27 replies to this topic

[DJS911]

Hi guys,

We're in the process of changing the clutch on my son's Mini but all of a sudden it's got very difficult to turn over and I hope someone can shed some light on why?
The engine was running fine when we took it out of the car as part of the restoration project.
Head, clutch bell housing and all ancillaries are now off and initially the engine turned over by hand no problem.
Over the course of a couple of revolutions (as we were lining up the crank to have the slot horizontal prior to removing the clutch) it started to stiffen up and very quickly appeared to seize. It can be turned over by using a 2 foot breaker bar but I have only used that for a couple of degrees movement as something is obviously wrong.
The only v minor thing that went awry whilst stripping the engine was that when removing one pushrod a cam follower came out of position but It dropped back into position easily.
Any ideas anybody?

Thanks in anticipation.

[gazza82]

Spark plugs in or out?

Edited by gazza82, 07 October 2016 - 10:49 AM.

[DJS911]

Spark plugs in or out?

Out - as the head is off.

[Dusky]

Timing chain etc still on?

[DJS911]

Timing chain etc still on?

Yes.

[ACDodd]

Remove the dizzy drive shaft?

Ac

[DJS911]

Remove the dizzy drive shaft?
Ac

Distributor is out but not the drive in the block. I'll give that a whirl.

Thanks.

[mini13]

the shaft can lift out and wedge against the crank,

 

watch out on the earlier non A+ engines as it can fall into the sump.

[DJS911]

the shaft can lift out and wedge against the crank,
 
watch out on the earlier non A+ engines as it can fall into the sump.

Thanks - it is an A + so hopefully not fallen into the sump!

[slidehammer]

Is there anyway the drop gears have started to mis-meshed as you started to remove the flywheel, causing it to lock up?

[Cooperman]

Best guess would be the distributor drive shaft falling inwards and jamming the crankshaft.
If it is that you will almost certainly have to split the engine from the gearbox.
Then you will have to decide whether to fit new big-end & main bearings, etc., but that's jumping the gun a bit.

[tiger99]

There sometimes is a very slight chance of fishing the drive shaft out. If the engine has a removable distributor mounting, taking that out first may help. It may save time to have a quick look.

Actually with the distributor mount out, some of those nice fancy tools like borescopes and flexible grippers stand a slight chance of getting it. Worth a close look with a torch.

Having had the inevitable bad experience way back in about 1971, I now put a very long 5/16" UNF bolt in the threaded hole in the shaft when I take the distributor off. That way it can't drop. Probably too late on this occasion unless the shaft is lying at an angle where the bolt can be inserted.

I wish you success.

[Cooperman]

You are not the only one to do that, Tiger. I did it in about 1965 and had to take it all to pieces again. It was an original 998 Cooper.

[DJS911]

Ok guys - here's an update:
Distributor drive shaft hadn't fallen down - I managed to remove it quite easily by popping a finger down the appropriate hole.
I then took the timing chain cover off and all appears ok there.
After these actions I popped a spanner on the crank pulley and the engine now turns over - albeit somewhat stiffer than before.
Prior to these problems I could turn the crank pulley by hand moderately easily but now it is a significant effort. However this is a big step forward as yesterday I needed a 2 foot breaker bar!
Only other thing we've done is to persevere with attempting to remove the clutch/flywheel. This will not shift and I have actually stripped th thread on the puller centre bolt. Could the two events be related?
Any other ideas/comments would be appreciated.

[Spider]

I wouldn't be trying to turn it over using any tools at all, I think you're only asking for some damage by doing so. Given the head is off and it's done some miles, it should tun over very easily by hand.

 

Now you've the timing chain cover off, when turning by hand, can you see it taking up and tightening in the timing chain or does it remain fairly slack?

 

If the chain tightens up, then obviously it's something to do with the Cam, ie, a follower or something that's fallen down a follower hole, dissy drive or Oil Pump.

 

If the chain remains slack, then I'd say you'll need to split the engine from the gearbox to see what's going on, as it sounds to me like there's something between a rod and the crank.

Edited by Moke Spider, 08 October 2016 - 10:03 PM.