A&Q about 350Z
Q:
Hi All,
My '91 16v's gearbox seems to be a bit leaky, I've checked the speedo cable drive, reverse light switch, breather and drain plug and they are all ok. The oil seems to be coming from around one of the driveshafts where there is a green plastic part, will this be a driveshaft seal leak? Are they easy to rectify?
It's not a massive leak, doesn't seem to affect the oil level much so I've been topping it up now and again for a year or so but I'm going to be taking the 'box out anyway to fit a lightened flywheel soon so thought I might as well sort it.
Any tips, pics, part numbers or advice much appreciated!
Cheers
Stu
A:
A:
Thanks for the link, will have a good read and report back if I'm still stuck!
A:
Is there any way that a gearbox leak in this area could cause contamination on the clutch?
The reason I ask is that my clutch has now started slipping, I've just installed a new head on the car and it has noticably more power/torque now and the clutch can't seem to handle it. As the entire clutch is only about 1 year/6k miles old I can't imagine that it's knackered already so wondered if maybe it's getting oil on it?
Any ideas appreciated - looks like the 'box is going to have to come out sooner than planned
A:
Slippy clutch in isolation relates to pushrod seal leaking oil onto the clutch.
But if greater power introduced at same time, then could be a weak clutch.
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Cheers Chris - I've just been doing some searching on the subject and it does seem to point to the pushrod seal. I should have changed the seals before fitting the 'box I expect, oops.
Now I think of it, it might have been slipping slightly on fast standing starts even before the new head, but the new head's extra power has certainly highlighted it now!
I might just swap my old original gearbox back in the car for now, that never leaked oil or gave any slippy clutch symptoms, just was a bit more crunchy on the cold 2nd gear changes.
Are the seals I need available from GSF as a kit?
A:
Stu, you'll need to fit a clutch if it's been leaking or not really.
Mine always had a standard genuine clutch in it, was never any bother. well other than the clip coming out of the disc and having to drive from the m6 home with no clutch.. ahem!
I fitted a Helix clutch (ex Tub) with the new engine, but Ian V has that now.
Think GSF do the seals, ask Hotgolf.
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There's also the input shaft seal - worth doing at the same time just in case.
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There's also a brass/bronze bush in the input shaft that wears (clutch rod passes through it) if it wears , the seal will leak.
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There's also a brass/bronze bush in the input shaft that wears (clutch rod passes through it) if it wears , the seal will leak.
More info from a thread yesterday, and
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Thanks for the replies - what a pain, you fit one thing and something else goes wrong!
The joys of 'upgrading' old cars I suppose!
Do you think the friction material on the current clutch will be knackered if it's had oil on it? I wonder if it can be cleaned up successfully, don't really want to spend any more money on the car at the moment.
At least it's an excuse to fit my lightened flywheel although from what Hotgolf said on another thread I'm not sure if that'll need re-balancing with my pressure plate attached?
I would have thought if it was balanced to begin with it'd be ok to fit with a standard pressure plate as that would be balanced to itself anyway, if that makes sense?
Edit: noted about the bush Gary, something else to check while it's in bits. All this is making me side more towards swapping in my old 'box although it would be sods law that the old 'box would have magically developed some problems from being sat in the corner of the garage for a year!
A:
every time i took a box off where i didn't know how recently the seals were replaced i'd always change the pushrod seal, pushrod bush and input shaft seal.
The only time i didn't do it i got 500 miles before the clutch started slipping. Might be worth changing the seals on your old box, once you're happy that they are all done then just swap boxes.
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Might be worth changing the seals on your old box, once you're happy that they are all done then just swap boxes.
That sounds like a good plan, that way the car is still useable in the meantime (albeit not for quick acceleration!) and I can swap 'boxes when I'm happy the old one isn't likely to leak!
Thanks for all the replies, much appreciated. I just about know what I'm doing with engines now but gearboxes are still something of a mystery to me
A:
Do these sound like the right bits from GSF?
31155 GEARBOX SEAL-INPUT SHAFT G2 1.8 8v GTi £3.50 (don't seem to list 16v, same?)
31156 ROD OIL SEAL-MAIN SHAFT G2 16V 2/86 >10/91 £4.50
31157 GEARBOX MAIN SHAFT BUSH G2 16V 2/86 >10/91 £1.50
When is says 'main shaft' bush and seal - does that refer to the pushrod bush and seal or is it something else?
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See other my post about the clutch strength, but it you decide it is just an oil problem and the clutch isn't worn then you can just clean the oil off and it will be fine. I think Hotgolf soaked one in petrol which did the trick.
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Cheers Ian, I will take it apart this week hopefully and have a look. Hopefully just a bit of oil contamination that can be cleaned up as you say, don't really want to fork out for a new clutch just yet!
