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So my gearbox fell out today...

Posted: Thu Jul 11, 2013 6:37 pm
by Captain Jack
Urgh... Not a good time! Driving home today, I heard a loud bang followed by a horrible rumbling noise. Thankfully I was on a quiet residential street 50 metres away from home so stopped immediately. Looking under the bonnet didn't reveal anything obvious and the engine itself ran OK.

Coasting it home and taking a closer look revealed that the gearbox mount gave up. Or more precise the pin holding the gearbox completely stripped its thread, releasing the nut, so the gearbox is resting on a subframe at the moment. Already ordered this but has anyone had any experience replacing this - either the pin or the whole assembly? I seem to remember mjb never managed to unscrew the thing so maybe removing the plate bit is easier? It looks like I should have enough room to do this without removing the subframe (something I REALLY don't want to do) but want to make sure.

I NEED the car next week as I am moving house - the worst time for this to happen! Is there some way to hold the gearbox up temporarily? Maybe get some guy wire cable and joist it up somehow?

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 6:47 pm
by GingerMagic
Is it not possible to get some threaded bar the same diameter ( Builders merchant or similar ) and cut it to length with a nut/washer each end, once Captain Jacking up the gearbox?

I am not a mechanic but does just look like a long bolt.....

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 7:00 pm
by Captain Jack
Yep, I was thinking the exact same thing. But I need to get the thing out first and I don't have the sockets to do it... A run to Homebase in a minute to buy a set....

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 7:19 pm
by jasper5
Wow, how the hell did that happen?

Anyway, I got the long bolt out from mjb's gearbox for him using one of these ....http://www.toolbox.co.uk/draper-14156-1 ... tAodQgsAnw

On the gearbox of rwb, which is a 90, is a long bolt but that is held onto the gearbox by 2 bolts.

You need to remove the air filter box assembly to get at the gearbox mount, plus, maybe the left side inner wheel arch liner.

If yours is the same as the one on mjb's gearbox let me know asap and I will send you the tool to unscrew the bolt from the gearbox......you have a half inch ratchet?

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 8:14 pm
by Captain Jack
Thanks very much for your generosity, John. Unfortunately, I need the car working ASAP as I am driving up to Manchester for the in-lawss 60th anniversary so need it fixed tomorrow ideally.

I've just come back from a brisk run to Homebase with a beefy looking socket set and undid the mounting plate from the gearbox in less than 10 mins. Removed the air box and moved the TPS and the glow plug relay out of the way.

Good news! It looks like it's the nut that was stripped of its thread, not the pin. There's a little bit of damage at the top of the pin, which suggests that the bolt was working itself loose for some time already and worked its way to the top where it gave way. Probably to do with the excessive vibration that I still haven't gotten to the bottom of (seeing steering wheel rattle thread). Unfortunately, I don't have the nut any more as it disappeared, so I don't know the full story - though I did find the "half-moon" washer thing.

I'll run down to the local motor factors tomorrow with the whole pin/plate and find a tough nut to bolt onto the pin. Should I put some thread lock on the pin - the same one that I put on the crankshaft bolt?

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 8:29 pm
by jasper5
Good news in a way then!

Get yourself a "nylok" nut for the bolt, if you can't get one of those get a shake proof washer and a standard nut, it won't do any harm to put some thread lock on anyway.

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 8:47 pm
by Captain Jack
Quick question. With the gearbox being essentially dropped onto the subframe, is there likely to be any kind of damage to driveshafts or the gearbox itself? Like I said, I could still drive it a few metres home and reverse into my garage but couldn't tell if anything else was amiss...

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 9:29 pm
by jasper5
Hopefully, if there is no oil leak and if all the gears can be selected and no noise from the gearbox you should be fine.

Re: So my gearbox fell out today...

Posted: Thu Jul 11, 2013 10:05 pm
by Doggy
Sounds like bad luck Alex, but what if you been tooling it down the motorway? :shock:
Hopefully you'll get it sorted in the morning. If you're in any doubt about how good the thread is and there's room, consider putting a second nut on it to lock it good & proper.

If you should be unfortunate enough to have damaged the 'box, I may be able to help you with a fairly low mlleage ML5C with a marginally higher final drive ratio. It would need the clutch housing casting transferring from yours tho......

Looking on the bright side, maybe you'll 'lose' the vibration now, fingers crossed.

Re: So my gearbox fell out today...

Posted: Fri Jul 12, 2013 12:09 am
by grasmere59
Does that mean theres a 6 speed lurking in yours now Eric?

Re: So my gearbox fell out today...

Posted: Fri Jul 12, 2013 11:54 am
by Captain Jack
Well, it's in - in a Heath Robinson kind of way. No apparent damage and it seems to drive OK. The annoying steering rattle is still there :(

What a pain in the backside. Went down to Homebase and got some M12 nuts required for the pin and set about getting the whole thing together. The biggest issue was that I couldn't line up all three holes on the gearbox bracket when the pin is going through the rubber mount. Took a lot of lifting and lowering the gearbox to get TWO bolts in - the third one is still out of alignment and gets stuck about a 1/3 of the way in. The pin itself has two nuts holding it.

It wouldn't have been so bad if I had the T40 bit for the ratchet to remove the mount itself - only the T40 L-shaped tools and there's not enough leverage to undo the bolts. Once I get the new pin and mounting bracket, I'll get it all apart again with my dad's proper tools and bolt it back together properly.

Let's hope it holds a week.

Re: So my gearbox fell out today...

Posted: Fri Jul 12, 2013 12:41 pm
by Doggy
Well done Alex, the main thing is you're up and running again. 8)

You can always temporarily re-install the Greenpeace ecu map and/or take it easy for a week. :wink:
grasmere59 wrote:Does that mean theres a 6 speed lurking in yours now Eric?
No - it's still lurking in the shed, but soon......