Gs430 mk3 gearbox woe

Ogayford · January 23, 2022

Hi all,

I'm a new member here and would really appreciate some help with understanding whether the ls430, sc430 and gs430 6 speed a761e gearboxes are interchangeable? My gs430 gearbox has bitten the dust, and it seems there are more LS 430 ones than GS ones. The part numbers appear to be different, but is that due to ECU configuration, physical differences, or just some manufacturing process.

If anyone has a gs430 6 speed that would be super as well.

Thank you.

Olie

NemesisUK · January 23, 2022

I'd imagine gear ratios will be different across the models.

Would it not be more feasible to have the gearbox reconditioned/rebuilt?

steve2006 · January 23, 2022

Hi Oliver and welcome to the LOC.

Engines are the same so bell housing should be the same, gear ratios are the same, sensors and wiring should be the same.

Could I ask what happened to your transmission....not engine coolant contamination in the transmission fluid by any chance?

Ogayford · January 23, 2022

I bought one of those coolant radiator kits to avoid the coolant mixing with the ATF. Unfortunately the hose didn't seem to be of very good quality because it split and the ATF drained. We didn't realise and then when we came to slow down at a roundabout we had to coast in!

My mechanic drained what was left, replaced the hose with some better hose, and refilled it. He tested and it was fine. I took it out the next day and it wouldn't go into 4th. I tried to use the sequential to go into 4th and got some grinding noises. Now i just have gears one to three.

Thank you for the info. I would think the recon would be quite a lot more than a used box, if the used boxes are interchangeable. There's an LS one on eBay that is reasonable that I may take a punt on now I am armed with a little more info. Thank you both.