Slow manual gear change

[N1ck]

My 2000 Z3 2.3 (USA) roadster (120,000 miles) is fitted with the Getrag 250 gearbox and seems to have a slower manual gear change than I would expect.
I haven't had it for long so I don't know if its always been like that but it detracts from the driving pleasure.
Its not clunking its just not very slick when changing gear.

I have changed the gearbox and rear axle oil using the BMW oils and its improved a bit.
It had a new clutch in 2016 and the clutch pedal engages about a third of the way up (I believe that the adjustment is automatic anyway).
The tick over is a bit high (c.800rpm) for my liking but I don't have OBD software to lower it.
I have read that the clutch hydraulic hose can flex when it gets old and create problems.
Is there anything else that it could be?

 

[NZ00Z3]

It could be the shifter rod bushings and cup.

With the shifter in neutral. give it a wiggle left and right. You can feel the free play until it starts to hit the spring loaded detents. Mine had over 50mm (2") of free play. This was halved to 25mm (1") by replacing the shifter bushings and shifter cup. Made a good improvement to the accuracy of the gear shift.

Parts List:

• 25117507695 Bush Bearing Oval. I used a 2 piece hard plastic bushing off E-Bay
• 25111222015 Rear bearing, shifter arm
• 25111220439 Gear shift rod joint
• 25111220439 Yellow plastic washers
• 25111220600 Bearing Shift Leaver
• 25111221849 Bolt/clip AKA "The Barstard Clip". Very likely to get damaged on removal, so have one on hand.

 

[Devon Z]

You may well have the worn bushings as above at your milage, but my experience of this issue was at much lower mileage when she was only six years old.

The Zed forums were in very early days here but were fairly active in the USA and they were replacing the gearbox oil with fully synthetic Amsoil or Royal Purple, I was only able to get Amsoil in the UK but it worked and improved the change greatly and is still in there today.

 

[N1ck]

Brilliant comprehensive response thanks. I will test the play tomorrow. I assume that the fix involves dropping the gearbox.

 

[NZ00Z3]

Brilliant comprehensive response thanks. I will test the play tomorrow. I assume that the fix involves dropping the gearbox.

No need to completely remove the transmission.

• Remove drive shaft
• Lower transmission cross member.
• For the six cylinder Z3's the touch point (minimum lowering point) is the back of the inlet manifold onto the heater valve mounted onto the fire wall.

While you are in there, check that the sifter rod seal in the transmission is not leaking. If it is you can either remove the old seal to fit a new one, or tap the old seal in and fit a new one on top.

 

[N1ck]

No need to completely remove the transmission.

• Remove drive shaft
• Lower transmission cross member.
• For the six cylinder Z3's the touch point (minimum lowering point) is the back of the inlet manifold onto the heater valve mounted onto the fire wall.

While you are in there, check that the sifter rod seal in the transmission is not leaking. If it is you can either remove the old seal to fit a new one, or tap the old seal in and fit a new one on top.

I have tested the play in the gear lever and found the following:

• The gear lever naturally aligns with 3rd and 4th.
• When I move the gear lever to the left to select 1st or 2nd there is immediately a reassuring spring resistance which returns the lever to align with 3rd & 4th if I let go.
• When I move the gear lever to the right to select 5th there is no spring resistance at all and if I let go of the level stays aligned with 5th gear.

Is this correct or should there be a similar spring resistance when selecting 5th to the resistance I feel when selecting 1st or 2nd?​

If this is not correct, is it still symptomatic of worn bushes or has the return spring inside the gearbox failed?​

​

Finally, and looking ahead, if I lower the gearbox as described does this give me access to the gear selector mechanism from the cabin or from underneath the car?​

 

[t-tony]

It's sounds as though it is ready for the detent springs and pins being renewed. @Lee has a lot of knowledge on this subject.

Tony.

 

[Lee]

Tony's on the money, sounds like it's time to pull the gearbox and replace the indent pins. I've just bought some another kit from BMW and have another gearbox in this weekend. With the gearbox on the bench this takes around 20mins.

The guide I learnt from is here: How-to: Service Your BMW Transmission Shift Pins. - Eat, Sleep, Tinker. (eatsleeptinker.com)

 

[N1ck]

Tony's on the money, sounds like it's time to pull the gearbox and replace the indent pins. I've just bought some another kit from BMW and have another gearbox in this weekend. With the gearbox on the bench this takes around 20mins.
View attachment 215785
View attachment 215787

The guide I learnt from is here: How-to: Service Your BMW Transmission Shift Pins. - Eat, Sleep, Tinker. (eatsleeptinker.com)

Hi Lee,
Thank you for the feedback and the 'How to guide'. The guide seems to be for the ZF gearbox whereas mine is the Getrag 250. Do you know if the process is the same?
Just for clarity, I thought the detent pins were to hold the gear in place once selected. I don't have any problems selecting the gear (pushing the gear lever into gear albeit it doesn't feel very crisp) and it doesn't jump out of gear once selected. The problem seems to be more a lack of spring return from left to right across the gate and a general sloppiness. Is this still due to the detent pins?

 

[Lee]

Hi Lee,
Thank you for the feedback and the 'How to guide'. The guide seems to be for the ZF gearbox whereas mine is the Getrag 250. Do you know if the process is the same?
Just for clarity, I thought the detent pins were to hold the gear in place once selected. I don't have any problems selecting the gear (pushing the gear lever into gear albeit it doesn't feel very crisp) and it doesn't jump out of gear once selected. The problem seems to be more a lack of spring return from left to right across the gate and a general sloppiness. Is this still due to the detent pins?

Sorry didnt read the first bit of your post, I'm not aware of any fixes for the Getrag boxes they dont like the high miles. Your best bet would be to buy a ZF they're a stright swap you'll just need the front section of the propshaft as the flange face is larger again very simple to do I've done it myself.

Thats if its too annoying

 

[Jams]

Hi everyone,

The drift tools to ‘knock’ these bushings in are no longer being made by the mentioned Zed community member. Online, it seems only expensive options from the USA are possible with whatever imports fees to the UK. Also, BMW don’t have a record of these tools from the mentioned part numbers. Does anyone know where to get them in the UK/able to lend them to me (I would obviously be happy to pay)?

Thanks v much,

James