purebliss

I just took ownership of a 1991 Lexus LS400 that has only 56k miles. Now I know the owner had never changed the tranny fluid. Do you think it's safe if I bring it to Lexus to have them do a drain and fill. I just don't want to open up a can of worms by changing some of the fluid out. But on the other hand its been in that car for a real long time. Do you think I will cause leaks if I do a drain and fill? Thanks in advance for any help. I know level is fine now because I have checked it. But I do notice sometimes when I drive I get a vibration like I am driving on rough gridded concreate and then it goes away.
Thanks

19psi

do the drain and fill. leaks aren't caused by fluid exchanges; besides these tranny's are very durable as long as the fluids are changed.
the vibrations are a seperate issue. probably the trans mount or wheel balance.

j stuff

iTrader: (5)

91 with 56k thats insane

sonyman

Fluid is almost never the cause of a vibration unless it's during a shift or clutch sequence, such as when the torque converter lock-up clutch engages. However, since the fluid is 17 years old, it's due for a change regardless. Have the dealer or any competent mechanic make use of the transmission drain plug. Be sure that whoever changes the fluid uses Toyota T-IV transmission fluid.

purebliss

Yes it is during a shift or a clutch sequence.

K thanks guys!

nolyaw

The car is probably going into overdrive when you are doing about 40mph. The rpms drop low and thats what you feel. Turn off the overdrive when going below 50. When you drain out using the plug you will only lose about 2 quarts. Total capacity is about 9. To get it all out you need a flush.