Help! $6500 and 2-3 months in the shop... and the drive train whine persists...

[Vettelt193]

I am a bit late popping in on this but here is my $.02 worth anyway. I have never seen a set of quiet 4:11s after they have a few thousand miles on them. Even the ones from the factory start to whine while they are still ¨new¨.

The 2nd thought about 4:11s is the daily drivability; it is almost as uncomfortable as driving around town with a 3000RPM TC. Of course if your daily driving is on the strip with an 8000RPM engine and close ratio 4 speed the 4:11s are the way to go.

With a 6-speed, you really don't have daily drivability issues with the 411 setup because there are two overdrive gears (5th is .75, 6th is .5). By the time everything gets multiplied out, your cruise RPM doesn't go up that much.

 

[Skant]

Well, I took it to another shop today for them to look at it. In another thread, I commented that I was concerned about vibrations it was making... especially around 5500rpm or so. Well, they were very concerned about the vibrations. They asked if the shop that had put in the new flywheel and clutch had balanced any of it... I don't think so, says I. They said they were prebalanced. Well, apparently not very well.

Sooo... this shop says my car has three problems... the transmission in it is noisy (and the wrong year) and unhealthy sounding... the differential is whining on the freeway... and the flywheel/clutch is out of balance.

So... pretty much everything that I paid the first shop about $7000 is messed up, and needs to be redone right.

So this shop is offering to replace the transmission with a _BRAND NEW_ 96 ZF6 with a warranty. And they'll put in brand new OEM 4.11 gears with a warranty that are guaranteed to be quiet. And they'll balance the flywheel/clutch stuff. All of this for about $6000 total. And... it's all under warranty... so if they do it, and it's still noisy and bad, they'll redo it over and over until its right and it won't cost me a cent.

So... I guess I should look at other options, too. But that one is pretty attractive. I should have gone with them to begin with. The other shop charged me much more, had my car _FOREVER_, used parts from a junk yard that seem to be about as bad as the parts they were replacing, and generally failed to do what I gave them all that money for. So I guess I just plain threw away $7000 on the wrong shop. Damn.

- Skant

 

[Ken]

It ain't gonna make ya feel any better Skant, but you ain't alone. I've had my fair share of ****-ups in this latest round of projects.

Good luck with getting yours right!

 

[SPANISHVETTS]

It ain't gonna make ya feel any better Skant, but you ain't alone. I've had my fair share of ****-ups in this latest round of projects.

Good luck with getting yours right!

A lot of us have been down this road. Before I bought the race track and became associated with the Team I had given up on project cars and bikes. The TLC rock climber was in pieces for 3 years trying to get the trany & xfer-case to fit together and the 82 GoldWing stayed in various shops for over 5 years waiting for parts that I later found out did not exist.mad

The Team owner taught me to pay ½ on completion and the balance when satisfied with the work done. Any shop that will not agree to these terms does not get our business . So far we have had 5 years of good luck following this guideline but I still keep my fingers crossed every time we have to use a third party for any service.

 

[Skant]

Well, that shop did have me pay half up front. And I paid the other half when I picked the car up. And now I've figured out that most of the work they did is messed up. I guess I made a mistake in paying them the other half. Though I imagine they wouldn't have let me take the car without paying the rest. How does that work?

At this point, I'm thinking I should ask them for a partial refund (the new clutch seems to be working... the flywheel and transmission are no good). However, I tend to doubt they will comply.

Isn't there some law about a shop not being allowed to charge you for a failed repair in California? Something along the lines of not having to pay for service you didn't receive?

*shakes head* I'm probably just screwed.

- Skant

 

[Skant]

I've been calling around for additional professional opinions and such. And I'm disturbed by the response I got from S&K Speed in New York. I was referred to them to ask about it by a corvette shop here in Mountain View.

S&K Speed said that it's an engineering problem with the ZF6. If you change the rear end ratio, it changes all the vibrations in the car, and it will make the ZF6 noisy. They say that the rear end is probably actually quiet. If you put it behind another tranmission, it would be quiet. This whining sound is normally present around 90mph and the 4.11's just bring it down to where you hear it. Any different gear than stock will make it happen mated to a ZF6.


Could that be true? I can't be the only one who's ever tried putting a 4.11 behind a ZF6. Am I trying to make the impossible work? Are there other people on CAC with this combination that don't get this noise?

Are there maybe other CAC members in the bay area with 4.11's and ZF6 that could maybe take me for a ride and I could hear what their cars sound like. I've driven 3 other C4 corvettes with ZF6 trannies in them and they weren't loud at all. But they didn't have 4.10's in them, either.


