Crunching gears randomly

[toenheel]

Morning all

Cecil every now and then won't engage a gear and crunches it, I've had it to bmw but it's intermittent so can't get it to do it in front of a tech. I've replaced the salmon relay. I've got full warranty on it but they can't claim until something fails apparently. Any ideas? Makes you look a right wally when you boot it past someone and its crunching and screaming up the revs!!

[Chad]

Morning all

Cecil every now and then won't engage a gear and crunches it, I've had it to bmw but it's intermittent so can't get it to do it in front of a tech. I've replaced the salmon relay. I've got full warranty on it but they can't claim until something fails apparently. Any ideas? Makes you look a right wally when you boot it past someone and its crunching and screaming up the revs!!

For me I wouldn't spend. £1000 + on warranty. Each year. On a twelve year old car,, But put it into proper maintenance.and that includes not spending hundreds of pounds at dealers on services, on a few pints of oil and oil filter,,for a poxy stamp...do it yourself,, Problem could be sticking clutch issue, or gear engagement problem, eg possibly springs and locating pin or ball bearing in box, they are a easy job, and the cheapest, 4or five hr job, also do gearbox oil change at same time. Could also be in hydrolics, but unlicly , sure there will be plenty of other suggestions on possible causes

[toenheel]

Cheers. Warranty has more than paid for itself over the years and I've a good relationship with my local dealer so never have any issues with claims but something needs to fail first. I personally find the warranty brilliant considering the age of the car I've had diff's and all kinds replaced.

[shimmy]

For me I wouldn't spend. £1000 + on warranty. Each year. On a twelve year old car,, But put it into proper maintenance.and that includes not spending hundreds of pounds at dealers on services, on a few pints of oil and oil filter,,for a poxy stamp...do it yourself,, Problem could be sticking clutch issue, or gear engagement problem, eg possibly springs and locating pin or ball bearing in box, they are a easy job, and the cheapest, 4or five hr job, also do gearbox oil change at same time. Could also be in hydrolics, but unlicly , sure there will be plenty of other suggestions on possible causes

Depends how much and how hard you use it.

My warranty pud out £30k in 4 years. Not bad for a £5k outlay. And after you are left with new gearbox, engine, diff(s), SMG pump, etc

[Chad]

Depends how much and how hard you use it.

My warranty pud out £30k in 4 years. Not bad for a £5k outlay. And after you are left with new gearbox, engine, diff(s), SMG pump, etc

That's what happens shimmy, if you drive Csl about in sixth gear all day ,:blalalala:

[shimmy]

That's what happens shimmy, if you drive Csl about in sixth gear all day ,:blalalala:

186mph in 6th gear ;)

[Chad]

186mph in 6th gear ;)

Out of interest shimmy , how long do you wait for repairs on warranty claim , reason for asking my lad waited two years for new motor, not warranty paid for it himself, not sure if waiting time is any better, Chad

[Chad]

Depends how much and how hard you use it.

My warranty pud out £30k in 4 years. Not bad for a £5k outlay. And after you are left with new gearbox, engine, diff(s), SMG pump, etc Won't deny that's a good result, nice to get something from insurance :thumbs:

[shimmy]

Out of interest shimmy , how long do you wait for repairs on warranty claim , reason for asking my lad waited two years for new motor, not warranty paid for it himself, not sure if waiting time is any better, Chad

Mine has always been quick but that's just luck I think, if they haven't got the parts or motors made up, sometimes you just have to wait

Cams were 18 months previously

[Mike R]

I have the same issue, and car is going back to BMW to see if they can find out. They did all the same things your dealership did and it is pretty random when it does it. Sometimes on track, sometimes just poodling around.

Speed and load seem irrelevant. Sometimes it has even done it in auto mode.

If you find out before me, please post here and I will do the same.

[toenheel]

Hi Mike, will do cheers.

Phil

[Monkey]

Hi Mike, will do cheers.

Phil

I've replaced a couple of boxes recently for the same issue. You do not need to wait for it to fail completely, if the dealer takes a sample of oil and finds swarf (they will do if it's not engaging gears correctly) then that is sufficient to satisfy warranty procedures.

A common issue with these boxes, only seem to do them on CSL's though as opposed to normal M3's.

They are available currently, checked on Friday and there were 2 in the country and several in Germany.

[shimmy]

https://youtu.be/NsfvmE-kD6I

They changed my box when I used this clip to prove the slip

[s1csl]

Its a new gearbox needed, had the same symptoms as described here the only difference with mine the crunch was from 2nd to 3rd under hard acceleration, done on warranty

[toenheel]

Well bit of an update, CSL is in my local dealer now as still having gearbox crunching issues! They are replacing a bonnet sensor as precaution as been getting warning lights on and flashing gear display. Managed to capture a couple of videos of the actual crunching so hopefully be enough for them to agree a warranty claim: https://vimeo.com/186336508

If they agree to replace I'm starting to wonder if its worth replacing the clutch whilst box is potentially out, any idea on cost?

