15 replies to this topic

[Chris.Williams]

Hi all,

I'm about to strip a cooper s remote gearbox down, has a broken mainshaft.
Is there a list of specific tools required?
All the video and guides online are for reassembling not dismantling.
Any help always appreciated.

Cheers
Chris

[nicklouse]

sure your Haynes manual has the info.

[nicklouse]

Cir-clip pliers mainly. and some small screw drivers.

[Wiggy]

This should cover it.

[Chris.Williams]

sure your Haynes manual has the info.

Insightful as always

[whistler]

sure your Haynes manual has the info.

Some Haynes manuals don't include the gearbox.

[whistler]

Minimania has a good youtube video and also look at Guess-works tutorials.

[Chris.Williams]

Minimania has a good youtube video and also look at Guess-works tutorials.

Thanks for that, all of these tutorials explain the reassembling, in great detail but nothing about dismantling

[nicklouse]

Like I said just done Cir clip pliers and small screw drivers and possibly a puller. And get a Haynes workshop manual.

[InnoCooperExport]

 

Minimania has a good youtube video and also look at Guess-works tutorials.

Thanks for that, all of these tutorials explain the reassembling, in great detail but nothing about dismantling

 

 

In the words of Haynes, the same but in reverse! 

 

But seriously, tool wise I used nothing special to dismantle my gearbox. The absolute number 1 most important thing is to not take out the laygear before you have undone all the nuts holding the mainshaft together. I did this and as a result was unable to lock the mainshaft meaning I couldn't undo them easily. 

 

From memory this is a rough guide on how to take it apart sensibly. Basically what you want to do is take everything off the box first. i.e. diff, speedo takeoff, dropgears. until you just have the casing and the gears inside left. (bare in mind that the oil pickup is stuck under the laygear and won't come out just yet)

 

Then you rotate the selector rod to disengage it from the selector linkage that controls the selector forks that the synchrohubs sit in. With the selector rod disengaged the two selector forks and subsequent synchrohubs can now move independantly allowing you to select two gears at once, thus locking the gearbox solid. 

 

With the box locked up solid you can now undo all the locktabs and bolts holding the mainshaft together. The main nut will be absolutely rock solid so will take some undoing, look at the methods people give for doing it up and use the same to undo. I did mine with my old man standing on the upturned box steading himself against me and me with a long pole on a huge socket. YMMV

 

With all the nuts holding the mainshaft together off, you start looking at undoing the retention plates around the main bearings and the one holding the layshaft in place. With those removed you can slide the layshaft out and remove the laygear. Removing the mainshaft and the main bearing is a bit tricky but it basically has to come out as one. You need to drift the bearing out around the mainshaft and then the whole thing has to come out in one piece. Mine was so worn that the inner race came out with the shaft and the outer race more or less stayed in place... I used a brass drift for this so that if it wouldn't damage any of the cast parts or gearbox shafts if it inevitably slipped off. 

 

That's more or less it. 

[imack]

Depending on where the mainshaft has broken could cause difficulty dismantling it in the conventional manner

[nicklouse]

https://youtu.be/qcqY8vo59pM

[viz139]

I've done a few boxes the easy way and the hard way, I would highly recomend this tool for disassembly from guessworks to make life easy.

http://www.guess-wor...play.htm?id=491

 

Not as critical but very handy to have if you do more boxes is the synchro tool

http://www.guess-wor...play.htm?id=279

 

To release the main nuts I use a load strap to strap the box (mating face down ) to a heavy workbench than open with a socket and long bar.You will need a deep socket as used on ball joints.

 

Starting your first box can seem daunting but if you follow the sequence in the Haynes manual and lay everything out in order  reassembly shouldn't be a problem.

[Its a min]

As others have said, Haynes, Minimania and Guessworks video's are really helpful.

 

I also found this site easy to follow for stripdown:

 

http://waynesminipro...own-part-1.html

[PiG]

Classic mini DIY on YouTube, we used this and John Guess(works) YouTube and John's guide on this forum, made it very easy