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Fifth gear at high speed grinding

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Old 07 May 2003, 09:20 AM
  #1  
jwhitton
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MY00 spec almost standard UK spec Scooby turbo.
Ran from 1500 miles on Silkolene Syn5 gearbox oil, just changed at 25000 miles (2 years). Original clutch which judders a bit from 1st when cold but otherwise ok.

Changing gear up from 4th to 5th at high speed and greater than say 75% throttle load in 4th (equates to anything above about 105mph, on the track of course!) on selecting 5th gear there is a clunk/grinding noise as though it were a really poor gear change. This only happens at high speed and load, below this a 4th to 5th gear selection is as smooth as a babies bottom. All other gear changes are fine at any speed or load. At say 90mph it is fine and a normal fast gear change can be used.

I am guessing it might be a clutch issue rather than a gearbox one since the gears are all ok except for the up change from 4th to 5th at high speed and throttle. Been happening for the last 1000 miles only (car has now done 27000 miles).

Load of SYN5 gearbox oil in there and is clear as a bell.

If you let the revs die down and perform a slow up change there is no grinding/notching.

Advise help please.
Old 07 May 2003, 10:10 AM
  #2  
AlanG
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Synchro's.

Mine a couple of years back had the same issue. Would only happen when the car was hot. At low speeds and / or *normal* gearchanges, (i.e. not pressing on..) the box would be fine.

Subaru changed the spec of the synchros in either 2000 or 2001, can't remember when, to rectify such an issue.

Mines was replaced under warranty.

Alan
Old 07 May 2003, 12:36 PM
  #3  
vindaloo
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When I enquired about gearbox issues I was told that there was a '5th gear mod'. I was asking the dealer about P1 gearbox issues following on from a thread on P1WOC.
Old 08 May 2003, 09:08 AM
  #4  
jwhitton
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Alan,

Not heard of the synchro issue before.

Why does it only affect the change at high speed / load?

The downer is the car is out of warranty.

Jon
Old 09 May 2003, 07:11 PM
  #5  
GeeDee
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I have a similar problem on mine but it tends to occur 80ish and above especially with quick changes. Trick is to feed it in gently.

First noticed it around 45k I guess. Now just had 75k service and it does not appear to be much worse.

I have found that it can be noticeably worse after oil is changed and I have taken it back a couple of times for them to check it out. It has been better each time. I can only assume the level is critical.

Now I ask them to check the oil rather than replace.

I am told it is possible to sort the synchro out with the gearbox insitu. I seem to recall a cost being quoted in the order of £150 but I could be wrong.


Graham (MY99 WRX)
Old 09 May 2003, 09:58 PM
  #6  
rally colin
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if you need help with your gearboxes give me a bell 07771767874
Old 22 May 2003, 10:05 AM
  #7  
AlanG
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Whoops!! Two weeks later....

I think it was probably due to thinning of the gearbox oil with high speed running.
It would be fine when cold, driving round town etc but after a long run, it would then show up.

Alan

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Old 22 May 2003, 11:51 AM
  #8  
IOW_duder
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Colin, YHM!

Luke
Old 22 May 2003, 12:38 PM
  #9  
5 Type R
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Had exactly the same on my MY99 Type R, started in fifth and then fourth and third etc over time.

Eventually took it to pieces and it was indeed the syncros.
Put in a complete new set and all is now dandy.

Can highly recommend Dave West at Risborough 4WD Centre.01844 274 652
Old 22 May 2003, 01:04 PM
  #10  
IOW_duder
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Where is that Type R?

L
Old 22 May 2003, 09:19 PM
  #11  
5 Type R
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Princes Risborough ,, Nr High Wycombe
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