E46 M3 Gearbox Recon

[mpwr343bhp]

Has anyone ever had an E46 M3 6 speed manual gearbox overhauled. I know there were not many peopole offing to do this for the E36 for example.

Just wondering what happens when the gearboxs (Sealed for life lol) start getting notchy after a few thousand miles of over zelous 2nd to 4th dashes that leave the gears slighly worn shall we say.

cheers in advance

[dadofbud]

So are you saying that you have a knackered gearbox ? that would be quite rare.

[M5Dave]

I know that with the six speed box in the E36 M3 Evo it was very difficult, if not impossible, to buy the parts needed to recon the box.

The only solutions for a knackered gearbox were a new one from BMW, or a secondhand one from a breaker.

I don't know if it's the same box in the E46, or if the same issues with parts still exist.

[Egbert Nobacon]

mpwr343bhp said:

Has anyone ever had an E46 M3 6 speed manual gearbox overhauled. I know there were not many peopole offing to do this for the E36 for example.

Just wondering what happens when the gearboxs (Sealed for life lol) start getting notchy after a few thousand miles of over zelous 2nd to 4th dashes that leave the gears slighly worn shall we say.

cheers in advance

This happened to mine, fortunately it was under BMW AUC warranty so they popped a new box in - I got the feeling that it was a reasonably common occurance.

Someone like Munich Legends may be able to steer you in the right direction.

[mpwr343bhp]

Its fine when you drive carefully, but if you change gear with a bit of sprit it just feels notchy, not a real issue, just worse than my mates 53 plate 36K.

Clunky gearboxes are a real bug bare of mine, hence it being an issue, most people probably wouldn't care if that makes sense, just as I know it should be smoother I'm aware of it when driving her as I don't want to make it worse.

[stuthemong]

You can try different gearbox oil if notchness matters. I wouldnt bother. I'd stick OEM and just put up with it, its how they are on the e46. Some are better than others, but I wouldnt be overly worried. If it goes, it goes. Sort it. Don't baby it IMO.

Stu

[mpwr343bhp]

dadofbud said:

So are you saying that you have a knackered gearbox ? that would be quite rare.

No. Just not as happy with it as my old low mileage E36 gearbox. Wonder if its had a few owners how have driven it quite hard.

Prob not do anything about it, but if there were a quick fix id give it a try. :0)

[mpwr343bhp]

M5Dave said:

I know that with the six speed box in the E36 M3 Evo it was very difficult, if not impossible, to buy the parts needed to recon the box.

The only solutions for a knackered gearbox were a new one from BMW, or a secondhand one from a breaker.

I don't know if it's the same box in the E46, or if the same issues with parts still exist.

When I looked with the E36 a few years back I was told that the tollerances were so small that they were difficult to rebuild, and when I replaced my 125K gearbox with a newer one with only 75K on it, it was actually worse.

Its tricky trusting second hard gearboxes, as when its installed if its not right its a costly pain getting it out and returned to the seller etc.

[< FORZA WEST]

Just rebuilding one now and one in 2 weeks time, both E46 6 speed SMG boxes with 4th syncro failures....

Luckily i have a contact at Getrag, the only down side is waiting for the bits..can take upto 21 days to appear but it saves £4k for a new boxor £1250 for seconds.

[dadofbud]

mpwr343bhp said:

dadofbud said:

So are you saying that you have a knackered gearbox ? that would be quite rare.

No. Just not as happy with it as my old low mileage E36 gearbox. Wonder if its had a few owners how have driven it quite hard.

Prob not do anything about it, but if there were a quick fix id give it a try. :0)

E46 M3 Manuals all have notchy gear change, try removing / replacing the CDV it won't 100% change the notchy feel when changing gear but it will remove the overall damped and delayed action of the clutch which will give you more rewarding gear changes. As for change oil I have heard of this, but no real knowledge of if it works, however I have previously read that additives should not be used.

Think that you will just learn to live with it in time.

[Cheburator mk2]

dadofbud said:

As for change oil I have heard of this, but no real knowledge of if it works, however I have previously read that additives should not be used.

Think that you will just learn to live with it in time.

It definitely works - I have had the gearbox and diff oils changed twice in my Z4MC within the last 30k miles. I don't use additives, just very high quaity Castrol / Motul oils. The oil that we take out at each change is horrible - burned, black and breaking down. If you subject your car to hard driving like mine (Nurburgring tool), changing the oil can only do it good...

[Mroad]

[quote=< FORZA WEST]Just rebuilding one now and one in 2 weeks time, both E46 6 speed SMG boxes with 4th syncro failures....

Luckily i have a contact at Getrag, the only down side is waiting for the bits..can take upto 21 days to appear but it saves £4k for a new boxor £1250 for seconds.
[/quote]

That's good to know, can you get parts and rebuild E36 M3 boxes too?

[< FORZA WEST]

Should be able to the internals for all BM boxes auto or manual

[mpwr343bhp]

mpwr343bhp said:

dadofbud said:

So are you saying that you have a knackered gearbox ? that would be quite rare.

No. Just not as happy with it as my old low mileage E36 gearbox. Wonder if its had a few owners how have driven it quite hard.

Prob not do anything about it, but if there were a quick fix id give it a try. :0)

Hi already replaced the oil with new oem, makes a slight differnce, but id guess the 3rd year has had some hammer from the 2nd to 4th dashes, shame as the rest of the car seems to have been looker after.

One thing I did notice was that when prviously selecting 1st at a stop, it seemed hard to select, but now goes in noticably easier.

Been quoted £850 + vat to recxon the box, but its not that bad, + as I dont know anyone thats had a box done, it could be just the same when its returned, if not worse ;0(

[mpwr343bhp]

dadofbud said:

E46 M3 Manuals all have notchy gear change, try removing / replacing the CDV it won't 100% change the notchy feel when changing gear but it will remove the overall damped and delayed action of the clutch which will give you more rewarding gear changes. As for change oil I have heard of this, but no real knowledge of if it works, however I have previously read that additives should not be used.

Think that you will just learn to live with it in time.

My friends 36K 53 plate manual is much nicer, he drove mine, as did the mechanic and they both agreed its not quite right, I just hate having to change gear carefully, as it means you end up sticking you foot hard to the floor on the clutch and carefully slotting in the gears, as else it feels like you could do damage, as the boxes seem generally rough, you defo feel it slotting into gear, especially on 3rd.

[mpwr343bhp]

stuthemong said:

You can try different gearbox oil if notchness matters. I wouldnt bother. I'd stick OEM and just put up with it, its how they are on the e46. Some are better than others, but I wouldnt be overly worried. If it goes, it goes. Sort it. Don't baby it IMO.

Stu

Stuck with the oem, the stuffs like water ;0) made some differences, but thisng main issues may be worn syncros? had similar issues with ould porsche.