I have a 2000 LT 4.3L, about 150,000 miles.

Here is my problem:

To start, all my gears do work. Whenever gas is applied in any gear, I do hear a whinning sound and it seems to be pretty sluggish in first gear. Sometimes it will be just fine and shift easy with no problem, but other times (mostly when its cold) the first shift will tend to be a little rough.

Other times when I put it in drive and start moving, it will slip and try to shift and there is a clunking noise. When this happens, I have to put it in first and manually shift from 1st, to second to third until it warms up then I can put it in drive no problem. Either way, it always seems to be sluggish and there is a whinning noise.

I went to my friends shop to check it, and it is not pulling any codes. Any ideas?

Thanks in advance for all your help.

 

Ever had the tranny flushed? Low fluid? Check the simple stuff first

 

What type of scanner did your friend have? A generic OBD2 scanner may not be able to access the transmission codes.

 

Just recently had the transmission flushed and the fluids are good.

To be honest with you im not sure what kind of scanner it was, he is the maintenance manager for National rent a car, so its the one they use on the newer model GM cars they rent.

 

That would prolly catch any codes but the parts stores have really good scanners might try that. Im kind of thinking its not going to be throwing any codes...yet Try autozone tho for the scanner its free and they work well