are evil in these motors.....

[JamesM3M5]

to the OP: Check the balance on your crankshaft.

How do you do this w/o tearing down the engine?

Agreed. Pull the motor apart and measure crank radial runout at journal #4. Also measure flywheel axial runout at the friction surface while bolted to the crank. Have the crank balanced from front to back - balancer to flywheel/pressure plate.

Wonger broke several PPs, and it was probably from a bad junk-yard motor that was dropped in as a temporary stop-gap. His latest motor blew a rod through the block. We're going through a whole engine rebuild process to ensure he doesn't continue to have these sorts of failures. Doing it one time, the right (and more expensive) way, will save you money and hassle in the future.

[S.Lang]

Agreed. Pull the motor apart and measure crank radial runout at journal #4. Also measure flywheel axial runout at the friction surface while bolted to the crank. Have the crank balanced from front to back - balancer to flywheel/pressure plate.

Wonger broke several PPs, and it was probably from a bad junk-yard motor that was dropped in as a temporary stop-gap. His latest motor blew a rod through the block. We're going through a whole engine rebuild process to ensure he doesn't continue to have these sorts of failures. Doing it one time, the right (and more expensive) way, will save you money and hassle in the future.

Yeah, note that my issues were resolved only after the flywheel AND the crank ended up being replaced. I had suspected the crank as well but it HAD been checked thoroughly before the build. I will never know for sure if the crank had an issue since the last round of vibrations basically made it useless. The flywheel, however, definitely had issues.

I agree with your advice, but as the next step after determining that the flywheel is ok.

[RacerX]

So what spec are you guys using to determine what is acceptable and unacceptable FW runout?

[JamesM3M5]

TIS states 0.3mm (0.012") axial runout and 0.2mm (0.008") radial runout measured at outer rim. For a race motor, I'd go with half that, about 0.005-0.006" axial runout and 0.003-0.004" radial runout.

[RacerX]

TIS states 0.3mm (0.012") axial runout and 0.2mm (0.008") radial runout measured at outer rim. For a race motor, I'd go with half that, about 0.005-0.006" axial runout and 0.003-0.004" radial runout.

Of course the TIS is based on dual mass vs single mass correct? Any discussions with the FW manufacturers? James I understand that you would have a good mind for this stuff with a strong technical/engineering background but there is so much dribble about these problems that I'd like to see some data to support some of the logic behind "solutions." I mean do we really all think that a FW being out of spec is the underlying problem with all this stuff? Shea's FW was inspected and it was determined that it was a good part. I did not ask what all their measurements were as we were focusing on a couple other things, wish I had now. I do still have the part here.

Do you have a particular basis for using ~half the factory tolerance? I'm just curious if you have made some calculations, it's based on experience, etc. I certainly see value in "best guesses" when they come from those with knowledge/experience/understanding to make them.

I have felt for quite some time that it is absolutely an interaction between various parts....a SYSTEM interaction. Some of this may be due to FW runout, crank runout, damper condition, etc. I don't know and from what I've seen, no one else does either. Scott's posts have been by far the most informative yet that I've read though I have not read them all I'm sure.

At least it continues to be some interesting reading amongst a lot of drivel.

Cheers.

[S.Lang]

Of course the TIS is based on dual mass vs single mass correct? Any discussions with the FW manufacturers? James I understand that you would have a good mind for this stuff with a strong technical/engineering background but there is so much dribble about these problems that I'd like to see some data to support some of the logic behind "solutions." I mean do we really all think that a FW being out of spec is the underlying problem with all this stuff? Shea's FW was inspected and it was determined that it was a good part. I did not ask what all their measurements were as we were focusing on a couple other things, wish I had now. I do still have the part here.

Do you have a particular basis for using ~half the factory tolerance? I'm just curious if you have made some calculations, it's based on experience, etc. I certainly see value in "best guesses" when they come from those with knowledge/experience/understanding to make them.

I have felt for quite some time that it is absolutely an interaction between various parts....a SYSTEM interaction. Some of this may be due to FW runout, crank runout, damper condition, etc. I don't know and from what I've seen, no one else does either. Scott's posts have been by far the most informative yet that I've read though I have not read them all I'm sure.

