help - vibration problem aaargh

[DeanS15]

guys, can you help me?

since getting my car back from having some work done i have had a problem with vibration - some from the exhaust, which is now sorted and clear of everything underneath so thats ruled out, and some from the transmission. basically i had a load of engine work done which for now ill rule out, but as the noise seems transmission related im suspecting the exedy single plate paddle clutch thats been installed. the car drives very well, but when you lift off/decelerate there is an awful vibration/noise coming from what sounds like the diff, but this could be coming through the locking collars from further up the prop - even the gearbox, its hard to tell. if you put the clutch in the noise dissappears immediately. there is no real noise when going up through the box other than the norm, no problems engaging the clutch or changing gear.

the noise has been there from the day i collected the car from the garage, but wasnt there before, and has become even more pronounced when i fitted the locking collars which im going to remove anyway......at the moment im panicking that something was damaged during mapping as its a nightmare to prove and get corrected......

can anyone suggest what may cause such symptoms as im going to have a look when i remove the collars, i dont want to drive another 120 miles if its something that could be sorted myself, but im not holding on to much hope as it sounds serious

its worth mentioning that the engine and box were removed, the prop disconnected and all refitted as part of the work - as i was wondering perhaps about the possibilty of some form of imbalance in the propshaft or something - i really am clutching at straws. any help or suggestions would be very much appreciated:thumbs:

 

[Auss15]

Check the centre bearing on the prop shaft is not damaged,have a look at the universal's for free play. Worth checking the gearbox alignment,box and engine mounts for cracks

 

[jonny b]

had a simmilar problem dean when i put the triple plated paddle clutch in the s15 after weeks of investigation found it was the gearbox alignment,

 

[vti_coupw]

if it disappears when the clutch is in its could be the release bearing?

 

[DeanS15]

thanks for the suggestions guys, ill tke a look. i definitely suspect something hasnt gone back quite as it should of, the new clutch has a new release bearing and i know what one of those sounds like on its way out. believe me, this noise is horrendous. i'll take a look

anyone else got any more suggestions of what to check while im there? by the way theres a tiny leak from the prop seal on the box, is that worth sorting before it gets any worse?:thumbs:

 

[jonny b]

release bearing has deffinatly nothing to do with it,if the vibration is as u described

 

[DeanS15]

well i spoke to jez and he has said its not right going by what i said....he said to take it back and he'll sort it. he even apologised, very happy so far with the way he's dealing with this:nod:, just a shame its happened in the first place but oh well.......

 

[Matt_S]

Dean, I have a rear prop seal if you need it. Was a few weeks wait from Nissan. TUrned out mine wasnt the prop seal, but a leak from the top of the box/gear lever housing. Common problem according to Gary at APT. Just removed it (bastud job, even on a ramp!) and resealed it. Might be worth asking Jez to double check its not that.

 

[DeanS15]

cool mate, if it turns out i do need it ill give you a shout if thats alright:thumbs:

 

[craig8585]

Did you get this sorted in the end Dean? If so, was it gearbox alignment or anything to do with the clutch release bearing or spigot bush?

 

[DeanS15]

mate i dont know .....i took it back to jez, he had a look at a few things and didnt come up with anything concrete....gearbox alignment is ok, he reckoned there was some play in the output shaft, also others reckon that most lightened flywheel setups for this car cause some vibration somewhere in the revs....its all irrelevant now anyway as the box will probably need replacing quite soon and i'm having a hell of a time finding a decent kit to fit a better box that isnt a bodge in one way or another .....

 

[craig8585]

Sounds like a nightmare mate. So is it currently being blamed on internal wear in the box? I saw your threads on SXOC but it doesn't seem theres many people with experience of box swaps that are done properly :wack:


I've got a heavy duty ACT clutch ready to go in and a prolite fly wheel too, but as I read up about them, more and more issues start coming to light such as people geting irritating vibrations and noises. I'm trying to decide if its worth buying a genuine release bearing and spigot bush as this seems to be the bits people have trouble fitting.

