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-   -   Gearbox failure on Volvo XC60 at 30,000 km (https://www.team-bhp.com/forum/technical-stuff/212686-gearbox-failure-volvo-xc60-30-000-km.html)

I own a late 2014 XC60 2.0L Diesel D4 with the Aisin 8 Speed Gearbox. The car has run 30,000 kms. The car was serviced in June this year from Kerala Volvo where in an Oil and Coolant change was done apart from replacing a faulty wheel speed sensor. Everything was going great till recently.

The problem began earlier this month in August, when on a drive I noticed a warning message showing "Coolant Low - Switch off Engine". Upon checking under bonnet, I saw the coolant reservoir tank was empty and it had a brown oily kind of residue. After checking with Kerala Volvo, the dealer in Kochi I decided to send the vehicle by Flat bed to their workshop in Kochi. A couple of days later after checking, the dealer informed that the Coolant had leaked into the Gearbox resulting in shift shock. The service advisor said that Volvo recommends the Gearbox to be replaced! To replace a Gearbox in a car that's run only 30,000 kms sounded shocking and absurd. After all I bought a Volvo hoping for a good ownership experience.

This is the same 8 Speed Aisin Gearbox that comes in the current Volvo XC60,XC90 and XC40.

My Volvo experience seems to quite short lived.
So much for "Volvo for Life".

Hi. Sorry to know about this failure.

Coolant leaking into gearbox is hard to believe. But it is possible through the radiator. In some vehicles, the automatic transmission fluid too goes to (the same) radiator to emit the heat. If a part of radiator is used for the engine coolant and the remaining part for the ATF, the coolant can leak through the partition between the two circuits inside the radiator.

In some vehicles, I have seen two separate radiators, one behind the other. One is for the engine coolant and the other is for the transmission fluid. Such design bails you out of this risk.

So check the case with your car.

Otherwise I am not able to think of any way for the engine coolant to leak into the transmission. So if you did not damage the radiator yourself (impact or collision), please suggest Volvo to carry out the repair / replacement as a Goodwill.

The coolant entering inside the automatic transmission is destructive for the transmission too. So please get that checked.

Q1. Is this a car you bought new from Volvo or did you buy this second hand. Q2. Has the car been involved with any serious accident

A gearbox needing replacement is too dismaying to hear of. After all the engine and the transmission is the heart of a car. I assume the car is out of warranty. Talking to the Volvo India management may be worth it.

Unfortunate to say the least.

Try getting a second opinion from someone who knows about these things and is independent of the Service Center. Let him have a look at the vehicle and form an opinion.

At the same time, speak to Volvo officials and tell them that something like this is bad for their reputation. Specially since the damage is because. of no fault of yours. A reasonable management should respond positively.

Thanks. Yes the dealer mentioned that since the Coolant had gone into the Gearbox, Volvo's policy is to replace. Reason being, there would be shift shock if they drained and serviced the gearbox. I don't understand how a leak could occur as the car's never been in an accident and I am the only one who drives it.

I am surprised that the problem was not noticed at service. I have been charged for coolant tank cleaning and for new coolant.

Thanks for the info. To answer your question, I bought the car almost brand new from a friend with around 9000kms on the ODO. The first service onwards was done by me. It's not been any accident at all till date. I have not faced any major issues at all till date other than a couple of faulty wheel speed sensors which was replaced on payment basis. Routine services were done in Kochi and Coimbatore. The car is a gem and I bought it especially because of the responsive nature of the new 8 speed box compared to the older one.

I have written to Volvo India on an e-mail address shown on their website but I have not received a reply.

This is what probably happened. Usually happens due to corrosion. A lot of the late 1990's/early 2000 Mercedes (read Daimler Chrysler era) had this issue. Ideally, the dealer should have checked the cooler for corrosion.

In autotransmission vehicles the coolant inside the transmission is routed through a heat exchanger. In most standard vehicles this is a liquid to liquid heat exchanger with two circuits inside it 1) an oil circuit and 2) coolant circuit. Both are separate from each other and flow through their own passages.

