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I flushed my tranny (automatic)some months ago.. it has been running and shifting great. However, after a trip of about 300 miles, it started shuddering, not downshifting appropriately, etc. After sitting for a few days, it stopped and again ran and shifted flawlessly.
Then, another long trip.... after similar non-stop mileage, I encountered the same symptoms. My mechanic said that it is possible that the tranny's "clock" needs to be reset to zero. It thinks it still has old, worn-out fluid in it and increases the hydraulic pressure after so many miles, which might be causing my symptoms.
I thought I read about something like this a long time ago... but after much searching, I can't find it again. Does anyone have any experience with this? Do I need to reset the tranny's "clock" or "computer" to let it know I now have good, new ATF in it?
Thanks in advance for any replies!
Steve
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Your 4 speed tranny does have a learning curve, but it doesn't have to have the memory booted up when you flush the fluid. Check the level again when it is hot, you may be a little low after the flush. When the fluid gets too hot, it will not want to shift into 4th, by design.
If you want to erase the memory, remove the battery ground and then the TCU, wait 10 minutes and put it back in and reconnect the battery - reset the radio
:(
Flush your bevel gear also.
Klaus
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posted by
someone claiming to be ksg
on
Fri Jul 6 06:05 CST 2007 [ RELATED]
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I think your tech is pulling your leg or guessing. If pressures are not building up there's something wrong, not just a little dirt in the fluid - the designer would build in some tolerance for changes in the characteristics of the fluid.
Do you have a warning light on and if so what is the code? Is the trans becoming very hot during steady running - suggesting it slips sometimes?
If no warning light, maybe the fluid was very dirty and some dirt got dislodged and has moved somewhere in the system.
Alternatively is it possible you put in the wrong kind of fluid?
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There are no warning lights or codes... nor does it seem to be running hot. It runs smooth as silk on the highway, and I don't encounter the problem until I slow down to where the car has to shift. As far as fluid goes, I've flushed it twice... once before the problem with Mobil 1 synthetic ATF (which I understand is okay for the older cars), and then with regular Dextron II/Mercon (spelling?)after the problem, in an effort to correct it.
Thank you...
Steve
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I thought automatic trannies 99- on needed the synthetic Volvo fluid, and not the regular ATF, check on that.
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My owner's manual states "Fluid type: ATF Dextron IIE/III and Mercon". I'm assuming that means it does not have to be synthetic.
I agree that it sounds a little bit too "high tech" for the tranny to compensate for older/thinner fluid as miles wear on... but I'm almost positive I saw a thread on it somewhere. Most likely, here on the Brickboard. I've searched, to no avail.
Thanks...
Steve
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Perhaps I can ask my questions another way.
Considering that the car runs and shifts very smoothly at all times... seemingly like a new car...
what, after a few hundred continuous highway miles, would cause everything to go "topsy turvy" when driving at any speed other than high-gear highway speeds?
When this happens, the engine/transmission literally sounds like it's self-destructing... even at idle. Upon removing ATF (before adding replacement), all of that noise goes away... which tells me it is transmission related.
Right now, the car is running beautifully... knock on wood! I would just like to figure this out before I go on another lengthy jaunt!
Thanks...
Steve
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Just a question. You do your own flush, but do you drop the pan or pump it out? And if you pump it out, do you do it 2 quarts at a time?
The Mobile 1 fluid will work just fine in your tranny, so long as it is a 4 speed. 5 speed automatics require Mobile 3309.
Klaus
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Just a question. You do your own flush, but do you drop the pan or pump it out? And if you pump it out, do you do it 2 quarts at a time?
The Mobile 1 fluid will work just fine in your tranny, so long as it is a 4 speed. 5 speed automatics require Mobile 3309.
Klaus
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I don't drop the pan, but I pull the plug and drain it prior to the "flush". After it is drained and closed back up, I then attach a clear hose to the top hose going into the radiator and flush two quarts at a time. One thing I noticed that I hadn't with previous flushes (other Volvo), was it took quite some time to pump out two quarts... much longer than the 20 seconds or so it normally takes.
BTW... it's been almost a couple of weeks now, and the car is running and shifting beautifully. BUT... will it do so after another 200-300 continuous highway miles??!! That's what set the problems in motion the last two times.
Thank you all for your replies...
Steve
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I don't drop the pan, but I pull the plug and drain it prior to the "flush". After it is drained and closed back up, I then attach a clear hose to the top hose going into the radiator and flush two quarts at a time. One thing I noticed that I hadn't with previous flushes (other Volvo), was it took quite some time to pump out two quarts... much longer than the 20 seconds or so it normally takes.
BTW... it's been almost a couple of weeks now, and the car is running and shifting beautifully. BUT... will it do so after another 200-300 continuous highway miles??!! That's what set the problems in motion the last two times.
Thank you all for your replies...
Steve
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