Yesterday while driving around 20mph in local stop and go traffic, out of the blue the transmission shifted by itself into neutral which caused me to red line the engine immediately and then in the MID a message said something to the effect of: "Transmission to hot, put the car in park, and turn off the engine."

I did that immediately and after a few minutes to let it cool down, I started it up again and it seemed to operate normally. I called the dealer and told them what I just experienced and to ask for advice. Obviously I was going to the dealer asap but I wanted to know what might have caused that to happen. The dealer told me that the last time I had serviced the transmission and rear differential was at 33,000 miles. I was now at 92,000 miles and was horrified that I had not performed that service 30,000 miles ago. I never saw a warning message and the dealer never told me that it had not been done at 60,000 miles, but I never experienced any performance issues at all, to provide a kick in the ass that I was stupid and did not get that service done a long time ago. I don't blame the dealer. I blame myself as it is ultimately my responsibility. So I got it done today and they showed me what came out of both ends of the car. It was effectively mud colored fluid. It looked like used motor oil. That is bad. However on further inspection they discovered a leaky seal at the transmission where the drive shaft connects. I am getting that maintenance done next week. It is not a major leak but it is there.

So if you have not completed this maintenance at the 30,000 mile increments, here is your reminder. Be well and be safe.

The Blackbird is back up in the air again!

 

Glad it was nothing more serious! Also glad I literally just had the rear diff and ATF fluids changed last week (at roughly 38,000 miles).

 

92k miles! Wow. You'll have to post up a 100k mile review before long! Still enjoying the car?

 

Absolutely still really enjoying the car. It performs every bit as well as day one of ownership. Gas mileage is the same, still rock solid structure, and just as quiet as day one too.

 

OK then, it's time for me to put in yet another plug for the "old school" guys.

We are the ones who refuse to trust the MID, sensors, and other claptrap that is "supposed" to tell you when to change fluids. Do it at proper MILEAGE intervals and you should always be good.

Just sayin'.....

 

Just because the altimeter says you are at a certain altitude, does not mean you shouldn't look out for a mountain ahead of you. You don't want to have to use that shinny new ejection seat and scuttle the plane. The old manual log of maintenance is a good thing. Don't need an app for that, just a pen and paper.

 

OK that may be the WORST fuckin' analogy I ever heard!!

Flying a plane is analogous to maintaining an automobile? Really!!?

 

90k!

 

It was intentional bad humor. Smile a little. No charge.

 

@George Knighton has more miles on his Sport Hybrid, IIRC. Several of the original Sport Hybrid “beta testers” like him and RLX Sport Hybrid above still have their cars. I, on the other hand, am easily distracted by shiny flashy things with new tech...

 

That's because the plane flew over your head.


One is to one as two is to two.

 

Math isn't my forte. Neither is joke telling. Sorry.

I will say that I didn't notice any functional issues prior, but the transmission is shifting buttery smooth, which is slightly different. I guess I got used to how it was shifting before, and now it feels sort of new again. Must be the clean fluid. Or it could be in my head. Not a measurable thing, just an observation.

 

Speaking of which, this is my list of service intervals for my '07 RL. I understand the "transfer case" is no longer there for the RLX Sport Hybrid, right?

Does anyone know the interval for the "Twin Motor Unit " on the RLX Sport Hybrid? Is it as low as 15K or closer to 25-30K?

 

I don't believe there is a transfer case as there is no drive shaft going to the rear of the car, but it is my understanding that for all sport hybrids, the fluid changes need to happen front and rear at 30,000 mile intervals. NOT the 60,000 that I did foolishly. I'm still pissed at myself for missing that. Although the dealer should have said something to me that is was not done for the last 30,000 miles.

 

That's a great help...thanks. So ATF and Twin Motor Unit at 30K. I think that's all the components in that drive line system.

I'll see if I can get the dealer service guys to confirm that.....and I agree with you about the dealer. I mean jezz, he missed a great revenue opportunity!!

Thanks.

 

No, there isn't. The two rear motors are not connected to each other or to the front motors, and if the two rear motors are supposed to be pushing equally, they rely on the computer programing to decide the torque differential. :-)

 

OK so that leaves me wondering what the Twin Motor Unit does. Since, I think, there's only one of them does it drive the two rear motor through separate shafts, and if it doesn't, what's its function and how do the two rear motors get driven??

TIA

 

It doesn’t “do” anything. It just just a housing.

 

The twin motors are just that motors. Each one drives one wheel independently as well as recaptures energy when coasting, turning or braking. It will send power or recapture energy independently of each other to enhance performance and stability. The front motor is sandwiched between the DCT transmission and the ICE engine and provides both positive performance and regenerative capture too. It is a very slick system and the performance overall is amazing. Very unusual overall.

 

Yes, I got more info from my service manager.

The front is powered and controlled by the ATF as we would suspect, and the service interval for fluid change on the ATF is "generally" 30K miles.

That big honker "case" that George showed us drives the rear two wheels (as well as recapture, etc., etc.). Now I was told it is produced and sold with "break in" fluid that "generally" gets changed at 15K miles and replaced with the ATF stuff. After that change interval is "generally" 30K miles.

I say "generally" (a word he kept using) because the manager was really in love with that MID sensor system and kept trying to get me to accept what it tells me. Took a while for him to realize that wasn't going to cut it for an "old school" fart like me.

Thanks to all. Got what I needed.

 

Generally 30,000 miles yes. 60,000 miles like I did by accident is just stupid! For someone who is so OCD about this kind of stuff, it really angers me that I missed this service. Car runs great! Love it! My mpg ticked up by 1mpg but that makes sense that it might. Less friction, better efficiency.

 

I changed the tmu and transmission fluid around 60k and there was a noticeable improvement in shifting performance. Probably should have done it sooner, but the industry standard is for longer service intervals.

DCTs need more frequent oil changes. Maybe even more frequent than currently recommended. The TSB on premature degradation of oil could be an indicator of a systematic problem.