Gah! Now I'm afraid of the idea that I could spend another $6000 and still be wasting it. What if I'm trying to do the impossible?

- Skant

 

[DkBG]

Well , on the bright side , if these are the sounds your hearing , (and I believe thats very possible ) then maybe running it with those sounds won't do any damage to anything . Did they say anything like that ? Cliff

 

[Moonunit 451]

Two words: Gordon Killebrew --- http://www.gordonkillebrew.com/

 

[SPANISHVETTS]

Moon,

When did you put on the GS strips? I like them but I already draw too much attention so I try to keep Thunder looking rather dull.

Skant,

I stand by my guns on the 4:11´s… no matter what you do they are going to talk to you. Rereading the thread your tranny worries me more than the third member. For the $ you have spent you could have stuck in a Richmond…but then looking at Ken’s ordeal that may or may not have been a better choice.:confused

Do you still have the original 3rd member? It is not that much work to reinstall it and see what happens.

 

[Moonunit 451]

Moon,

When did you put on the GS strips? I like them but I already draw too much attention so I try to keep Thunder looking rather dull.

Hey SPANISHVETTS Just put on the hashmarks around mid June before I went to the PE 130. I thought about the attention, and the GS stripe as well. Decided against the stripe, but went with the hashmarks, left only for accent. No troubles so far

 

[Skant]

Alright.. the saga continues...

The 1st shop called me because the 2nd shop had talked to them wondering about this thing with not standing behind their work. So the 1st shop called me concerned that I was still unhappy.

Well... umm... yeah... I spent $6500 on eliminating one bothersome noise... and ended up with the same bothersome noise plus two new problems.

So I took the car over there and we talked about it. They agreed the car had an out of balance problem with the new flywheel. They'd definately need to take care of that (for free).

I started talking about the possibility of the ring and pinion being an issue.

They want to prove stuff to me, so they call up Tom's gears... where they got the gears from... Tom's says the gear we're using is actually made by US Strange Gears. And... they say they set it up in the same way and in the same application, and they experienced the very same warbling whine on the freeway I have!

Go fig.

They also said that if the customer would not accept the noise, use Dana thick cut 4.11 gears.

That shop doesn't think I should use the Dana gears. They say they're too soft and they'll break (?!). I find that a little hard to believe. Especially considering how accurate the rest of their assessments on that particular matter have been.

So here's the deal I was able to work out:

They will replace the transmission with a brand new one for just the difference in cost between the used transmission I've already paid for and the brand new unit (which has a 12 month/12,000 mile warranty).

They will rebalance the flywheel totally for free.

They think I won't need the different 4.11's after having a new tranny in the car. I expect I will. I arranged for it anyway. They are providing two options:

Option 1: They put the Dana 4.11's in a used Dana 44 rear with a new rebuild kit, and then swap it with my rear end (so that they can use my rear end on a race car)

Option 2: They install just the ring and pinion in my existing rear end. But they will charge me the cost of the new Dana gears (something around $530, they think).

In both cases, they will not warrant that the ring and pinion won't break. They think they're too weak.



So there... well, on the plus side, at least the 1st shop is willing to try to fix the problems (where I thought they had given up on it.. and maybe they had. I'm not going to have to pay labor on anything.

I really have a hard time believing that a Dana gear is going to break in my vette... which is essentually a stock LT4. Maybe I'd need something stronger like a Richmond if I was modifying the engine a ton (supercharger)... but anyway... multiple sources tell me that Dana 4.11's are quiet.

I'm leery of swapping the rear end. I'm afraid of inhereting yet a new problem into this mess somehow. So I'm thinking of going for option 2.


It's possible that Spanishvette is right and there just is no way around annoying noises with a 4.11. But I'm gonna try... and hope he's wrong...

I know I've heard from some folks before who had 4.10's that were quiet. So I'm thinking that it's possible.. but only with the right manufacturer and proper setup.

- Skant

 

[Moonunit 451]

Well that sounds promising at least I know it sucks for ya to keep going through this, but it might just not double cost ya. I'm really happy to hear that the first shop is gonna try to make you happy, could be worse.

I think you should be thankful I'm sure it's really uncomfortable dealing with them at this point, but it sounds like at least they're trying. Don't you think it would be worth a few bucks at this point to give Gordon a call? He would likely be able to give you some good input on your choices.

 

[tntcorvette]

I feel for you. Just to tell you about the bull**** i've been through, my recent motor built by on the Chicago lands most "respected" engine builders has another, yes another, leaking head gasket.

