Z4m - Graunching 2nd gear on fast changes?

Ed Doe

Ed Doe

Veteran
 Ashbourne or Frimley
Evening chaps,

Quick question - I've had my M for a few months and on the odd occasion have had cause to use full throttle in first and 2nd gear, with a fast change between. In this scenario I have found that shifting to 2nd it seemingly doesn't fully engage the gear, but rather just graunches, and then after a second or so goes in. It makes me cry a little inside when I hear the noise - I just had it happen on the way back from Hereford rejoining a dual carriageway off a very short slip road from services, and I've been worrying about it since!

I rarely have to do this (and if course can drive around the 'foible' - I don't want to trash the gearbox!) but it's maybe happened 4 times or so now - and I'd like to know if this just par for the course and 'they're just like that'? I appreciate the synchros have a hell of a job when the engine is at 8k rpm in 1st trying to match 2nd and I appreciate its probably not quite designed to be crashed into 2nd gear hard in this scenario - I just want to make sure I'm not on my own with these symptoms?


Thanks in advance!

Ed
 
Don’t want to worry you but that’s what my 3litre e89 did, diagnosed as knackered synchros and i luckily got my money back on the car :?
Rob
 
First to second is typically known to be a bit of a dog with our cars. You do have to be positively firm with the selection compared to anything else I’ve driven, could you just be being too gentle with it ?
 
Thanks chaps -

Smart bear - it's only when I'm really going from 1st to 2nd really quickly, normal changes are no issue at whatever speed. Ditto going down the box - 3rd to 2nd is as quick as you like with heel an toe.

Tom - I don't think I could be accused of being gentle with it.... :oops: The only thing that has changed slightly in the last few months is the shift knob is a non-oem one and it's not a great fit - it has started to loosen (grub screws) and now wobbles a bit - I wonder if it's making the shift action a bit less positive which is contributing to the issue. I've just purchased an RTD shifter for it which I hope will resolve :lol:
 
I assume you have removed the CDV, being an old hand here Ed ?
 
Angelus - I know what you mean, the zhp certainly sorted out my si shifting. I've just bought an rtd shifter though - hoping this will still have the desired effect!

Bing - yes believe the cdv is gone, but to be fair I haven't checked since purchasing the car December last year! It certainly doesn't feel like it has one still!
 
It's stange as what you are describing is the common 1st-2nd gear denial on fast shifts associated with this gearbox and the s54. The 'fix' is to install vt engine mounts, but I see you already have them so not sure what to say now :? You could try uprated gear box mounts but most things I've read about them suggest they don't do a lot. Worth checking the state of yours and also the vt mounts.
 
Also, I’ve found that if I row through the gears with the engine on before I set off it does make it smoother all round.
 
I do think it's partially due to the shift knob being a bit flobbery and just making the shift more recalcitrant.

Thanks for the advice chaps - I'll take a look at the mounts, and update once the new shifter is fitted :)
 
Bad sychro-mesh, feel sorry for you.
As mentioned, try another oil to see if it gets good enough, or else you'd have to renew the 2nd gear synchro.
 
i dont find the shift stiff at all..... however their is definitely a knack to getting it smooth... ive got the VT , uprated GB mounts ( these were a waste of time) braided clutch line, fresh O.E fluid and it feels really nice....

Re your issue, try the cheap things first and then lean towards actual GB issues...... i think our box is ZF, instead of the getrag units from the m3. ( basically 3.0si based)
 
Beedub thanks - you're exactly right it is a zf box - apparently well known to be a good strong box so I'm hopeful it's not the synchros.

I've already got the vt engine mounts - next stop is Deffos a fluid change, and I think I do need to also modify my approach - its not a hot hatch I can just crash into gear - 8k is a pretty big number to be forcing sunchros together at repeatedly!!

My beautiful new shifter has arrived too so hopefully that'll eliminate the sloppy current shifter setup :)

To be clear my shifter isn't stiff, to be honest I don't feel it's much different to my old si, as I say the only thing I've noticed is a few occasions when I've really wanted to slam it between 1st and 2nd it didn't seem to like it!
 
I have to say - and this is NOT a criticism - I don’t think I’ve ever driven first to the line, or anywhere near it. Second and third yes, but I reckon I get to 4/5k max in first and change, mainly because it happens so fast, sounds demented, and it scares me how short first gear actually is. Of course it’s possible I am just being a pussy about it :lol:
 
TomK said:
It's stange as what you are describing is the common 1st-2nd gear denial on fast shifts associated with this gearbox and the s54.
Click to expand...

I’ve had that a couple of times (possibly won’t happen again now since have VT mounts) but the gear was denied with such violence it basically kicked the lever back into neutral (admittedly against a fairly relaxed grip on my part). I can’t imagine persisting with the shift until it engages, as Ed describes. It’s very unsettling!

Worth checking the bolts on the engine side of the mounts as well as the VTs.
 
^it was only the one time - don't make me out to be a bad person :roll: :lol:

My new shifter arrived yesterday evening - it's a thing of beauty, I cannot wait to get it installed!!
 
Hi and welcome, I think a lot of us had this issue when we first got the cars, I find there is a definate knack , you cant just crash it from first to second with no “feel”, I keep a little pressure over toward the passenger seat and think about not FIRST Bang SECOND !! But two stage change that feels like “out “ of first and “into” second. Just because you are nearly redlining it you dont have to rush the gearshift movement , still take a split second to come out of first then into second. You will soon get the “feel” people are talking about. As mentioned by others ,all the other things may help ie, fluid , knob, cdv and mounts but your shifting action will be the most productive.. I think someone posted a sequence of hand positions and direction of pressure while shifting on here . It may be on the zuckhausen website possiblt to but google it , I also find that if I havent driven the M for a few weeks I also forget how much right pressue I need to apply to shift from 4th to fitfth as its a long way across and I get a missed shift, it may be actually 2nd to 3rd , shows I havent driven it much lately! Been playing in the beach buggy and now bought a motorcycle too 🤣👍
 
I remember that pic - useful! The “palm out” way of shifting 1-2 definitely helps, but you do need to change your muscle memory to do it. And possibly relax a bit more.

Been driving a few different boring cars recently and had forgotten just how mechanical and positive the Z4M box is (in a good way). It’s only when compared to other sports cars cars that it can feel a bit obstructive and knuckly.
 
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