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Long story short : I changed the oil in the gearbox a few weeks ago - the old stuff was sludge and I caught in a shallow plastic tray which I finally got around to decanting into a plastic bottle for a trip to the recycling centre. As I got to the bottom, I noticed a shiny glint - washing with petrol in a gold-panning swirling motion revealed this horror show.....

It’ been 15 years since I drove the car and a don’t recall any crunchy noises from the gearbox, though I didn’t drive it far. This looks to me like the remains of a needle-roller bearing - do you think this kind of damage would make itself known? I suppose I’m clutching at the straw of it having been repaired after the bearing was destroyed...... but any normal person would have drained the oil to remove shrapnel, right?

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Sorry Rick,

That is a gearbox-out situation. 

Read all the info on this forum on soft lay shafts, a modification to the lay gear shaft (extra besring) and use of quality bearings before you attack it.

Good luck,

Waldi

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Rick - if you are thinking of changing your box, I may be able to help you out, as I have a couple of gearboxes/ODs surplus to my requirements, but how we get one to you is another matter!!

If this might be of interest, please send me a PM ( personal message)

Cheers

Rich 

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Thank you all for your advice. I’m just going to see how the gearbox behaves once I get the engine running - I’m holding out hope that it has been repaired by the PO. This based partly on my reflection that John Yarnell would surely have spotted something when it was being recommissioned after its trip over the pond in a container. 

Reading previous posts I can see that symptoms of a collapsed layshaft bearing include difficulty getting into gear, which I have not experienced - are there any other symptoms?

cheers

Richard

Edited by ricky30dk
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Horrendus noises comimg from gearbox !

There is also a needle roller bearing between input shaft & mainshaft.  but in both cases even if they fail & start breaking up there is not much chance of the debris finding its way out of its location , & into the casing. If the box behaves normally, & sounds sweet, then after perhaps another flush through, & re-fill, I would suck it & see.

By the way, to my eyes the stuff you recovered from the oil looks more like broken up gears to me - possibly reverse, as it uses a spur gear. is reverse noisy ?

Bob.

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Hi Bob, to be honest I don’t remember ever using reverse (I drove it less than a mile in total before it was parked up).

If I can get the engine running, I may sneak it across the road to the car park one night and try it.

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Ricky,

If you have an overdrive fitted, drain that too and clean the filter and magnets.

You may cause irreversible damage if tou continue running.

An intermediate step is to lift the GB cover off and do a visual inspection.

Waldi

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18 hours ago, ricky30dk said:

Long story short : I changed the oil in the gearbox a few weeks ago - the old stuff was sludge and I caught in a shallow plastic tray which I finally got around to decanting into a plastic bottle for a trip to the recycling centre. As I got to the bottom, I noticed a shiny glint - washing with petrol in a gold-panning swirling motion revealed this horror show.....

It’ been 15 years since I drove the car and a don’t recall any crunchy noises from the gearbox, though I didn’t drive it far. This looks to me like the remains of a needle-roller bearing - do you think this kind of damage would make itself known? I suppose I’m clutching at the straw of it having been repaired after the bearing was destroyed...... but any normal person would have drained the oil to remove shrapnel, right?

62EF617B-7806-4034-9CDE-B08FB01D6D30.jpeg

4D3FCE02-3DDB-4490-AD00-77F8BE2AD770.jpeg

Hi, Ricky, Sorry, but I can't see how the previous owner would have replaced anything with the oil still in it, this has happened since it was last buttoned up, Driving this any further or even running the engine, is only going trash anything that might be still serviceable. Open the top and look inside, you should be able to see movement in the lay shaft and see broken teeth if there are any, might be cheaper to get a replacement and rebuild it as there could also be bits of gear teeth in the pictures too.

 

Mark

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+1   sorry but if that came out of the drain hole how much more is still in there.No rebuilder would have left anything like that behind.

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By the way, to my eyes the stuff you recovered from the oil looks more like broken up gears to me

I'm with you on that Bob, the debris appears too angular to be from a roller bearing and if all that had come out of the end of the layshaft you would certainly know about it when trying to shift gears, the damage would be huge for particles that size to escape from the end of the layshaft considering it is captured within thrust washers at either end & only a few thou clearance.........possibly a combination of both & this is the end result due to the change in meshing angle caused by collapsed bearings?

Either way for me it's box out & strip.

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At the least I should take the top off and have a good look.....damn, all that buggering about with the gearbox cover, h-frame, wiring.....

Never mind - let’s see what I find.

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  • 3 weeks later...

Right then - after much faffing about I bit the bullet and stripped out all the sweary stuff so that I could take off the top of the gearbox. What I was unable to see with the naked eye, I could at least use my phone to take a picture of.....and at least the gears on the main shaft look ok to my untrained eye. With the possible exception of the big spur gear which looks a bit chewed on one side.

