Gearbox Issues

[fletch63]

Hi guys and gals,

Anyone one know how to diagnose gearbox problems out there?

My 33 GTR (only recently purchased) has a gearbox issue.

Hard to get into 1st gear.

When cold almost impossible (hard to get into any gear), so I have to "force" it into 4th gear and then I can slip it into 1st.

When at normal temp it is easy to get into any gear but a lot of the time still hard to get into 1st.

This is all while car is stationary. Once moving easy to get into all gears at all times.

So my work around is to either slip it into 1st just before cars stops moving (if I come up to a stop sign)

or if stopped at lights I slip it into 4th and then straight into 1st (goes into 1st really easy using both methods)

I have changed gearbox oil and still same

Any ideas

Do you think gearbox or clutch problem?

I have one of those cheap "purple" clutches. Heavy duty but cheap...can't think of the name at the mo.

The only thing that points me to a clutch problem is that from cold it makes a bit of a bearing noise on first take off and

you can feel a vibration thru the pedal.

Goes away after that.

Any ideas???

Please

[xALmoN]

synchros most likely.

[fletch63]

That's what I thought

But why would I be able to slot it in nice and easily at 5-10km/h into 1st if it was?

Every time!

[89CAL]

What oil did you use?

Hows yoyr clutch fluid? Keep in mine it absorbs moisture pretty nicely so does degrade over time. Wouldnt hurt to change and bleed the clutch lines/cylinders

Start there anyway.

[SargeRX8]

I'd say start with the easy stuff. You've did the fluid change, what I would also do it get some nulon gearbox additive in there two. I think two tubes suits the RB box. I'd then do the bleeding of the clutch system and if I were you, Id get a braided line from the master to the slave and bypass the crap in between. Makes bleeding alot easier and you eliminate the other unnecessary components(don't hold me to this but I believe they're not needed). After you've done all this and if everything is still the same, I'd say its out of your hands. Unless your master or slave are faulty and not throwing the clutch out far enough. My car is abit tough to get into first and reverse at times but definitely not what you are experiencing. Two things you can do, drive it until it gives up or get it pulled apart and rebuilt. I really wouldn't rebuild it, whats happening sounds like a nuisance but wouldn't be enough for me to justify a build.

[fletch63]

I'd say start with the easy stuff. You've did the fluid change, what I would also do it get some nulon gearbox additive in there two. I think two tubes suits the RB box. I'd then do the bleeding of the clutch system and if I were you, Id get a braided line from the master to the slave and bypass the crap in between. Makes bleeding alot easier and you eliminate the other unnecessary components(don't hold me to this but I believe they're not needed). After you've done all this and if everything is still the same, I'd say its out of your hands. Unless your master or slave are faulty and not throwing the clutch out far enough. My car is abit tough to get into first and reverse at times but definitely not what you are experiencing. Two things you can do, drive it until it gives up or get it pulled apart and rebuilt. I really wouldn't rebuild it, whats happening sounds like a nuisance but wouldn't be enough for me to justify a build.

Yeah I did the nulon additive with Castrol oil. Maybe I need to go better oil but thought with the Nulon would be sufficient

Haven't tried the clutch bleed yet

I suppose that is next, as I agree with you not prepared to pull apart yet

[SargeRX8]

I recall an older oil referred to as smurfs blood because it was blue. No idea which oil that was but it was in my car prior to my first oil change. It was good shit but couldn't find it so I went with the VMX stuff from castrol and it does pretty well. The shop I get my juice from doesn't have very many options. You could go with a really premium oil and see how it goes. The Nulon additive should have helped.

[niZmO_Man]

Smurf's blood = Redline Shockproof Lightweight

[scotty nm35]

My suggestion is to drain the thick oil and additives out, flush the crap out somehow and fill it with Dextron III.

[Dose Pipe Sutututu]

Smurf's blood = Redline Shockproof Lightweight

2nd that, both my R33s has VMX80 and was a little notchy, dropped in Redline Shockproof lightweight and it felt completely different.

[fletch63]

2nd that, both my R33s has VMX80 and was a little notchy, dropped in Redline Shockproof lightweight and it felt completely different.

Thanks

I might as well give it a try.....as its probably my cheapest option

Have now bled clutch and still same

Cheers

[Dose Pipe Sutututu]

is the clutch fully disengaging though? I had some ling long piece of shit PBR clutch in my current R33 and with the pedal down the clutch wasn't fully disengaging. It went in the bin within 2 weeks, replaced it with a NPC clutch and happy days

[jiffo]

Like John said, eliminate the simple items before you go down the synchro or expensive oil change road.

It really does sound like the clutch isn't disengaging properly.

This might be an adjustment issue or the spigot bearing could be dry, any workshop worth the name will soon tell you.

So don't force it into 1st, try to select reverse (gently) since it has no synchro.

If you get a consistent crunch or worse, a gear on gear grinding noise, your clutch isn't disengaging fully.

[SargeRX8]

So don't force it into 1st, try to select reverse (gently) since it has no synchro.

If you get a consistent crunch or worse, a gear on gear grinding noise, your clutch isn't disengaging fully.

This interests me as my car sometimes needs a couple of goes to get into reverse. It feels like its in but its not. I know my master is probably the problem but often if a problem isnt enough of a problem, im a lazy lazy man.

[central coast person]

Reverse gear is straight cut, not helical so its sometimes not easy to get into so you have to roll a bit to get it in the right spot.

When was your clutch last replaced? Sounds like there is not enough throw to select the gears, but once moving it helps it get into gear. I had the same problem but the sleeve my bearing slides with cracked and my thrust bearing wouldn't engage the clutch springs completely. i drove my car to the workshop with only the bearing pushing on the clutch a little. i noticed skyline gearboxes are fairly easy to get into gear will very little clutch there.

Adjust the master cylinder from behind your clutch pedal and there should be a difference.

[KiwiRS4T]

How far does the clutch pedal come off the floor before it begins to bite?

[fletch63]

yeah its fairly high....cant adjust any lower.....have tried

How far does the clutch pedal come off the floor before it begins to bite?

[Aazzy]

Our track car was like that, had a twin plate in it at the time but was notchy and shitty as when cold then got better when hot. Dropped out the twin plate and put in a heavy single plate with a rebuilt box and its smooth as silk. My 33 street car (which before the track car got its overhaul felt smooth as) now feels like a piece of snot in comparison. New syncros make a hell of a difference. Both run redline oil.

[niZmO_Man]

Which redline oil? I'm considering using lightweight shockproof in my R32 GT-R but not sure if it'll be fine for track days. Heard the smurf's blood cakes the gears/synchros when subjected to high heats (track use).

[Aazzy]

Using lightweight at the moment in both track car and street car. Have done 4 track days with rebuilt box and redline oil, no gearbox worries what so ever. Street car did pump out about 100ml from breather after an aggressive hills run, but I put that down to filling gearbox up with only the front lifted off the ground when filling. (slight angle may have overfilled).