13 replies to this topic

[colinu]

Folks,

Looks like I've got a couple of mm end-float on my crank (visible when depressing the clutch). I'm planning on removing the engine and splitting it apart soon to investigate/fix, but before diving in too deep (i.e. ripping too much apart!) I'm hoping someone here can offer some advice/tips.
Basically where do I look for signs of wear etc that would lead to excessive end-float, and what parts would most likely need replaced. I'm guessing the thrust washers at the ends of the crank will need replaced, but is there anything else? Or in fact is there anything I should check first before splitting the box off the block?

Cheers,
Colin.

[samsfern]

ive got exactly the same situation as you, lol, althought ive managed to do 12000 miles and 3 trackdays since i noticed, lmao! i have been building a new lump in that time though. itll be the crank thrust washers that are worn. i thought they were in the centre of the crank/main bearing....

Edited by samsernie, 21 June 2010 - 08:32 PM.

[Cooperman]

It's always those thrust bearings on the 'loaded' side of the centre main. if you have that much travel, don't drive it as the worn thrusts have been known to 'spin' in the housing and friction-weld themselves to the bearing housing and/or blok. Then it may be a scrap crank and/or block. I had one brought to me last year exatly like that. Needed a new crank and expensive block machining.
You need to strip it all down and take a good look at how muh float you have. If the blok and crank are undamaged, i.e. just very worn bearings, you will be able to fit new thrusts with standard, and +0.003" available, so some slight crank face wear can be taken care of. If with 2 x 0.003" thrusts (i.e., 0.006" float taken out) there is more than 0.005" float, you'll need to try to obtain a set of +0.030" thrusts and have the crank re-faced at the thrust faces to allow these to be fitted. Some engine builders machine down the +0.030" bearings to fit a lightly faced crank which means that in the event of further future wear there is still the possibility of re-building it within limits again.
Let's hope your crank and block are OK, but you won't know that until you have it stripped right down.
Keep the thrust wear down in future by not starting the engine with the clutch pushed down and not sitting in traffic with the clutch down. That's what 'does 'em in'.

[colinu]

Thanks for the reply... confirms my suspicions and plan of attack.
This is a recently built engine (by previous owner) - I've only put 600miles on it. When I discoverd the end-float a few weeks ago I decided not to chance driving it any further.
The crank is already ground 0.003" so while I was in the UK earlier this month I bought a set of +0.003" thrusts. Let's hope there nothing more serious than that!

Ceers,
Colin.

[bmcecosse]

Where are you seeing this 'end float' - and are you SURE it is as much as 2mm = 0.080" ?? If so - as others have said - don't run the engine because the thrusts could easily escape with that much clearance - causing much damage.

[samsfern]

same goes for me, recently rebuilt engine, only werent done properly, same goes for a lot of things on my car really... but as i said, i noticed my endfloat 12000 miles ago, whilst changing a fan belt, and have been using it on track, and everyday, and i dont drive slow either...
but they will go eventually, in a big way, lol

Edited by samsernie, 21 June 2010 - 09:24 PM.

[colinu]

I'm seeing this end-float at the pully on the end of the crank. I can lever it with a screwdriver, or see the same with someone pushing the clutch.
I found it after putting a post on Minifinity about my megajolt starting problems (wouldn't start if I had the clutch pedal pressed down). One reply suggested I check endfloat as the crank (and hence pully and trigger wheel) could be moving just enough so that the timing sensor can't pick up on the trigger wheel. And true enough that seems to be the problem.

Cheers,
Colin.

[MRA]

It will also "cant" over your conrods to the extent that the bearing shells or crank pins will be severelly damaged, this amount of wear I would also expect your engine to stall when you push the clutch down on tick over ?

[colinu]

That's the sort of thing I'm worried about... excessive horizontal play on the crank wearing/damaging tings that are moving or rotating in the vertical plane. Sounds like a thoroug stripdown and inspection is required.

Does it stall when the clutch is pressed down?... Yes, but only on the last 100miles or so on the engine and so far I'd only experienced that when the engine is hot after a long run. I'd assumed it was caused by the trigger wheel moving too far away from the sensor. That's probably still a valid cause, but maybe not the only cause

[Cooperman]

The one I had to sort out had about 0.050" float and the clutch-side thrusts had spun-up and friction-welded themselves to the crank. It needed a replacement crank, but I found an A+ crank at standard/standard for £50 and it didn't even need a grind, just a miro-polish. The block, however, was badly graunched and the centre bearing area had to be faced off, which was an expensive job as a boring head had to be used with a facing tool attached. After machining, even with a new crank, the float with two pairs of +0.003" thrust bearings was still too much, so I used one set of +0.003" and machined down a set of +0.030" bearings for the other side. Those +0.030" bearings are hard to find now as no-one seems to make them anymore. If you find that you need a pair, let me know and I may be able to help.
Where are you in CA? My very good friend who has a 1963 Cooper 'S' 1071 lives in Newbury Park, near Thousand Oaks, if you know where that is.

[colinu]

I'm starting to feel I may have a big (and expensive) job ahead of me. I'm just praying that the crank is OK.

Thousand Oaks, CA... I'm assuming that's down near LA (a stone's throw from Port Hueneme where my Mini was shipped into). That's way south of where I am... Santa Rosa (about 60 miles north of San Francisco). I'm guessing your friend must be a member fo MOALA? I'm hoping to make it to one of their meets later this year... assuming I get my Mini back on the road without too much fuss!

[Cooperman]

I'm starting to feel I may have a big (and expensive) job ahead of me. I'm just praying that the crank is OK.

Thousand Oaks, CA... I'm assuming that's down near LA (a stone's throw from Port Hueneme where my Mini was shipped into). That's way south of where I am... Santa Rosa (about 60 miles north of San Francisco). I'm guessing your friend must be a member fo MOALA? I'm hoping to make it to one of their meets later this year... assuming I get my Mini back on the road without too much fuss!

Yes, he's 60 miles north of LAX. The CA registration of his car is '1071S'.
Come back on here or PM me if you do need a crank or any other help, as I should be able to find one at a sensible price - more sensible than a price in the US even if shipping is included. A bigger issue would be damage to the block in the centre main bearing area. See what it's like first before you worry too much. It could just be light machining and a set of thrust bearings. Plus big ends and mains and an oil pump, I guess.

[colinu]

Cooperman,

You've just become my new best friend I'll PM you if I need help finding a replacement crank.
Just goes to show that the Mini community is truely a world-wide family

Cheers,
Colin.

[Cooperman]

Cooperman,

You've just become my new best friend I'll PM you if I need help finding a replacement crank.
Just goes to show that the Mini community is truely a world-wide family

Cheers,
Colin.

You are most welcome,

Peter