GEARBOX Urgent Help please.....leman 6weeks away.

[TonyS15]

Hello,

Right my first biggy question that I need good info on.

1) About 2 weeks ago I changed my gear oil (sorry I mean that thick blue stuff called redline oil) in the box and since then the noise has increase 10fold?.
I took it to very good friends of mine and both say that they believe it?s the bearings on the layshaft (counter-shaft) as it happens in 1,2,3,4 and 6th and also when you push the clutch in, the noise disappears. Right I believe it to run on needle Barings, is this true?
Well im going to get it rebuilt at a place I have had good feedback from, however I want to supply my own parts, as it is coming off the car this week if poss, so question is shall I order my replacement parts off perfectrun and what would you recommend I order as it may be an idea to get the main baring changed. Is the NISMO or HPI really expensive??

HELP!!

2) Also the another question, but I found the thread about the gearbox
This one: http://forum.s15oc.com/showthread.php?t=1150&highlight=gearbox

The circlip on the 3th/4th counter gear?..
QUOTE ?box can be strengthened by removing the 3rd/4th counter gear, getting a new, tighter, groove machined and a tight circlip?

Is this available anywhere off the shelf part? Or anyone got dimension or anything so when I take my gearbox I can tell them exactly what to do??..


Any suggestions, im currently looking at the diagram now trying to get part numbers.

Do they sell these parts in the UK? On any other variant of this box?
Or is there an upgrade kit which would be just as good?

To top it off I have 6 weeks to do this before Leman???

Thanks in advance?..pity no-one is in the North-West to help out.
Does Dammsy have that spare box if all else fails?

 

[Nicely]

Yep, that sounds like the 3rd/4th counter gear circlip

Its a case of taking it apart (which you are having done anyway), machining a new groove (separate from the existing one) and fitting a fooking tight clip. The problem with the old one was that some of them weren't as tight as they should have been and worked free.

Needless to say, don't use the car till its done.

Quite possibly the change of oil to a slightly thicker type was enough to push it over the edge. However, it probably would have gone at some point if that's the case.

 

[TonyS15]

Yep, that sounds like the 3rd/4th counter gear circlip

Its a case of taking it apart (which you are having done anyway), machining a new groove (separate from the existing one) and fitting a fooking tight clip. The problem with the old one was that some of them weren't as tight as they should have been and worked free.

Needless to say, don't use the car till its done.

Quite possibly the change of oil to a slightly thicker type was enough to push it over the edge. However, it probably would have gone at some point if that's the case.

What the noise sounds like the ? counter gear circlip..? Does it make the noise of a worn bearing as I thought it was the actual barings that are worn. I thought that whilst replacing the bearings that I would buff up this circlip up a bit at the same time. I would have liked to send the company the gearbox and get them to machine a new groove?(in the countershaft???)
Do I need to order the parts from perfectrun? On a different thread it is mentioned that ordering the parts from perfectrun will save a lot.

Also I was thinking about replacing the syncro?s whilst its in bits along with the main shaft bearing. Anyone done this?
Car is not currently being run sat on a disused taxi way at the minute on a secure site.

When I mean about the change of oil, I believe IMO that the oil that I pulled out was really really thick which has been deliberately put in the box to dampen the noise of the worn bearing when I bought the car. So now I have put new stuff in, it feels thinner hense hearing the noise more now.

 

[Topper]

When i'm sitting idling and release the clutch i get a noise, i'm not sure how to describe it, but doesnt do it with the clutch down nor can i hear it when moving..... is there anyway to check the gearbox for wear? Other than taking it out and looking?

 

[Dazz0i]

Topper...that just sounds like the clutch release bearing.... shouldn't worry about it.

sorta thing that you change when comin' to change a clutch when the box is already off.

 

[Nicely]

Tony, its not the circlip which is the direct problem. It just causes it. It holds everything together. When it comes off, everything moves - with predictable consequences. Here's a diagram. I'm not entirely sure which of these three causes the problem, but its one of them:

As for parts; no idea till its taken apart. Further damage may have resulted.

The gearbox is normally noisy, but not to the degree that I would notice it in day to day driving. What you've described is exactly the same as what happened on mine (mine was probably a lot worse, as I was overtaking something when it went). My box struggled to stay in 3rd and reverse was not a pleasant experience, and that was just getting home and taking it to the garage.

Sorry, mistook which oil you changed. If it was blue Redline stuff, that was Shockproof Lightweight, the stuff recommended for the box, and used by many people with 6MTs and 5MTs.

BTW, you didn't put Silkolene in the box did you? Its notorious for increasing box noise. And what power are you running?

 

[Topper]

Cheers Dazz0i :thumbs:

 

[TonyS15]

Tony, its not the circlip which is the direct problem. It just causes it. It holds everything together. When it comes off, everything moves - with predictable consequences. Here's a diagram. I'm not entirely sure which of these three causes the problem, but its one of them:

As for parts; no idea till its taken apart. Further damage may have resulted.

