Transmission mount replacement. Ls400

[The-Acre]

5 hours ago, 39buss said:

Be very careful about "leaving it" as I think the trans oil pipe runs through the bottom header of the radiator and its this unseen bit that fails and oil and water are mixed.  Maybe the coolant with corrosion inhibitors should be changed every couple years. You can see the two pipes from the g/box entering the bottom header at either end looking from above the rad.  I remember my1968 P6 Rover 2000 TC having the same arrangement. 

It is on my to do list. The problem isn't on the inside as the cooler is aluminium and stays perfect. The problem begins with the exterior washers rusting causing the O rings to fail and allowing  the fluids to mix.  If Lexus has used stainless washers I doubt we'd be hearing much on the subject.

[Matt1986]

Replacing the mount definitely improved driveline vibration. Most of my vibration issues stem from worn suspension components unfortunately. At this point I'm unlikely to spend anymore on it as I think it's probably needing to much work regarding suspension and bodywork. 

[Stupot]

On 1/9/2019 at 9:35 PM, Matt1986 said:

Replacing the mount definitely improved driveline vibration. Most of my vibration issues stem from worn suspension components unfortunately. At this point I'm unlikely to spend anymore on it as I think it's probably needing to much work regarding suspension and bodywork. 

Thanks for that update Matt. There is little doubt that various suspension parts on my 160k LS will be a contributing factor to the occasional steering wobble/vibration I experience between 60-70 mph, but I find it interesting that the vibration seems to be worse when the drive train is working harder (up hill. acceleration etc) than when the car is coasting on the flat or going down hill. Thus my interest in the trans mount. 

[39buss]

On 1/9/2019 at 8:05 PM, The-Acre said:

It is on my to do list. The problem isn't on the inside as the cooler is aluminium and stays perfect. The problem begins with the exterior washers rusting causing the O rings to fail and allowing  the fluids to mix.  If Lexus has used stainless washers I doubt we'd be hearing much on the subject.

I was basing my comments on the MK3 LS 400 I had a few years ago where the trans oil pipes are rubber and run to 2 stubs on the bottom header and secured with jubilee clips. Different set up now then.  

[The-Acre]

10 hours ago, 39buss said:

I was basing my comments on the MK3 LS 400 I had a few years ago where the trans oil pipes are rubber and run to 2 stubs on the bottom header and secured with jubilee clips. Different set up now then.  

I guess it is different now, a shame it was changed really, I don't ever remember reading about an LS400 transmission going kaput due to water contamination.