Car juddering when accelerating at low revs

[Daniel S]

Hi guys,

So I recently bought a car with the p2757 code and after your suggestions I did a gearbox service replacing the filter, gasket, o-ring and doing a flush to get it started (all using genuine Lexus parts). The error code has gone away and so have the warning lights on the dash. 

Unfortunately now I have a new issue that at first started when at low revs driving uphill where the car is juddering lightly until it goes past 2k revs or switches gear (kind of juddering you find on a rough road, nothing violent but noticeable). The problem seems to also be there in cruise control on the motorway when the car is accelerating to stay at 70 but overall seems exclusive to low rpm accelerating.

Can anyone give me some information or suggestions on what this could be? And possibly how a gearbox service could have caused this?

[Texas]

Two things come to mind, the gearbox flushing may have dislodged some old contamination and this has caused a problem at some point in the system, or ( hopefully ) the fluid level is not sufficient, There is quite an involved process to determine the correct level.

[Daniel S]

8 minutes ago, Texas said:

Two things come to mind, the gearbox flushing may have dislodged some old contamination and this has caused a problem at some point in the system, or ( hopefully ) the fluid level is not sufficient, There is quite an involved process to determine the correct level.

I'll be honest with you the gearbox was leaking oil through the gasket, I collected all the oil in a tub and all that came out when the pan and filter were removed was 2L of pitch black oil. From there I replaced what needed replacing and when filling the oil back up I used the over flow plug as a guide and the filling hole at the top right of the box. 

Afterwards I ran the car through its gears on a A road and repeated the process until oil came back out from the over flow plug which this time was browny black. 

Can you point me towards the correct way?

[Texas]

Searching for it now…..

[Texas]

Here’s one vid on how to do a Lexus fluid service, the Important thing is the temp of the fluid at the time of checking, when it flows out of the ‘level straw’,

 

[Texas]

Here’s another Toyota/ Lexus ‘sealed for life’ gearbox fluid change but a lot easier on the eye to watch😉

 

[Daniel S]

4 minutes ago, Texas said:

Here’s one vid on how to do a Lexus fluid service, the Important thing is the temp of the fluid at the time of checking, when it flows out of the ‘level straw’,

 

Ah perfect thank you very much mate ill have a proper watch when I'm home from work. Fingers crossed its just the oil I bought too much of it anyway 🤞🏻.

[Daniel S]

1 minute ago, Texas said:

Here’s another Toyota/ Lexus ‘sealed for life’ gearbox fluid change but a lot easier on the eye to watch😉

 

She has my attention. 

[Daniel S]

I'm a little confused though since my issue is that I don't seem to have enough oil I obviously will need to put more oil in than what comes out, do i put more oil in straight away let it get warm then use the overflow plug or do I warm the oil up then use the overflow plug to add on the missing oil? 

[ColinBarber]

Not sure it is fluid level, but the correct procedure is this:

IS250 transmission fluid.pdf

Did you use Toyota WS fluid? Sounds like clutch contamination possibly in the torque converter, although that should be in lock-up on the motorway

[Daniel S]

20 minutes ago, ColinBarber said:

Not sure it is fluid level, but the correct procedure is this:

IS250 transmission fluid.pdf 107.16 kB · 0 downloads

Did you use Toyota WS fluid? Sounds like clutch contamination possibly in the torque converter, although that should be in lock-up on the motorway

Yes I'm using genuine oil. How would I tackle clutch contamination? 

[ColinBarber]

4 minutes ago, Daniel S said:

Yes I'm using genuine oil. How would I tackle clutch contamination? 

Another flush/drain & refill, otherwise it would be a transmission strip down.

Definitely check the fluid level first, and inspect other things such as engine/transmission mounts. Then do another fluid drain/refill and go from there.

[Daniel S]

8 minutes ago, ColinBarber said:

Another flush/drain & refill, otherwise it would be a transmission strip down.

Definitely check the fluid level first, and inspect other things such as engine/transmission mounts. Then do another fluid drain/refill and go from there.

Lovely thank you very much, I got 4L of oil left think I'll buy some more just incase. Is a flush best done straight away after circulating oil, or after driving it a bit?

[steve2006]

When I did mine on the LS I did a drain and refill five times so used 10 litres of fluid, I didn’t get all the old stuff out but it certainly looked better afterwards. I did the drains over a week to allow the fluid to circulate and mix. Last year it got 2 more drains over 2 weekends and the colour looks fine.

[Daniel S]

6 hours ago, steve2006 said:

When I did mine on the LS I did a drain and refill five times so used 10 litres of fluid, I didn’t get all the old stuff out but it certainly looked better afterwards. I did the drains over a week to allow the fluid to circulate and mix. Last year it got 2 more drains over 2 weekends and the colour looks fine.

I guess I'm just going to have to keep flushing. Car feels awful it's juddering in every gear today, hopefully it'll fix the problem tomorrow. 

[Daniel S]

Well gearbox flushed, weird one here, car feels better than ever holy crap I now understand the smoothness everyone talked about. Only problem is while the shuddering is gone in gears 1-5 it still appears in 6th gear when accelerating between 1.5k-2k revs. What do you guys think, another flush?

[ColinBarber]

It sounds like the existing fluid is in a poor state, or the wrong type, so I'd continue with another drain and refill (actually probably worth doing it a couple of times).

[Daniel S]

Well yet again I am confused, the car has been driving like an absolute dream for the 150 miles I put on it today but just as I was getting home the check engine light came on and the gearbox code P2757 has made a reappearance resulting in the car instantly from driving 10/10 to juddering in every gear under 2k revs. Looking for advice on whether to continue with flushes, change solenoid and slap a new filter in or just say **** it and hand it in to Lexus? I am really losing my mind here.

[toffee_pie]

On 6/20/2021 at 2:19 PM, Daniel S said:

So I recently bought a car with the p2757 code

why did you buy a car with a error code? do you know how much transmission's cost? sorry to be abrupt but you really should not buy a used car with such a malfunction, or any even.

You might get lucky and have the error correct itself with a fluid change or then again you might be very unlucky and need a new transmission.

Transmission flushes are totally unnecessary - Japanese cars like Lexus are precision engineered  - they don't need 'flushes' what they do need is correct oil changes. That is all - and anyone who says its lifetime fluid is talking BS, just change it.

Totally unrelated but the OEM gearbox on my Subaru costs around 12K euro, these things are not to be messed with.

When you flush the transmission you may inadvertently clog delicate solenoids with gunk and screw up the entire system, its totally unnecessary and just snake oil - another money spinner for garages

[Daniel S]

On 6/29/2021 at 10:06 PM, toffee_pie said:

why did you buy a car with a error code? do you know how much transmission's cost? sorry to be abrupt but you really should not buy a used car with such a malfunction, or any even.

A combination of good price, young stupidity and inexperience lol!

For anyone ever experiencing this issue in the future I took it to lexus they reserviced the gearbox, reflashed ecu and calibrated the gearbox. All solenoid problems fixed as is the juddering car is so smooth you can't feel a single gear change, and quite frankly the service was superb and everything all in with diagnostics was only £770. 

[toffee_pie]

8 hours ago, Daniel S said:

A combination of good price, young stupidity and inexperience lol!

For anyone ever experiencing this issue in the future I took it to lexus they reserviced the gearbox, reflashed ecu and calibrated the gearbox. All solenoid problems fixed as is the juddering car is so smooth you can't feel a single gear change, and quite frankly the service was superb and everything all in with diagnostics was only £770. 

its pretty cheap for Lexus, but it would be even cheaper if it was not flushed in the first place

Glad your motor is back running as it could have been very costly indeed!