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Why Am I Getting A "crunch" Noise When Shifting 2Nd To 3Rd?

maxzugkraft

By maxzugkraft,
in R35 GTR

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maxzugkraft Enthusiast

maxzugkraft

Posted
Posted

I've got my 2009 from new, as daily driver & doing 2-3 track days a year.

Has done 53,000kms now, with Custom Willall Cobb tune by Martin, LC5, HKS mid pipe and Willall Lite Trans fluid. Has been a beautiful car to drive.

Clutch relearned. CC= +1, TP= -1.

Started noticing a "groan" noise ("oarkk") about 1 month after I changed to the Willall Fluid (2months ago). Only happens between 2nd and 3rd gear. Intermittent usually, when car is cold.

But, today it happened when fully hot in a roundabout going "clockwise", whilst accelerating moderately hard.

It sounded like gears clashing ("crunch") when changing gears inaccurately in a manual stick shift. Tried to reproduce it but couldn't. This is the 2nd time it has happened when lateral G force is associated. ?coincidence?

Anyone experience this? My feeling is that the "groan" noise has progressed to the "crunch" noise.

Car still drives normally, and out of warranty.

Is this serious? Thank you all in advance.

Wardski Rising Star

Wardski

Posted
Posted (edited)

Sounds like diff bind to me. If it only happens when turning. I'd say its quite possibly normal.

You should hear the noises my rear diff makes reversing up my driveway every time... Lots of crunching, followed by bunny hops etc, etc.

Check out NAGTROC as well. For sure someone has had the same issue there

Edited by Wardski
maxzugkraft Enthusiast

maxzugkraft

Posted
  • Author
Posted

Thanks guys.

Its good to know that it doesn't sound serious. Although, being so loud, it doesn't give me a good feeling, mechanically.

Why only 2nd to 3rd and not other gears? If it's diff related, shouldn't it be any gear?

Hi Martin:

How can I tell if it's some problem with the gear stops, circlips, fasteners or piston clips/seals?

What symptoms should I look for?

By the way, your Cobb tune is bloody awesome: I was doing a drag (no launch, just plant foot) yesterday with a friend's stock MY2012, and my 2009 fully kept up with it to about 120kmh then started to slowly creep further beyond that. I wonder if it would beat it by much more if we had kept pushing towards 200kmh!

Good work, mate!

Wardski Rising Star

Wardski

Posted
Posted (edited)

Hi Martin:

How can I tell if it's some problem with the gear stops, circlips, fasteners or piston clips/seals?

What symptoms should I look for?

Drop the transmission oil pan and look for metal fragments. If anything nasty was going wrong in the trans you'll find debris, plus the GTR trans is pretty sensitive to throwing CEL codes when things start to go wrong.

I still think diff bind to be honest. Why it happens going from 2nd to 3rd, who knows. There could be other factors at play, not necessarily related to the gear change from 2nd to 3rd, and turning right.

IMO I would start thinking about getting Martin's 2009/2010 refresh kit done. Once my '10 is out of warranty, its the first thing I'll be doing.

I'm in no way an expert in all of this, Martin is surely the man to ask/confirm. However I've read enough horror storys on NAGTROC to have a fair idea.

Also on the positive side, the fact that you've done 50 something thousand kms in yours without issues is simply amazing and gives me hope!!!!! :D

Edited by Wardski
maxzugkraft Enthusiast

maxzugkraft

Posted
  • Author
Posted

Hi Martin, am I using your 2009 Renew Tune, currently?

Also, the "noise" doesn't come all the time. Hard to record, but I'll try.

It lasts for about half a second, just before 3rd gear engages.

And sounds like - "k r k r k r k r k r k r k r k r k shhaarrk " !!!

Hey Wardski,

the car has been pretty good. Don't wanna drop the oil pan yet as i've just put in the expensive trans oil 3 months ago.

Thanks for your thoughts. I hope you are right about the diff bind.

Wishing you all a HAPPY NEW YEAR, guys...

.....and ever increasing reliable power and torque!!!!! :yes:

  • 5 months later...
maxzugkraft Enthusiast

maxzugkraft

Posted
  • Author
Posted

Hi Guys,

The "Krkrkrkrk" sound is still happening occasionally. I've taken it the track since then. Also had Martin's new tune.

Still happening sporadically and very irritating.

I've been able to reproduce the "krkrkrk" when shifting from 2nd to 3rd gear by doing this procedure:

1) Drive the car in (manual) 2nd gear at 3500rpm for 3 seconds without accelerating. Stable throttle.

2) Then manually change to 3rd gear, with throttle still stable.

3) I hear a "krkrkrkrkrkrkkk" before 3rd gear engages. It also feels that gearchange takes longer and more jerky to engage.

I am wondering if it really is diff bind or something more sinister.

Any help appreciated.

Thanks!

  • 3 weeks later...

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