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31155 GEARBOX SEAL-INPUT SHAFT G2 1.8 8v GTi £3.50 (don't seem to list 16v, same?)
31156 ROD OIL SEAL-MAIN SHAFT G2 16V 2/86 >10/91 £4.50
31157 GEARBOX MAIN SHAFT BUSH G2 16V 2/86 >10/91 £1.50
Picked these bits up from GSF today, they do all look like the correct ones.
They don't sell flywheel bolts unfortunately so I will probably re-use the ones in there now as I didn't overtighten them or anything when I installed them, they'll be ok with some Loctite won't they?
Off to study Broke's site now on how to get that brass bush out...
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Picked They don't sell flywheel bolts unfortunately so I will probably re-use the ones in there now as I didn't overtighten them or anything when I installed them, they'll be ok with some Loctite won't they?
Noooooooooo. Bin 'em - get some from the dealers or whereever - not worth it imo
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They should be alright as Broke proved they are not stretch bolts, but they are also not expensive from the stealers. i generally replace them every 3rd gearbox swap!!!
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If they're easy to get and cheap enough, it won't hurt anything to use new. If you tightened them in the right criss-cross pattern and didn't exceed 15 ft-lbs, they'll be fine to use. No loctite needed, they don't come with it new or from VW, but a dab of blue wouldn't hurt anything, it just isn't REQUIRED.
Shouldered M7 10.9 bolt specs show they begin to get elastic at 11 ft-lbs (not to be confused with stretching or stretch bolts, as all bolts exhibit some amount of elasticity when properly tightened), at 30 ft-lbs they will stretch 1mm, and then they will yield at 40 ft-lbs.
My real world tests showed nearly the exact same results...at around 30 ft-lbs, they get easier to turn, and you know they're not tightening anymore, they're stretching. At around 40 ft-lbs, they broke, each one breaking in the same expected place at the PP.
Broke
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I wonder if I might be confused about which bolts are which and be using the wrong names for them?
The ones I meant were the six larger bolts that hold the centre of the pressure plate to the crank - are those ok to use again or not? Last time I got new ones in with the clutch kit but I'm hoping to clean up and re-use my existing clutch this time you see.
I think Broke must mean the smaller ones (that there are nine of?) that hold the flywheel to the clutch assembly as they only tighten to 15lbsft whereas the centre ones I mean are very tight, like 70lbsft or something if I remember from last time?
I called the VW dealer to order some (asked for pressure plate bolts for Mk2 Golf), the six centre ones I was after really though, and the parts guy called me back to say he'd ordered nine of them in for Saturday for me...? I get the impression he must mean the small ones too? Confused?!?
Should I renew both sets of bolts then to be on the safe side, and if so, what should I ask the parts guy for to get the six larger ones? Are they flywheel bolts, pressure plate bolts, crank to clutch bolts or something?
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I'd definatly replace all of the bolts, unless you like taking the gearbox off.
Parts to ask for are:
N 100 134 01 x9 12 point head bolts.
N 902 061 03 x6 Hex head bolts.
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I'd definatly replace all of the bolts, unless you like taking the gearbox off.
Parts to ask for are:
N 100 134 01 x9 12 point head bolts.
N 902 061 03 x6 Hex head bolts.
Brilliant, thanks for that, just what I needed to know!
I'll call the parts man back tomorrow and make sure to get them all ordered ready.
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The ones I meant were the six larger bolts that hold the centre of the pressure plate to the crank - are those ok to use again or not?
No, do not use those again.
I think Broke must mean the smaller ones (that there are nine of?) that hold the flywheel to the clutch assembly as they only tighten to 15lbsft
Yes, I'm speaking about these...
I called the VW dealer to order some (asked for pressure plate bolts for Mk2 Golf), the six centre ones I was after really though, and the parts guy called me back to say he'd ordered nine of them in for Saturday for me...? I get the impression he must mean the small ones too? Confused?!?
Most cars have the flywheel bolting to the engine crank, ours do not. This means the names are more likely to be confused. If they secure the pressure plate, I call them pressure plate bolts, and if they secure the flywheel, I call them flywheel bolts.
The 9 small flywheel bolts are OK to use again if you want, the 6 large pressure plate bolts are stretch bolts and shouldn't be used again.
Should I renew both sets of bolts then to be on the safe side
They're not expensive, so just renew both sets
The picture was an old picture I used when fighting with some guy on the Vortex about them being stretch bolts at 15 ft-lbs. Most clutch install kits sold here for about $50 include both sets of bolts, the clutch centering tool, TO bearing, green end cap, seals, and so on.
Broke
A:
Cheers Broke, that clears it up, you seem to know a lot more about this stuff than my local VW dealer parts guy... no suprise there!
Called the dealer and they have tons of the larger bolts in stock already, so just waiting for the order of the smaller ones to come in now and I should be ready to get the 'box off, fingers crossed...