Looking for some help here on next steps...
Background: '97 LX450 with 288K miles, original transmission, which had Amsoil 100K mile ATF for more than 100K miles. I drained it because I was worried about towing and heat. Everything work fine, oil was still red, and the shifting was normal, if a bit firm. I topped refilled it with standard O'Reilly store ATF ( Dev IV or whatever - the right stuff) at 277K miles and did a drain and refill again at 287K miles. The second drain and refill didn't really change the shifting behavior...
The result of a single drain and fill (4 quarts) was that the shifting everywhere got softer. Reverse didn't seem to lock up so easily, but importantly, the shift between 1st and 2nd gear got longer - up to 1.5 seconds long, depending on the how hard I am on the gas. If I have it floored the shift will take about 1.5 seconds and it feels like things are slipping bad, but then I can feel the 2nd gear kick in and lock up. If I'm light on the gas it will shift nicely in about 0.5 seconds. It feels like the problem exists only between 1 and 2. All other gear shifts are good and firm.
Question 1: During this long time of shifting, what is slipping? Is it oil is it a band? Do I have a concern about burning something up?
Question 2: Since it still locks up nice in 2nd, what is the recommended course of action?
I've done a fair amount of research and it seems like the 1-2 solenoid could be leaking at the O-ring, or the oil circuit could be a bit plugged up, or the solenoid could be dying, causing a long engagement between the oil circuits, or the oil could be crap and I should do the whole purge and refill option. Above all, I'm trying to maximize lifespan and reliability from the transmission.
My following thoughts are,
A: Purge and refill with Valvoline high mileage ATF.
B. Drop the oil pan, put new seals on the the solenoids or replace them, depending on condition, and increase the line pressure. Clean everything up, and put it back together with new fluid.
C. Leave it, its fine.
D. Plan for a rebuild.
Please let me know if you experienced this and know how to resolve it.
Background: '97 LX450 with 288K miles, original transmission, which had Amsoil 100K mile ATF for more than 100K miles. I drained it because I was worried about towing and heat. Everything work fine, oil was still red, and the shifting was normal, if a bit firm. I topped refilled it with standard O'Reilly store ATF ( Dev IV or whatever - the right stuff) at 277K miles and did a drain and refill again at 287K miles. The second drain and refill didn't really change the shifting behavior...
The result of a single drain and fill (4 quarts) was that the shifting everywhere got softer. Reverse didn't seem to lock up so easily, but importantly, the shift between 1st and 2nd gear got longer - up to 1.5 seconds long, depending on the how hard I am on the gas. If I have it floored the shift will take about 1.5 seconds and it feels like things are slipping bad, but then I can feel the 2nd gear kick in and lock up. If I'm light on the gas it will shift nicely in about 0.5 seconds. It feels like the problem exists only between 1 and 2. All other gear shifts are good and firm.
Question 1: During this long time of shifting, what is slipping? Is it oil is it a band? Do I have a concern about burning something up?
Question 2: Since it still locks up nice in 2nd, what is the recommended course of action?
I've done a fair amount of research and it seems like the 1-2 solenoid could be leaking at the O-ring, or the oil circuit could be a bit plugged up, or the solenoid could be dying, causing a long engagement between the oil circuits, or the oil could be crap and I should do the whole purge and refill option. Above all, I'm trying to maximize lifespan and reliability from the transmission.
My following thoughts are,
A: Purge and refill with Valvoline high mileage ATF.
B. Drop the oil pan, put new seals on the the solenoids or replace them, depending on condition, and increase the line pressure. Clean everything up, and put it back together with new fluid.
C. Leave it, its fine.
D. Plan for a rebuild.
Please let me know if you experienced this and know how to resolve it.