At least it continues to be some interesting reading amongst a lot of drivel.

Cheers.

Jack, my stuff is based only on experience and a little common sense. I don't have any calculations - I'm not that smart. I absolutely believe that it CAN be a "system" issue as you state, but I can't ignore someone who comes in, like the OP did, and says that basically "everything was fine until I bolted up this flywheel and now my car goes through PP's like crazy" (paraphrasing)....

In THAT situation, common sense dictates that at that point you look at what's up with the flywheel, before you go pulling the motor and yanking the crank out for a tolerance check, or just keep slapping on new PP's and breaking them. FW bolt torque (BEFORE you remove the FW for inspection) balance and runout all need to be checked. The tolerance between the rear crank nose and the FW center bore also needs to be checked.

I think James is on the right track with the runout specs, as regardless of dual- or single-mass flywheel, the vibrations created by runout beyond those specs will probably be problematic. The typical lighter flywheel SHOULD create less vibration at the same given runout as on a dual mass flywheel, given that it weighs less, but the problem is, is there a damaging harmonic that's created at a given imbalance/runout on one brand of LTW FW that wouldn't be an issue on anther brand, or the factory DM FW? That's the question that will probably never be answered. In light of that, maximizing balance, minimizing runout, making sure the FW mounts up correctly and FW bolts are new/torqued/loctited is the only "best guess". I will never put another FW on my car without having it verified first.

Unfortunately, in my case, I will never know if the crank was part of my issue, as in the end, it was basically destroyed. I DO know, however, that a VERY reputable machine shop checked the crank thoroughly before that motor was built, so I am confident it was good going in. If only I had sent my flywheel in, too, at that point. Once my flywheel was checked I had basically already decided to not use it again.

On that note....used flywheel for sale!

[RacerX]

Jack, my stuff is based only on experience and a little common sense. I don't have any calculations - I'm not that smart. I absolutely believe that it CAN be a "system" issue as you state, but I can't ignore someone who comes in, like the OP did, and says that basically "everything was fine until I bolted up this flywheel and now my car goes through PP's like crazy" (paraphrasing)....

In THAT situation, common sense dictates that at that point you look at what's up with the flywheel, before you go pulling the motor and yanking the crank out for a tolerance check, or just keep slapping on new PP's and breaking them. FW bolt torque (BEFORE you remove the FW for inspection) balance and runout all need to be checked. The tolerance between the rear crank nose and the FW center bore also needs to be checked.

I think James is on the right track with the runout specs, as regardless of dual- or single-mass flywheel, the vibrations created by runout beyond those specs will probably be problematic. The typical lighter flywheel SHOULD create less vibration at the same given runout as on a dual mass flywheel, given that it weighs less, but the problem is, is there a damaging harmonic that's created at a given imbalance/runout on one brand of LTW FW that wouldn't be an issue on anther brand, or the factory DM FW? That's the question that will probably never be answered. In light of that, maximizing balance, minimizing runout, making sure the FW mounts up correctly and FW bolts are new/torqued/loctited is the only "best guess". I will never put another FW on my car without having it verified first.

Unfortunately, in my case, I will never know if the crank was part of my issue, as in the end, it was basically destroyed. I DO know, however, that a VERY reputable machine shop checked the crank thoroughly before that motor was built, so I am confident it was good going in. If only I had sent my flywheel in, too, at that point. Once my flywheel was checked I had basically already decided to not use it again.

On that note....used flywheel for sale!

Hi Scott,

Yeah, your post seems - to date - by far the most informative and scientific. I thought there was going to be some good stuff in another thread but the first few posts seemed to indicate otherwise so I stopped reading it.

