Overdrive Problem?

[Bugsy]

So I've noticed in the past week that my transmission jerks when overdrive downshifts on the freeway. For example I'll be going 55, I'll get on the gas moderately and the car will jerk a few times before downshifting. Interestingly, if I'm going 55 and floor it the car will accelerate and downshift with no problem. It's only when im lightly accelerating that i experience the hesitation. It's like the tranny is confused with whether or not it should downshift.

Is this a common problem? What should I do to fix this? And if the tranny is on its way out how much time do I have before I do the A4 to M5 swap? :P

[LETZRIDE]

Re: Overdrive Problem?

have you checked your tranny fluid to see if maybe you are low, or it needs to be changed?

[LEOMAC23]

Re: Overdrive Problem?

Did you fix this Bugsy cause mine does the same thing,its like it doesnt want to downshift unless i floor it even when it should be downshifting, and i can actually see the rpms flucuate and feel the light jerking/hesitating??

[loser]

Re: Overdrive Problem?

miles? kinda sounds like a converter issue.

[flamingchicken]

Re: Overdrive Problem?

mine has always done it after long trips. its cause its overheating.

[LEOMAC23]

Re: Overdrive Problem?

68000 mi , it does it even when its -20c out here, could it still be getting hot? and only after driving for 5 or 10 mins?

[flamingchicken]

Re: Overdrive Problem?

it all depends on the integrity of your cooling system. year of your car? have you ever done a coolant flush?

[Rob Bell]

Re: Overdrive Problem?

Maybe it has something to do with the TCC system. Maybe the TCC is not disengaging as it should, so the car cannot downshift. But when you floor it, for some reason it disengages, allowing it the downshift immediately.

[Chase Walker]

Re: Overdrive Problem?

Mine has been doing the same for the past couple of months, it has 123000 miles on it but it also seems like its doing it in other gears with light throttle at low rpms. I changed the fluid and filter but it didn't help much. I have a 180 thermostat and have flushed it and it runs about 180 or so all the time. The transmission might be going out but I don't know how cause I don't beat the car

[pace2006]

Re: Overdrive Problem?

Has the valve body in the transmission ever been replaced? If not, search the P1870 code and see if your cars are behaving in similar ways. It results in TCC slippage from the trans overheating. It is a common problem with the stock valve body in the 4L60E. Symptoms are commonly hard 1-2 shifts after long trips, hesitations in shifts, and problems engaging/disengaging. If not corrected in a timely manner, it can progress to hard shifts in all gears at any time and eventually result in the loss of gears.

[dgreet77]

Re: Overdrive Problem?

^ what pace said.

The fix for it is pretty easy to do yourself if you are at all mechanically inclined. I did mine and had never been into a transmission before besides to change the filter. And actually I have heard a shift kit can help with it too, but when I did mine I did the shift kit and the the 1870 fix from 4l60-e.com. Fixed it and it works like a dream now, plus the shift kit is awesome.

[LEOMAC23]

Re: Overdrive Problem?

My car is a 97 and i also have a hard downshift to 1st, but only the first couple of downshifts as im leaving my neighborhood, after that it goes away, dont know if thats because of this 1870 but im gonna look into it, how much would it cost to get a mechanic to replce it? estimate.

[pace2006]

Re: Overdrive Problem?

My car is a 97 and i also have a hard downshift to 1st, but only the first couple of downshifts as im leaving my neighborhood, after that it goes away, dont know if thats because of this 1870 but im gonna look into it, how much would it cost to get a mechanic to replce it? estimate.

I got the Sonnax kit a couple years ago and had someone at Aamco replace it. Total cost of product plus installation, flush/filter change came to a little over $300. Personally, if I could do it again I would get the TransGo Shift Kit ($80) and follow the install video or have a professional install it. The shift kit comes with the valve body and a few other things and is a lot cheaper. If you're not comfortable with what the video shows, then have someone professional install it.

You'll have to call your local shops for an estimate. What I paid may be less than today's cost and location can also play a role in differing costs.

Edit: Another note, if you're talking about the first couple of downshifts being hard, is this right after starting the car or after it's been running for a while? The first shift or two for a car is going to be a little rough. The transmission is cold and hasn't had a chance to warm up.

[LEOMAC23]

Re: Overdrive Problem?

Yeah its when the car is first started,if i let the car warmup in the driveway for a while it doesnt do it, its like when you manually put the car 1st when its still going a little too fast, i geuss this is normal then? Could you point me in the right direction of where to find the shift kit, and this is all i need to fix the problem?

[pace2006]

Re: Overdrive Problem?

A transmission is mechanical and, like an engine, needs fluid to circulate to work properly. Those first few shifts are going to be a little more harsh or prolonged, but after that it should be fine.

You can find Transgo Shift Kits off of Ebay. Be sure it's for the 4l60e. I'm not sure if there's a difference between the HD2 kit or whatever else might pop up, but that's all I've been able to find. Another site previously mentioned in this thread should have them too and may be able to tell you the differences in kits.