RB25DET Gearbox buildup

[akira]

Has anyone here rebuilt their gearboxes with strengthened gears etc?

Can GTR internals be used and is this is a good idea?

Any info appreciated before my 5 speed box is installed:cool:

[meggala]

you can get a gearset from osGiken which is rated upt to 800 ps and also allows you to change ratio's a bit they aren't cheap ask jsut jap they are distributer.

you you could get a rebuild done with new syncros but thats not cheap either I have heard 700-1k

meggala

[fatz]

all jap car km's r in dog years drift spec

pete

[Cubes]

Drift Spec:

Just do a full service on the car your self.

I.e Fuel Filter, Gearbox Oil, Diff Oil.

And Slap a tube of Nulon G70 in the Gearbox and Diff.

You will be amazed how much difference it makes.

Use Castrol VMX80 for the gearbox, with Nulon G70.

Give it a couple hundred kays to work in then feel fourth again.

It should be better.

[Cubes]

If the R33's are the same the fill plug is on the passengers side of the gearbox and roughly centered.

The empty plug is also roughly centered and is on the bottom of the gearbox (duh).

Grab your self a length of general garden hose make sure it is clean and dry.

Empty the oil then put the plug back in (duh) before filling

Feed the hose from your engine bay under the car following the exhaust and then put the hose in to the fill hole.

Fill her up from your engine bay.

My Gearbox takes roughly 2 ltr's of oil so I would shove 1ltr in then the Nulon G70 then the other ltr.

Castrol VMX80 is very good but if you want they (AutoBarn) will point you in the direction of Mutol Gearbox oil which is very expensive but does basically the same job just probably a little better maybe?!?!?!

[Cubes]

Yer... I've already replied i think

[Brody]

Hey Meggala,

Just curious in regards to "gearbox rebuild with new syncros for 700-1k", my 4th is rooted, and the gearbox is abit rough/slow. Is 1k common for this? Ive looked around already and am being quoted *much* higher...

[kjb_r33]

parts must be damn expensive........

Tell ya what, i'll swap my auto for your manual and i'll do the change over????:uh-huh: :burnout:

[meggala]

its was a rough sort of guess part of the cost is pulling the box out etc.

there is a place in melb selling a reco one for 1650 change over seemed steep to me

meggala

[Brody]

Well a box rebuild is coming even faster...

1st and 2nd either go in fine, or i really have to jam them. Can't reproduce the problem consistenly just happens for no apparent reason. Some1 mentioned the gates might be dead?

Meh this is going to rip me for $$

[Guest Timbo R33]

It costs a bitmore than 700-1000 for a rebuild, trust me ya better off paying for a 2nd hand box and using that unless ya car is putting out some serious grunt!! Rebuild with factory parts is $3000 roughly - depends on who is doing it. If ya want one with race parts, I highly suggest you call somebody who does them, lets just say you wont be getting much back from $5000 if ya lucky and getting mates rates!!

Lets jsut say after calling a lot of places around.. Ive decided "box is good!!"

[NIZ180]

i just did a service and i used castrol syntrax 75w-90 full synthetic gearbox oil and a tube of nulon G70. the syntrax is a ****loads better than the vmx80 and cost about triple the price. Not as expensive as redline which was way too dear $140 for 1 gallon/ 3.7L. I must say that the box is sooo much smoother now even in the morning. Give it a go you will not regret it.

[grepin]

You guys have proven that additives do work through trial and error. However I was talking to Steve Cramp (Drifty you may want to call him at Manta Racing) and he claimed that it is not a good idea. From memory it was to do with the fact that the synchros require a certain amount of friction to change properly.

I cant remember exactly what he said however Food for thought.

[matlowth]

Akira - FYI - The GTS25-t gearset is identical (internally) to the GTR. Obviously the transfer case etc etc aren't there, but strength wise, they're the same.

Double synchro's on 1st->3rd, and only singles on 4th and 5th... 4th seems the most common to go.

You've either got to be a really bad driver (who crunches alot), or have a *****load of power (and wearing slicks) to break one of these suckers...

matt

Originally posted by akira

Has anyone here rebuilt their gearboxes with strengthened gears etc?

Can GTR internals be used and is this is a good idea?

Any info appreciated before my 5 speed box is installed:cool:

[matlowth]

Oh - and as with what others have said... Stick some Castrol VMX-80 in as well... It's fairly cheap and makes a big difference to your shift.

matt