One other thing in the OP's thread that is a big difference is the use of a sprung hub disc vs the stock solid hub disc....this is something no one has ever mentioned that I've seen. It's a factor. Plus I've yet to see someone change ONLY the FW....leaving the disc and PP the same as before the change. Well, Shea did this but I don't recall seeing anyone else do it, they were always installing kits. So from what I've read it's not just a FW thing per se. Sorry, I'm scientific and I have a lot of testing experience so these threads just kill me with the types of conclusions so many people come up with. ; ) Interestingly, and I've noted it before, I installed the excat same FW as Shea's - even bought the 2 that I had in stock at the same time) on another S50 with the Schrick cam kit and that car ran great until it dropped a valve....it never had any driveline issues. It was driven by many different drivers of many different skill levels - which also leads me to believe that PP's are not nearly as sensitive to reverse loading as it commonly discussed on these forums and other places. I do admit this is limited data but given it's a single car it's better than a single driver in many cars.

I definitely agree that the FW, at least as one of the components here, should be checked if there is any suspicion of a problem, just as any of the others should be checked. In fact, even switching just the FW and having a problem does not necessarily dictate that the FW is the problem. Perhaps there is something in the DM FW that otherwise masks an existing problem. I mean let's face it, a DM FW is designed as another method of absorbing engine vibrations. Essentially one is removing a damper by changing to SM.

I'd be curious to know how sensitive other components are to FW changes....DM, SM, etc. This would be an excellent experiement though obviously due to the scope of it, it's likely to never happen.

The amount of vibration due to runout a given FW will cause isn't really a function of the weight of the FW itself, it's the amount of runout and where it's located. Now a DM FW may be less sensitive to the amount of runout because it is "flexible" to some extent. That's what I mean, there are so many factors here and we are changing the system quite a bit. We all know the cranks are already sensitive at higher RPM's....we are deliberately changing one of the components designed to help this.

Cheers.

[S.Lang]

The amount of vibration due to runout a given FW will cause isn't really a function of the weight of the FW itself, it's the amount of runout and where it's located. Now a DM FW may be less sensitive to the amount of runout because it is "flexible" to some extent. That's what I mean, there are so many factors here and we are changing the system quite a bit. We all know the cranks are already sensitive at higher RPM's....we are deliberately changing one of the components designed to help this.

Yeah, I understand that, my comment was more of an "all else being equal" one. With two equal size, shape, etc. flywheels, but with one weighing half what the other weighs, with a runout issue located in the exact same location (let's say, at the outer edge), the lighter flywheel should create less vibration, yes?

Problem is..."all else" is rarely "equal". That's why the vibration issue is so damn frustrating.....the only true way to minimize/kill it, is during the build, zero balance EVERYTHING....damper (even with the bolts!), crank with hub and bolt/washer, FW, and PP. Not to mention the piston/rod assemblies.

[JamesM3M5]

Sorta blew by this on the first read but it's a very good point. James Clay and I discussed this at length during my issues and the determination seemed to be, go VERY light, or dual-mass (stock). Anything in between might exacerbate the issue.

I have this same exact thought. A single-mass flywheel directly couples the mass of an entire (albeit lighter) flywheel AND the pressure plate to the crankshaft. A dual-mass flywheel de-couples approximately half the mass of the flywheel and the entire mass of the pressure plate from any crank vibrations. a super-light starter ring and multi-plate clutch is much lighter than the dual-mass flywheel's first section (bolted to the crank), and its polar moment is much smaller, as well. For 3.2L race motors with long-stroke cranks, high power output, high RPMs, etc, it makes more sense to stay with a dual-mass FW or go with a really light multi-plate clutch. All the aforementioned conditions - broken flywheel bolts, broken damper keys/keyways, broken oil pump shafts, etc - are much more common in cars with lightweight flywheels.

[magnetic1]

Wonger broke several PPs, and it was probably from a bad junk-yard motor that was dropped in as a temporary stop-gap. His latest motor blew a rod through the block. We're going through a whole engine rebuild process to ensure he doesn't continue to have these sorts of failures. Doing it one time, the right (and more expensive) way, will save you money and hassle in the future.

That's what I get for not listening to you guys. But this time Im even getting the crank balanced.

[JaredM3]

Update* Flywheel went back to the manufacturer and they installed a new friction surface, not quite sure why and they claimed it was within spec as far as balancing.

When I got the flywheel back I brought it to a highly recommended balancing shop that specializes in engine balancing.

