Transmission causing heavy vibrations in certain gears.

[Fsport]

I have a 2005 RX300.  

About 2 yrs ago  I started to experience pronounced delays in acceleration.  The car would not pull away upon stepping on the accelerator and when it did, it often did so in a jerky movement.  6 months later, this manifested into heavy vibrations and shaking of the entire car when pulling away or accelerating.  Trying to diagnose the issue I found out that the car had been low on gearbox oil.  When I realised and topped it up, it required a full 4 litres of type IV gearbox oil.

The car would have been low on gearbox oil for about 1 year and I am surprised the gearbox did not seized up during that time.  

Whilst the car has significantly improved with the correct amount of gearbox oil, it does still vibrate and shake when driving in certain gears.  The car typically vibrates around the gear 2 or gear 3 range i.e shortly after pulling away and shortly before coming to a stop.

Does anyone else have this issue?

Could the cause be due to one faulty gear (perhaps damage from running lthe car for approx 1 yr on low gearbox oil)?

Should I embark on a full geabox oil change or would this makes this worse given the age of the car and lack of previous gearbox oil changes.

Could the vibrations be due to something else?

 

 

 

[LexusRbest]

There is an electronic solenoid plate that can play up and cause that problem with sticky solenoids but if the transmission has run without oil that long you can expect it to be worn.

I would replace it and check the level with the dipstick a little more often.

[steve2006]

That’s a lot of missing fluid, driving it for so long with such a low level must have resulted in major damage and as you mention it is surprising it didn’t completely seize.

Personally given the complexity of the transmission I would be looking at either a known good secondhand replacement or find a specialist on Aisin transmissions and have it rebuilt.

As David mentions sticking shift and lock up solenoids could be one cause but so could brake bands and clutches not to mention internal bearings all of which have been starved of lubrication.

I would also be asking where all the missing fluid went if there are no obvious leaks.

[m4rkw]

How do you know the car was low on gearbox oil for a year? If it developed a leak that could have happened at any time, the transmission is normally a sealed unit so there must have been a leak.

A proper service will never hurt the transmission but given the damage that has likely resulted from running it without oil I'd be surprised if it helped much.