The first one was on the driver side. I took the motor out and had the shop replace the head gasket. Put the motor back in drive it for awhile and drop it off at the body shop for a paint job. The paint job is taking longer that i'de like. My car has been sitting at the body shop since July 1, 2004. It is sanded down, masked off and ready to paint. I can deal with the delay as I want my paint job done right and know the owner personally. He has 4 Corvettes, a GNX, and about 10 other cars so no big deal.

Well wednesday I stop by to check out the car which has been sitting for about a month and a half and what do you know...the passenger side head seems to be leaking. SON OF A *****>>>>>>>>>

There was a glob of oil/antifreeze looking stuff between cylinders 2 and 4 on the block where the head sits on the block.

I was so ****ed I almost did not goto work today.

I do not trust anybody now.

Moral of the story: You want something done right, do it yourself or do your homework and deal with the best of the best.

My motor is gonna come out again. In all honesty I do not feel like taking it out. Im proabbly gonna sell the car and get a Porsche.

 

[SPANISHVETTS]

My motor is gonna come out again. In all honesty I do not feel like taking it out. Im proabbly gonna sell the car and get a Porsche.

Dealing with the Porsche will make you appriciate just how good the SBC is. RE does a lot of ¨tunning¨ on P cars. Forget doing your own work unless you are willing to spend $$$ on special tools and schools. RE has dedicated Germans to work on P cars. Yes they are good and No the cars do not drip oil when they are put back togather but at what price?
What can you say about a car that needs ¨special tires¨ to corner almost as good as a Vette?

I see a pattern of poor workmanship across the forum and it really bothers me.ad I spend most of my days telling people that Americans are proud of their workmanship or ¨if you want it done right get an American to do it.¨



There is no excuse for leaky gaskets, out of balance clutches, oil pan leaks, etc. You guys have every right to rip these so called mechanics a new A**hole.



Skant, I still think that 4:11s are overkill and that they will be noisy within a few thousand miles. Unless you are running big, fat, drag slicks there is no way to connect the power to the ground. This might be a good time to look at milder ratio. Maybe 3.89?



Anyway the first shop trying to make things right is a good sign. Good luck.

 

[DkBG]

Skant , those guys probably don't want to use the Dana gears because of the cost . They're not going to break ! Cliff

 

[Idaho Slim]

skant, sounds like the origial shop really is trying to work things out for you, perhaps going with their offer they made, EXCEPT try 3.73's instead ??

 

[MMM]

Sorry I had not read this post until today, but in the first post you state that the whine ceased whenever you stopped transmitting power to the rear gears. In the forty years I have been working on cars, this always indicated too much clearance between the pinion and ring gear. Either the pinion depth was improperly set or the contact pattern was incorrect (laterial adjustment of ring gear). I know it can be caused by bad bearings, but I suspect these were replaced during the installation of the 4:11's.
I have always done my own auto repair and sometime in my life have touched every part of a car. I am continually amazed how "professionals" cannot even properly troubleshoot problems these days. And not to pick on anybody, but I don't believe ASE certification really means much either. I have seen too many mechanics that can only respond to whatever code(s) they get from the Engine Management Systems. If the computer doesn't tell them anything then they cannot diagnose the problem.
Example - I bought a 6 month old C1500 Chevy PU in late '94. Made the mistake of not taking it out on the interstate for test. Drove fine around town, but at a steady 65 it would make you seasick because the engine surged so badly. Took it to the dealer. They put it on the computer and said it was fine. I said no. My experience with carburetors told me that the engine was running too lean. The Service Manager acted like I was just a PITA customer and told me the problem was out of round tires.
I then put him in the driver's seat and headed for I95. Got it 65, got stumble. SM said "see it is in your tires". I said take it to 80, put it neutral and coast. He did and it was as smooth as glass while coasting. Not the tires. As we drove back to the dealership I told him I wanted to see the Technical Service Bulletins on '94 PU's. While I looked thru the bulletins he took out the file on the truck. The original owner had brought it back 15 times in six months complaining of a "miss or a skip". Within 30 seconds I found a TSB that covered my truck, which stated "If the truck has high speed miss or stumble, then check to see if EPROM #xxxxx is installed. If it is, then replace with #xxxxx. The original EPROM was programmed to run the engine too lean above 60 mph." Luckly they had the replacement EPROM in stock, installed it and the problem went away forever. Enough said.
Mike

 

[Skant]

MMM: They set it up by contact pattern only. They say it was a very wide pattern and centered. They have pinion depth measuring tools, but they don't use them. Tom's Gears said they don't use pinion depth measurements either.

