C Class W204 Lost 2nd Gear and Reverse (Manual Transmission)

[HITECH]

Quick update for those who find themselves reading the post.
I Got the gearbox from the recommendation ( prestigeallparts) they were reassuring and had the correct gearbox for the car (which was for my car model 711670) worth the recomendation and would use again obviously early days but I’m sure the gearbox will surpass the guarantee . (Thanks hi-tech) the gearbox was Priced lower than most places £780. Ended up having the engine mounts clutch and flywheel all renewed in the process as there was excessive play in the flywheel and mounts were worn.. all possible reasons why gearbox may have failed supposedly but got the car back yesterday with a nice £3000 all in bill but needs must. Question I have tho is, is the temperature sensor for the cat in the way of carrying out a gearbox change as I picked the car up from the garage and engine light was on put it on star and they said it has a short circuit to positive …I’m paying for a sensor but not entirely sure why this would come out a garage with this issue when it went in with no sensor issue so wondering if this has likely been caught/damaged ?

there is no reason what-so-ever to be removing or messing with any kind of temp/pressure sensor. I did advise do no fix which aint broken if everything was ok before the gearbox went faulty. It is a design weakness fault in a batch of gearboxes. If the gear box oil is not refilled at least twice within 100,000 miles then the weak batches of gearboxes, will suffer corrosion as the oil turns almost to water gradually thru mileage. Engine mounts, clutch and flywheel ???? See people who say hey well its all apart anyway might aswell throw a new clutch n flywheel onto it. They will most likely outlast your ownership of the car and the extra price for parts and labour. In this day n age. You fix replace whats broke. Ide hazard a guess that there is a badly joined exhaust clamp somewhere which will give all sorts of temp/pressure errors. Ide tell them double check everything. Because you had no sensor problems before and after the gearbox fault. £3000 you coulda got a brand new gearbox fitted.

 

[Grahamc250]

I’m not trying to justify what iv paid but I was advised of and shown video footage of excessive play from a flywheel hence the change of that and the clutch

Engine mounts were also worn on inspection so having them done whilst more accessible on one side shaved off labour costs at a later date

Granted all the above is seperate from the gearbox fault I was told that these issues could in addition cause the failure of the gearbox.

I’m not a mechanic so you put your trust in what you’re shown/told
As for the sensor fault having a broken circuit I was asking as I wanted to know if that was anywhere near the area of works as seemed odd why that decided to flag up whilst car was in but having it not needed touching I’m guessing the possibility is that it may of unintentionally got knocked or just genuinely packed up. (Changed sensor today at just cost of sensor)
Pretty sure the gearbox and full service was done when I first bought the car second hand for peace of mind and before the remap got done but having the car has only done 80k and me owning it since 35k I would have hoped the gearbox wouldn’t have flopped as soon as it did but that’s cars for you.
Thanks again for advising and recommendation of prestige
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