I have a 1996 Monte Carlo Z34. Has 3.4 engine and 4t60e transmission. The transmission leaks when I start it up, continues to leak at low speed and idle, doesn't leak much while in higher RPM's. I have taken it down and changed the seals, fluid, and filter. Any ideas on what could cause this???

 

ususlly age or the gaskets at the time got pinched and started to make fluid to leak. also keep a eye on the bolts were they loose?

 

how can you tell it doesnt leak at high rpm? is it leaving a trail of fluid when driving?

have you checked the lines to the transmission cooler?
like Monte07 said are there bolts loose? i have seen transmission pan bolts work loose.

you "have taken it down"? you mean you are doing a rebuild? or do you mean you dropped the pan and are doing a service?

if you are leaking fluid while parked and engine running i would look at the cooling lines coming out of the trany. if it is leaking at the pan, it shouldn't matter if the engine was running or not. only other thing that makes sense is if the bell housing is cracked and the Tq converter is spraying fluid? very very unlikely.


we deff need more info to help... how much is it leaking? how low is the dipstick? if parked where about is the drip or puddle at?

 

I took the transmission down a couple of weeks ago because it was leaking (looked like it was coming from the front seal on trans). I changed all 3 seals and changed fluid and filter. It stopped the leak for a little while, but has started back. At startup it leaves a puddle, looks like about a quart, then it leaves a trail of fluid down the driveway and then the trail stops. Someone told me that there is an o-ring around the pump inside the trans that may be bad. Ever heard of that?

 

All bolts on the pan are tight. The leak is coming from the torque convertor area. Cannot pinpoint the exact area it is coming from. It doesnt sling transmission fluid all over the bottom of the vehicle, usually drips straight down. (which is why I say it doesnt leak at higher RPM's) I can get a transmission out of a 1997 Grand Prix GTP, but it is a 4t65e, and I do not know if it will bolt right up or if the electrical connections are the same. Please help!!! Thanks!

 

a 4t65e wont work on a 96 the connectors are diff, gear ratios are very diff. the PCM will not control it. i have friend who got a 97 Z34 harness and PCM to use his 96 DOHC engine and run a 4t65e. it worked but was a lot of work.

how does the vacuum modulator look? could it be leaking there? try to spray the trany case down with degreaser and hose it off and look for fresh fluid. maybe the dipstick tube is loose?

it doesnt sound like a pan prob. and if the trany cooler in the rad is good, and the lines are good the only parts could be the distick or Vac Modulator. there is a top vent on the trany i think it is there to drip off extra fluid.... but doubt the trany is that over filled.

 

I have checked everything on the outer of the transmission (I think). There are no leaks coming from the lines or the modulator. I installed a new rubber grommet for the trans dipstick. The transmission is not overfilled, barely shows on the bottom of the stick after start-up and a quick ride down the street. I do not know how to check the trans cooler in radiator, but it circulates through. The lines are clean so no leaks from there.

I am guessing I may have to do a rebuild on the trany. I was going to attempt the swap to the 4t65e, but seems to be too much trouble.

Is it extremely tough to rebuild a trans with a kit from the auto parts store? Never rebuilt a transmission before, but have rebuilt engines (never front wheel drive though). Any suggestions? Thanks!

 

I have 2 transmissions. Both are 4T60E, but have different numbers on top. One has 760 and the other has 771. Is there a difference in the gears ratios or is there a difference in the transmissions? I do not know what exact vehicle the transmissions came out of.

I am installing the transmission in a 1996 Monte Carlo Z34. Please help identify the differences if any. Thanks!!

 

Is there different color plug-ins on different transmissions for 96 monte carlos?