2nd gen losing overdrive after a few mins driving.

[Lewd Lux Lover]

Hey guys, any ideas here would be much appreciated.

My mates 2nd gen has developed a fault with the box. All is fine for the first 5mins driving. Box selects all gears up and down, kick down works right etc etc.

Then after a few mins driving the overdrive refuses to lock in. No fiddling with the button or selector helps till its cooled right down again and you get a few mins of correct function.

So far we have given it a Rodney flush as the oil was stinking, brown and gungy but that has not solved the issue, just given the box a total 12l change of oil.

Research shows this could be down to the ECU showing its age maybe? Or a solenoid sticking? I think he can check the actual overdrive function by unplugging the solenoids and changing manually? Would this then help narrow down where the fault lies?

I am asking for any other ideas or pointers as the next step will be taking it to OVER FAB for a look see and I would like to close down as many options as possible before he has to reach into his pocket.

Many thanks for any ideas or experience.

[Jameswallace]

How is the oil looking now? Bizarely mine has a similar problem in that it jumps out of o/d at speed sometimes. Not that that helps you..

I have an a343f rebuild manual. If you need any pages scanning let me know

[Lewd Lux Lover]

Cheers. Hoping not to get that far!! though you never know.


We pulled out 15l in all and put in the same. By the last bit it was really coming clean but still not like it was going in. Clear and sweet smelling but still had a brown touch to it. Another 5l would have seen it run clear I think but thats another £30 and he didn't fancy it given that it still has the issue. I recommended he now keep to a regular sump drain and refill rather than another rodney. Saves cash if nothing else and the majority of the fluid in there now is brand new.

I cant recommend the rodney flush enough though. The first 10liter of oil that came out was truly horrid. The last liter was really nice in comparisson. We moved through all the gears while swapping over so it got all round and the next step DIY will be remov the sump and clean out/inspect the magnets and filter.

I think a cap in the ecu has blown so we will be looking for a breaker or a repair.