Need A Diagnosis

[nisskid]

alright guys, im not much of an expert on gearboxes, so this may be obvious or not enough info but looking for a rough diagnosis as i would just pull apart the box and check myself, but im travelling soon and dont want to pull out the box unless there's any point to it, would rather wait til i get back before i deal with it, but if it's something easy enough id probably fix it before i went, just to make life easier for my old man to be able to move it.

basically it happened on a hot day, was out at mallala competition in G1 (drift) and on the transition to one corner (drifting) i grabbed 3rd from 2nd and was just a lot of metal scraping and rattling. was still drive in 1st and 2nd, and pretty sure 3rd, trying to remember that part but not 100% on 3rd. then trying to reverse into the garage it jammed, went back to 1st, drove around a bit, then that jammed, not seized, it just didnt wanna go any further in that direction. before the incident i had some decent whine from the box whenever the clutch was disengaged (even in neutral), that was for a good few months before the incident, but on the day the whine seemed more than usual. now the rattling occurs at the same time, whenever the clutch is disengaged, even when idling in neutral, soon as the clutch is pushed in it goes away completely.

im hoping scopot, but this is the first box this car's done so really not sure what to expect.

any input would be great, cheers

[_Wing_]

so what i gather is you saying you think you broke some but not all teeths on 3rd, and those pieces jammed in your other gears, randomly?

[R31 POWER]

It would be stuffed, stripped teeth would be my guess. 25det box time

[nisskid]

It would be stuffed, stripped teeth would be my guess. 25det box time

yeh could be the go, 25 box is on the list regardless, but if i could get a few more days out of the 20 box id go for it lol

[nisskid]

so what i gather is you saying you think you broke some but not all teeths on 3rd, and those pieces jammed in your other gears, randomly?

i can check tomorrow whether there is drive in 3rd, but cant do it now as its a straight through exhaust and would wake up the neighbourhood. but if i remember right it still had drive in 3rd, just sounded brutal as hell so i limped it back to the pits in 2nd, something has given way, i can hear it rattling around, but i dont know what. like i said it only jammed when i went to reverse, it drove the whole way from turn 8 to my garage without jamming once, which is probably 700 meters or so, it was only when i went to reverse i only got a few meters before it jammed, chucked it into 1st, drove about 10 meters and it jammed again. like i said, wasnt seizing.

[Birds]

Yer you've stripped the cluster most likely. Won't know until you crack her open, but I'd say it's time to give the box a chuck cause it's now something of a paperweight.

[nisskid]

alright sounds like ill leave it til after im back, cheers.

[nisskid]

had a crack today, has drive in all gears, doesnt even make any noise slipping the clutch a bit in gear (didnt fulling disengage the clutch), only when fully disengaged in neutral.

and here's the funny part, my car was originally auto, and it has a auto panel next to the steering wheel, this has never worked obviously being a manual, but since the break the power button comes on, and when i put it in reverse, the little reverse light comes on lol

so really, seems the only thing wrong with it is the chronic noise rattling coming from it, and these bits of metal getting caught in the gears.

[Birds]

Hmmm if you have drive in all gears...it could be salvagable with a recondition. Does it make the noise in all gears or just one/some? Or only in neutral? Does it make any grinding/rattle sounds in any of the gears?

[nisskid]

the problem is i dont really want to go drive the thing, but as i was just sitting in my driveway slipping the clutch out in each gear, feeling for some drive, none of the gears made any noise, im sure if once i fulling disengaged the clutch the rattling would come, but just slipping the clutch and getting just enough drive to move the car a few cm's there is no noise in any gear.

i dont wanna spend a lot of $$ on the gearbox, but if it's just a bearing or something small, then im happy to pull the box out and fix it, as i said, 25 box is on the shopping list, but no point going 25 box unless the 20 box is gone, afaik there are no advantages of the 25 box over the 20 box besides strength, and if the 20 box hasnt given way, then there doesnt sound like any point in upgrading yet. are the gear ratios the same in the 25 box? quick search didnt come up with anything on that.

[Birds]

Gear ratios should be pretty close to the same in the 25 - I am only speculating however based on the acceleration of both vehicles being pretty well respective to their power/torque-weight ratios. All round it's a better feeling box , along with the added strength...you wouldn't regret the converison IMO. Would cost around $700 to completely recondition your RB20 box with all new bearings/seals/synchros, assuming you're doing the R&R. You may have damaged a shaft in it, could be a synchro, could be teeth off a gear...it's very difficult to speculate these things without opening the box let alone driving the thing. Sooner or later you're going to have to do one of the two.

[nisskid]

yeh fair enough, i wouldnt bother with a whole recon, was just thinking if maybe if the bearing was all that needed replacing i could get away with it for bugger all $$.

[Birds]

You can get away with just replacing broken bits but not many places that will do this sort of patch up work for you let alone warranty it. Once you crack open a box and start playing with it you upset the balance/tolerances all the components once had...you'll put it back together only to cop another noise or worn synchro in a few months time. Not the first time I've seen it happen...

Best to save up and fork out to do it properly IMO.

[nisskid]

yeh sounds like a plan, will start looking out for a 25 box when i get back.

cheers for u help man.