Sonet's transmission fluid gushes out while driving: Leaves me stranded

I was driving in the city when I started hearing a whining noise in all gears above 1st.

BHPian ToyoCabbie recently shared this with other enthusiasts.

Two years ago, I made a thread when my Kia Sonet HTK+ 5MT started dripping transmission fluid in our parking lot. The car was towed and a new seal was applied and we were offered an extended warranty after escalating multiple times.

Yesterday (30-4-2023), I was driving in the city when I started hearing a whining noise in all gears above 1st. This has happened once before and it randomly stopped before I could get it checked, but this time the noise kept getting louder. I was asked to pull over by other road users as they kept pointing at my wheels.

Check the video for the noise.

I got down and was shocked to see transmission fluid gushing out and a long 2km trail of oil behind my car.

Kia roadside assistance towed the vehicle to the nearest service centre and she sits there till Tuesday as Sunday and Monday are holidays.

Any opinion on what the problem may be would be appreciated.

Here's what BHPian Omkar had to say on the matter:

For starters, that's an eerie noise from the gearbox. The noise would be from the bearings in the gearbox and that's because there's no oil around them.

Did you notice any issues with shifting? If that's the case, then there might be some damage to the gears.

I believe your car is still under warranty (3 years?), so would strongly suggest you push for a gearbox replacement. Leaking transmission is not a common occurrence in new cars, so this might be some sort of defect as it has happened twice to your car.

The workshop could suggest opening up the gearbox and checking for any damage on the inside. Then replace the damaged parts and this works as well, as it is the affordable way. But for the additional peace of mind, replacement is the way to go.

Here's an update from BHPian ToyoCabbie on the matter:

One week before this incident the car was stuck in first gear and would not move or make any sound even with the clutch released. But the issue quickly resolved itself after shutting off the car and somehow pulling it out of 1st. It drove normally after that.

The workshop called today to confirm that there is no external damage to the transmission and it is something internal. They've asked for my approval to tear it apart to send proof to Kia for further assistance.

Here's what BHPian Turbanator had to say on the matter:

That's good for you as sometimes dealerships try to pass on external damage. Were there any signs of leakage under the engine, even a minute greasy area around the seal that you got changed? Do you park your car in the same place and on a cement floor?

It has to be some seal leak only, can be the one they replaced before or another but this time since a lot of oil got drained, it would have damaged some other parts like bearings and in the worst case, teeth of the gears. Given the history of the leak in the initial ownership, you should press for the complete gearbox change. But if they don't agree, all parts should be carefully inspected. Try to take the dealership into confidence, they can pressurise the manufacturer.

Here's another update from BHPian ToyoCabbie on the matter:

I just received pictures of the gearbox and it is absolutely horrifying to look at. This time it didn't leak from the seal, unfortunately. The entire gearbox shell is cracked and there were no prior signs of oil leakage since the initial fix.

Here's what BHPian MinivanDriver had to say on the matter:

Looks like it destroyed itself from the inside. Shaft and/or bearings came loose or broke off while rotating at speed. Then hit the casing and cracked it. I would recommend seeing for yourself the internals of the transmission and taking pictures so as to have proof in case the dealership / Kia tries to do a U-turn and blame external impact later. It would also help the OP to push for an entire gearbox replacement in case they say that only the replacement of damaged components is necessary.

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