350 Second Gear Grinding :(

[allanuber 0]

I can't believe I've got a sad story already ...

So, I took the car in today to a recommended mechanic, who's had it for two days. They fitted the front spoiler, fixed a few LED lights in the spoiler brake light and it all looked good to go.

I pick up the car, get it onto the street carefully so as not to catch the new spoiler lip, roll through first and all is wonderful, pull down to second and GRIIIND.

WTF? Clutch was to the floor, nice clean shift of the box, I'm used to it being a bit baulky now - up to third, no problems there. Back down to first at the lights, gently into second and GRIIIIND again.

Car was shifting PERFECTLY before being taken into the mechanic, and I'd run it for about 300K's across royal national park, over to see a DB9 photo shoot at Olympic park and tootling round our offices - and not a single problem/grind etc etc.

So I take it back to the mechanic, and he says he's the only one to have driven it - he gave it some herbs in first and said he heard a crunch when he shifted to second ... then he said it was OK driving it around post this.

What do you guys reckon - is there anything else that would cause this - or is the mechanic who seems a nice enough guy likely to blame?

(Gutted as the Eastern Creek trackday is tomorrow and the 350 is back with that mechanic...)

[peter_england99 6]

Could be the 2nd gear synchros. Not an unknown problem, especially if the car is driven mechanically unsympathetically. The 1st to 2nd gear ratios are quite spaced out, so the synchros need to do a lot of work to synchronize the shaft speed when changing up. Hence, the higher wear rate.

It seems that most gear box upgrades make the 1st gear higher so as to reduce the ratio difference with 2nd gear. Also allows for quicker shifting and hopefully less wear.

Regards,

Peter.

Edited April 7, 2009 by peter_england99

[andydclements 758]

I'd second Peter's thoughts on cause.

It's only about

[Bibs 11,167]

Obviously ask your mechanic to check clutch travel first, just in case it's an easy fix!

[Dave Freeman 23]

Seems strange that it has happend all of a sudden, normally you can feel signs of crunching well before it fails. I would check linkage and slave cylinder before takling the gear box, that will be expensive.

Dave

[allanuber 0]

Thanks guys. We've been discussing this on one of the Aussie forums too and the prognosis seems pretty glum.

Is it likely to be a clutch problem if it is grinding in second on *every* shift? Even at low speed/revs it is really crunching when you put it in second - I tried one shift into second at slightly higher revs (about 4K) and the angry noise made me not do that again.

Every other gear is fine to shift into at the moment - second crys for mercy every shift.

Sorry, I meant to add that the car was absolutely perfect before I dropped it off at the mechanics two days back. Second was a problem from the very first shift when I picked it up (definitely something happened during the stay there). The mechanic did say he ran it hard once in first, shifted hard to second and heard a grind - but then said he didn't hear it grind again...

[Bibs 11,167]

If it was due to go, it was due to go and it would have happened if you were driving it, it's not something the mechanic has done I wouldn't have thought.

If you give it a good few seconds between first and second, giving the synchro all the time in the world to change the speed of the shaft, does it still crunch?

[ajb1967 0]

Hiya,

If all other gears are shifting fine then i would think it is the synchro's which are worn.I had my gearbox refurbed at the factory and that synchro was gone also.Apparently this happens when you do a very fast shift at high revs from first to second.I have a feeling your mechanic might have done this and not taken into account that the shafts do need some time.If you dont give them any time you are liable to break something.

Anyway,just my 2 cents worth but if the slave cylinder is OK and levels are fine then the culprit is the box.

Adrian

[andydclements 758]

If it's the clutch you'd espect it to crunch for all changes not just into 2nd. Your clutch starting to fail can put undue stress on the 2nd gear synchro and cause premature failure of it, and it can go if it's abused (which a VERY hard first to second change could be classed as).

I'd suggest to your garage they shouldn't do such destructive first to second changes and the rpelcement of the synchro should sit with them to pay for.

[peter_england99 6]

If you do open the gear box, then check how many dog teeth are still on the 2nd gear. When my GB went it was due to the dog teeth all having broken off.

[allanuber 0]

hi again, thanks for the responses.

2nd grinds even at lower revs, allowing time between out of first, pause, gently into second.

The syncro issue looks like being the most likely, followed by damage to the 2nd gear. Other dicussions seem to suggest 2nd gear being damaged is also a certainty given the symptoms.

Clutch was fine before dropoff - I'd only picked up the car last week - it's only seen 20K miles, and I'd run it about 500k's through some great roads here and it didn't miss a beat. Kicking myself as the garage was just fitting the front lip/rubber spoiler and doing a wheel alignment and general check over - nothing major and nothing that needed the car thrashed.

[Bibs 11,167]

nothing major and nothing that needed the car thrashed.

With that in mind I'd change my opinion insomuch that the mechanic is taking the piss then. If you've asked him to fit some bodywork and he's taken it out and trashed it, he needs to be liable for the damage he's caused. I thought before that he was driving the car hard testing some work he'd done, not just having a jolly in your supercar!

[neal 4]

It's unusal for the 2nd sychno to completely fail, usually it's a gradual procecss.

But what can happen is when it starts to wear, the syncho ring will jam into the hub and the baulk ring isn't strong enough to pop it back out, rendering the syncho useless. This happened to me on a number of occasions.

My quick and dirty fix was to try reversing with the handbrake full on. Since the reserve idler gear turns the 1st/2nd syncho hub in the opposite direction to normal the opposite force on the hub can sometimes pop the syncho ring out. This usally did the trick for me. Alternatively try reversing at speed.

Of course it's only a temporary solution. Chances are it will happen again until you replace the worn syncho ring - the part is cheap but the labour on pulling and splitting the box is a lot. But as Peter says don't let it grind - that will just break the dog teeth off the 2nd gear which is a lot more expensive.

[kyliesmith.com 3]

With that in mind I'd change my opinion insomuch that the mechanic is taking the piss then. If you've asked him to fit some bodywork and he's taken it out and trashed it, he needs to be liable for the damage he's caused. I thought before that he was driving the car hard testing some work he'd done, not just having a jolly in your supercar!

Thats the first thing I was thinking too. theres no reason to test drive car at all for that work. God i hope its something simple like a blown out Slave cylinder

[allanuber 0]

I spoke to the mechanic at length today, and he's stepped up to take responsiblity for the problem, and is going to fix it so the car is in his words 'as good as new' at his cost. I'm just waiting on the actual plan of attack, including things like making sure the right transmission fluid is used, as it's not easily available here in Oz. So a slight win, but would have been better if this hadn't happened in the first place.

[matk 17]

Well its a load of hassle, but I think some credit to the mechanic for taking responsibilty. There's a few I've come across who wouldn't.

[mondial32 0]

Ah, here you are.

[Bibs 11,167]

If you struggle to get hold of TAF-X for your gearbox, I'd be happy to buy some over here and post in nondescript packaging!

[Paula&Marcus 0]

Hmmmm ... now I definitely know, that it is a great habbit to at least take out the ECM-fuse and disconnect the battery, when I leave it at the paint- or body-shop.

[Simon350S 192]

Only just noticed this!

God I hate the motor trade! Hope you get it back as promised mate

[MKE40 0]

I had the same with mine , I put it down to trying to shift from first to second too quickly ( being used to bike shifting) a small piece of the dog chipped off and was trapped under the cone and exactly the same thing occured.

Moral,

Quick times are for journos to set when they dont pay for gearboxes !

Mike

[DBredS4 0]

Well I'm stunned he stepped up, but good on him, I only hope he does the job properly.

Good luck.

[M3S2k 0]

Sorry to hear about your problems. Hope they are able to get your car fixed up properly and quickly!

[islandbloke 1]

Whilst I agree that the mechanic should put this right - he had no business hooning your car - I'd suggest the parts were maybe getting worn anyway, and could as easily have failed when you were driving.

So to spread the love, and keep a guy on-side who may be useful to you in the future, how about offering to supply the parts (cheap enough, evidently) if he'll do the labour?

I had a similar dilemma here a year or so ago when my local specialist (a good bloke to know) damaged a new head gasket while fettling it to fit on my ARP studs. I actually paid for the replacement too (although I made it clear I wasn't happy about it). Some may think I'm too soft, but being a hardass isn't always the best long-term option.

[flamestone 0]

Hi all,

Just thought I'd drop by to finish off this saga... allanuber's Sport 350 is finally back on the road.

It's sort of a happy ending I guess (ie. mechanic rebuilt the gearbox at own expense), but no one is really happy that it took this long.

I'll post some photos of it in the Esprit chat section soon.