Very interesting conversation with my transmission builder on the TL
04-18-2009, 10:11 AM
#41
Three Wheelin'
I didn't have the problem with my 04 and so far not with my 08, but it is great info nonetheless. As common as this problem seems to be, perhaps the mods could make this post a sticky in the "problems and fixes" sub-category.
04-18-2009, 10:32 AM
#42
Burning Brakes
Well this fix is still just a theory at this point as there is no hard proof that replacing those sensors will in fact prolong transmission life.
What confuses me is, if this will in fact fix the problems people have with the AT, why did it take this long to figure this out? The 3G has been out for over 5 years now, and even the later model 2G has the same or very similar auto tranny. I find it very difficult to believe that not a single mechanic realized this until just now.
In any case, I probably won't do this for $140 because I'm thinking of trading in my 5AT TL for a 6MT one in the next few months.
What confuses me is, if this will in fact fix the problems people have with the AT, why did it take this long to figure this out? The 3G has been out for over 5 years now, and even the later model 2G has the same or very similar auto tranny. I find it very difficult to believe that not a single mechanic realized this until just now.
In any case, I probably won't do this for $140 because I'm thinking of trading in my 5AT TL for a 6MT one in the next few months.
04-18-2009, 11:45 AM
#43
10th Gear
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Well... I think this is def worth a try. I have an 05 TL with 83k on the clock and 3rd gear seems to have this weird vibration when trying to shift (at below 3k RPMS). it does not slip... almost like it does not know what to do. If I step on the gas though...and it shifts at 3k....its smooth. Sensors may just help 
Thanks for the info!
Thanks for the info!
04-18-2009, 12:44 PM
#44
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04-18-2009, 02:27 PM
#45
Senior Moderator
I hate cars, do the switch's fail becuase of being gummed up with stuff or is it just simply like a computer, once it gets old it starts slowing down?
04-18-2009, 02:41 PM
#46
Team Owner
Thread Starter
The way it was explained to me is these sensors were added to achieve soft shifts. They monitor many times a second how long it takes for one clutch pack to release (in miliseconds) and how long it takes for the one that's coming on to apply. The goal is to have one clutch pack applying right as the other one is releasing for a soft shift. Line pressure is based off of these inputs as well as shift timing.
When you experience shudder, that is a clutch pack slipping when it's not supposed to. It takes very little slipping to burn one up. It's not like a manual where it's made to slip. Just a second or two is all it takes to ruin an automatic clutch pack. If anyone is experiencing shudder, you should not drive the car until you replace the sensors.
When you ride in a performance car and you notice the firm shifts, that's not to make it faster, it's to make the transmission live longer.
04-18-2009, 08:07 PM
#48
Senior Moderator
What he said is that it starts slowing down and of course instead of failing on the high line pressure/hard shift side, it fails on the low line pressure/slip side. The ones that he showed me that had failed looked extremely clean.
The way it was explained to me is these sensors were added to achieve soft shifts. They monitor many times a second how long it takes for one clutch pack to release (in miliseconds) and how long it takes for the one that's coming on to apply. The goal is to have one clutch pack applying right as the other one is releasing for a soft shift. Line pressure is based off of these inputs as well as shift timing.
When you experience shudder, that is a clutch pack slipping when it's not supposed to. It takes very little slipping to burn one up. It's not like a manual where it's made to slip. Just a second or two is all it takes to ruin an automatic clutch pack. If anyone is experiencing shudder, you should not drive the car until you replace the sensors.
When you ride in a performance car and you notice the firm shifts, that's not to make it faster, it's to make the transmission live longer.
The way it was explained to me is these sensors were added to achieve soft shifts. They monitor many times a second how long it takes for one clutch pack to release (in miliseconds) and how long it takes for the one that's coming on to apply. The goal is to have one clutch pack applying right as the other one is releasing for a soft shift. Line pressure is based off of these inputs as well as shift timing.
When you experience shudder, that is a clutch pack slipping when it's not supposed to. It takes very little slipping to burn one up. It's not like a manual where it's made to slip. Just a second or two is all it takes to ruin an automatic clutch pack. If anyone is experiencing shudder, you should not drive the car until you replace the sensors.
When you ride in a performance car and you notice the firm shifts, that's not to make it faster, it's to make the transmission live longer.
