4.5l GSX Gearbox Synchros

[pascalkreuger]

Hi There guys,

New guy to the forum. Just picked up my first patrol. A '99 grx 4.5l with 173500km on the clock. Gp Car with no rust thank christ. Drove it back to KZN where i stay, had to go through a once over, everything fine expect the gearbox synchros might be shot. Took her in today, and changed the oil in the box/trans case. Very dirty oil came oout, but since changing it seems to have remedied the issue i was having. Occasionally when gearing down from 5th to 4th, and generally while shifting i get a slighr grinding noise. Mechanic says its probably the synchros that are worn, as the vehicles stays strong when in gear. Ive managed to find a decent second hand box for 5k on the interwebs. My question is this. Do I:

A: Purchase the second hand box, have it refurbished, and keep running around with the gearbox as is.
B: Remove the current box, and refurbish. (Takes around a week with the car sittinf at the mechy)
Or C: Keep babying the gears, and drive her as is, until my gears become a little harder to engage?

I thought the gearbox oil change would help remedy the situation, and it has made a world of difference, but with my wife driving the van, she tends to find every grind/grate the box has to offer, vs me where it happens only once or twice a drive. Its not a hectic CRUNCH noise or anything, just a grrrr and then it stop immediately once the gearbox engages the gear.

Any help/advice appreciated.

Regards,

Pascal

[Tinus lotz]

Hello and welcome
All manual partol boxes has a bit of a clunk to it becouse of being a truck box ....i would not worry about it rather use it for a while and change the oil again to get rid of any bad build up sluge ect wil double check but 80w90 GL4 for gearbox

[Tinus lotz]

Dont get me wrong there are plenty with no scratching patrol boxes out there but i will only worry once you start hearing bearing sounds and just give the clean oil some time and it might get better

[David M]

Thought this was totally normal on the truck box. Make sure she depresses the clutch fully and learns the timing on the change from 5th to 4th. Mine has been like that for 50 000 km and is no biggy as long as you use the clutch and gear lever correctly.

Is definetly worse before the oil warms.

[IanT]

There is also a gear box additive called "tranyfix" have used it a few times in my Disco's auto boxes and worked like a charm, however I have never put it in a manual box but I don't see why it should not work, gets rid of all the junk and the burnt on stuff in the box

[iandvl]

There is also a gear box additive called "tranyfix" have used it a few times in my Disco's auto boxes and worked like a charm, however I have never put it in a manual box but I don't see why it should not work, gets rid of all the junk and the burnt on stuff in the box

I'm not a massive fan of additives to gear lubrication - not on Patrols at any rate... Landies need all the help they can get...

However, on a serious note - the 4.5 has a big gear box. It's not a high-performance smooth platkar box. It's big, and unwieldy. And awesome. :)

[ricster]

Also.... VERY IMPORTANT..... When the oil was changed .... was it a GL4 spec oil?? If not drain it out immediately and fill with a GL4 spec oil, I would drive it around again for a about 2 - 300 Km, drain that oil out and refill again with GL4 spec oil.

[Tinus lotz]

Also make sure you use GL 4 oil Micheal recommends 75 90 if you can find but definitely GL 4 not GL 5 those are for diffs and doesn't work with sincro rings

[pascalkreuger]

Hey Guys! Thanks so much for all the replies.

When I changed the oil yesterday the shop put in Fuchs Titan gear oil. The shop manager phoned the nissan dealer here and they recommended this oil vs the standrad one they put in. Whats your thoughts guys? It says Gl4/Gl5.

One another side note. Is it normal for the vehicle to idle around 1000rpm when starting up and sometimes driving? Its got a Dastek Unichip in it, but usually once warm, the rpms drop to the usual 650 rpm. Thanks for all the help again guys!

Pascal

[iandvl]

Hey Guys! Thanks so much for all the replies.

When I changed the oil yesterday the shop put in Fuchs Titan gear oil. The shop manager phoned the nissan dealer here and they recommended this oil vs the standrad one they put in. Whats your thoughts guys? It says Gl4/Gl5.

One another side note. Is it normal for the vehicle to idle around 1000rpm when starting up and sometimes driving? Its got a Dastek Unichip in it, but usually once warm, the rpms drop to the usual 650 rpm. Thanks for all the help again guys!

Pascal

Mine is unchipped (I prefer it that way). However, I believe it is normal for the vehicle to idle a little higher for the first minute after starting. Mine does so. My father's does so. And I seem to recall Graham telling me this was normal one day when the vehicle was there for servicing.