Transmission Problem, Help Please

[techmanbd]

Hello,

 

I have a 2001 Chevy Silverado. I have a problem with my transmission. Can't take to dealer because no money and wouldn't you know, at 37000 miles, 1000 miles after the warranty I have a problem.

 

Ok here are the symptoms. When I take off from start, it will not shift into 2nd until 4000 RPMS with the gas barely pressed, If I gas it, it hits the rev limiter and stays there and will not shift up. Another symptom I have is that when I am cruisin on the freeway and I need some speed and I gas it and it hits the overdrive it will tack out and the rev limiter and will not shift back.

 

I have put a diagnostic computer onto it and have no fault codes.

 

I was thinking maybe a vacuum problem? I checked for any leaks but don't have any that I can find. The fluid level is fine and not burnt.

 

Anybody think of why it doesn't shift?

 

appreciate any advice on where to look at.

Thanks in advance

[citydriver]

I dont think its a vacuum problem You may have a 4L60E tranny,and its electronically controlled....FRED(Freekin Rediculous Electronic Device)...Could be a bad solonoid,Might wanna check 4 service bulletins...but you need to knw which tranny you have...

[Shaners]

In an '01 the tranny would be a 4L60E.

[mikez]

I fixed a transmission for a friend of mine one time in his 1994 Z28. He had just put a shift kit in about two weeks prior and he was having similar problems to what you are describing. The car would not shift into 2nd gear and the only way that you could get it to upshift was to let off of the gas or just barely give it throttle. When I pulled the transmission apart I found that the band had come loose from the plunger out of the servo. The band is in the front of the transmision or valve body. You shoud be able to pull the pan and look towards the front of the valve body towards the servo and see if this is your problem.

[citydriver]

Best to do a test drive w/a scan tool to see if the tranny is shifting when FRED(PCM) is telling it to..It may not always set a trouble code..could be a loose pin in the wiring harness...if you have access to a scan tool..have someone else read it,or drive while you reads it..Some tranny shops in my area will do this service relatively cheap ($30) or even FREE Wouldnt hurt to let your fingers do the walking in your local yellow pages....The dealer is NOT the only game in town,as some would make you beleive

[techmanbd]

thanks for all the responses. I do have a scan tool a friend from work let me borrow that works on My year truck.It is the predator diablo. So if the FRED(PCM) tells the tranny to shift and it doesn't then that means possible electrical? when it "TELLS" it what does the scanner show. Like binary? if I see a 1 then it is telling to shift. or another code?

[citydriver]

Its been awhile for me,but There should be readings in the flow for tansmission shifts,my PRO-LINK would read it as IN GEAR-yes/no,1st-yes/no,2nd..etc.. CONVERTER LOCK UP...usually FRED will send a signal to the correct solonoid to shift the tranny to the appropriate gear...and Yes that part is electrical..you should try a visual check on the wire harness connectors at the tranny,you should be able to disconnect them and plug them back in(do this gently,so not to bend pins or break plastic connectors)...anyhow,you should be able to see if the PCM is sending the commands or not...By the way,just in case there is a problem w/the computer, it should still be covered under the 5yr/50kmi FEDERAL EMISSIONS WARRANTY BUT that would take a little more research,at least thats what it was when I was still a tech....DEALER service writers wont always confess to this...

But all this is just a starting point B4 gettin in2 dropping the tranny pan 2 take a looksee to check for somethin loose or disconnected

[citydriver]

Also see if you can get your hands on a good service manual(factory manual is best) But Chitons or Haynes will do...The good ones will have a DIAGNOSTIC flow chart to assist in finding problems(step by step)Sometimes they can be found in your local libraries B4 you shell out the $$$$

[Mule]

I have had the dealer fix things just after the warrenty as a "Good Will" repair. I had two head leaks and an intake leak and they fixed them for free. Doesn't hurt to ask the service manager.

[techmanbd]

That was nice, I called my dealer and they were just like the warranty is over basically.

 

Anyways. I checked all my wiring and didn't find anything wrong so it sounds like I am going to have to pull the pan and check the solenoid. I guess while I am at it maybe put in a shift kit in it. Any suggestions on what brand name kit?

[intruder217]

Fix the problem before you add a shift kit.

[citydriver]

Just 4 giggles,see if you can get ahold of a GM rep,couldnt hurt to try that or try another dealer...BUT you should find the problem 1st B4 try'n you add a shift kit.I'm not familiar w/the predator diablo,I guess I can assume that didnt help... ...

[techmanbd]

The only thing it helped me on is that none of the sensors are bad. No faults. When in the live mode it didn't have that option of FRED. it just gave voltages of O2 sensors and percentages of something and MAF sensor data.

[JDahl]

start with your tps make sure it as the correct voltages. Take you truck out for a drive, start off in manual first then take it to second see what happens If it doesn't hit you may have a broken 2/4 band. The 1/2 solonid may also be faulty. It will work electrically but it will not mechanically. If you can geta snap on scan tool you can also comand the trans to shift. It will tell you if the solenid is working by watching the pressure switch readings.

I hope this helps you out

John

[techmanbd]

Thanks JDAHL

 

I did the driving in manual mode and came up with hopefully a better discription of problem

 

When I am in first I tach up to 5000 rpm then when I put it in 2nd there isn't any shifting up to 2nd. When I put it in 3rd it feels like it quickly shifts into 2nd then right into 3rd.