So, quick automatic gearbox lesson please
Discussion
hi
last weekend we dropped the gearbox sump on my brothers 155k old lexus ls400 5speed asin gearbox. we dont think the oil had ever been changed (or at least not since it stopped visiting lexus), it was black, smelt slightly burnt and there was what i would consider a lot of sludge on the bottom of the sump (that said, its only the second time ive ever dropped the sump on a auto box - the first being a long time ago and with assistance). i also cleaned the filter gause.
since then, when leaving the train station, it has twice lost drive, only for a few seconds, and both times about 100meters from the car park, once when he turned left, once when he turned right, no not in quite the same location, but roughly the same distance from turning the car on both times, to within 10 metres or so. both times it lost drive when setting off from a standstill.
last night we checked the oil. still very red (considering we only changed 2 of the 9 litres of ink black old oil contained within the gearbox). which made me wonder how auto gearboxes work. i imagined since its basically a fluid pump, should it not pick up and change all of the oil in the sump every couple of seconds? or does it do it from within, just using the sump to pick up oil if its low in level?
we had planned on changing the rest of the oil using the pump it out through the oil cooler hose and back in through the filler method described on the lexus forums.
-note we did use the proper toyota spec fluid.
thanks
last weekend we dropped the gearbox sump on my brothers 155k old lexus ls400 5speed asin gearbox. we dont think the oil had ever been changed (or at least not since it stopped visiting lexus), it was black, smelt slightly burnt and there was what i would consider a lot of sludge on the bottom of the sump (that said, its only the second time ive ever dropped the sump on a auto box - the first being a long time ago and with assistance). i also cleaned the filter gause.
since then, when leaving the train station, it has twice lost drive, only for a few seconds, and both times about 100meters from the car park, once when he turned left, once when he turned right, no not in quite the same location, but roughly the same distance from turning the car on both times, to within 10 metres or so. both times it lost drive when setting off from a standstill.
last night we checked the oil. still very red (considering we only changed 2 of the 9 litres of ink black old oil contained within the gearbox). which made me wonder how auto gearboxes work. i imagined since its basically a fluid pump, should it not pick up and change all of the oil in the sump every couple of seconds? or does it do it from within, just using the sump to pick up oil if its low in level?
we had planned on changing the rest of the oil using the pump it out through the oil cooler hose and back in through the filler method described on the lexus forums.
-note we did use the proper toyota spec fluid.
thanks
sounds like alevel problem
dropping the sump on a landcruiser auto (a very very similar aisin box) liberates about 5l of oil- you can get the rest out by tipping the whole car backwards to drain the torque converter.
Basically the box works by sucking oil out of the sump, injecting into the torque converter which then uses the power of the engine to pump the oil past a fan blade, the blade is attached to the gearbox. the gearbox changes gears using clutchplates which can open and close (a bit like a dog box) to change gear).
If the box is slipping- either you've buggered the box (clutches gone, blocks oilways, buggered torque converter etc etc), or the level is low, or you've used the wrong oil, or you've not adjusted the throttle linkage assembly.
dropping the sump on a landcruiser auto (a very very similar aisin box) liberates about 5l of oil- you can get the rest out by tipping the whole car backwards to drain the torque converter.
Basically the box works by sucking oil out of the sump, injecting into the torque converter which then uses the power of the engine to pump the oil past a fan blade, the blade is attached to the gearbox. the gearbox changes gears using clutchplates which can open and close (a bit like a dog box) to change gear).
If the box is slipping- either you've buggered the box (clutches gone, blocks oilways, buggered torque converter etc etc), or the level is low, or you've used the wrong oil, or you've not adjusted the throttle linkage assembly.
The oil level is too low.
Each manufacturer has their own procedure, but it involves getting the fluid to a specific warmth, cycling the gears through R, N, D, etc to prime all the clutch circuits, then check the level.
With the issues you have I'd add a litre before doing anything, it is way too low.
Each manufacturer has their own procedure, but it involves getting the fluid to a specific warmth, cycling the gears through R, N, D, etc to prime all the clutch circuits, then check the level.
With the issues you have I'd add a litre before doing anything, it is way too low.
Sounds like what happens when you don't put Toyota's expensive gearbox oil in.
Did you change the filter?
Might be worth putting as much as you can in, perhaps drain more out if you can to get as near a full change as possible.
Could be the thick fluid taking longer to pump round than the thin stuff.
Did you change the filter?
