RB20det G-box blown?

[R31 POWER]

Ok long story

Was driving normal (I know it's hard to beleive) down my street and went to put it into forth and the clutch went straight to the floor so I popped in into nuetral and rolled down my street and up my driveway.

I jacked it up and noticed the rod coming from the slave cylinder was fully out and upon closer inspection i noited the pivoit ball that the clutch fork piviots on had sheared in half.

SO we pulled the box out and put a new pivoit ball in,puit g-box in and the pedal was not as heavy as before.Mmmm but it still charred thru second and was fine except a crunch into second when i slammed it into gear hard.it had never crunched that bad before.

Ok morning after I'm on my way to work and I romped it thru second and it started knocking/clunking from the gearbox bad.I stopped to look underneath but can't see fark all so I try and get it into second and it just keeps on crunching.I finally got it into first but it wont go into second but goes into third and forth.

So i'm idling it along in forth home and it's knocking the whole way.

I noticed today after work that with the clutch pushed in and in nuetral there is no noise but as soon as I take my foot off the clutch it knocking bad.

What do you guys think it is?Input shaft

[SteveL]

A couple of possibilities:

- broken or damaged 1st/2nd shift fork. If your lucky may just be a broken roll pin.

- failed/damaged/collapsed countershaft bearing(s)

First thing to do is to pull the gb oil drain plug and check the magnet. Lot's of steel bits/shavings suggests bearings or possibly a gear/selector ring. No or not many steel bits suggests selector fork (it's an aluminiumk alloy casting).

Either way your looking a stripping the gb.

[R31 POWER]

Thanks fo the reply SteveL.I have a spare RB20det box so it may have to go in then.I will check the drain plug magnet tomorrow.

[R31 POWER]

I drained the oil and there are 3 teeth and bits of metal so it's ****ed

[Roy]

good luck with it. Are you going to bother with an RB25 box?

[GTRsean]

I got teeth too when i took out the drain plug. R32 gtr gbox. 3rd gear blown but other gears worked, but it was very noisy and rough.

Now I've got a busted box(complete with transfer case) and don't know what to do wit it.

I could sell it as is or fix it up$$$$ expensive, and use it as a spare.

[SteveL]

R32 gtr gbox.  3rd gear blown but other gears worked

Bad news....original R32 GTR type 3rd gear is NLA from Nissan. Same goes for 4th gear. 'Updated' parts are available (same as late R33 GTR...approx mid-96 on from memory), but to fit to R32 GTR gearbox requires replacing a whole bunch of other parts. Bottom line is.....are you sitting down ??......$1900 (and that's trade !!!!).

You could go secondhand.....$800-$1000+.

Other option is a brand new R33 GTR gearbox from JustJap for $3200. Of course that will also use a pull type clutch....

Good Luck

[GTRsean]

It's all good anyway. Happened after XMas It blew up in QLD so I got onto Option 1 Garage in Bris. Within 2 or so days they sent me a secondhand one complete with shifter and transfer case for $890. It's in better nick than my old one was. Took me 2days to do the whole job in my parents front driveway, pain in the a##. Still going strong. So thats why I want to do something about the busted box.

I'll end up selling it as is I guess