They did indeed replace the various bearings and such in the rear end. At least, I remember paying $120 for such a rebuild kit.

About the option of having them put the replacement ring and pinion in mine, or setup a different rear end out of a 91 to swap with mine... they say that everything will be new except the case itself anyway... and the 91 case they know is square. So it shouldn't be a problem and will cost me less. Does that seem sensible? Or could I end up inheriting some new problem?

You know... if the problem was caused by a new bearing that's defective, having them setup a different case entirely may actually be a good thing. If they just replace my ring and pinion in my current case, I don't think there will be a second rebuild kit installed.


Idaho Slim: I've been thinking about that a bit. I know that more people have gone with 3.73's. However, I'm kindof worried that after having 4.10's, 3.73's are gong to feel anemic to me. Plus, the stock car has 3.45's in it... it just doesn't seem like much a jump from 3.45 to 3.73.


DkBG: Yeah, I have a hard time believing that Dana gears would be that weak. The shop claims they had some trouble with customers breaking them... but I gotta wonder what these guys were running and what they were doing. They're likely to be heavily modified cars power shifting down the drag strip. I mean... geez... this is Dana 44 stuff... how weak could it be?


SpanishVettes: I have thought a bit about 3.89. My car is able to hold down the 4.10's, but only just and only in a straight line. Are you saying that 3.89 is quiet where 4.10 is not? It's only a 5% different ratio... so that may be a small enough change to not feel anemic to me. And if it makes all the difference in sound issues... maybe that's the right thing to do.

I do find the 4.10 with a ZF6 tranny to be a good match, gear rangewise, though. It'd be too much with another transmission, for sure. But with the ZF6, it's really a good matchup imho.

- Skant

 

[motorman]

Please... I know this is a very long description of the history of this problem... but particularly if you know corvette drive trains, I hope you'll read this.

I'm feeling stuck. I need help. At this point, I'm so frustrated that I'm starting to become tempted to sell my previously beloved vette.

Okay... here's what's been happening.

I had 4.11 gears (Tom's Gears) installed in the car along with a number of other mods. The shop that did it guaranteed me that they would be quiet (I've heard 4.11's are prone to whine if not installed juuust right).

Got the car back after the mods. The shop warned me that they were concerned about the transmission. It was noisy. And they didn't like the metal content in the transmission fluid they had replaced.

Followed the breakin instructions to the letter. The car produces a warbling whine sound cruising on the freeway starting about 65mph. Mostly present between 65-80mph. Loudest at 70-75mph. Letting off the throttle stops the sound. Giving it more throttle lessens or stops the sound. Pushing in the clutch stops the sound. The sound has a sort of omnipresence. The sound seems to come from the rear, but it is most audible near the shifter.

I took it back to the shop that did the mods. They did a road test with me and decided that, because the sound went away when the clutch was pushed in and because of the metal they had found in the transmission fluid, it was not the rear end. They say they spent a lot of extra time setting up that rear end, and it must be perfect. The transmission needs to be rebuilt.

I am not so certain. I take it to a transmission specialty shop and another corvette specialty shop for other opinions. For both of them, on explaining the problem over the phone, they thought it would be the new 4.11 gears. And for both of them, when they actually road tested the car (the tranny shop actually put it up on a lift and used a stethoscope, too), they agreed with the first shop that the noise was from the transmission.

The first shop also claims that the car made these sounds before their modifications. And two of my friends say so as well, though they think they may have become louder. I think if it was as loud as this, I would have noticed. But the sound may have been present (quiet) before.

Okay. Well, everyone seems to be in agreement that it's the transmission. So I have the first shop rebuild the transmission. Two months pass while they have it because they broke a specialized tool and had to wait for a replacement. Then, when they're finally supposed to be done, they call me and tell me I'd better come look at this.

The car is on the lift with its transmission and driveline removed. They tell me to rotate the flywheel back and forth by hand. It moves freely. It shouldn't be able to move like that. That's bad. They say they've never seen such a damaged flywheel and clutch. It gets worse... they show me in the partially disassembled transmission where there's a lot of metal shards in it. One of the dogs is missing a tooth. The shafts and certain gears are losing their hardness and need to be replaced. And they're not even all the way into it yet... already the cost of replacing the damaged hard parts is prohibitive. The transmission is too damaged all over to be worth rebuilding.

The idea here is that, for whatever reason, the springs in the dual mass flywheel have broken. So each shift is slamming hard against the drive train. This has done a lot of harm to transmission. Probably before I ever owned this car.