Might be worth putting as much as you can in, perhaps drain more out if you can to get as near a full change as possible.
Could be the thick fluid taking longer to pump round than the thin stuff.
Edited by BlueMR2 on Saturday 7th September 02:04
apologies for the lack of reply.
quick replys, used the proper oil, didnt change the filter, toyota parts man told me it was a "none servicable part" and wasn't interested in selling me one. so since its a gauze strainer, rather than a paper filter, i cleaned it out though (wasnt much debris in it though, despite the gearbox oil being long overdue for a change.) by lack of drive, he describes it as it popped out of gear.
i rechecked the oil level with it running and added about 400mm of oil. will give it a week or 2 to see if its ok.
im still wondering how long it should take for gearbox oil in the sump to mix completly with the stuff in the rest of the box though?
quick replys, used the proper oil, didnt change the filter, toyota parts man told me it was a "none servicable part" and wasn't interested in selling me one. so since its a gauze strainer, rather than a paper filter, i cleaned it out though (wasnt much debris in it though, despite the gearbox oil being long overdue for a change.) by lack of drive, he describes it as it popped out of gear.
i rechecked the oil level with it running and added about 400mm of oil. will give it a week or 2 to see if its ok.
im still wondering how long it should take for gearbox oil in the sump to mix completly with the stuff in the rest of the box though?
bigfatnick said:
apologies for the lack of reply.
quick replys, used the proper oil, didnt change the filter, toyota parts man told me it was a "none servicable part" and wasn't interested in selling me one. so since its a gauze strainer, rather than a paper filter, i cleaned it out though (wasnt much debris in it though, despite the gearbox oil being long overdue for a change.) by lack of drive, he describes it as it popped out of gear.
i rechecked the oil level with it running and added about 400mm of oil. will give it a week or 2 to see if its ok.
im still wondering how long it should take for gearbox oil in the sump to mix completly with the stuff in the rest of the box though?
2 weeks is too long- you need to be sure you have the right fluid level- follow the proper instructions. My landcruiser box was very very sensitive to oil level. quick replys, used the proper oil, didnt change the filter, toyota parts man told me it was a "none servicable part" and wasn't interested in selling me one. so since its a gauze strainer, rather than a paper filter, i cleaned it out though (wasnt much debris in it though, despite the gearbox oil being long overdue for a change.) by lack of drive, he describes it as it popped out of gear.
i rechecked the oil level with it running and added about 400mm of oil. will give it a week or 2 to see if its ok.
im still wondering how long it should take for gearbox oil in the sump to mix completly with the stuff in the rest of the box though?
Sump and box oil will mix as you suggest- ie pretty much instantaneously.
Sounds like you could be a litre or so out still. Just remember you can't accurately measure the fluid level one minute after you dumped fluid down the dipstick! Go to It cold one its settled and see how it looks.
Same as yours?
http://www.lexls.com/tutorials/transmission/transc...
The ones I've seen have a cool and a hot section on the dipstick.
Putting it in gears will send hydraulic fluid to all the brake bands therefore making sure its gets everywhere.
http://www.lexls.com/tutorials/transmission/transc...
The ones I've seen have a cool and a hot section on the dipstick.
Putting it in gears will send hydraulic fluid to all the brake bands therefore making sure its gets everywhere.
You need to have the engine running to check the level. Before you check, prime each gear. You will feel the transmission engage for each position, until it does this then you need to wait.
Set the level of the fluid according to the dipstick readings which provide compensation for temperature. Do not overfill the fluid or it will froth when hot and cause further problems.
Set the level of the fluid according to the dipstick readings which provide compensation for temperature. Do not overfill the fluid or it will froth when hot and cause further problems.
You need to have the engine running to check the level. Before you check, prime each gear. You will feel the transmission engage for each position, until it does this then you need to wait.
Set the level of the fluid according to the dipstick readings which provide compensation for temperature. Do not overfill the fluid or it will froth when hot and cause further problems.
Set the level of the fluid according to the dipstick readings which provide compensation for temperature. Do not overfill the fluid or it will froth when hot and cause further problems.
You need to have the engine running to check the level. Before you check, prime each gear. You will feel the transmission engage for each position, until it does this then you need to wait.
Set the level of the fluid according to the dipstick readings which provide compensation for temperature. Do not overfill the fluid or it will froth when hot and cause further problems.
Set the level of the fluid according to the dipstick readings which provide compensation for temperature. Do not overfill the fluid or it will froth when hot and cause further problems.
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