My '93 Ls400 'burps'

[MickAtHome]

Hi

Had my '93 LS400 for a couple of weeks now and other than the 'common' faults (flickering dash, blacked out clock and temp guage) I have also noticed an odd vibration from the auto box. If I'm cruising at say 50mph and put my foot down lightly to overtake someone the transmission makes a short burp, a bit like driving over a rumble strip, as it changes out of overdrive. If you put your foot down harder so that it kicks down a full gear, no burp. If you turn off overdrive, no burp.

Anybody come across this before - should I be worried? The car has (only) done 110,000 miles and for the last 2 years before I got it it did less than 2000 miles per year. Other than this it drives really well.

Any help greatly appreciated.

Thanks

Mick

[chips229]

Hi,

It might be worth checking the gearbox mount that could be causing the vibration.

Chips.

[MickAtHome]

Hi,

It might be worth checking the gearbox mount that could be causing the vibration.

Chips.

Thanks for suggestion but I would expect worn gearbox mounts to show up during all box changes. This only occurs when the box drops out of O/D. It is a 1 second 'burp' that could be a selector solenoid 'chattering' or something similar.

Mick

[MickAtHome]

I changed the transmission fluid last weekend and it has cured the problem. I did a complete pan-off clean of of filter and sump magnets + a flush through as recommended on the Lexus maintenance site. It took about 10 litres to flush the old (dirty brown) fluid out and replace it with nice bright red stuff (Toyota Type IV).

Makes a big difference to the smoothness of the changes too.

Mick