Gearbox trouble

[micky 32]

Has anyone experienced any problems with the TDI 6 speeds? Well the other day i was parking and went to put it in reverse and it wouldn't go in so when i put it in first i had no drive just like it was in neutral. 1st to 2nd had barely any resistance so thought a cable broke but no. Now its stuck in third gear.

I have been told a selector fork pin could have broke or come loose , at least i picked up a second hand box for 450 euro with approx 30k on it.

 

[chillcupra]

That does sound like a selector fork IMO.

 

[basstard]

just out of curiosity, how many miles you've done with it?

 

[Triple D]

iirc he has done over 100k

 

[micky 32]

153k. This is weird, my friends PD150 gearbox done the exact same thing on the same day as it happened to mine! A selector fork breaks in them and is a weakness in them. They can go anytime as his has only 60k.

 

[muddyboots]

Maybe the cold snap has just caused a tiny bit more stress
I know it's definitely harder to engage gears in mine when it's very cold, they crunch even more than usual too.

 

[basstard]

maybe you uk guys need to use a lower grade cold oil,,,

 

[andy43]

I'm surprised no one has mentioned that the standard gearbox isnt designed to have all that power going through it, you've uprated everything else but not the gearbox which must be taking a hell of lot of stress, in fact I'm amazed it's lasted this long. I know its big business remapping etc.. but I'm pretty sure that even the standard ECU is programmed to protect the gearbox by artificially flattening the torque curve, getting it tuned up to 220bhp will put a huge amount of strain on the whole of the drivetrain. I'm very happy to be corrected on this one.

 

[micky 32]

I'm surprised no one has mentioned that the standard gearbox isnt designed to have all that power going through it, you've uprated everything else but not the gearbox which must be taking a hell of lot of stress, in fact I'm amazed it's lasted this long. I know its big business remapping etc.. but I'm pretty sure that even the standard ECU is programmed to protect the gearbox by artificially flattening the torque curve, getting it tuned up to 220bhp will put a huge amount of strain on the whole of the drivetrain. I'm very happy to be corrected on this one.

Im afraid you are way off the mark here. The 6 speed drivetrain can handle all that power. It wasn't the drivetrain part that gave up. All cogs and bearings are fine it was the selector fork that broke and is a common problem with these gearboxes. A mates 6 speed gave up with the exact same fault but with half the mileage and his car is standard. If my car was standard it still would have broke. The only stress that gets is when changing gear.

The gearbox was taken apart and everything else was perfect. Total mileage 154k. It has been remapped since new and is running 200bhp+ since 80k.

 

[basstard]

I'm surprised no one has mentioned that the standard gearbox isnt designed to have all that power going through it

I guess this is because it was about obvious!!!

To say it all, these gearboxes are pretty solid, I've seen some cars with double the power on stock gearbox and they had no problem [afaik]. Uprating a gearbox would mean an aftermarket one or using stronger gears [which means taking them from another car, with different gearing,,,, ]. Aftermarket ones are VERY expensive and not everybody is satisfied with them and I've only seen them on petrols, not on diesels so I don't even know if there's some company producing them. In the end the only way is learning to drive without putting too much strain on the transmission,,, a modified car has obviously smaller safety margins and one has to drive according to this,,,

some say that a limited slip diff helps in preserving the gearbox, being not informed at all about these things I don't know if this is true or not,,, can someone enlighten me?

 

[micky 32]

Basstard, after 154k and nearly 80k running 200bhp the gears and cogs and bearings were all ok so i dont thinks its a concern really. The car is also on its original cv joints and they are perfect too.

 

[basstard]

This is good. I guess tho that you're driving in a reasonable way,,, I mean, flooring it on low revs in high gears with all that torque would at least put some serious stress on the box,,,,

 

[muddyboots]

Remember, it's the input torque that you need to be concerned about, not the maximum power. At the point where maximum power is developed, the torque will have dropped off considerably.

 

[micky 32]

When comparing PD130 and PD150 they both use the same 6 speed gearbox but what they did with the PD150 was they added a cooling vent that comes from the front spoiler to the gearbox, i wonder would it benenficial to add one or a waste of time? It would actually be a cheap mod.

 

[muddyboots]

Interesting you mention that. I noticed my Passat has a couple of air intake ducts about halfway back in the engine undertray, wonder if they're aimed at the gearbox ?