04-18-2009, 09:56 PM
#50
Senior Moderator
04-19-2009, 01:53 PM
#52
Drifting
subscribing to the thread. i dont have any problems on mine (in fact just did a drain/refill yesterday) but if in case something comes up, ill know where to look.
04-19-2009, 03:42 PM
#53
Cruisin'
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04-19-2009, 05:40 PM
#54
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Just purchased a certified used 2008 tl. Noticed it shifts a little abruptly (not smooth like my 96 Camry). This thread makes it sound like these sensors might be the problem. Is there a test to determine if these are indeed at fault or do you just buy new sensors and see if replacement is the cure? Alternatively, wait for failure and have Acura replace/repair the transmission under warranty?!!!! Any insight appreciated.
04-19-2009, 11:43 PM
#56
Chapter Leader (Southern Region)
The theme seems to be going downhill.. as stated the changing out of the pressure switch is preventative maintenance.
A little background on pressure switches. Given an input in fluid pressure the switch will cycle (open / close) based on the input pressure, typically a range. I think the physical operation is similar to a capacitor. The switch is normally open and as pressure increases the effective distance between the charge layers decreases which will eventually allow charge flow between the layers (switch closed).
The MTBF of pressure switches varies but I think the standard lifetime is 10+ years of continuous operation at a given temperature (typically 25-55C). As temperature increases the lifetime of the switch drastically reduces. So the more heat the switches are exposed to the faster they will wear out which will start leading to damage. Although the MTBF is usually specified in hours of use it is more purely based on cycle lifetime, how many times the switch cycles on / off. You relate the cycling to gear shifting 2nd-3rd, 4th-3rd as hydraulic pressure fluctuates between 3rd gear. So if you shift between gears more than 'typical' operation.. the faster the switch lifetime will reduce.. constantly fluctuating between gears is also related to fluid wear and heat which further reduces the switch lifetime.
So I think a conservative recommendation for replacing the pressure switches would be 50k miles if you drive mostly city or often commute through traffic. Also if you don't change your ATF in consistent recommended intervals I would probably change the switches every 50k miles as well. I would also sell the switches.. at 50k miles they should have a lot of life on them so you might be able to get some money back.. if I can sell my tires with 20% tread on them.. I'm sure many of you can get some money back on the pressure switches.
A little background on pressure switches. Given an input in fluid pressure the switch will cycle (open / close) based on the input pressure, typically a range. I think the physical operation is similar to a capacitor. The switch is normally open and as pressure increases the effective distance between the charge layers decreases which will eventually allow charge flow between the layers (switch closed).
The MTBF of pressure switches varies but I think the standard lifetime is 10+ years of continuous operation at a given temperature (typically 25-55C). As temperature increases the lifetime of the switch drastically reduces. So the more heat the switches are exposed to the faster they will wear out which will start leading to damage. Although the MTBF is usually specified in hours of use it is more purely based on cycle lifetime, how many times the switch cycles on / off. You relate the cycling to gear shifting 2nd-3rd, 4th-3rd as hydraulic pressure fluctuates between 3rd gear. So if you shift between gears more than 'typical' operation.. the faster the switch lifetime will reduce.. constantly fluctuating between gears is also related to fluid wear and heat which further reduces the switch lifetime.
So I think a conservative recommendation for replacing the pressure switches would be 50k miles if you drive mostly city or often commute through traffic. Also if you don't change your ATF in consistent recommended intervals I would probably change the switches every 50k miles as well. I would also sell the switches.. at 50k miles they should have a lot of life on them so you might be able to get some money back.. if I can sell my tires with 20% tread on them.. I'm sure many of you can get some money back on the pressure switches.
04-19-2009, 11:50 PM
#57
Chapter Leader (Southern Region)
Just purchased a certified used 2008 tl. Noticed it shifts a little abruptly (not smooth like my 96 Camry). This thread makes it sound like these sensors might be the problem. Is there a test to determine if these are indeed at fault or do you just buy new sensors and see if replacement is the cure? Alternatively, wait for failure and have Acura replace/repair the transmission under warranty?!!!! Any insight appreciated.
04-20-2009, 12:14 AM
#58
^^ Some good info up there....