The facts:

Flywheel was in fact out of balance (enough to cause significant vibration in high performance applications) according to the shops initial specs on the flywheel were 15 gr/in (not too good) and the friction surface was less then .002 of runout (good)

The flywheel was balanced to less then 2 gr/in

I also had the pressure plate balanced and the disk

I tossed it all back together, upon start up I immidiatly noticed how smooth the motor idled, I had originally thought it was rough due to poly motor mounts...also through out the rev range there are no vibrations especilly between 6-7k where I had a significant vibration that I wrote off as the trade off of motor mounts...

Those are the facts so far so good Thanks for all the support guys

Moral of the story: Have rotating components balanced for both race cars and street cars.

[savage217]

What a pita. Glad you got it all sorted.

[99MPower]

What a pita. Glad you got it all sorted.

no kidding.... a 3rd party shop that determined with no bias that the flywheel was improperly balanced....

good to know

[Brad @ evosport]

what make was the flywheel? That could help lots of us. I have a certain brand on my e46 now and am having all kinds of weird crap starting to happen. I have to pull it and see on the balance. I was rushing to install and did not balance (even though I know better!)

[bennyfizzle]

what make was the flywheel? That could help lots of us. I have a certain brand on my e46 now and am having all kinds of weird crap starting to happen. I have to pull it and see on the balance. I was rushing to install and did not balance (even though i know better!)

???

:d

[Brad @ evosport]

oh, if it turns out mine is a problem and/or out of balance, I will have no problem naming it. It is a brand we have never had a problem with, but if it is the same as the OP here and one other person I know who is having problems, then it would appear to be a product QC problem.

[raydoc]

Update* Flywheel went back to the manufacturer and they installed a new friction surface, not quite sure why and they claimed it was within spec as far as balancing.

When I got the flywheel back I brought it to a highly recommended balancing shop that specializes in engine balancing.

The facts:

Flywheel was in fact out of balance (enough to cause significant vibration in high performance applications) according to the shops initial specs on the flywheel were 15 gr/in (not too good) and the friction surface was less then .002 of runout (good)

The flywheel was balanced to less then 2 gr/in

I also had the pressure plate balanced and the disk

I tossed it all back together, upon start up I immidiatly noticed how smooth the motor idled, I had originally thought it was rough due to poly motor mounts...also through out the rev range there are no vibrations especilly between 6-7k where I had a significant vibration that I wrote off as the trade off of motor mounts...

Those are the facts so far so good Thanks for all the support guys

Moral of the story: Have rotating components balanced for both race cars and street cars.

I had my prior lightweight flywheel/friction disk/pressure plate balanced, likely at that same shop and was shocked at how far from spec it was. When it all fried and I had to replace it (with a brand with far less history) I had it too balanced. It was far closer to balance from the factory.

If you believe Mike (the balancing guy), if it spins, you balance it. Get your trailer tires balanced, it makes a difference in towing stability. Get everything balanced!

[=BA=]

Is it just the flywheel that needs balancing, or the clutchdisk and the pressureplate as well?

[ZHP]

Is it just the flywheel that needs balancing, or the clutchdisk and the pressureplate as well?

Everything, as an assembly. I just recently had to deal with a majorly out of balance pressure plate. For serious track duty seeing extended high rpm use, it's wise to include the crank and damper as well.

[gdeangel]

2 years ago I replaced the original clutch and flywheel with a UUC ltw flywheel that uses a M3 PP and a sprung disk.

......

My finger is pointing toward the flywheel because I never had clutch problems before it went in.

Update* Flywheel went back to the manufacturer and they installed a new friction surface, not quite sure why and they claimed it was within spec as far as balancing.

When I got the flywheel back I brought it to a highly recommended balancing shop that specializes in engine balancing.

The facts:

Flywheel was in fact out of balance (enough to cause significant vibration in high performance applications) according to the shops initial specs on the flywheel were 15 gr/in (not too good) and the friction surface was less then .002 of runout (good)

The flywheel was balanced to less then 2 gr/in

I assume the UUC flywheel is the one that was out of balance. Correct?