What Caused this Clutch Disaster?

[geodon]

Today I began dismantling my gearbox. (Ser 2A 186 Holden)

The "top hat" section thingy that pushes against the pressure plate via sliding thru a ball bearing has been demolished: 1st photo. There is a fine layer of swarf over the inside of the bell housing.

This thing is presumably supposed to slide thru a ball bearing when pushed via the slave cylinder but it is siezed onto the inner race of the bearing & the bearing now moves in/out of its housing rather that the thingy sliding thru it!!

When I unbolted the clutch actuating mechanism from the bell housing, the next 2 photos show what I found: the bolt & 2 thrust washers had fallen off the layshaft (? - sorry if that's wrong but this is my 1st time inside a GB!)

The last photo show the pressure plate and there is a small spring visible that obviously belons elsewhere.

I have a spare GB with a servicable clutch operating mechanism but I need to work out what happened.

Now, there seems to be a lot of slop when I wriggle the end on the mainshaft. Is this normal? My only experience here is with air-cooled VW's. The early 36bhp ones were as tight as but the later ones had heaps of slop as they relied more on the spigot bearing in the flywheel\ than the early variants.

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[geodon]

these may be better41994

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[Blknight.aus]

chicken or the egg,,,

did the spring come loose from the clutch and take out the throwout bearing
OR
did the throw out bearing let go and the resultant mess take out the clutch spring.

my best guess without having it in my hands says that the pressure plate lost a spring and the uneven loading on the throwout bearing totaled it. For a II box this can be bad karma as the bearing dying can wind up throwing swarf backwards into the cover plate and into the box.

[geodon]

Agreed Dave.

But the pressure plate disintegrating is unlikely to SIEZE the throwout bearing? I mean the sleeve is as one with the bearing. The bearing moves in & out of the casing/housing instead of the the thrust doover sliding thru it!

Can this be a result of poor alignment ie a low quality conversion?

[Lotz-A-Landies]

What brand of adapter kit is it?

I ask this because, some brands of kit have a reputation of being out of alignment in multiple planes and if so the pinion can bind on the throwout which will cause the type of damage you describe.

Before doing anything with a replacement box, check the alignment with a dial indicator. See: http://www.aulro.com/afvb/holden-powered-series-land-rovers/133415-before-fitting-holden-engine-check-aligment-first.html

[Blknight.aus]

Agreed Dave.

But the pressure plate disintegrating is unlikely to SIEZE the throwout bearing? I mean the sleeve is as one with the bearing. The bearing moves in & out of the casing/housing instead of the the thrust doover sliding thru it!

Can this be a result of poor alignment ie a low quality conversion?

if the pressure plate is not putting even pressure on the throwout bearing it will cause uneven loading on the throwout. It may run that way for years because the throwout bearing isnt constantly in contact (and this only normally applies to radial bearings) and under load but eventually the uneven loading causes the casings to fatigue and let go.

to check for misalignement simply check the condition of the spigot and the input shaft support wear there will indicate which way the alignment is out, if the spigot and support are ok then its most likely the throwout or clutch thats caused the problem.

[geodon]

Amazing what you find when things get cleaned!

Here is the adaptor plate. 1st photo. Un-branded. Is that normal? The only other converted vehicle I've had was a 1963 J3 Bedford with a thumping 265 Hemi. Great conversion. By Haddon, from memory. The name was embossed on all the non-std bits.

The next 2 show the back of the Holden block. It's on a stand & the shim is still in place but it seems to have only 2 locating dowels: one under the starter mtr mount & one opposite. There seems to be a non-threaded hole at the top between the two engine stand top mounts. Is this meant to be another dowel? There is no corresponding hole for it in the plate. I find it hard to believe that 2 dowels are enough to locate the GB?

The next two photos show that the plate has split along the welding line.

That's a quarter inch whit bolt for reference & I can see daylight thru the crack. It's about 15 thou.

But to reiterate Dave's point:

Did the split cause misalignment or vice versa?

I guess the 1st step is to squeeze the plate back together & weld it. Then it will need to be refaced on both sides to make sure it's true. Can I assume the back of the block is OK? Otherwise I have to strip it & get it faced as well. The only problem I have with that is I may be throwing good money at something bad. I may source a new plate? Castlemaine Rod Shop used to SELL adaptor plates eg Toyota Celica 5-speed gearboxes to MGB's. They may have patterns etc to do one from scratch.

Then the all important dial-indicator alignment.

BTW most of the slop in the mainshaft is at the bearing.

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[geodon]

Land Rover (http://www.rodshop.com.au/land_rover/land_rover.htm)

GEEEEZE!

