follow up
08-18-2018, 08:23 AM
#1
Melting Slicks
Thread Starter
follow up
I started a thread a while back regarding an oscillating "shudder" at highway speeds. It didn't match the speed and stayed constant regardless if I accelerated or not. Well I had my transmission fluid,filter and gasket changed at the dealership 4 weeks ago and I noticed it was less pronounced. Still did it but not nearly as bad. I had the transmission flushed last weekend and it is completely gone. My mechanic said the fluid was dark and that's after having new fluid put just the transmission. I am tossing this out there for anybody else that may be experiencing or run into it later. I am being told it was the fluid in the torque converter.
FYI
FYI
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Landru (08-18-2018)
08-18-2018, 12:27 PM
#3
Race Director
Flushed? As asked, how many miles?
IIRC book says every 50K, though I'd guess many go well beyond.
Thing is, if say at 90-100K a flush could likely cause embedded debris to break loose.
Trans fluid's a powerful cleaner, unfortunately not all crap gets flushed completely out.
Chunks of crap only loosened break away winding up clogging many tiny passages/valves, necessitating a rebuild.
Not a Vette, but my Cady had 100K before tranny began to slip, very uncharacteristic reminding me fluid had never been changed.
Wanted a ;flush', wrench advised against it for above stated reason.
Said he'd drain ever drop he could & refill whatever it needed w/ fresh, leaving embedded crap alone..
Of 10 qt capacity it needed 7, all but 3 remained.
Tranny is like new, no slippage whatsoever & little concern it may crap-out completely.
Glad you're golden now and hopefully for many more happy miles.
Just don't be surprised if things go sideways down the line w/ tranny either.
IIRC book says every 50K, though I'd guess many go well beyond.
Thing is, if say at 90-100K a flush could likely cause embedded debris to break loose.
Trans fluid's a powerful cleaner, unfortunately not all crap gets flushed completely out.
Chunks of crap only loosened break away winding up clogging many tiny passages/valves, necessitating a rebuild.
Not a Vette, but my Cady had 100K before tranny began to slip, very uncharacteristic reminding me fluid had never been changed.
Wanted a ;flush', wrench advised against it for above stated reason.
Said he'd drain ever drop he could & refill whatever it needed w/ fresh, leaving embedded crap alone..
Of 10 qt capacity it needed 7, all but 3 remained.
Tranny is like new, no slippage whatsoever & little concern it may crap-out completely.
Glad you're golden now and hopefully for many more happy miles.
Just don't be surprised if things go sideways down the line w/ tranny either.
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yellow2007 (08-19-2018)
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Landru (08-20-2018)
08-19-2018, 11:42 AM
#5
Melting Slicks
Thread Starter
Flushed? As asked, how many miles?
IIRC book says every 50K, though I'd guess many go well beyond.
Thing is, if say at 90-100K a flush could likely cause embedded debris to break loose.
Trans fluid's a powerful cleaner, unfortunately not all crap gets flushed completely out.
Chunks of crap only loosened break away winding up clogging many tiny passages/valves, necessitating a rebuild.
Not a Vette, but my Cady had 100K before tranny began to slip, very uncharacteristic reminding me fluid had never been changed.
Wanted a ;flush', wrench advised against it for above stated reason.
Said he'd drain ever drop he could & refill whatever it needed w/ fresh, leaving embedded crap alone..
Of 10 qt capacity it needed 7, all but 3 remained.
Tranny is like new, no slippage whatsoever & little concern it may crap-out completely.
Glad you're golden now and hopefully for many more happy miles.
Just don't be surprised if things go sideways down the line w/ tranny either.
IIRC book says every 50K, though I'd guess many go well beyond.
Thing is, if say at 90-100K a flush could likely cause embedded debris to break loose.
Trans fluid's a powerful cleaner, unfortunately not all crap gets flushed completely out.
Chunks of crap only loosened break away winding up clogging many tiny passages/valves, necessitating a rebuild.
Not a Vette, but my Cady had 100K before tranny began to slip, very uncharacteristic reminding me fluid had never been changed.
Wanted a ;flush', wrench advised against it for above stated reason.
Said he'd drain ever drop he could & refill whatever it needed w/ fresh, leaving embedded crap alone..
Of 10 qt capacity it needed 7, all but 3 remained.
Tranny is like new, no slippage whatsoever & little concern it may crap-out completely.
Glad you're golden now and hopefully for many more happy miles.
Just don't be surprised if things go sideways down the line w/ tranny either.
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Landru (08-20-2018)
08-19-2018, 03:09 PM
#6
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I weighed all the pros and cons and decided since things like embedded debris etc are theoretical but replacing 1/3 of the fluid is not, it only made sense and the fact that even after a recent transmission service the fluid was dark sealed the deal. I will still keep my fingers crossed that the later doesn't come true.
Although glad that everything is working well now, in the future you may want to change fluid more often and assure who is doing it, is doing it correctly.
08-19-2018, 03:50 PM
#7
Yep, problem with just pulling the pan, is your are only replacing the fluid in the bottom of the pan, and not the fluid that is still in the trans passages, in the torque converter, nor all the fluid that is in the cooler and lines.
So flush system using the cooler lines will push most of the old fluid out, and replace it with new fluid.
As for why GM does not put a drain plug in the torque converter is still a semi mystery, but the fact that the trans fluid should be power flushed ever 50K via the flush system before the fluid has become burnt or really contaminated, means that you really don't need a manual drain port on the torque converter to get the fluid out that way instead.
So flush system using the cooler lines will push most of the old fluid out, and replace it with new fluid.
As for why GM does not put a drain plug in the torque converter is still a semi mystery, but the fact that the trans fluid should be power flushed ever 50K via the flush system before the fluid has become burnt or really contaminated, means that you really don't need a manual drain port on the torque converter to get the fluid out that way instead.
08-20-2018, 06:59 PM
#8
Several years ago I watched a a service guy at a Valvoline (I think) quick-change oil station use a machine to completely replace all the fluid in an auto. trans. car by connecting to the cooling lines and running the car at idle until all fluid had been exchanged; took a minute or less. The reservoir with the new fluid in it had a sight window so he could monitor the exchange. I liked this approach. The only downside is the filter doesn't get changed, but if the old fluid looks clear may be able to get by without changing the filter. Each of these approaches has it's pros and cons
08-21-2018, 06:51 AM
#9
Several years ago I watched a a service guy at a Valvoline (I think) quick-change oil station use a machine to completely replace all the fluid in an auto. trans. car by connecting to the cooling lines and running the car at idle until all fluid had been exchanged; took a minute or less. The reservoir with the new fluid in it had a sight window so he could monitor the exchange. I liked this approach. The only downside is the filter doesn't get changed, but if the old fluid looks clear may be able to get by without changing the filter. Each of these approaches has it's pros and cons
08-22-2018, 01:20 AM
#10
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Several years ago I watched a a service guy at a Valvoline (I think) quick-change oil station use a machine to completely replace all the fluid in an auto. trans. car by connecting to the cooling lines and running the car at idle until all fluid had been exchanged; took a minute or less. The reservoir with the new fluid in it had a sight window so he could monitor the exchange. I liked this approach. The only downside is the filter doesn't get changed, but if the old fluid looks clear may be able to get by without changing the filter. Each of these approaches has it's pros and cons