dllhg

Today on track I had transmission Overheating several times. In the past this happened I changed the fluid and filter and it was fine again. Last session heard a bang then car would not go forward. Won’t go into any gear including reverse. Spectators saw smoke when it happened. No codes which I thought was odd. Sound like transmission is toast ? Could it be the CF drive shaft separated ? I didn’t have the recall work done on it yet. Ughh.

there were never any slipping or rough shifts before this happened. Just loud bang then done.

Take to good Indy shop or dealership ?

thebishman

I didn’t know there was a recall on the driveshaft on the GTRs; just some of the early GTS models.

It obviously sounds DCT related, at least to me since you’ve been pushing far more torque through the ‘box than stock, and doing it in a highly stressful manor multiple times.

Personally I would take it to your MB dealership to have it diagnosed/repaired, although in CA there may well be independent shops that are very familiar with the platform that might save you some money but either way it’s going to be expensive IF the DCT is toast.

Caveat: if you’re planning on keeping the car then searching for an independent shop that can upgrade the DCT would be worth the time spent, imho. If you know any local Nissan GT-R owners who’ve upgraded the GR6 in their car they might well be able to steer you towards a great transmission rebuild shop.

dllhg

It’s at dealer. Waiting for diagnosis. Could be related to the torque tube. I checked pricing and it’s 15k for a reman tranny from mercedes plus labor. 18k for brand new. Wow 🤯

dllhg

Deleted

MBNRG

Unfortunately, some early US 2018 MY GT Rs had the Recall for CF Driveshaft replacement

OP - did your GT R in fact have the Recall posted for your VIN for the CF DS? Or is this speculation/suspicion?

MBNRG

18K is actually relatively inexpensive - this SAME Transaxle is 30-50+K on the Ford GT and Ferrari models which use it

So sorry to hear of your troubles, hope they get you sorted!
Please let us now of the diagnosis and progress.

If it turns out it's the Trans - there is a specialist in SoCal who is exceptionally knowledgeable and rebuilds these trans with great frequency (very first video in thread - Hollywood Mechanic), in addition to other members who have posted in this thread:
https://mbworld.org/forums/coupe-roa...ml#post8799000

Best of luck

AMG 17GT

Yeah, sounds maybe carbon fiber shaft gave up the ghost.

dllhg

I’m not certain. Dealer told me they needed to take it apart to see the serial number on drive shaft and could not tell by simply looking up the vin. 🤷‍♂️

MBNRG

Weird. MB should know with precision which VINs are affected by the Older/Bad batches of CF DS, as everything and its momma is coded/scanned.

Some forum members with MY '18 GT Rs even received a Recall Notice for the CF DS update.

Have you tried checking this MB website below against your VIN? What does it show?
https://www.mbusa.com/en/recall

dllhg

I spoke two separate dealerships about this. Confirmed my VIN may be affected but would require dropping off the car for a few days so they could take it apart enough to check serial number of the actual CF DS. Maddening. Well now I’ll just wait and see what the damage is. Ideally it’s the shaft and they cover it of course. What happens if it is the shaft but they say the serial number isn’t included in recall ? Will see

Paul100

If you need a carbon fiber drive with torque tube, all assembled. Came out of accidented 2018 GTC. I have one with less than 5000km on it. Also have complete transmission from same car, 2018 GTC. I don't know if it is the same as a GTR. Located in Canada,

Thanks,
Paul

dllhg

TQ tube should be covered. Need to find out about trans. Low miles. Would be perfect.

dllhg

one thread I found said it’s the same. Same drive ratio vs the GT and GTS. I would def be interested if my transmission is in fact bad.

Stenzel-Germany

Hi,

GTC have not the same Transmission

GTR / GTC

I. 3,08 / 3,40
II. 2,19 / 2,19
III. 1,63 / 1,63
IV. 1,29 / 1,29
V. 1,03 / 1,03
VI. 0,84 / 0,84
VII. 0,69 / 0,63
R. 2,79 / 2,79
Diff. 3,67 / 3,88

With the GTC tcu, it could also work (not checked)

Best regards

Stenzel

G. P

Sorry to go off-topic a bit, but if I understand it correctly, you made an interesting comment Stenzel, that the transmission unit has to go together with is original TCU.

I know that one of the TCU functions is to act as an anti-theft mechanism. If you change a TCU unit, the car will not start. Should I conclude from your comment that the TCU is not tied to the vehicle's VIN, but to some code in the transmission unit only?

Is it possible to duplicate the original car's TCU into a 2nd TCU?

I'm asking because I haven't found solid references indicating that any of the sold TCU upgrades actually work (mainly in reference to gear change speed). Postings usually refers to "feelings" rather than measured facts. It would be interesting to compare a stock TCU and an upgraded one when done on the same day/track, but for that, you'd need two TCUs coded to the car. Any thoughts?

Wasserott

I'm sorry to hear that you are having issues. But you probably drive this platform harder than I see anyone doing it...time after time. I hope it's just a driveshaft and it's under the recall. I checked my vin on that platform and it came up with no recalls.

descartesfool

My 2016 GT-S had the driveshaft replaced at no cost. But as was a said above, even though my VIN was on the list for recalls, the dealer had to check the driveshaft itself to confirm it fell under the replacement requirement which it did.

Best of luck with your repair. I have had 3 failures on track with my GT-S. First one active motor mount failed on track, replaced under warranty. Then a couple of years later the high pressure power steering hose went (what a mess in the paddock and very expensive out of warranty fix!!) and an active transmission mount failed which I replaced myself. Not sure if pushing the car hard on track has anything to do with the failures though, but they did happen at the track.

AMG 17GT

The driveshaft replacement was a huge upgrade. The area where shaft was coupled was twice the size.

dllhg

Update :

not transmission !! 😁. Right rear drive shaft broke. $3500. Much better than $18k plus labor. Still awfully steep for one driveshaft. They charge $350 per hour 🤯. Feel better knowing the trans is holding up. Trans was overheating. Checked records only 6 days since last pan drop and filter change. Only does about 50% of the fluid. Perhaps there is another issue causing it to overheat like a cooler ?

sevenhead

Where was the failure on the half shaft,ie, at the CV joint or?

thebishman

I never saw the transmission overheat even in the hottest days of a KS summer. Are you sure that all of the fluid was replaced in the DCT at the last service?

So glad it’s a relatively cheap, for a GTR, repair!

dllhg

this was on track it overheated. Half way through sessions. I had five other track days since last oil change without it overheating. They can’t replace it all. Only about 50% each time. Drop pan and change filter.

dllhg

thebishman

Sorry, I was of course referring to multiple back to back runs; (my Son and then myself) on track in a KS summer; not on the street.

dllhg

that’s impressive. Depends on track and how hard it’s being pushed too. How many days on the oil too.