And it is true, that if you are already feeling some slippage like you state, that this change of switches will not fix it as the damage has already been done
And it is true, that if you are already feeling some slippage like you state, that this change of switches will not fix it as the damage has already been done
04-20-2009, 01:06 AM
#59
2008 335i e92 6MT
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just wanna make sure, shudder/slipping is when you see the rpms hold? i have a 07 TL and just hit 19k miles today, i'm sure my tranny fluid and other fluids shouldn't be anywhere close to needing changing but i just wanna have an idea of what signs to expect in case my tranny does start to go x_X
04-20-2009, 08:02 AM
#60
Chapter Leader (Southern Region)
just wanna make sure, shudder/slipping is when you see the rpms hold? i have a 07 TL and just hit 19k miles today, i'm sure my tranny fluid and other fluids shouldn't be anywhere close to needing changing but i just wanna have an idea of what signs to expect in case my tranny does start to go x_X
You'll first notice the transmission slipping.. as damage starts to occur you'll notice it shudder as it's holding gear.. I suggest when you change out your ATF. Take a sample and send it to Blackstone Labs.. the analysis will tell you the real story. Look for aluminum, iron & copper content.. that'll let you know what kind of wear your ATF has been through and what components are seeing the most wear. Also check the analysis numbers for change in physical properties.
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04-20-2009, 10:20 AM
#61
Racer
This makes sense and sounds like a great idea. I'm always concerned about the A/T. My tranny occasionally has a slight shudder and hold onto (I think - can't remember) third gear. Usually it's fine, though. I had the dealer change the fluid a few months ago, maybe 5-7K miles ago. I may go ahead and do the sensor swap out.
Does anyone know whether you lose fluid when the sensors are removed? Will a fluid change be in order at the same time? Just trying to be prepared and know what to expect. Thanks.
And thank to Ihatecars for the info. I love this forum.
Does anyone know whether you lose fluid when the sensors are removed? Will a fluid change be in order at the same time? Just trying to be prepared and know what to expect. Thanks.
And thank to Ihatecars for the info. I love this forum.
04-20-2009, 10:30 AM
#62
Team Owner
Thread Starter
This makes sense and sounds like a great idea. I'm always concerned about the A/T. My tranny occasionally has a slight shudder and hold onto (I think - can't remember) third gear. Usually it's fine, though. I had the dealer change the fluid a few months ago, maybe 5-7K miles ago. I may go ahead and do the sensor swap out.
Does anyone know whether you lose fluid when the sensors are removed? Will a fluid change be in order at the same time? Just trying to be prepared and know what to expect. Thanks.
And thank to Ihatecars for the info. I love this forum.
Does anyone know whether you lose fluid when the sensors are removed? Will a fluid change be in order at the same time? Just trying to be prepared and know what to expect. Thanks.
And thank to Ihatecars for the info. I love this forum.
Remember, these are the pressure sensors, not switches.
04-20-2009, 10:55 AM
#64
Chapter Leader (Southern Region)
Yeah.. it doesn't take long for transmission to take a dump. They're rugged until it starts to fail.. once it starts it's a steep downhill from there.. not too much you can do to stop it either.
04-20-2009, 12:21 PM
#65
3g Trans issues
I talked to a local acura dealer mechanic and he stated that the 3g tanny's are very good now. Shouldn't have any problems with them and you shouldn't have the need to replace the 3/4 pressure sensors...but he did mention that the 2g tl's had lots of tranny problems....
From a scale of 1-10 and 1 being the lowest how many 3g owners have had issues with their trannies?
From a scale of 1-10 and 1 being the lowest how many 3g owners have had issues with their trannies?
Last edited by warren4066; 04-20-2009 at 12:25 PM.
04-20-2009, 12:29 PM
#66
Chapter Leader (Southern Region)
.. I'm going on 4-5k on my REMAN tranny.. went out around 87k miles.. I was the 2nd / 3rd owner unfortunately.
04-20-2009, 12:41 PM
#67
Drifting
I talked to a local acura dealer mechanic and he stated that the 3g tanny's are very good now. Shouldn't have any problems with them and you shouldn't have the need to replace the 3/4 pressure sensors...but he did mention that the 2g tl's had lots of tranny problems....
From a scale of 1-10 and 1 being the lowest how many 3g owners have had issues with their trannies?
From a scale of 1-10 and 1 being the lowest how many 3g owners have had issues with their trannies?
04-20-2009, 03:08 PM
#71
I talked to a local acura dealer mechanic and he stated that the 3g tanny's are very good now. Shouldn't have any problems with them and you shouldn't have the need to replace the 3/4 pressure sensors...but he did mention that the 2g tl's had lots of tranny problems....
From a scale of 1-10 and 1 being the lowest how many 3g owners have had issues with their trannies?
From a scale of 1-10 and 1 being the lowest how many 3g owners have had issues with their trannies?
04-21-2009, 03:26 AM
#74
Three Wheelin'
Guys... just as an FYI the service manual has a whole process for this and call for measuring the resistance of the shift solenoid sensors. Might be a good place to check as well for a good walk through. According to Honda they call say the standard is 12-25 ohms anything out of stand is to be replaced...
04-21-2009, 03:56 AM
#75
Thanks for the thread.
Not gonna do anything for now since it shifts good enough, no stutter or anything but one the 7yr/100k warranty is up, I'm just going to replace the sensors for the hell of it. Our 2G isn't even at 50k yet last time I drove it but it seems like a good idea....
Maybe someone can correlate the frequency of transmission failures of cars < 50k and >50k miles. It seems to make sense, I'm not sure if Acura replaces the pressure sensors when they drop out a bad tranny and put in a new one, but it could connect the dots regarding why remanned trannies can crap out afterwards, despite being "improved"
Not gonna do anything for now since it shifts good enough, no stutter or anything but one the 7yr/100k warranty is up, I'm just going to replace the sensors for the hell of it. Our 2G isn't even at 50k yet last time I drove it but it seems like a good idea....
Maybe someone can correlate the frequency of transmission failures of cars < 50k and >50k miles. It seems to make sense, I'm not sure if Acura replaces the pressure sensors when they drop out a bad tranny and put in a new one, but it could connect the dots regarding why remanned trannies can crap out afterwards, despite being "improved"
04-21-2009, 07:46 AM
#76
Chapter Leader (Southern Region)
Camaros handle like shit, proof here: http://www.phy.duke.edu/~hartley/iroc/z28vs911.html
I just wasted 5 minutes reading this dumb blog.. lol.. did you have an argument with somebody?
btw.. I think the pressure sensors / switches are like a heart problem.. unless you replace them right away when they start going out.. they'll do irreparable damage. I'm sure the service shop won't touch them unless the ECU says there's a problem.. but then it could be too late. Good obs on the reman.. I guess I'll replace mine too..
Last edited by Majofo; 04-21-2009 at 07:51 AM.
04-21-2009, 07:54 AM
#77
Chapter Leader (Southern Region)
Could be a crap in the valve body. I would try either running a solvent and then doing a refill or putting in a detergent to try and clean up the valve body.. run it for 1k miles or so and do a refill. There's definite pros & cons to each..
04-21-2009, 09:32 AM
#78
Team Owner
Thread Starter
Guys... just as an FYI the service manual has a whole process for this and call for measuring the resistance of the shift solenoid sensors. Might be a good place to check as well for a good walk through. According to Honda they call say the standard is 12-25 ohms anything out of stand is to be replaced...
04-21-2009, 09:37 AM
#79
Team Owner
Thread Starter
Thanks for the thread.
Not gonna do anything for now since it shifts good enough, no stutter or anything but one the 7yr/100k warranty is up, I'm just going to replace the sensors for the hell of it. Our 2G isn't even at 50k yet last time I drove it but it seems like a good idea....
Maybe someone can correlate the frequency of transmission failures of cars < 50k and >50k miles. It seems to make sense, I'm not sure if Acura replaces the pressure sensors when they drop out a bad tranny and put in a new one, but it could connect the dots regarding why remanned trannies can crap out afterwards, despite being "improved"
Not gonna do anything for now since it shifts good enough, no stutter or anything but one the 7yr/100k warranty is up, I'm just going to replace the sensors for the hell of it. Our 2G isn't even at 50k yet last time I drove it but it seems like a good idea....
Maybe someone can correlate the frequency of transmission failures of cars < 50k and >50k miles. It seems to make sense, I'm not sure if Acura replaces the pressure sensors when they drop out a bad tranny and put in a new one, but it could connect the dots regarding why remanned trannies can crap out afterwards, despite being "improved"
I'll take pictures of the clutch packs next time I'm over there and it will show to any of you who have been inside a trans before that it's not a clutch holding issue.
One thing the builder did say is that when a Honda trans comes in for a rebuild they don't reuse and recondition the steels like they do in nearly every other trans. The Honda ones have a very specific and critical cross hatch pattern that they can't reproduce in the shop.