MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Pulling a Sierra gearbox

Getting ready to swap in my newly rebuilt engine so I'll be pulling my Sierra gearbox along with the old engine in a few days. These gearboxes don't have a drain plug and getting something up into the filler to syphon or suck the oil out seems like it'd be an execise in futility. What should I expect if I just pull it without emptying the oil? A gusher from the drive shaft hole as soon as I drop the tail end down?
Andy Bounsall

Hello,

Yes il will be a mess prone busisness. The best thing is when whole unit start to move and tail will be lower to wait until oil will empty. Where have you found your sierra swap kit?

Cheers,

Jean G.
Jean Guy Catford

Andy,
If all is well with your 5 speed tranny why are you pulling it?
The instructions I got with my 5 speed tranny were to first install the tranny and then install the motor. Leads me to think it would not be possible to remove the tranny and engine as one unit.

I put in the wrong tranny fluid and yes it was impossible to suck out the tranny fluid through the 5 speed filler hole from beneath the car. I ended up using a hole saw and cut a hole in the tranny tunnel about where the gas pedal is located. The hole I cut was the same size as the original filler hole
on the other side for the tranny tunnel. By cutting the hole behind and above the 5 speed tranny filler plug, I was able to suck the oil out by using a vacuum suction pump used on inboard motors designed to be put down the oil filler tube. It worked great. I flushed the tranny oil three times before taking it out on the road.

Ray
Ray Ammeter

Ray, Yes all is well with the gearbox but I'm switching to a 5 main 1800 and an MGB clutch. That means changing the throw out lever and the block that holds the lever. I suppose I might be able to do that either from underneath or by climbing into the empty engine bay, but...

I'll probably have to drop the tail of the gearbox down somewhat in order to separate it from the old engine and/or reconnect it to the new engine. At that point I guess I should plan on having a catch pan in position.
Andy Bounsall

Andy,
When I added the 5 speeed tranny I changed to the early B set up. Early B pressure plate,modified the flywheel to accomadate the B pressure plate, also had as you are doing to change the throw out lever and the mounting block. I believe changing the throw out lever and the block can be done by working from the empty engine compartment.
FYI....When putting the engine and tranny/bellhousing back together the upper right bolt and the lower left bolt needs to be put in first to "correctly center" the bellhousing and engine. This would be from the view looking from the rear of the car to the front. Thanks to Barney to get me straight on this. I am not sure if this holds true for the 1800 engine, but sure made a difference for my 1622.

Ray
Ray Ammeter

FWIW my engine goes in and out without having to do anything with the 5-speed box other than putting a few blocks of wood under the bell housing to hold it in place.

Steve
Steve Gyles

Steve,

I'm with you on that. The sierra box can be removed by:
1) unbolting it from the bell housing to swap the box.
2) unbolting the bell housing from the engine to swap the lot.



Andy,

can't see why you'd ned to drain or do anything to the sierra box.

Sounds like you'd be better off just unbolting the bell housing and removing the engine then removing the bell housing from the box (as you might need a different bell housing for a 1800 5 bearing). I know I had to have my kit I got from Bob West tailored, as I'm running a late 5 bearing in my A, and the standard A bell housing wouldn't fit the 5 bearing properly (so said Bob).

Good luck and have fun,

Grant :-)
G Hudson

Very good. That's what I was hoping to hear from those who'd already been there. Thanks.
Andy Bounsall

Just re-reading your post Steve. Do you not have to detach or loosen the rear of the gearbox from the cross member?
Andy Bounsall

Andy

All I have ever done is undo the bellhousing bolts and place a jack or wooden blocks underneath to stop the bellhousing dropping when I slide the engine forward and upward. I also do not remove the bonnet (hood), I tie it back to the luggage rack.

Steve


Steve Gyles

Thanks Steve. I'll try both of those suggestions. If it works (for me), it'll surely save some time and effort.
Andy Bounsall

Andy, There is an oil seal at the back of the gear box - this should prevent oil leaking out . The one fitted to mine does leak a little but certainly didn't gush out -I had to tip the gearbox upside down to get the oil out - new seals to be fitted before use. The Haynes manual for the Ford Sierra gives very clear diagrams of the seals by the way.
Cam Cunningham

Cam

You never told us that you had fitted your Sierra box. When did you do it?

Steve
Steve Gyles

Steve - I cannot tell a lie - it is still sitting on my garage floor. Note that I put - "new seals to be fitted" - i.e. not done yet. But I did find the Haynes Sierra manual in a local charity shop for 50p. Every time I save up the money for the Hi Gear kit it gets spent on a cruise - but I'm getting used to double declutching 2nd gear now - and I've got a good suntan!! cheers Cam
Cam Cunningham

There are plastic plugs that push into the back of the trans where the driveshaft goes and seal to the seal. Common tool come in many sizes. Makes a clutch job much easier than having to drain the trans. A spare output yoke would do the same thing.
R J Brown

Andy,

I was told that the oil in the Sierra gearbox is for life and should not be changed, hence the absence of a drain plug.Although older types had a drain plug.
Regards,
Guido
gva guido

This thread was discussed between 06/04/2009 and 09/04/2009

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.