[select]

New Clutch with new bearing is around £450.

I would wait and see how the clutch looks when its removed and depending on your mileage.

[Mike R]

Just had mine done as well and seems to have been an amalgamation of issues:
1. Bonnet switches had to be replaced.
2. Salmon relay was showing signs of overheating and had to be replaced.
3. Air in hydraulic actuation - system bled.

I was advised to have the the indent spring replaced by a BMW master technician that I met at the 'ring, but I was advised by my guy at Sycamores that if the indent spring needed replacing, the error comes up continuously in the system log and not randomly as it does with the above causes.

Waiting for the car to come back now in (hopefully) rude health :supz:.

[select]

@Mike Do you know how much it would cost to have the indent springs replaced? As i am told the gearbox needs to be dropped. So probably not cheap.

[Chad]

@Mike Do you know how much it would cost to have the indent springs replaced? As i am told the gearbox needs to be dropped. So probably not cheap.

Hi select. Spring is about £4. But best to replace the pin also ,as the roller bearings wears that's about £20. Four hour job to do yourself. You don't need to take box out. Did mine myself bit of a pig to do, also re use old knock in plug, you need to drop prop exhaust. And lower box as far as possible to pry out plug that holds spring in. Chad

[select]

Thanks Chad, my buddy confirmed that the box does not need to be removed. I will replace all the pins and the bearing while at it.

[Mike R]

Hi select. Spring is about £4. But best to replace the pin also ,as the roller bearings wears that's about £20. Four hour job to do yourself. You don't need to take box out. Did mine myself bit of a pig to do, also re use old knock in plug, you need to drop prop exhaust. And lower box as far as possible to pry out plug that holds spring in. Chad

The only thing the technician said when I was in Germany, that if the car has done above 60k and you're replacing the spring, you might as well pull the gearbox out and do the clutch and flywheel at the same time. Expensive, but at least it is done for the next 60-80k miles.

[select]

When you remove the gearbox in order to change the pins then i agree.
But seeing how its possible to change them without removing the box then i would say it isn't worth the extra effort as its at least 2-3 times the work.
Especially if your clutch&Flywheel is still in good nick. (You can check that with DIS, NZ_M3 has posted a guide somewhere).


Regarding toenheel's crunching gears issue, i am curious to hear what the fault was.
But i think bmw will just replace the gearbox and then repair it afterwards.

[Chad]

When you remove the gearbox in order to change the pins then i agree.
But seeing how its possible to change them without removing the box then i would say it isn't worth the extra effort as its at least 2-3 times the work.
Especially if your clutch&Flywheel is still in good nick. (You can check that with DIS, NZ_M3 has posted a guide somewhere).


Regarding toenheel's crunching gears issue, i am curious to hear what the fault was.
But i think bmw will just replace the gearbox and then repair it afterwards.

Also a good tip is to remove front section of air box , if not full air box, also all cabin air filter housing,gearbox support bracket,doing this allows gearbox to be tilted down more , that gives you more acsess to pry out that knock in plug, and easier to put back in,don't forget rollerpin has to be correctly possisiond, As Mike says, if your taking box out definitely would fit new clutch, Bang in some new oil,gear shifts will be bang on, no more faulse neutrals, actually not newtrals, but prity sure it's just clutch that's still engaged, as gps is not recognising proper true gear selection, chad

[toenheel]

Had a call back from my dealer today apparently it's a knackered syncro on 4th gear so they are looking to replace box under warranty. Just awaiting approval from warranty!

[toenheel]

New gearbox on its way under warranty!

[select]

Glad that it all went well.

Curious at how many miles has your gearbox done?

[toenheel]

Glad that it all went well.

Curious at how many miles has your gearbox done?

Cheers, 56k miles.

[GregorFuk]

For those of us that can't wave the warranty flag does anybody rebuild these? Just wondering.

[toenheel]

Picked car up this morning wow! Drivetrain feels much tighter and the car seems to have more get up and go!

[Chad]

Picked car up this morning wow! Drivetrain feels much tighter and the car seems to have more get up and go!

Hi did they actually find out what problem was ,know they suspected fourth gear problem, chad

[toenheel]

Hi did they actually find out what problem was ,know they suspected fourth gear problem, chad

They said a suspected syncro issue apparently. Drivetrain feels tight now driving really well. Few jobs to do over the winter inc a wheel refurb.

[Chad]

They said a suspected syncro issue apparently. Drivetrain feels tight now driving really well. Few jobs to do over the winter inc a wheel refurb.
Good result. If you got a new gearbox , would be good if they confirmed for sure the exact problem, for future reference, never know if it was just a simple compression spring,or busted locking pin

[Monkey]

For those of us that can't wave the warranty flag does anybody rebuild these? Just wondering.


No that I'm aware of. Pretty sure Getrag will not release the tools for anyone to be able to repair them, but as always where there's a will, there's a way:hahaha: