18 replies to this topic

[Bristolmini]

I have recently bought new cooper and already I have a problem, I stubled accross this forum and looks busy so I thought someone may be able to help...

I think the Diff has gone, it's an N reg Rover Cooper SPI, When driving I lost all power to the wheels accompanied by a nice grinding noise. The speedo was still reading above zero so drive is getting to at least some of the gearbox. The drive shafts appear to be OK and look to be located correctly in the CV joints.

I suspect it is the diff that has gone but is there anything else that I might have overlooked?

If it is the Diff, is there anything I should consider when replacing it?
Anything I particularly need to look out for or check?
Is it worth changing the whole gearbox?

Any help is greatly appreciated

Thanks

[Sprocket]

If you mean, when the gear is in fourth and you rev the engine and the speedo reads acordingly IE 30mph arround 1700rpm and the car does not move then yes your diff is broken. I would advise that you do not run the engine for long as there will be metal particles rushing round the oil system and do no good to the engine bearings. Its an engine out job and while at it, a rebuild of the engine would be worthwhile. Guess Works is the gearbox man, speak to him about the repairs or replacement of the box.

[Bristolmini]

I didn't run the car for long, just long enough to diagnose where the fault might be. It was enough to convince the AA Bloke to not even look at the car when he came to tow it. I don't really want to be rebuilding the engine at the moment because I might be going down the turbo route soon anyway.

Looks like I will be removing the engine to see how bad it looks in the box.

[AlexM]

I didn't run the car for long, just long enough to diagnose where the fault might be. It was enough to convince the AA Bloke to not even look at the car when he came to tow it. I don't really want to be rebuilding the engine at the moment because I might be going down the turbo route soon anyway.

Looks like I will be removing the engine to see how bad it looks in the box.

You could drop a metro engine in for the time being. That way you could take your time on the engine.

[Bristolmini]

Got a metro engine in a mini I am about to take apart, the SPI engine I have in the cooper seems to have a bit more power though so I would like to keep that. How bad can it be replacing a gearbox?

The metro engine will probably form the starting point for the turbo engine

[Guess-Works.com]

I have the strangest deja-vu feeling again !!!

[minimole]

i think i said the same thing before i attempted the same kind of thing....

Cut along story short my flywheel welded to the crank which made getting to the gearbox difficult

[Guess-Works.com]

Once the engine's out replacing the box is an hour tops... (helps if you have an engine stand where you can turn it upside down)

but as on Minifinity ( sorry guys been moonlighting :cheese: ) check the diff splines, etc.

SHoot it's just dawned on me..

Check one the of the pots, has just not popped off ( if the ring clip fails the this is a high probability ) you turn round a corner, and the drive shaft is pulled off. all of a sudden no drive and a grind...

Edited by GuessWorks, 13 January 2006 - 10:04 PM.

[Bristolmini]

I did post this on Minifinity earlier, didn't think there was any harm in posting it here too and getting a few more eyes to look at the problem. I can check the splines and the post as I dismantle it all tomorrow. I might get lucky and it not be too bad but I doubt it (Friday 13th syndrome I reckon)

I have a metro box attached to another engine which I know is OK, no crunching of gears, no dropping out of second or anything so I can use that (I drove it round for over a year with no problems at all). Ideally I would like to keep the final drive ratio of the cooper, 3.2 I believe? I am guessing this may be difficult if the diff is in fact damaged? The metro is 3.44. What needs swapping (or getting replacements) to keep the 3.2 ratio?

[Sprocket]

Its actualy 3.105:1 FD but keep the 3.44:1 FD in the metro box, it'll make for a more sportier drive and liven the car up.

Edited by Mini Sprocket, 13 January 2006 - 10:53 PM.

[minidaves]

drive shaft splines would be a look for sure but if the diffs gone pop then it happens done more than one

advice on here so far is correct just remember its an spi so u cant just drop a metro engine in as no crank sensor

dave

[Bristolmini]

I could just leave the 3.44 final drive in the metro box, I do kind of like the longer gears because it seems to have the power to cope with it OK.

If I did leave the 3.44 final drive what speedo drive bits will I need to use to keep a correct (as far as I can) reading?

[Guess-Works.com]

If you want to use 3.44 you will need to change the worm and pinion at the speedo take off in the gearbox to use a worm with 6 teeth and a pinion with 16, that should get a close reading using 12 or 13 inch wheels...

[Bristolmini]

It's not looking as bad as before, I think it may be something in the inner CV Joint gone, with one wheel jacked up if I turn it (car in gear) the opposite pot joint also turns. The driveshaft however stays exactly where it is. Half way through dismantling it so hopefully I will know soon, but the need for coffee and a bacon sandwich became too much and had to stop.

[Bristolmini]

In the end it turns out it was the splines on the driveshaft where the inner cv joint attaches, they were nearly flat. Time for a new driveshaft I think.