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PhilW
08-11-2014, 10:22
Quick piece of advise please.
I want to do a compression and oil pressure check on my engine before I pull it out of the car as part of my rebuild programme. I clearly should have completed this task earlier on before dismantling, however now seems like a good time to do it since I have the front suspension off and clear access to the engine pressure gauge.

However, the drive shafts now need to be removed as I cannot run the engine with them connected to the gearbox, since they will rotate with the gearbox with the engine running. The question is if I remove the drive shafts, can I run the engine OK without causing any thing to fall out or be displaced from the differential outputs?

If its OK for me to do this, I clearly cannot drain the gearbox oil before driveshaft removal, so am I OK to remove the driveshafts and allow excess oil to run out of the differential outputs, will there be enough oil to lube the gearbox?
Or should I just ensure that whilst the engine is running I ensure that the clutch is kept pressed down?

Any help with this question would be greatly appreciated :smile:

16v_paddy
08-11-2014, 12:17
Leave the shafts alone. Just jam a screwdriver into the vents on the brake disc so they can't spin

PhilW
08-11-2014, 13:21
Leave the shafts alone. Just jam a screwdriver into the vents on the brake disc so they can't spin

Wont work Paddy, just in the middle of dismantling the car, there is no brakes, suspension etc.
Just about to remove the drive shafts prior to dropping the engine and gearbox and want to do the compression and oil pressure test whilst I can.

katbloke
08-11-2014, 20:49
take the coil leads off and spin engine over to get oil pressure without it firng up, same as for compression test one cylinder at a time, you wouldnt want engine to run for compression test anyways i think

PhilW
08-11-2014, 21:09
take the coil leads off and spin engine over to get oil pressure without it firng up, same as for compression test one cylinder at a time, you wouldnt want engine to run for compression test anyways i think

Yea cheers, as you say I would run the compression test off the starter, but I would like to run the engine to get cold old pressure and hot oil pressure so that I can have some definitive values before removing the engine.

katbloke
08-11-2014, 22:05
A aah ok on that then if you have the discs spinning it's no biggy I wouldn't have thought

PhilW
08-11-2014, 22:48
A aah ok on that then if you have the discs spinning it's no biggy I wouldn't have thought

You would be right, however there are no discs, struts wishbones - any suspension at all:shock:
Was about to remove the drive shafts before taking out the engine & gearbox and then I had this idea of testing the engine.
Should have done it a little earlier I know, but I'm not putting the suspension back on now until the rebuild thats for sure ;-)

katbloke
09-11-2014, 00:11
Aha wonder if there any bungs to replace drive shafts that would do it

PhilW
09-11-2014, 15:11
Aha wonder if there any bungs to replace drive shafts that would do it

Yea, you might me right.
My main concern was that the gearbox spinning without the drive shafts in place would cause a problem with the internals of the gearbox /diff. If its just a case of stopping the gearbox oil from spilling out, thats less of a problem for me.
If I cannot find a safe way of doing this, I will just go ahead and give the engine a rebuild to get everything back to manufacturers spec.
The way I'm going with this, its going to be better when I have finished with it than it was when it rolled out of the factory :)

16v_paddy
09-11-2014, 20:43
I'd put the struts back on then tbh, it's just 1 nut at the top, leave the hub hanging off the shock with the shaft in then jam a screwdriver in the hub flange somewhere or some other contraption like g clamps or molegrips to hold it

PhilW
09-11-2014, 21:22
I'd put the struts back on then tbh, it's just 1 nut at the top, leave the hub hanging off the shock with the shaft in then jam a screwdriver in the hub flange somewhere or some other contraption like g clamps or molegrips to hold it

Yea cheers Paddy, fair point, may do that :-)