The kit ain't cheap, is it?

I'll price a new adaptor & we'll see where it goes!

[Blknight.aus]

so long as you're not in a hurry, I have a holden 6 adaptor plate sitting in a pile somewhere and I have another that comes with a completish holden 6.

[geodon]

What I thought was a siezed clutch mechanism bearing is nothing of the sort!

It's the status quo!

The two prongs forming the clutch throwout fork push on the outside race of the bearing. The whole bearing's MEAN'T to slide in & out. Wierd! If that's the way it works, one would expect to see a brass bush or something rather than a whole bearing race sliding in/out of an aluminium casting! Does this have a history of wearing? From my VW days I remember that early engines had camshafts that ran directly in the alloy crankcase and after a prodigious mileage a line bore & shell bearings were necessary.

Still, it swims in oil so I suppose it's OK.

SO! IMHO this could be what happened:

1.The adaptor plate split down one side.
2. The gearbox pulled away from the engine on that side.
3. The other side of the clutch thrust plate then took the the brunt of the thrust causing its demise & stuffing the 1st bearing ( at least) in the gearbox.

[JayBoRover]

Seeing as the adapter plate has split and therefore you have been running with misalignment, I'd be checking the Main Shaft very carefully. Mine failed completely but the interesting thing for you is that where the shaft broke it is very obvious it had been cracked for a long time before it finally let go. The colour of the shaft at the break point was different for half of the diameter. Check out my thread HERE (http://www.aulro.com/afvb/series-2-2a/132805-oh-dear-loud-bang-clatter-racket.html). (For some reason I posted it in the S2a Forum instead of the Holden powered Series Forum)
Best of luck with it.
Cheers
John B

[Lotz-A-Landies]

Given that your adapter plate has split, there is evidence of misalignment, I would be checking your engine and gearbox mounts for failure.

Re purchasing an adapter kit, there is no guarantee that a new kit will be any better in alignment than a second hand one. There are plenty of secondhand ones available, so if you don't take up Dave's offer place a wanted ad in the markets and attach it to a marketplace alert in the forums.

Then after all that, check the new setup with a dial indicator.

Diana

[geodon]

To paraphrase Paul Hogan: "That's not a set of mounts. THIS is a set of mounts!"

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The GB's are NOT a matched pair & I foolishly didn't label them. Are they are Left/Right on the original set-up?

But I LUUURRRVE the engine mounts! One of them is SOLID save for a token rubber pad.

I'm begining to think this conversion was done by a blacksmith!

[gromit]

I would think the time taken making the solid mount would outweigh the cost of buying a new one .......?

Four Wheel Drives in Blackburn have 4 mounts for $30 plus freight, I'm guessing the standard ones are OK with the Holden conversion.

LAND ROVER ENGINE / GEARBOX MOUNT | eBay (http://www.ebay.com.au/itm/LAND-ROVER-ENGINE-GEARBOX-MOUNT-/220914358816?pt=AU_Car_Parts_Accessories&hash=item336f859a20)


Colin

[JDNSW]

I would think the time taken making the solid mount would outweigh the cost of buying a new one .......?
........

Colin


This sort of a comment shows just how prosperous Australian society is today! But cost is not the only consideration. If you live out of town and need the vehicle back on the road today, and it is going to take a week to get a mail order one, and the town 100km away lost its Landrover dealer twenty years ago - fabricating a solid mount suddenly looks very sensible!

You have to remember that until the 1980s, most Landrover owners lived out of town, or at least in small rural communities.

John

[geodon]

Well I never thought of THAT angle! Well put sir!

Have no fear, John! I will put it thru the dishwasher and use it forever more as a paperweight/conversation starter on the coffee table.

She Who Must Be Obeyed will not object. In the past she has even put up with brake shoes in the oven full bore for a couple of hours to cook off the oil that had soaked in.

[gromit]

This sort of a comment shows just how prosperous Australian society is today! But cost is not the only consideration. If you live out of town and need the vehicle back on the road today, and it is going to take a week to get a mail order one, and the town 100km away lost its Landrover dealer twenty years ago - fabricating a solid mount suddenly looks very sensible!

You have to remember that until the 1980s, most Landrover owners lived out of town, or at least in small rural communities.

John


John,

I take your point but wouldn't you then get a replacement mount at the next opportunity. Mind you like most jobs if it worked OK you'd probably forget about it.....

Just removed some very large spacers from under the gearbox mounts in my Series 2. Looks like as the mounts compressed the shaft for the rear PTO started to hit the chassis crossmember, solution....make up spacers.
New mounts fitted and spacers removed, everything lines up.


Colin