Manual Gearbox issues

[sxtacy]

Anyone help?

This is annoying because I recently replaced my clutch and have only done a hair over 100kms.

I drove to work today, 45kms at 100km/h in the country. About 15mins into it my gearbox decided to knock itself out of 5th and into neutral.
I put it back in 5th and a few minutes later the same thing happened. Then it got worse, happening every minute or so.

So I gave up and drove the rest of the way in 4th. (by the way it nearly always crunches when you change into 4th, sits there fine though)

So after 8 hours of work, I drove back home and the gearbox didn't even last 2 minutes before 5th was knocked out. Drove the rest of the way in 4th. It didn't want to downshift into 3rd or second easily either. And when I stopped I couldn't get any gear until I revved the engine a little.

Also the gearbox makes a slight whine when accelerating.

Could any of this be from low fluid perhaps? or is the gearbox dying?

[Kranzy]

Whine noise normally points to bearings. It kicking out of fifth could be caused by a couple of things. Sometimes the nut on the end of the shaft comes loose causing those symptoms.

Best bet is to take it to a gearbox shop and see what they say.

[sxtacy]

Little more info

When I got the car I had  the same problems, kicking out of 5th and crunching in 4th,(kinda embarassing that) but couldn't here the whining because it was making a terrible grinding clunking noise. Which is why I replaced my clutch with the full clutch kit which fixed that.

I figure the crunching in 4th isn't going to go away anyway unless I get the box rebuilt though right?  Which is how much these days?
At which point I'm going to say I don't need a beefed up gearbox because I don't thrash my cars, so a stock one would probably be alright.

Or, I had a crazy idea. Everyone else here looks like they are swapping from auto's to manual's, I want to do the opposite. How strong is the auto? keeping in mind I don't usually launch hard.

[Kranzy]

If the gears are a little loose inside the box due to the end nut coming loose that may also cause the crunching in 4th. Take it to a decent transmission shop, they will be able to take your car for a quick drive and tell you straight up what the likely cause is. Then give you an estimate to fix it.

When i got my box rebuilt with new bearings and linkages (syncros and gears were fine) it cost me around $600 if i remember correctly.

[sxtacy]

Thats not too bad I suppose. Finding a transmisson shop around here might be a bit more difficult but I will definately have someone look at it first before I make any decisions.

[91TR.X]

get yourself a TRX manual box, or a TI manual box, either of the two run VISCOUS LSD and are extremely strong

reconditioning can be anywhere between 500-1000 depending on the work done and the place doing it, you could properly pick up a good box for no more then 500 (LSD), i happen to have one here somewhere i think, do you live in NSW?

[sxtacy]

I live on the NSW/VIC border, echuca/moama. I was thinking about a LSD box, but didn't know how much stronger they were, if any.

[91TR.X]

from what i can tell you unless mine was made on a wednesday it has been good without fail the entire time ive had it! i know the history of the box, i was the second owner of it (box and motor out of a granny dammaged TI) so i got it in good cond and have thrashed it from day one! never had a issue besides having cvs slowly wear from constant rev dumps in the dry

[sxtacy]

So they are pretty tough boxes then. Good to know 

Had a transmission shop here look at it, he said the bearings are gone but it might be something else as well. Said it would be cheaper to just get a replacement box, so that's what I'm going to do, don't think i'll go the auto route anymore, unless I have to.

[sxtacy]

Well, I got a new LSD box, finally got the driveshafts here (bloody couriers took 2 weeks!) and bolted it all up.
I managed to get it all for under $500. 

Runs perfect. no noise, no crunching, no slipping gears. Was a bitch and a half with the old gearbox.