Driving to work today, I got a 'xmission service required' message. I was in stop and go traffic...and on a 'go' I heard a 'thunk' and the msg and CEL came on.
However, I did not notice anything different after the 'thunk'.

I took it to my mechanic to read..."lockup function slipping" was the code. He says that the from his experience, the radiator fluid is leaking into the xmission cooler and contaminating the xmission fluid causing it to slip.

He basically says the only real fix is to replace the xmission because once it has been contaminated, the 'clutches' which engage the gears are ruined by the radiator fluid....and the cost is 6+k for a new xmission.

....as a bandaid fix, he said I could replace the raidiator and flush the xmission, but the problem will probably return.

....1st question...is this a common/known problem? Can radiator fluid really destroy a xmission...even a little?

I know the PO had a xmission flush and xmission software upgrade because I have all the receipts.


this is for a '01 XC70

 

I have seen this before.
But there is a test that can be done to check for sure.

I have also seen the tranny's come out ok in the end but you never know.

 

try fixing the leak and flushing the trans first. in fact, flush it then drive it a couple hundred miles and if there are no problems then flush it again. these parts are intended to wear over time and you may end up with no problems for a long time (or ever) after the clutch material gets roughed up a little. coolant would probably glaze over the clutches and over time this will likely disappear if the problem is not too severe. i wouldn't swap the trans until you're sure its broken.

 

Update:
After clearing the problem, the xmission didn't exhibit any problems until a week later. While driving at hwy speed, the msg/triangle/CEL all lit up again, but I did not notice any thing until getting on the offramp which was on an incline. I could definitely feel the slipping. Last night I drove it around to warm up the oil in order to do the flush. As I started to drive it up the ramps, it slipped so much it wouldn't make it up and the message changed to 'urgent'. I stopped the engine for a few seconds and was able to make it up the ramps.

Anyway with the flush done, all the symptoms have disappeared 'for now'. The old oil was a brownish color and there was no visible sign of water/coolant or metal flakes. I'm going to have the oil tested.

I know it's probably temporary, but I'm happy the darn thing is drivable now.

 

maybe it can be rebuilt if it does start doing that again