 

[DeanS15]

i wasn't sure if any s14 stuff would fit ie. the flywheel and clutches, i know they'll fit the crank but what about the box? i would also assume that with the amount of work i had done, the spigot bush would of been replaced along with everything else as a matter of course but i just dont know.....i'm considering just going with another s15 box and seeing how long it lasts. maybe given a year or so longer then someone may have come up with a sensible solution or kit to fit another, stronger box.

 

[craig8585]

You got me worried then thinking the S14 clutch I recently bought wouldnt fit! I just checked with Apex and they said the S15 had a fual mass fly so to fit an ACT or similar clutch you'd need a S14 or uprated flywheel, which luckily I already have!


Which particular part of the 6-speed box is the weak link(s)? Would it be a viable option to have a 6-speed box stripped and rebuilt with original gears but stronger bearings and better retainers etc?

 

[DeanS15]

people say it isnt worth it....it still drives lovely but the input shaft bearing is worn and noisy, 1st and 2nd whine like hell too. its definitely trying to tell me something LOL. companies are willing to engineer entire kits for installing a v8 into a jap sports car but no-one can deliver a decent kit that sort the tranny issue properly even the awesome looking powertune kit for over a grand still has compromises....

 

[craig8585]

It is a shame because the 6-speed is a really nice thing to have. I am suprised that no-ones come up with a solution too.. how hard can it be? If a supplier made a solution to this i'm sure they'd make their money back in no time.

 

[DeanS15]

^^100% without doubt:nod:

if i had the ability i would honestly try and get something designed myself....fact is you'd need an alternative gearbox, lifts, and engineering contacts....of which i have none lol. when you look at the powertune kit though, it does seem very simple - two solid pieces of ali machined and drilled to fit and a spacer for the crankshaft to flywheel - something i'm not entirely convinced of myself though...

 

[JEZ 8553]

This is why im probably going to settle with the standard tubbie. If i want more power in the fuure ill be aiming to replace the S15 with an R34. 350bhp just seems to be the safe limit of the car without going mental on expenditure

As you say Dean, cant believe that its so difficult to find a cost effective replacement for the S15 tranny system when you see so many cars running 400BHP + ??!

How much is a PPG replacement for a S14/S15 internals ? Id say a S14 is better as its simply cheaper and with high power you dont need such a close ration imo)

 

[craig8585]

If my box ever gets weak i think i'll find a specialist and try to get it rebuilt. The actual gears cant be that weak, surely its got to be bearings and retainers etc? Easier said than done, I know!

I'm in the same boat as you thoug Jez, the gearbox is the main reason I'm not going for more than the standard turbo's power.

 

[DeanS15]

when you guys standard turbo eventually admits defeat, you will find it hard not to pay that little extra for the 2871r or gtrs:nod:

it may be that my box was abused before i got it but it really didnt seem that way before....this is why i might take a punt, fit a known good 6spd and alter my driving style avoiding massive handfuls of boost in 1st and 2nd. they are the gears that have suffered, a boost controller with variable boost in gear would come in very handy at such a time. one thing i did notice though, when my tyres were in a sorry state before the back end would break away and the box didnt become any more noisy or worn, when i fitted new tyres the rear end stuck lots more but obviously rather than spin up to release pressures put on the drivetrain the box was bearing the load instead. grip was no longer the weakest link.

-jez, ppg dont quote prices and only cater for the s14 5spd which i wouldnt mind too much if it werent for the fact it would require all new clutch and fly, secondhand donor box and prop on top of the labour and k=kit cost plus fitting and whether or not it would be noisy as hell is another issue altogether which i think you'd struggle to get a 100% honest answer from the manufacturer, just as with the os giken kits. a few people reckon they are pretty noisy sets so i cant imagine the ppg being much different....it would be great just to get a stronger box and a fitting kit and swap it in - it really is looking out of reach now though:nod: