First of all, this is a car that I am just about to buy. Secondly, when I went to see it, (after I wrote an initial post about it having a seller-disclosed transmission issue) I found out it was an Automatic transmission. The person I was dealing with, was quite hard to understand. I am positive he told me on the phone (after I asked) that it would still go into 4th and all the other gears - it just would not go into 3rd. When I finally got to see the car, I was confronted with a very neglected Vette. Among the many issues that may be facing me, the transmission issue is the most worrisome. When I drove it, the transmission attempted to move from 2nd to 3rd at about the right RPMs, but it would instead go to a neutral state, and the engine would just rev under gas pedal demand. I found I could easily hold it in 2nd, so it will be drivable a short distance to my home, should I buy it.
My question now more accurately remains: what would cause this transmission to not shift into 3rd during normal driving conditions? I'm hoping it may be related to a failed solenoid, that can be accessed by removal of the transmission pan. More specifically, I was hoping that replacing the 1-2 shift solenoid valve and the 2-3 shift solenoid valve (both of which seem accessible by removing the transmission oil pan) could be a possible solution to this issue. Does anyone think a failed 2-3 shift solenoid valve could be causing this issue? If so, are they really changeable by just dropping the pan?

 

Since you don't believe the short answer, I'll give you a longer one. The way the trans basically works is that the computer energizes (or de-energizes) the shift solenoid (which there are only 2 for all 4 gears) and then the transmission shift gears. The transmission simply will not shift if a solenoid has failed. Your transmission does shift into 3rd but it just slips instead of engaging which means the clutch pack either fails to engage (due to a fluid leak) or is burnt so badly that it just slips instead of grabbing.

If I recall correctly, here is the pattern for the solenoids.
1 - X X
2 - _ X
3 - _ _
4 - X _

So, both are on to get 1st gear and you posted that 1st worked which immediately tells me it's not a solenoid failure. A failed solenoid would not energize and you'd be stuck either without having 1st and 2nd or 1st and 4th (and not slipping but just not shifting to those gears). I would have to believe GM did this so the trans would default into 3rd gear which allows the car to be driven somewhere to get fixed if a solenoid failed or the PCM driver or wiring to a solenoid failed.

A failed solenoid will also throw a code. Read the codes and see what you find.


READING YOUR C5 Engine Diagnostic Trouble Codes (DTC)

This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.

The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.

Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.

There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.

Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.

Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.

 

As stated. This is NOT a solenoid. Both shift solenoids are OFF for 3rd gear. The cause of a no 3rd or 4th is the 3-4 clutch pack is wasted.
I've been building these things since 1993. 3-4 failure is the most common issue with a stock 4L60E.

Frank

 

You are completely correct with all this information. Thank you...LOL This is stuff I usually have to write.

Frank

 

Is the price on this car so good that you can't pass up "a very neglected Vette" and search for something maybe a little less neglected and a functional transmission? If the transmission is the only thing acting up now, what might be next if it is so neglected?

There are lots of nice C5s out there and if you search/research you will find one that you will be able to enjoy.

 

>>Is the price on this car so good that you can't pass up "a very neglected Vette" and search for something maybe a little less neglected and a functional transmission?<<

Well under $10K.

Lionel and Thumpin - you both have my deep appreciation. With your welcome replies, I now have more data from which I can make my decision - buy or run. Fall and winter are just around the corner, my 2001 is in prime condition, and I am thinking this 2000 is a decent project. My concerns are still high, however, since Bill Curlee informed me that EBCM and Steering Sensor modules are no longer available for the 2000 year model. In my inspection (last night) I did not get to run the codes, but I did see that "steering sensor" was announced on the DIC.

I will see where negotiations take me, and will close out this thread with my decision.

 

Frank

I think you hit my problem on the nose, wont shift into 3rd,

Best quess please, how much to replace 3-4 pack

Thanks

Jack

 

While it is possible to just replace the clutches, it's not advisable. GM built many "design flaws" into the 4L60E that contributed to 3-4 clutch failure. We make many updates, modifications, and changes just dedicated to that particular area. I'm not sure what most other shops would charge for just repairing the 3-4 clutches, but we get $300 for it if you bring me the trans. The labor to remove/reinstall a C5 4L60E is $1000. That alone is a good reason to just have the trans completely rebuilt while it's out.

Frank

 

I have decided against buying this car. Thanks again to all who helped me understand this transmission issue. Mods, please close this thread.

 

My c5 shifts into gear an moves it even has reverse. But when i drive it doesnt want to shift. It has to be floored for it to change gears by itself

 

This trans is DUST !!! The 3-4 clutch pak is the weakest in the trans and always the 1st to go---It is not going into neutral----It is slipping--badly----and will only get worse--eventually losing the 2-3 pak and finally all of them----You would need a new trans---A rebuilt trans with a warrant can be purchased for around $2500 plus installation---
But as you say if the car appears to be NOT well cared for then I would suspect every system on the car may be ready to fail--- Unless you get the car super cheap and are willing to spend the $$ to get it back to good condition I would pass on it--By cheap I mean like 3-4 K

 

3 year old thread

 

Wise choice: There are lots of well maintained cars out there!

 

That matters not. 😠

 

Nice you noticed my comment on a then 3 old thread now that it's a 9 year old thread. 🤣

 

direct clutch is fried.