I was able to reach down with my fingers and press against the laygears and I think I can feel movement (and not just backlash). This prompted a closer look at the debris and there are definitely bits of needle roller in there (as well as a serious nugget from something more solid).

So I have finally accepted the inevitable - the box will need to come out.

I plan to fit an uprated 3 bearing laygear and pin the clutch bearing shaft - maybe even fit a reverse switch. Would you recommend anything else while I’m in there? who would you recommend to supply the laygear?

I’ve been reading about layshaft hardness - is there a known source of the correct specification? 

All advice most welcome - logistics and funds mean I’ll need to do this myself ....

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Edited by ricky30dk
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To my eyes the needles you are holding look too big to be layshaft ones,

there is also a needle roller bearing between the input shaft, & the mainshaft , they could be from there.

The marks on your spur gear look pretty standard, & should not cause a problem. & it is only used in reverse.

Bob

Edited by Lebro
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The nugget of metal on the right in the bottom pic looks like a dog tooth - should be able to see where that one has come from by slowly rotating the main shaft...

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Careful Bob - you’ll have me clutching at straws again....

I guess I could jack up the rear end and gently run the box through the gears (after flushing thoroughly and refilling with oil), like Ferris Bueler. Or would the gearbox need to be under load to reveal any injury? I have a live axle car.

It’s a moot point at present since the engine is not running - Danish postal system still has my new jets and since Easter is a three bank holiday affair, most of the country just takes the whole week off.

On the plus side, today I’m travelling to Padborg to use the gift my work colleagues gave me for my 50th birthday last year - 6 laps in a Lotus Elise ☺️ should take my mind off gearboxes for a bit.

 

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As John said above, rotate all the gears, & look for any missing teeth / dogs etc. if there are none then maybe a flush would do it ?

Parrafin, diesel or similar would be better than petrol !

see if there is any lateral movement at the front end of the mainshaft (suggesting a broken up needle roller bearing to the input shaft.)

Bob.

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I just recently fitted a new 3 bearing Laygear to my 3A and I got it from Moss UK it was the best price of all the normal suspects and their service was spot on, ordered on Monday delivered to my front door in Perth West Australia before lunch on Thursday can't complain about that.

 

Graham

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Well, driving the Elise was fun, though there’s not much room with a roll cage and a helmet.....I was scrunched up a bit too much - but still definitely something I could get into, motorsport, I mean.

Anyway, back to the gearbox - this is what I have to report:

1. After flushing through with diesel, I found no further metal debris

2. After inspecting the gears and dogs carefully, I found no missing gear teeth but I did find two missing dog teeth on what I think is second gear. One of these was in the debris that started this thread.

3. I could not feel any lateral movement in the mainshaft. Nor can I feel any in the layshaft, though this is difficult to grip with my fat fingers

4. With the clutch held in by a large piece of timber and the propshaft disconnected, I was able to run through the gears while rotating the rear flange. In all forward gears, the box felt and sounded smooth. Reverse was harder to judge - though it felt smooth enough, I could hear some, well “whirring “ might be the best description - certainly some noise that wasn’t present with the forward gears. I suppose this could just be because the layshaft is also turning - but could also be worn bearings. Is it correct that the layshaft is only engaged in reverse?

So this is my latest assessment - the gearbox is not going to implode in the short term and I now know that there is not a pile of metal at the bottom waiting to get drawn into the gears. I’m more than a little nervous about rebuilding the gearbox myself, but I don’t currently have the £2000+ needed for a rebuilt one. So my plan is to put it all back together, finish the restoration and enjoy the car this summer (I don’t have plans for any long trips) . This  will keep me motivated to finish this long project, gives me a chance to hear the box in action and will give me time to find the funds for a rebuilt box. 

The only real niggle is the 2 missing dog teeth - do you think this is from overzealous gearchanges? Do you think there will now be a domino effect on the adjacent teeth?

Please don’t burst my bubble .........

Oh, I nearly forgot to ask - this lump of iron attached to the back of the gearbox- can I remove it? And the straps/braces up to the selector casting?

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Edited by ricky30dk
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The big lump is a mass balance and the bracket work is needed to reduce remote chatter.

Q - did you remove the big brass plug in the bottom of the overdrive unit, then remove & clean the metal strainer - if so what did you find debris wise?

Cheer

Peter W

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A couple of adjacent missing dog teeth is far from ideal but in your position - also not a game changer, I like the idea of you cleaning it all out as best you can & zipping it back together and using it until you are in a position to pull the box & sort it properly. And don't be afraid of building these things yourself - lots of reading, a clean work area and a good understanding of the tolerances involved and it can be done on a very reasonable budget. I've done several over the last few years without any issue at all. 

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Right, so I undid the big brass cover and let the overdrive puke its guts into a pan - that was impressively disgusting.

More panning for gold revealed........iron filings......fahsands of ‘em......seriously : a heaped teaspoon full at least. But no needles or nuggets.

What do you think, Peter - was this what you expected? 

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Edited by ricky30dk
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