Notices
Drivetrain Gearbox, Diffs & Driveshafts etc

5th gear crunch

Thread Tools
 
Search this Thread
 
Old Sep 8, 2007 | 09:33 PM
  #1  
weeebell's Avatar
weeebell
Thread Starter
Scooby Regular
iTrader: (1)
 
Joined: Apr 2007
Posts: 696
Likes: 0
From: Ayrshire
Default 5th gear crunch

Hello all,

When driving the car about town its fine, but when driving hard and changing from 4th to 5th, it crunches. Is it just the nut thats slack?

Also, AndyF has just remapped the car to 320bhp on an MY99 so I know my standard box and clutch wont last for any length of time.

Its my daily driver, I dont do track days but I do drive it hard quite a lot so should I be looking to rebuild my own gerbox with stronger 3rd, 4th and 5th gears or would a bugeye 'box do the trick.

I'll probably be going for bigger injectors, another turbo (vf28 at the mo) and another remap in the future is this helps.

Many thanks. Every reply helps.
Reply
Old Sep 9, 2007 | 04:49 PM
  #2  
JohnD's Avatar
JohnD
Scooby Regular
iTrader: (5)
 
Joined: Apr 2000
Posts: 6,252
Likes: 1
From: Havering, Essex
Default

Do you know what oil is actually in the gearbox? I had the same problem with my 99MY when I put full synthetic fluid in the box (as did a number of people on here) Reverted to Castrol Syntrax (Driveline) - problem cured! I'm not saying that this is the cure in your case, but it's worth investigating.
JohnD
Reply
Old Sep 9, 2007 | 08:55 PM
  #3  
RON's Avatar
RON
Scooby Regular
 
Joined: Sep 2000
Posts: 10,011
Likes: 1
From: Deepest Darkest Dorset!!
Default

Weebel

there's a strong possibility that the nut that holds fifth on, could be loose, or, the synchro is wearing..... ir it's either of those, it can be sorted in the car..... API or other specialists should be able to assess and cure it!!
Reply
Old Oct 28, 2007 | 03:03 PM
  #4  
silent running's Avatar
silent running
Scooby Regular
 
Joined: Aug 2005
Posts: 3,957
Likes: 1
From: East coast.
Default

5th gear crunch just started on mine. Had my 752 box rebuilt by API sometime in the last year and fitted their lightened flywheel and Exedy clutch at the same time.

I get a light crunch from 4th into 5th, although strangely not coming back down again into 4th. I thought it might be the synchromesh and leaving it momentarily in neutral before going through into 5th does seem to cure it.

My question is, what are the possibilities: a knackered synchro, some kind of 5th gear nut, anything else? And secondly, is it something I can just drive through and live with or something that is gonna end up with a big repair bill? There's no way I want to pay for removing two gearboxes in a year. Running around 1.45 bar boost with a TD05-16G.
Reply
Old Nov 2, 2007 | 10:18 PM
  #5  
silent running's Avatar
silent running
Scooby Regular
 
Joined: Aug 2005
Posts: 3,957
Likes: 1
From: East coast.
Default

Anyone?
Reply
Old Feb 9, 2010 | 03:22 PM
  #6  
toby79's Avatar
toby79
Scooby Newbie
 
Joined: Feb 2010
Posts: 2
Likes: 0
From: Kent
Default

Hello there I have the same problem on my 97 WRX Wagon it crunches in 5th and if I pull the lever over to the right and put it in it doesnt crunch so much. I have read that there is a 5th gear nut that can need tightening and can be done with the gearbox in the car any info on this would be great as how easy is it to tighten up the 5th gear nut does the oil need to be drained from gearbox??
Reply
Old Feb 16, 2010 | 07:15 PM
  #7  
IMPREZASTU's Avatar
IMPREZASTU
Scooby Newbie
 
Joined: Feb 2010
Posts: 3
Likes: 0
From: Exeter, Devon
Default

Hi guys, im new to scooby net but ive been a mechanic for a while now so i will try to help people when i can. It sounds like you might have a worn 5th Gear synchro. They usualy only crunch going up through the gears but when they get very worn they start to crunch on there way down too. Hope this helps.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
JimBowen
ICE
5
Jul 2, 2023 01:54 PM
KAS35RSTI
Subaru
27
Nov 4, 2021 07:12 PM
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
Nov 18, 2015 07:03 AM
Ganz1983
Subaru
5
Oct 2, 2015 09:22 AM
crookedvulture
ScoobyNet General
0
Sep 28, 2015 07:20 PM




All times are GMT +1. The time now is 08:27 PM.