The shop bails me out by installing another ZF6... out of a 1992 (earlier style, straight cut gears)... for the same cost as I would have for rebuilding the one. Using the owners personal backup transmission for his car. But the flywheel and clutch must also be replaced. A single mass flywheel setup is actually _much_ cheaper than the stock dual mass, and it's more performant so I go for that option. So all this costs about $6500 and takes another week or so.

I get the car back... the transmission sounds different. Several noises have been deleted. The single mass flywheel makes it's rock grinding noises (they don't both me). However... the annoying warbling whine it made on the freeway remains exactly as it was. Not changed at all. Maybe a little quieter... maaaybe. But it's been more than two months since I last drove this car.

I take it back to them. They're surprised it's making the same sound. They still believe it's the transmission. I'm skeptical, but they tell me they're so certain of it that they're going to replace the transmission with a third transmission out of a 94 for free.

In a large way, I can't fault this shop. As expensive as it has been for me, they've been taking losses to do this stuff. An entire tranny swap for free is not a small sacrifice on their part. So I have to believe they are sincere!

Unfortunately, when I brought the car in for this, they said that the tranny appeared to actually be out of a 90 or 91. It was sold to them as a used 94. It has the older style shifter with the lockout, so it couldn't be a 94. They're doing the swap anyway.

When they're done, the warbling whine sound still persists.

They say they don't want to install a fourth transmission in this car. 'It must just be the nature of the beast'. So they've ended up calling it normal and letting it go.

So here I am. I can not believe that this is a normal sound. I drove two other C4's... including another LT4 like mine... they made a lot of the same sounds mine does... they made the sounds that don't bother me... but they didn't make this annoying warbling whine sound at all.

I have had three different ZF6 transmissions in my car. And I can say that each of them have had related but different characterstic sounds to them. Different personalities. Just by listening to them, I could tell you which tranmission was which. _However_, the warbling whine sound has remained exactly the same in each case. So I have a doubly hard time believing that all three transmissions are producing this exact same sound when all the other sounds they make differ somewhat.

I don't know what to do really. Maybe the obvious thing is that it's the 4.11's. My original thought. But if my friends are right, and it was making such a sound previously and it just got louder with the 4.11's... well... I don't know. The vette makes a lot of various noises, so I think that may be confusing.

My research on the forums shows a possible match for the wheel bearings or the u-joints. I have noticed, with the car on a lift, that I could rock the rear wheels in the 12 and 6 o'clock maybe 1/16th or 1/8th of an inch. The fronts do not have any such movement at all. The shop says they've checked my wheel bearings and they're fine.

I guess maybe what I need is a shop which really specializes in corvette drivelines that's somewhere near San Jose, CA to take it to. Or... just someone to turn to. Some super expert I could show the car to and they could say "Oh yeah, that's the u-joint on the left side."

The shop where I had all this done is supposed to be one of the best corvette specialty shops around. And, as much as they've failed to fix my problem, I think that they still are. They sure tried, and then some. I've just been in very bad luck. Plus, they did show me the old transmission and fly wheel and all... they were quite damaged, so the money I've spent so far is maybe not in vain.

I think the problem may be elsewhere in the driveline. Possibly also caused by the flywheel. If the jarring forces wrecked the previous transmission... they may have also done damage elsewhere. However, the shop said the rear end looked good when they put the 4.11's in. And they applied a rebuild kit to it as well while they were at it for the various wear parts (they recommended I do this since it wouldn't be much more expense and it would already be open).

Anyway... I'm just feeling pretty bad about all this. I've spent so much money on it, and the irritating noise persists. It makes me not want to drive my vette anymore. The noise is annoying in the first place, but becomes extra annoying with the emotional baggage attached. I'm so frustrated!

Any advice? Help? Please? If I can't resolve this somehow, I'll probably end up selling this car. It's my first taste of vette, and I liked it before. But maybe it's all just too expensive and problem prone for me.

- Skant

if you have a aluminum housing the gears will be noisey as the aluminum does not quiet the noise like the cast iron housing.

 

[Ken]

I am continually amazed how "professionals" cannot even properly troubleshoot problems these days. And not to pick on anybody, but I don't believe ASE certification really means much either. I have seen too many mechanics that can only respond to whatever code(s) they get from the Engine Management Systems. If the computer doesn't tell them anything then they cannot diagnose the problem.

Sadly, that's the way it is with a lot of things the kids are (not) taught today. Common sense seems to have taken a back seat to the computer. :eyerole