Sometimes the metal/or plastic inside the heatexchanger degrades/corrode or break allowing both liquids to come into contact with each other and they mix. Once they mix the coolant only circuit will get contaminated by oil and oil only circuit will get contaminated with coolant and this mix goes everywhere it is not supposed to.

In some vehicles the trans oil heat exchanger is a separate unit usually seen as a metal box with 4 lines coming out of it and in some vehicles (more common) this heat exchanger within radiator itself with the lower tank of the radiator having couple of metal loops inside it which carries transmission oil. Failure in both cases would result in a similar failure.

If you are paying out of your pocket I would suggest you to first replace the failed heat exchanger and get the coolant loop repaired and after that flush the transmission completely using new transmission fluid (follow service manual, the procedure can be lengthy, there is more to it than topping up through the hole after draining what's in the pan) and then finally replace the oil used for flush with new transmission oil.

If you stopped driving as soon as you detected the fault the damage would be too low to warrant a transmission change.

Edit: This can happen to all vehicles with a liquid to liquid heat exchanger (be it for engine oil or for trans oil). Usually caused by corrosion of metal or plastic cracking which can be accelerated due to poor material or use of wrong coolant or environmental reasons.

Dear @vicskster. This is wise and practical advise you have got. Check this assessment by brother Sankar with the number I have PMed you. You can even have your centre engineer talk to the person I suggested. Best of luck. If the fight has to be taken to Volvo I'll help you. But we'll hold the brahma astra for a bit right now.

Sir thanks very much for the detailed info. As you mentioned, the advisor has confirmed there is a cooler on the gearbox which circulates the coolant coming from the radiator. According to him, a seal preventing the coolant going into the gearbox has most likely failed which caused the mix up. He said some oil drained from the gear box was almost white in colour because of the mix up.

He also told me shift shock has already been noticed while moving the vehicle which means the gearbox is probably damaged.

Personally speaking I have no intention of paying a fortune on a new gearbox. I am just frustrated with Volvo India not responding to me. The dealer has informed Volvo will not take responsibility because of out of warranty status.

Yes, the white or pinkinsh oil&water emulsion is expected in this type of failure. But still do not lose hope yet. The shift shock is also expected in this scenario because the oil emulsion is no longer able to provide the necessary lubrication and viscosity required by the gearbox and the valve body inside which controls the gear changes. Try filling fresh fluid and flush out the system it will get better. Remember the procedure followed should be for transmission fluid replacement and not topping up.

Though your vehicle is out of warranty you should get goodwill warranty from them since this part (seal) failing is a quality issue rather than user created problem.

Adding to Sankers points, after changing the fluid, run it to 6-8 months and replace the fluid once again to thoroughly remove any contaminants

Sharing a few pictures of the Car, the coolant and oil mix in the coolant tank and drained Oil/Coolant mix from the gearbox.


XC60 D4 2 Liter - with the 8 Speed Aisin Transmission


The condition of the drained Gearbox Oil


Engine bay showing the Coolant tank


Notice the mixture in the Coolant tank

I would go with Sankar’s advice. Fix the cooler, flush the box and see what happens before replacing it.

Good luck
Jeroen

Since the company is not covering the replacement of the gearbox under goodwill warranty(which they should have since this kind of failure is not acceptable), what Jeroen,Sankar and Ajmat suggested is a reasonable chance to take . If it works, then you have solved the problem at the fraction of the cost of a new gearbox.

Like other distinguished members of community have mentioned and i would agree with them in totality-"Fix the cooler, flush the box and see what happens before replacing it". This is the way i would go too. Maybe the gearbox is not damaged to the extent that it demands a total replacement. There would be no harm cause either ways you have to replace the gearbox cooler and seal, you may as well take a chance and try it out. If it works then nothing like it, if it doesn't then there is no option left but to fight it out with volvo.