20,000 Miles ago I had the hummm & cattle grid problem with my gearbox that was made worse by a useless ‘gearbox specialist’ who insisted that his use Dexron 3 when doing it for me was fine. After lots of arguments i bought 20 litres of the correct specified Mobil LT71141 and had repeated changes of oil to get it all out and correct in - the result being that I have had 20,000 Miles of trouble free motoring. However the low ‘hummmm’ has now returned so I am trying to decide wether to just do the ATF again, or if I need to do more with the gearbox. Is it just the torque converter, or is it more? What exactly is causing the ‘hummmm’? The RR is now on 47,500 Miles. Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

Did you really mean 47,500 miles? That’s incredibly low mileage and I wouldn’t have expected the torque converter lock-up clutch friction plate to have worn sufficiently to be generating the problem at that mileage.

You could try a tube of Instant Shudder Fixx to prove to yourself that this was the cause, just as a temporary measure, but a replacement converter is the only long-term solution if it’s a worn LUC causing the problem.

Phil

Oops! And I read it first before posting! Sorry it’s 147,500 miles!!! Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr