Ok, I searched for this pretty extensively, but found nothing similar. This may not be anything to worry about, but if anyone has any input I would appreciate it.

For the most part, my transmission shifts just fine...nice and firm, moderately quick shifts. Occasionally, though, when I am running out second at about 2/3 throttle, it will jump in and out of third, like it wants to shift to third but then decides it wants to downshift back to second. It is not slipping, just shifting back and forth. Like I said, it is only occasional, and only at around 2/3 throttle. If I put it to the floor at this point, it winds out second a little more, then shifts firm into third and is fine.

Is this just a throttle position issue and I need to live with it (in other words, avoid 2/3 throttle from 2-3?)

Any help would be cool, even if it is "don't worry about it."

 

It'd probably make more sense to ask this on the Transmission and Drivetrain forum instead of the V6 forum.

 

Most likely it is just the position of the throttle at that second when the tranny is shifting.I have the same problem sometimes when it shifts to 4th.It bucks almost and then downshifts to 3rd.

 

Thanks V8 Slayer, makes me feel a little better at least knowing someone else has experienced it too.

I'm not real worried about it right now, but if it gets worse...

I've only had the car for about 2-1/2 months, but I'm loving it so far.

 

When it does it your probably around 40mph, that's when my car does it. I just accelerate to 43mph or slow down to 35 and it'll go away, it's like 39mph to 41mph that it does it.

 

Check the ATV cable that goes from the accelerator to the tranny...it could be stuck.....the other thing is that the TCC is working bad......it looks like the same situation I had when my car had not speed sensor...TCC worked whenever it wanted to......

 

Yeah this sounds more like a TCC issue to me and you're misinterpreting it as a shift.....

What Nocturnall is describing is DEFINITELY TCC. The lockup point seems to be right at 40 mph, and this is where the TCC issues primarily happen.

This is TEXTBOOK stuff, seems to be real common for the 700-R4's

Follow these directions: https://www.thirdgen.org/newdesign/t...ueswitch.shtml

then when it starts happening, flip the switch and see if that doesn't solve it. If it does, you've got a jittery TCC lockup switch. My Camaro had the same issue.....I installed the lockup switch, used it as necessary, and had no more problems. (FYI: Leave switch OFF until you reach cruising speed. Only leave it on during cruising, or when youre only making slight acceleration or deceleration movements. If you get going too slow, you need to turn it off or it will start to buck. Basically smooth steady driving. Using it otherwise will cause excessive wear on the converter and lockup solenoid and possibly cause damage.)

 

Thanks all, going to try the switch.

 

my tcc is starting to have a locking/unlocking problem. where it will feel like a shift but really its only a 2-300 rpm difference when it happens

but for me to have someone replace a tcc is almost the same to have a trans swap. and a used tranny comes with a tcc. and my od bands are shot anyway.

theres also performace tcc's you can get.

so when mine is too bad to drive any longer, aka drive it till it blows, i will do a used tranny swap and a new tcc.

 

Go under the hood and with engine off, play with throttle. You'll probably find the cable to be taught and OK
It's the way you are driving that makes ya "feel" this.
No need for a switch due to it's probably fine.
Yeah the up shift in the 35-45 range.
What I would do is get it serviced and that service will tell ya it's it's toast or not.
And your year 700R4 if never swapped out for an earlier vesion, is one of the best year trannys to have. When rebuilt right, it's strong (so I hope, I have an 88 or 89 rebuilt tranny in my 1985). A 10 vane pump compared to earlier 7 vane pump is the main ingredient of extra strength in the later trannys.

 

Thanks KED85. I played around some this morning while driving and I'm pretty sure you are right about it just being the way I drive. Like I said before, other than that, it seems to be working great.

 

IF it hasn't been serviced, tho I would do that soon as in getting ready for summer driving.
I killed my tranny last year due to overheating engine.
And this way you'll have strong educated guess on tranny condition.
Hardest part is finding the good tranny shop.
It does take a bit of learning how to "drive these" 700R4s.
The key is city driving. Once learned accepted "operation" of that condition, ya learn to relax on those upshifts.
The lighter on the gas pedal, the better is the driving. The torque convertor lock out "feel" in 3-4 gearing is the hard part to get used to. And it all happens during that 35-45 MPH range, city driving.

 

Karl is right about all that. However, you can't always 'drive through' the lockup issues. I tried for 6 months, but it got progressively worse, to the point that it was causing excessive wear on everything, because I couldn't always go that 2 or 3 over or under due to the traffic where I live. So, the switch worked for me and stopped those issues..and overall made the car much more enjoyable to drive. And it only took me about 30 mins, and I'm about the worst electrician you could possibly imagine. So if I can do it...it's really not that hard.

What it boils down to is, if you can deal with it, okay! But the switch isn't some bad thing or a "duct tape fix"... If you use it properly, it will do its job exceptionally.

 

That is also a correct response, too.
If previous history of servicing is kinda unknown, it is wise to have it serviced within some time soon. The guessing can then stop, cause you will know.
At same time check your cooling system as you say the car to you is used and recent.
Cooling problems will also harm your tranny, as I mentioned. Summer is coming.

 

Cool. Thanks for the good avice from all. Everything was serviced after I bought the car, but like you said, previous history is unknown. Seems to me like it was well maintained. 89,000 miles and no leaks, doesn't burn a drop of oil or lose any tranny fluid. Oil looked good before I changed it, and I was told it was about 2,700 miles since last change. Cooling system works fine but is stock, which I will be addressing shortly (180 thermostat and fan switch.)

This board is awesome, glad I found it. It is nice to be able to benefit from so many other peoples' experiences (good and bad) and hopefully give some back soon.

 

The key to these cars is making them work correctly, stock.
GM did alot of work to make them not come back for warranty work.
Fans should come on at 220* & shut off at 200*. Or come on with AC operation.
What could be done more is replace all those hoses and be prepared for one day the dreaded heater core challenge.
Replace those hoses to the heater core area & in front of engine and the upper & lower radiator. Then see if the thermostat needs replacing. IF all cooling shields are there & car does the 200*-200* drop your system is good. Fresh anti-freeze fluid is the key, also. Get the pre-formed hoses (ask for gates or goodyear products) that hose choice is mandatory.
Another key to good shifting is a good exhaust system.
Street legal headers are available.