The gearbox is normally noisy, but not to the degree that I would notice it in day to day driving. What you've described is exactly the same as what happened on mine (mine was probably a lot worse, as I was overtaking something when it went). My box struggled to stay in 3rd and reverse was not a pleasant experience, and that was just getting home and taking it to the garage.

Sorry, mistook which oil you changed. If it was blue Redline stuff, that was Shockproof Lightweight, the stuff recommended for the box, and used by many people with 6MTs and 5MTs.

BTW, you didn't put Silkolene in the box did you? Its notorious for increasing box noise. And what power are you running?

No didnt put silkolene, i put the redline stuff lightweight in the gearbox and heavyweight in the diff.

Well i spoke to the company who are going to do the box and he said just pass them the box and they are gonna see whats worn and are going to replace what ever is needed, i asked him about the circlip and he said he'd take a look and if it is possible to buff it up he will do, but i said i want it totally secure so well see what happens. he said he would be able to get the correct parts anyway so said dont worry and leave it with him. At least its garenteed....
if i knew more about gearboxes then i would completely strip the countershaft and get it machined with a new circlip however machining a hardened steel shaft has gotta be tough. Has anyone got theirs machined or done it themselves?

 

[Nicely]

The one guy I know who fixed it doesn't post on here any more. However, he did know his stuff and said that the fix made the box stronger than the 5MT.

I would imagine they can get parts because its essentially the same internals as the RX8 box.

I never got my replacement box done for the same reason as you. It was a bit too daunting to do it myself. If I'd pulled my finger out, I could have got someone to do it while the other box was OK. Hindsight is wonderful...

Just re-read your other posts. If the oil you took OUT was thicker than the Shockproof Lightweight you put in, it wouldn't have been doing your box any favours :no:

And about how much power are you running?

 

[TonyS15]

The one guy I know who fixed it doesn't post on here any more. However, he did know his stuff and said that the fix made the box stronger than the 5MT.

I would imagine they can get parts because its essentially the same internals as the RX8 box.

I never got my replacement box done for the same reason as you. It was a bit too daunting to do it myself. If I'd pulled my finger out, I could have got someone to do it while the other box was OK. Hindsight is wonderful...

Just re-read your other posts. If the oil you took OUT was thicker than the Shockproof Lightweight you put in, it wouldn't have been doing your box any favours :no:

And about how much power are you running?

Hmm i havnt sent the box yet, it is a bit daunting your right and my old man is a mechanic and dealt with a load of gearboxes and he's always sayin "nissan dont pay their designers uber$ to design crap.....its fine!!"
Im prepared to do the fix and im prepared to pay for it to be done, ill explain to him when i go round and ask him but i dont really know which Circlip it is outta the 3.
So did you bust your other gearbox completely?

yeah re-read the posts, the stuff i removed was like treakle, but very new!!So the new stuff (redline) is thinner which i believe didnt dampen the noise as much....

Embarrasing but i went to a RRday on sat just gone and with just Exhaust and Filter mods wise i got 256.1BHP at the fly... i will be wanting to increase this which is why i want to do the mod but with 6 weeks looming till leman, its just trying to find out how to get it done.....

 

[Nicely]

TBH, if its the circlip (or snap ring), its going to be pretty obvious when they take it apart.

256 pretty much rules out the high power theory about the boxes going.

 

[TonyS15]

Yeah thats what leads me to believe that its just a worn baring. However I took it to get rolling roaded to see the starting power, as i do want to increase this more to around the 300 mark eventually. Thats why im gonna try get this done, but ill need to work out depth of groove, position of groove and working out a correct size of circlip.
I have a friend who works on Hard metal machinning its just giving him the dimensions.

 

[Nicely]

What I meant was that the box doesn't necessarily go due to high power.

I'm afraid I have no pointers for you on this, as I never got it done. It would have been a case of looking and doing it. All you are wanting is a new groove and circlip...only fitted tight as it should be. Nothing particularly special.

 

[TonyS15]

Right well the gearbox is off now....what a bit of a ball ache removing it, had to slightly lower the subframe to release it.
Gonna drop it off at the place tomorrow with instruction to pay special attention to that circlip and mention about a new circlip.
I also noticed the clutch and flywheel set up is a bit different to the 13/14. Its one of those dual mass flywheel isnt it? The ones that are on a few of them rover diesels v6 and some of the new focus...
is this true...if so what did they change it, does anyone know why.

 

[dcoghlan]

the s15 seems to have a terrible resonance when you replaced the standard dual mass flywheel with a solid flywheel. Ask anyone running a Nismo super coppermix!

If they put the dual mass flywheel back in, the resonance dissapears.

 

[raytsang]

humm but does the solid mass fly make much off a difference in performance?? how noticable is the differnce.

 

[Nicely]

the s15 seems to have a terrible resonance when you replaced the standard dual mass flywheel with a solid flywheel. Ask anyone running a Nismo super coppermix!

If they put the dual mass flywheel back in, the resonance dissapears.

This is very true. I didn't think it took too well to mixing and matching clutch and flywheel....