Hi all,
ok, i have a 99 camaro z28 with the automatic tranny, in march the camaro started going into neutral when it should be shifting into third. I took it to AAMCO. They said they recommend a transmission rebuild with something called their "banner kit". I dont know anything about auto trannys so they told me its a rebuild of every aspect in the tranny, and they replaced the converter too. I was out $2300, but the car worked fine.

This week the EXACT same problem happened. slips right into nuetral when its suppose to go into third gear. I took it back to AAMCO and the say the warranty is voided because the car pulled 5 codes;

p0101 - MAF circuit out of range
p0108 - MAP pressure signal high
p0137 - 02 signal low B1-S2
p0157 - 02 signal low B2-S2
p0507 - Idle control system RPM too low

Now if you were here and here and feel this car when its on you wouldn't think there's anything wrong with it, it purrs perfectly, accelerates perfectly, gets great gas mileage, idles perfectly. however AAMCO is saying that these failures are the direct result of the transmission failing with the exact same problem I took it in for originally. Oh yea, and I only put a little over 3000 miles since the rebuild.

Im assuming that just replacing every one of these sensors and resetting the codes will fix all those codes, which is something I can easily do myself, but once that's done AAMCO wants to charge me $1000 to rebuild the tranny again.

My question is, can those sensors being bad seriously cause a rebuild transmission to loose 3 and 4 gear within 3000 miles?? Even when the car still ran flawlessly with "bad" MAF, MAP, 02, and TPS sensors?? Or is AAMCO full of it?

 

sounds like BS to me. no way a trans should fail that quickly after a rebuild. they suck.

 

They showed me some fine print on the back of the contract that says the warranty is voided on any computer controlled transmission if if the damage is due to failure of any electronic controlled components, like the computer, sensors, and solenoids. so does that mean any f*#%ing sensor that pulls a code dispite it being relative to the issue of the tranny will void warranty on a $2300 rebuild job??

I want someone to honestly tell me could those sensors really cause a transmission to loose 3rd and forth gear. It seems so much like an internal transmission problem, and i dont know much but arent those sensors mainly used to control fuel delivery and timing? What do they have to do with the shifting of the tranny?

 

Well, the first problem is where you took the car. The second is their "banner kit". That's just barely a rebuild. It's certainly not a rebuild of every aspect of the tranny. Go to ebay and search for 4l60e rebuild kit. Then search for the banner kit and you will see the difference. When the tranny is fixed, get those codes taken care of.

 

No, none of those sensors have anything to do with the operation of your transmission. The only sensor that would have an effect on trans operation is the TPS sensor, but you are not getting a code for that.

So if they are doing work on a car do they check it for codes before starting trans work and make you aware of it? If they didnt Id do something about it.

 

1. The MAF sensor meters the air going into the manifold.
2. The MAP sensor reads the air pressure in the manifold.
3. The O2 sensors monitor the air fuel ratio of spent exhaust fumes to make sure your engine isn't running too rich or lean.
4. The P0507 code is there because your car likely has a vacuum leak and your idle RPM is off.

As has been stated already, none of those codes should negatively affect the transmission. If it were me, I would go to the shop and ask to talk to the manager. Ask him to explain specifically how any of those codes could've caused the transmission to fail

If worse comes to worse, and they refuse to make things right, threaten legal action. Hopefully it doesn't come to that.

Good luck man.

 

Wow.... what a crappy shop. Give them hell!
More then likely they knew the service engine light was on when the car came in the first time. Their paper work may even reflect this. When I worked in a shop, techs were required to write down on the inspection sheet whenever a car came in with a check engine light on. This was done to cover the shop in case a customer came back and said the light wasn't on before we did the work. This happens surprisingly often.

I would bet they have a similar practice in place.

 

Very important to the operation and life of the trans is the internal line pressure which is controlled by the PCS (pressure control solenoid, also called EPS). This solenoid in turn is controlled by the PCM according to the "load" on the engine, which consists of input from the TPS, MAF and MAP. Often, if the the PCM detects a bad sensor, it maxes the line pressure (via the PCS) to preserve the trans; this results in hard shifts.

So, it is theoretically possible, that the reported codes are causing the PCM to think the engine load is much less than it really is, resulting in low line pressure in the trans; this in turn will cause the 3/4 clutch to slip and quickly burn out. All theoretically.

More likely, the fussy 3/4 clutch circuit developed a leak, causing your original problem. The quick rebuild did not find/correct the leak and the 3/4 clutch wore out again.

I think that jakemussman makes an excellent point which you should follow up on, perhaps with an attorney.

 

The MAF can cause the PCM to see load wrong causing low line or early shifts but it should have been very noticeable in the shift quality or timing, I would suspect a leak in the 3-4 circuit bad seals or a pretty common wear in the stator bore where the rings ride. This will cause failure in quick order. But indeed Big chain trans shops basically do minimal repairs in general they strive for parts cost to be 15 percent or less. and use only the most basic kits.

 

This happend to my tranny as well. My 3 and 4 bands went out

 

had this exact same problem on my ws6
car was in 3rd and drive or overdrive and it would just act like its in neutral but sometimes would catch the gears, what it is, its the clutch pack on the inside of the trans, i also did some online searches and i got back the TPS sensor would be one option so i replaced it myself for like 45$ then got the same problem took it to a trans shop guy told me exactly what was wrong and i went ahead and bought a whole new trans for a good price, wouldn't suggest doing any rebuilds unless there performance rebuilds and if you don't go to a big shop such as aamco, they just want your money,

as for the problem being resolved after that just don't dog the car in low rolls stick to higher pulls and you won't have any problems with this happening again

 

As recommended earlier, seek legal aid. They owe you a good trans.

Don't do this^.

Because of this:

The automatic downshift from 3/4 to 1/2 causes the 3/4 pack to drag because there isn't enough time for the fluid to drain out of the 3/4 clutch pack apply piston and centrifugal force uses the remaining fluid to apply the clutch pack partially.

That is why these transmission can burn up 3/4 so quickly. Much faster if you're harder on it, like high speed pulls dropping from 4th to 2nd quickly.

 

No joke, that kit is ridiculous. That kit is like rebuilding an engine with only gaskets, bearings, and rings.

Sure it'll work, but if anything else is wrong with it it'll quit again in short order.

 

So what is the correct way to shift when racing?

 

Wow I sure hope you go and raise hell with a manager or even the corporate office. I would also try and see if there's anything your credit card company can do about the charge if you paid that way.

Next time, take your $2300 and go to any of the sponsors here and have them build you an actual transmission. For that much money you can get a serious build, not some AAMCO special...

 

Manually drop it to 2nd if roll racing and hold it for a few seconds at low rpm to let the fluid drain out of the 3/4 apply piston. Then hammer it.

You're best bet is to dig race it in OD until you get the input drum drill mod done.

 

hrcslam what is this input drum drill mod you are referring to?

 

It's where you drill a very small hole in the input drum in a particular spot. It allows the fluid to escape the apply piston for the 3/4 pack but it's small enough to not hinder intentional 3/4 apply.

 

Wow, Another one for AMMCO...

A banner kit is around $100 or less. This is NOT a full rebuild. This is more of a refresh service. This kit usually includes New Clutches, New seals, New gaskets, New filters.

A Full Rebuild would address everything inside the unit including bushings, bearings, any worn hard parts, Remanufacture the pump, clean and inspect the valve body, and provide detailed list of what needs to be done to your specific unit.

The pump housing is often worn especially when the unit fails. That's why it should be serviced as well as the valve body. Often the bores can wear in the pump and in the valve body and these things should be inspected and serviced as needed. Companies like Sonnax make kits to address worn valve bores in both the valve body and the Pump so that you don't have internal pressure leaks.

As far as converters go, Most shops typically just exchange them for a remanufactured unit which can be $50-$100

As Frank from Performabuilt stated these big name shops try to keep their parts cost under 15%

As you can see, with new fluid and parts they are under that percentage. They also don't pay their techs at the top of the pay scale for that industries either so figure another $200-$300 in labor and maybe an additional $100 going back into the shop for supplies, electricity, rent. The rest is basically profit for the shop...