Z3 gear change?

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srichards
Joined: Sun 11 Oct, 2015 08:24
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  Z3 roadster 2.8

Z3 gear change?

Post by srichards »

I have recently bought my first Z3. The only real niggle I have with it now is the gear change. I'm finding it tough to get it to change gear smoothly. 2nd to 3rd is the worst. It usually clunks and thuds through the car.

I've not driven any other z3 so I don't know whether they're all like this once they get to this age. Mine has 80k roughly. I've had the gearbox oil change but it is still the same.

The gear change is the only real thing I don't like about it. What's the likely cause of this? Is it reasonably fixable?

Suz
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Southernboy
Joined: Thu 07 Oct, 2010 12:39
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  Z3 roadster 3.0i
Location: Johannesburg

Re: Z3 gear change?

Post by Southernboy »

First question..... does the lever spring back to the "central position" freely, and does the gear change improve once the motor / gearbox warm up ?
If it doesn't, this is a fairly common complaint with BMW e30 and e36 boxes. It's not a major problem and is very easy to rectify. It does however require the gearbox to be removed from the car. There are small shift pins which are under spring pressure. These little pins get bunged up and stick making changing gear difficult and clunky. Generally the gear shifting improves as the box heats up. I had a similar issue on my 3.0 which has less mileage. I had it attended to at the same time as replacing the clutch.
The clutch could also be the issue however. If it isn't disengaging the gears 100% when you press the clutch pedal, it will be difficult for the gear changes to take place smoothly.... so once again, the gear box will need removing to sort a clutch issue out.
Having said all the above, it could also be a simple matter of the master or slave clutch cylinders being in need of repair. There are small rubber seals on little pistons which should be 100% seals under pressure. If fluid leaks past those seals, you will have gear change problems, although it would be apparent in all gears and not "mostly 2nd - 3rd." as you have stated.
The Z3 gear boxes are really good, and in my previous 2.8 I had covered over 230,000 kms without any problems. My best advice would be to take the car to a reputable clutch / gearbox repair place and have them do a test drive and advise you. You must go to an outlet which has sound BMW experience, because they will immediately recognise the symptoms and the remedies, whereas joe on the corner who fixes fords or peugeots, wouldn't have a clue, and would be "guessing" vs knowing.
The guy I took my 3.0 to knew exactly what the fault was before I even finished describing the symptoms... very comforting to know his experience. Here in Johannesburg, he charged me £15 to sort the sticky pistons out - although the total cost for the clutch replacement parts and labour was considerably more (£200).
The Z3 gear box wasn't just fitted to the Z3. It was also used on many of the 3 and 5 series cars, so it is a fairly well tested and rugged piece of mechanics.
Hope you get it sorted.
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srichards
Joined: Sun 11 Oct, 2015 08:24
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

Thanks for that. I'll have to check the next time I use the car. I'm fairly certain it does spring back reasonably well. 2nd to third is most noticeable but I do have issues with other gears. I haven't really used it for longer runs yet. It's mostly local trips under 10 miles each way so it may not be getting properly warmed up. Plus I haven't had it that long so there could be some user error involved :)

There is a local place that does do BMW and most other German cars so I'd probably try them first.

At least it sounds fixable.
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Southernboy
Joined: Thu 07 Oct, 2010 12:39
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  Z3 roadster 3.0i
Location: Johannesburg

Re: Z3 gear change?

Post by Southernboy »

Good. My 3.0 was a 2nd to 3rd problem too, but it "eased" up once the mechanicals got up to heat. Must add, here in Johannesburg, it'll get up to running temp inside of 2 to 3 miles... so perhaps you would need a longer trip.
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lightning
Joined: Tue 27 Nov, 2007 08:15
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  Z3 roadster 3.0i
Location: Stockport

Re: Z3 gear change?

Post by lightning »

Also you could try replacing the gearbox oil. This improved the gear change quality on my 3.0 Z3 and is fairly easy to do.
For the oil l would recommend Castrol Syntrans B75w.

While you are at it, change the fluid in the clutch hydraulics. And consider removing the CDV (if fitted) as this also improves gear shift quality.
The CDV (clutch delay valve) is fitted in the hydraulic line to the clutch and general consensus is that it's better off without it.
Google "Z3 CDV" for more information.
Flight
Joined: Mon 16 Sep, 2013 20:43
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Re: Z3 gear change?

Post by Flight »

Hi Suz.
Changing the ZF gearbox shift pins is not too difficult once the gearbox has been removed. There is a thread under "Gearbox shift pins". The new pins cost me around £50.00 complete with Teflon bushes. A set of precision punches are required these can be made quite easily on a lathe. If you Google "How to change BMW transmission shift pins". there is a splendid write up. After the gearbox was removed and the punches made it took around a couple of hours to change the pins. It is a worthwhile and rewarding job.
Cheers
Flight
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Tufarlian
Joined: Sat 14 Mar, 2009 20:21
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Re: Z3 gear change?

Post by Tufarlian »

Changing the gearbox oil is a very good idea and I suggest also fitting an Earl's braided clutch hose.

