What are the symptoms of a slipping auto transmission. How does a slipping auto transmission on the is250 feel? Is a slipping transmission a dying transmission? What kind of work is involved in fixing it

 

Slipping transmission = either your transmission is dying or you can still saving it by doing a last resort solenoid, pan filter and fluid replacement.

Can easily be avoided with regular transmission pan filter servicing.

you will feel a "clunk" when shifting into drive. while the transmission goes in and out of specific gears. Slipping is like, when the engine "spins freely" for a second before catching the gear it is supposed to be in. as if you're in neutral for a split second. not good.

If it behaves weirdly while coming to a stop sign (clunky downshifts, more clunky shifting when gently re applying the throttle) that would be another sign. Hard shifting. Etc.

What is your mileage. Is it worse when the transmission is still cold? or happens all the time? are you a careful driver or do you drive the thing hard? did it just start happening recently? does it only slip or behave strangely in specific gears?

 

Pan filter servicing? I thought these were sealed units. I had a few solonoids changed and fluid changed about 70k miles ago. It's at about 189k now it's a 2006 RWD.

I don't get any clunk when putting into gear from park. Just a small jerk as it goes into gear from park to Drive but that's always been the case.

So you say slipping is like the engine is spinning freely when gears are shifting between each other? Is it a bit like feeling there is no power for that split second while that is happening? That doesn't happen either. My only symptom is that on slow moving traffic it's a bit jerky if I don't rev enough.

Are there any tests you can do to test for slippage?

 

Have you ever driven a manual trans and not let the clutch out far enough while applying throttle and had the engine rev up and the car not move? It's a lot like that.

That said, during a shift the engine can flare too. Example is it holds in 1st, then during the 1->2 shift, the engine flares up while the trans is slipping in that gear, thus not really moving the car forward. It may skip a gear or flare and catch or flare and chatter.

Mind you to differentiate between gear chatter and torque converter chatter, slightly ride the brake to keep the converter from going into lockup in 4th, 5th, and 6th.

It take no time at all to cook clutches / bands and damage the friction material and/or warp the steel discs between the clutches. Don't leave it this way too long!

Get the fluid level checked asap and at a bare minimum replace the filter. Cut open the old filter and look for debris.

Low fluid could cause your issue as could a lot of other problems. Fluid check sooner than later; i.e. before the trans spits parts out.

 

Your gearbox sound fine to me.

No, it's not a sealed unit. You wouldnt of been able to drop the pan to replace the solenoids if that were the case.

It's a good idea to replace the pan filter every 60k or so. If the transmission shop or whoever serviced your solenoids cleaned the existing pan at the very least, before sealing it back up, that's fine too.

I

 

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Yes where the revs go up but you can't feel any power in the car? I'm not having any of that on the IS250 though.


How do you check fluid level? From what i've seen on youtube it seems like there is a drain plug, and just near it an overflow plug. And on the side of the pan there is the fill plug. It seems like people remove the drain plug, measure the amount that comes out then put the drain plug back on and then fill that same amount using a pump through the fill plug. Then apparently you need to run the car until transmission is up to temperature and then remove the overflow plug and let excess fluid drain out. Is that the procedure? Do you need to change any washers when you open the overflow or is the washer just on the drain plug and fill plug?

What is involved in changing the filter? I'm assuming the actual black pan cover has to be removed right? to do this I am assuming I still have to drain the pan first then remove the entire pan, change the filter etc put new pan gasket and close it up then refill the same way i mentioned above? from what I understand this has to be done with the car level. draining the pan and changing filter wont take out all the fluid right?

I'm thinking to try and attempt this but need to be sure I know what i'm doing first

 

No, you don't necessrily need to drain out the fluid first. Just get to work immediately taking the pan (black plastic thing) off, as more fluid will get a chance to drain out this way. I'd recommend you measure how much comes out. Do this when the transmission is fully warmed up. this would also be your chance to replace the solenoids which Isn't difficult to do, but you might want to let a reputable transmission shop deal with it.

Make sure you do not over tighten the bolts when putting the new pan filter back on! tighten them gradually in a criss-cross pattern, You do not want to risk seating the pan unevenly or bending/cracking it.

To be safe, I would suggest using a gasket (seal) paste on the mating surface between the transmission and the pan. Make sure the mating surface is thoroughly cleaned before resealing.

 

There are several threads on this. A key ingredient to checking fluid on an overflow style check is being at the correct temperature so the fluid displaces the right volume. Which is NOT fully warmed at 195°, but just 100° which takes no more than 10min to get too and its too hot.

The pan is metal btw.

So to check that temp there is pin jumper button push method, Techstream or the Fusion app. Too hot and your fluid level will end up low. Too cold and its overfull.

 

There ya go. If you do this, drain the pan, start it for like 5 seconds or so to dump more fluid from the the TC. Pull the filter and replace it. Install pan and torque to spec. Do not use slippery sealants as they can easily displace the gasket and cause a leak. Fill and check per instructions.

 

Noticing a slipping trans should be obvious. When in DRIVE and under load, you'll be pressing the accelerator and your rpms will increase, but your mphs will not or will slightyl (but not at the normal rate of increase).

Have you pulled any trans fluid to test for color and smell yet?

 

My car also clunked from Park into Drive. And also it jerks in low gears cause i drive in alot of stop and go traffic. Anyways a buddy told me to use Lucas Stop Slip Transmission. I also researched it online with mixed reviews. I decided to use it anyways and as it stats it worked instantly. Unfortnately i have only run it in my car for a month so i dont know any of the long term effects but so far my tranny has worked great. No clunks, jerks or any type of problems that i had everyday before i put it in.

 

I contacted a Auto Transmission specialist that deals with the Lexus IS250 transmission to get a quote to get fluid and filter changed and they have quoted for a full fluid exchange. They say to do the full fluid exchange it will require about 10 Litres of new fluid, a new filter, new filter O ring and new gasket with about 2.5hrs of labour

Question:

1. Is that how much fluid goes in to the transmission?
2. I've read that it's risky to do a full fluid exchange and that people usually just only drain what comes out of the pan, change the filter and seals and then do the fluid level check. So that's usually about 1.5L. Whether I do a full fluid exchange or just the partial, there wont be a huge difference in price. Seeing as i'm paying for the labour is it worth doing the full fluid exchange? Is it worth doing a full exchange (which I assume means a system flush). I read that a full exchange can cause particles to get lodged in places etc.

Any advice will be much appreciated. Thanks

 

Old wives tales. Do ALL THE FLUID NOW!

 

I had a transmission start to slip on an old Camry that I owned. Our transmissions don't really "slip" per se as that is a term from the older automatic transmissions that used belts. Our transmissions use solenoids. My camry also used solenoids. When it started "slipping" it was very sluggish to shift into gear. It was like going out of gear and being in neutral for a few seconds and then clunking into gear. What is happening is that your transmission uses hydraulic pressure to shift the gear. The solenoids control this action. There are seals, check valves etc that keep the hydraulic pressure high enough to allow the gears to shift when the solenoid opens or closes. Old fluid losses it's property to keep any rubber seals soft and allows the solenoids and check valves to stick. Replacing the fluid not only provides clean fluid but it also restores this additive to soften seals. It takes awhile for the seals to restore. SO the best bet is to change your fluid and add an additive like "Trans-X", drive the car for a few thousand miles and repeat. On my Camry when it started to do it it had 138k miles on it. It took about 15k miles before the transmission started to act completely like normal again. I drove that car to 270k miles before I sold it and the transmission was good as new ( I also started a 40k mile transmission drain and fill cycle after the tranny was back to normal). You are more likely to experience a "slipping" transmission when the ambient weather is colder. It will also most likely start to get better when your transmission gets up to normal operating temperature. As long as your car does actually shift, albeit hard shifts, the solenoids are good. Just change the fluid several times. It takes repeated heat cycles for the seals to have the additives leached back into them.

EDIT: I recommend NOT doing a full fluid change. It will make your condition worse as the fluid will be more likely to bypass seals and check valves until they are moving freely again. DO drain and fills. If you do a full fluid change your car might not shift at all. It takes time to soften the seals. An additive like Trans-X dumps a ton of these additives into your transmission.

EDIT 2: I read through the thread far enough to see that you most likely are not experiencing the symptoms I mentioned. I would recommend doing a full fluid change. It sounds like it might cure your symptoms. My IS always shifts buttery smooth after changing the transmission fluid. It's very noticeable and I've been doing it every 50-60k miles. I learned my mistakes with the Camry.

 

I read a lot about people doing the drain and fill then after a while do another drain and fill and repeat few times. But if using a garage to do this, it's going to be very expensive compared to what the automatic transmission specialist are suggesting which is a fluid exchange. They say I need about 10L of new transmission fluid. Not sure exactly how they do the exchange of the full fluid. I can only imagine it's some kind of flushing that will flush the fluid out completely.

@firelikeiy are you suggesting I do the full fluid exchange or not? i'm a little confused What are the risks of a full fluid change and if I do a full fluid change including filter etc, how many thousands of miles will it need doing again? It's a bit scary because i've read people saying that you can damage the transmission by doing a complete flush.