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Approximately 3000 miles ago, I modified my transmission's pressure control solenoids so the transmission runs at a higher line pressure for firmer shifts. What I did is I unplugged the pressure control solenoids and plugged extra solenoids into the connectors so it doesn't set a code and go into limp mode.
So far my enhancement is working great. The shifts are firm but not harsh (by my standards anyways) and the TCC applies much quicker and feels more like a shift, which I prefer.
However, I am wondering if I am causing excessive wear on the transmission by forcing it to run at a higher pressure. I don't see how I would be, and if anything I think I may be significantly reducing wear on the clutches by reducing slipping during shifts, and reducing wear on the TCC by eliminating its slipping.
I know that when the trans goes into "limp mode" it runs at maximum line pressure to prevent slipping and further damage, so I can't imagine it could be that bad to run it at maximum line pressure at all times. I am also pretty sure that if something bad was going to happen it would have done it by now since it has been this way for the last 3000 miles. However, I am certainly no expert on transmissions, so please let me know one way or the other.
Thank you very much in advance, any input is greatly appreciated!
I would expect the opposite effect for your modification.
Originally, the transmission would drop the pressure, switch valves to next set of clutch discs, and then turn pressure back on. In that manner the transmission minimized overlap of two gears.
Now, you have transmission thats switching valves to next set clutches even though previous set is still fully locked until the pressure bleeds off. (Sure it’s milliseconds but that’s the issue). So for every shift your transmission is literally engaged in two gears with both slipping for a moment.
Like you said it not a break it instantly modification, but a significant reduction in lifespan is what I would expect as your transmission is literally fighting internally because you no longer have a “between” gears moment.
I would expect the opposite effect for your modification.
Originally, the transmission would drop the pressure, switch valves to next set of clutch discs, and then turn pressure back on. In that manner the transmission minimized overlap of two gears.
Now, you have transmission thats switching valves to next set clutches even though previous set is still fully locked until the pressure bleeds off. (Sure its milliseconds but thats the issue). So for every shift your transmission is literally engaged in two gears with both slipping for a moment.
Like you said it not a break it instantly modification, but a significant reduction in lifespan is what I would expect as your transmission is literally fighting internally because you no longer have a between gears moment.
Thank you for letting me know. So what I perceived as quicker, firmer shifts is really because 2 gears are engaged at once and fighting each other and not because the clutches are engaging quicker?
Just saying you absolutely right, your getting quicker and firmer shifts at the expense of longevity in not only the clutches but possibly the planetary gear-sets themselves.
Honda decided it was worth hundreds of millions of dollars to put those solenoids in to achieve acceptable transmission life for the common user.
I like the jist of what you have done, maybe take it to the next level and have a switch to change modes, next level after that monitor throttle position to switch modes only when your flooring it /smile.
Just saying you absolutely right, your getting quicker and firmer shifts at the expense of longevity in not only the clutches but possibly the planetary gear-sets themselves.
Honda decided it was worth hundreds of millions of dollars to put those solenoids in to achieve acceptable transmission life for the common user.
I like the jist of what you have done, maybe take it to the next level and have a switch to change modes, next level after that monitor throttle position to switch modes only when your flooring it /smile.
Thank you for your help, I plan to check the magnet on the drain plug for excessive metal particles to see how much damage was done, if any. I presume that if damage was done there would be more metal particles on the drain plug than usual?
I like your idea to wire a switch for different modes, although that seems a little complicated and I don't have time to figure that out, at least not at the moment. I may look into that in the future though.
Another question- Is shifting with the torque converter locked up harmful to the transmission as well? I have been manually controlling lockup with a switch to get better gas mileage, and I am wondering if it is harmful to the transmission to let it shift with the converter locked.
I discovered that I can measurably improve my MPG while accelerating by locking the converter shortly after 2nd gear engages and leaving it locked as it accelerates to the torque converter isn't slipping and wasting energy. I don't lock it in 1st gear though because doing so seems to make the transmission quite unhappy as it shifts to 2nd gear.
I know that in stock form it shifts from 3rd to 4th with the TCC applied, at least partially. However, with my modifications, I wait until it is in 4th gear to lock the converter because I am unsure of the effects on the transmission of shifting it with the converter locked.
Well I checked the magnetic drain plug for particles a few days ago when I installed a transmission temp gauge, and I didn't see anything that I consider terrible for 7K miles of driving. Here's a picture of it. Thoughts?