The original flexible pipe can expand when hot leading to the clutch not fully disengaging. The Earl's braided hose sorts that.

https://www.earls.co.uk/earls/index.html
srichards
Joined: Sun 11 Oct, 2015 08:24
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

I've already changed the gearbox oil fortunately. Someone else had already taken out the CDV...that was the first thing I had checked.

I'll enquire about clutch fluid change and a re-bleed etc. Braided hose is also a good idea. I've just had it serviced but I don't know which things they would have done.

I'll use it a bit more and see whether it improves or whether I get used to its quirks. Then if it doesn't or I don't then it will time to take it to bits and get those pins done...
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lightning
Joined: Tue 27 Nov, 2007 08:15
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  Z3 roadster 3.0i
Location: Stockport

Re: Z3 gear change?

Post by lightning »

Find out what oil was used in the gearbox, it does make a difference, although don't get too paranoid about it.....there have been long and involved "what gearbox oil" threads in the past.

The Castrol stuff worked best in mine. I actually ended up in the phone to Castrol technical, and they said their Syntrans oil was specially formulated NOT to attack certain metals in older gearboxes.
Del
Joined: Sat 19 Nov, 2011 18:35
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  Z3 roadster 1.9

Re: Z3 gear change?

Post by Del »

These gearboxes do seem sensitive to the gear oil used - if you plan to change again (just to rule it out) I would suggest the nice thin B75w (GL4) gear oil mentioned above along with a fluid flush through the clutch slave cylinder. The latter tends to get ignored with the service regimes. A lot of minor niggles seem to get sorted out by these two issues.
srichards
Joined: Sun 11 Oct, 2015 08:24
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

The gearbox oil will be whatever BMW recommends I'd think. Clutch fluid change, bleed, check master/slave cylinder seals is what I'll do next. It does need a longer run out at some point too.
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lightning
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Re: Z3 gear change?

Post by lightning »

BMW don't actually recommend a gearbox oil for the Z3, as it is listed as "lifetime" as in no need to ever change it!

They will sell you gearbox oil, but it's really expensive.
srichards
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

Oh. It'll probably be a VAG sort of one then.
srichards
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

It's definitely better after a longer warm up time. Clutch still feels like it is dragging a bit so fluid change is next.
Andyboy
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Re: Z3 gear change?

Post by Andyboy »

It sounds like it's time for a new clutch. Even if it hasn't worn much, the trouble is rust and dirt forms on the gearbox input shaft splines. This causes the plate to drag on the flywheel. I had an old 320i E36 (same gearbox) that did this, and a new clutch sorted it. It's not a massive job or hugely expensive.
srichards
Joined: Sun 11 Oct, 2015 08:24
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

How much is a clutch change usually? We may have a different view of 'not hugely expensive' :)
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Southernboy
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Re: Z3 gear change?

Post by Southernboy »

Pop into your local BMW man and ask for a quote for a clutch replacement. At least that way you will have an idea and can plan ahead. Considering the mileage on the clock, it's thankfully not the sort of thing one needs to have done too often.. :wink:
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srichards
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Re: Z3 gear change?

Post by srichards »

Looks like it is about £400 all in. Less than I thought.
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Southernboy
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Re: Z3 gear change?

Post by Southernboy »

Considerably more than it cost me - by around 50%. But I guess the cost of labour there may account for that.
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srichards
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

I took mine to a bmw place that deals with a lot of Z3s. They test drove it and said gear change was fine and just how they are (user error :D) . The thumping and slight take up weirdness is wear in the drivetrain but the usual suspect, propshaft something or other, wasn't the issue. They said I'd got a good example so that was cheering :)

They did mention input shaft to the diff as a possible cause but that was not that easy to sort out.
MpowerRob
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  Z4 roadster 3.0i
Location: North London/Cockfosters

Re: Z3 gear change?

Post by MpowerRob »

I recently changed my gear stick for a AC Schnitzer one and that has significantly made my gear change better, pretty sure is down to the added weight of the new gear stick/knob. Just a thought.
srichards
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

Changing the gear stick is a good thought.
deni2s
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by deni2s »

srichards wrote:Changing the gear stick is a good thought.
Storm V1 is one of the heaviest on the market (I think at least twice as heavy as AC Schnitzer one). I would recommend it.
srichards
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

Had a look at the ac and the V1. Don't like the look of either of them much.
Mike Fishwick
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Re: Z3 gear change?

Post by Mike Fishwick »

The usual cause is clutch drag, caused by either a worn-out clutch or (more likely) the need for re-greasing of the splines on the gearbox input shaft and the clutch hub.

Bleeding the clutch slave cylinder and changing the oil also help.
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srichards
Joined: Sun 11 Oct, 2015 08:24
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  Z3 roadster 2.8

Re: Z3 gear change?

Post by srichards »

Mike Fishwick wrote:The usual cause is clutch drag, caused by either a worn-out clutch or (more likely) the need for re-greasing of the splines on the gearbox input shaft and the clutch hub.

Bleeding the clutch slave cylinder and changing the oil also help.
Think I will start with clutch slave cylinder bleed rather than the more complicated things :)

Is the spline re-greasing a tricky take it all to bits so may as well change the clutch while it's in pieces kind of job?
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