Ever since i have owned the car, my tranny keeps switching from overdrive to drive(that is what it seems like i think) randomly from 35 mph to 40mph? And from 40 to 50 mph? As if it thinks im going up a hill so the rpms drop as if to a lower gear.

Is there an easy fix for this without taking out the tranny? PLEASE HELP!!!!!!!!

 

have you tried draining the ATF and replacing the filter?

 

actually i haven't! and i'm sure it needs to be! thanks!

 

This sounds like the torque converter clutch coming on and off. Disconnect the wire from the plug on the drivers side of the transmission, and make sure that it is out of the way so as not to get burned from heat from the exhaust. Take a drive and see what happens.

 

That's what I was thinking - torque converter lockup is "hunting" - locking and unlocking at these low rpm/speeds. The TC can lock as low as 35mph, but subtle changes will make it lock/unlock - One way to avoid is shifting into D rather than OD when these instances occur - like if you know it always does it on a particular stretch of road, then switch to D during that stretch - this will raise the RPM's a tad and keep the TC from locking due to higher rpms.

 

that's very common with 700r4's I just leave it in D when around town and go in to OD when on higher speed roads , It's a pain in the *** cause most speed limits are right in that 35-45 range .

 

And i guess i should mention that it really doesn't do it until the car warms up. Like it wont do it for the 1st start of the day until about 5-10 min later and will start! Thats kind of what i always thought it was, the TC messing up. "Pro Built Automatics", so take a drive with the wires unhooked(or just unhook em to check em)??? Thanks yall!

 

Seems to me that if your driving around town in OD than its going to jump back n forth from 3rd and 4th. As already mentioned above I only drive around town in D and anything over 45 is OD.(and Im running a 3.42 rear end ratio)Like entering and driving on the free way is OD.Thats it.Driving around town in OD also makes the car work harder especially if your running 2.73 gear ratio. Its like riding a bike up a hill in 5th gear.

 

But it won't shift into 4th gear until it's ready. It was designed that way. No where in the GM manuals does it state that you should use anything other than OD ... UNLESS you are towing, going up/down steep grades, etc. Just like any automatic 3 speed transmission for the last upteen decades. OD is just a 4th gear added for fuel economy - it shifts into and out of 4th gear when it's supposed to, based on load, rpms, speed (ie tranny pressures). There's nothing about OD that suggests it should only be used on the highway, written or otherwise. OD even in town doesn't hurt anything, and will save on gas mileage. Saves mileage in my 1992 carbed car, saves mileage in my 1997 Z28 LT1, saves mileage in my 1987 Ford Bronco II. My 1987 Bronco II has 280,000 miles - ALL of them in OD and most in town, with no tranny issues. The 1997 Z28 LT1 has 140,000 all in OD and 90% of it in town.

And ... ESPECIALLY when you consider the fact that, regardless of what lies you tell your mother, WE ALL KNOW that you are never going 35mph anyway (unless you are in a 25mph school zone)! EVERYONE speeds! Every old grandma, soccer mom with 18 kids in a minivan, etc - YOU ALL SPEED! Don't bother lying to me otherwise

So, given that we now can all admit that it's a cold day in hell when we are ever going under 45mph anyway, you can take rest assured that dropping into OD and never leaving is just fine for you, your car, and your gas expense.

 

"camaronewbie", see when im going on a flat and straight road, it wants to shift from 4th to 3rd, 3rd to 4th, 4th to 3rd, and so on from 35 to 50. Not on a hill, not around curves, on a flat road. It has been doing it forever, i'm just tired of it doing that. So you think that maybe it needs a rebuild and a new TC?

And could it have anything to do with the rear gears possibly being out-of-whack?(3.70s being put in tomorrow)

 

Have you adjusted the TV cable? www.thirdgen.org/detent

 

Actually i just bought the Sonnax TV cable adjuster deal(a spring) last night gunna try that out.

I just did what the article says to do, and seems like it fixed it! Definitely alot better! But when it says "you will hear a series of clicks" never heard that but ill do a lil more adjusting, but definitely helped! And shift points are at a higher RPM. Lets just say it chirps the tires a whole lot easier now!

 

Be careful with that TV cable - there's ONLY ONE position it should be in. I have no idea what a Sonnax adjuster thing is - sounds like a waste of cash to me - GM designed the cable to be adjustable, and the ONLY way to adjust it is according to the directions I linked above. There's no "play room" here - it needs to be set where it gets set by following the instructions I posted - anything different and you'll burn up the tranny!

There's many folks here that burnt up their trannies in less than 5 miles after improperly "adjusting" their TV cables.

 

Well i seated the cable deal evenly with the housing(where its snapped in the bracket) and pulled throttle in WOT, like it said, and i did not hear a series of clicks so that right there left me confused!

 

it doesn't click extremely loud , it may need to come in/out 1 or 2 clicks to be perfect . I have never herd of a aftermarket adjuster either . If anything you might need a new cable if it is not holding in place or adjusting right.

 

well i adjusted it until i got it into a sweet spot, still doing the problem as i was describing above, but not as bad so the cable is definitely the problem.

Here is the cable adjuster deal im talking about (Sonnax AS1-01K TV cable corrector). Copy and paste in eBay and you will see it.(found 1 for 7 bucks on different website)

 

here's a link for ya https://www.thirdgen.org/forums/show...9&goto=newpost . I just read a couple things real quick , make sure your trans is " healthy " first it increases line pressure and may cause damage if there are underlying problems . But it does sound pretty neat , I might look into it after a little more research .