4th Gear

[Guest EVL-R33]

hey ppl, recently when changin to 4th gear from high revs from either 2nd or 3rd my 4th gear keeps crunching for no reason i know its something wrong but i just wanna see if anyone would know the problem or experience it b4,

At the start it would crunch really hard and not go in, now after 2 weeks it goes in but still crunchs softly, it needs fixing a.s.a.p i just got back from my holiday and its time to get it done...

thank you..

[GTS-t VSPEC]

Sounds like a f#cked synchro to me. If you put the redline shockproof gearbox oil in it is meant to help, but if it is the synchro then your most likely going to need to have it replaced.

See'ya:burnout:

[Jon R33]

mine does the same, synchros are rooted.

it's bloody embarrassing, people must think I can't drive... and they may be right

[2rismo]

Mine does it on 4th as well. I just figured the synchro was on it's way out and am living with it. If you're just cruising then try and match the revs to the gear when you're changing up into 4th. If you don't know what i mean, try pulling the shifter 'against' the gate into 4th when you change up with your foot on the clutch instead of just forcing it in. You'll find that as the revs of the engine match the revs of the flywheel, it will just go in by itself.

I don't know if this makes any sense at all but I hope it helps. It's just like riding a motorbike. I hardly ever use the clutch on up-changes. All I do is put a little bit of pressure on the shifter with my toe and back off the revs slightly so it clicks into gear.

Good Luck

[Guest EVL-R33]

thanx for the replys guys, anyone know the price to get a new synchro ?

[NIZ30]

I got same problem.

Price? Not real cheap, R33s cost more too. On R32 it is cheaper to buy 2nd hand gearbox.

When cruising I just let the revs die down to idle then changed into gear. If racing live with the crunch.

[T0nyGTSt]

Does some shockproof oil help?

Strangely my gearbox is good despite what I give it.

T.

[Jon R33]

There was a similar thread a while back on SDU i think and from memory they suggested a good oil change with a stick of Nulon GE70 (i think that's what it was), drive nicely for 500kms then see if it still crunches when giving it a bit of welly.

I haven't tried this so dunno if it makes a difference.

[GTS-t VSPEC]

The shockproof oils will definately help, they should lessen any additional strain on the synchros and reduce the crunching noise. It is not however going to fix the problem, therefore I think that saving up to replace the synchro might be a good idea. At the same time get them to check the whole box, if one synchro is going then the box may be on it's way out.

See'ya :burnout:

[gtrken]

The problem with the syncro's is sometimes an issue with the oil being too slippery and not slowing the shaft down before changing.

Nissan did an upgrade to the GTR boxes which had the same problem but cost about 2K for parts alone.

I have solved the problem on 3 x Nissan boxes so far for about $100-$120 by using Redline Lightweight Shockproof oil ( blue smurf ).

Is amazing stuff and ask Micko who will vouch how well it is still going.

Ken

[Guest EVL-R33]

so whats the next best thing to do?

get my mecanhic to check out my box or change the oil to the shockproof stuff?

[GTS-t VSPEC]

I'd try the shockproof first, it's the much cheaper option, and will at least prolong the existing box. It might be worth saving in the future to replace the synchro though, depends how rooted it is.

See'ya:burnout:

[Duncan]

I changed my oil to redline shockproof today, and my stuffed synchros are about 1000% better. Expensive, but give it a try first.

[benm]

where do u get this redline shockproof oil and what does it cost ?

[Silver-Arrowz]

Where did u get yours from duncan?

[Duncan]

I got it from CRD in silverwater. Bloody expensive @ about $100, but cheaper than pulling out the gearbox and reconditioning it :;

I don't think its a permanent fix, the gearbox still baulks at a quick change, but the crunching is gone and the motion is smoother. Thumbs up from me.

[whatsisname]

I've run Redline Shockproof in both box & diff. I can't recommend it more highly!

[benm]

Dumb question but where and how do u replace gearbox oil ? Anyone got any pics of exactly where it goes ?

[Duncan]

Easy. Go to mechanic. Pick it up when they're finished.

[Silver-Arrowz]

Originally posted by benm

Dumb question but where and how do u replace gearbox oil ? Anyone got any pics of exactly where it goes ?

On the bottom ot the box there's a plug, undo that to drain then plug back up. On the drivers side of the box, there's another plug. Open and fill up until it starts pouring out a little.

Duncan, you bum!