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 Midget and Sprite Technical - Gearbox swap - how long

I’m toying with the idea of swapping the gearbox in the girlfriends 1500 shortly, maybe on my next shutdown from work. To go with the usual whines and noises its started a very concerning knocking/rattling on the overrun, very bearing like!

Anyway I have a spare box kicking about, without getting too technical is there any way to tell the condition, there’s minimal play on the input shaft.

How many hours (at a leisurely pace) would it take to remove the engine/box and replace?

Could someone give me a list of parts that I will need so I can have EVERYTHING ready. It’s a daily driver so I don’t really want to get too held up when doing it if possible (I know a 5min job usually takes 50!)

I was intending to put a fresh engine and ford box in when funds allow, but it looks like I’m going to get practice removing the engine sooner than I thought!
D Tetley

Perhaps I can help I just did my clutch;

2 hrs out. Assuming you have a hoist ready.
3 hours in.
Plus time to actualy swap the gear box over which should be minimal. Also add any time for rusted/stripped bolts, and other things you WILL find which need to be put right while you're there. Add further time for leisure!

I would recommend;
* Taking the engine/g'box out and back in together.
* You should be able to dissconnect the manifold and hold the exhaust out of the way on a bundgy cord whilst it's still attached to the down pipe.
* The intake manifold and carb assy should be left connected to choke and accelerator cables, the carefully rested on the heater.
* Leave the clutch slave cylinder with the car, i.e. detach it from under the car.
* Drain the g'box oil (or it will run out of the tail shaft bearing when you tip the engine on removal).
* Check that you have sufficient wear left on the carbon release bearing, don't assume you can re-use the one coming out.
* I can't remember there being any perishable items like gaskets that you will need to replace.
* You will need fresh 20W50 to fill the gear box (once installed!).
* You shouldn't need to realign the clutch plate as it's not coming out. But if you do, tighten the clutch sping plates very lightly so they just hold the plate. fit the g'box to align the plate, then remove the gearbox, torq up the spring plate hardware, and fit g'box back on with no alignement issues.

Regards James Eastwood
J E G Eastwood 1

James, Thats excellent. Ill print that off! Anyone else got any other info to have at hand?

Did you take the rad out? Im presuming it would make sense to remove it for a few mins extra work.

I'll stick another clutch plate and bearing in (rumbles when the clutch is up) as a matter of course.
D Tetley

A good days work if all goes well, Ive had mine out twice,no need to drain the oil on a 1500 as the drive flange remains with the gear box,also tie a thin rope to the tail of the gearbox and have an assistant guide the flange over the crossmember, also I left the manifolds attached to the engine and removed the exhaust, the manifold bolts are a pain to get at in situ.the engine and box come out at an angle of about 70 degrees the front pulley just clears the front panel,the 1500 is much larger than the a series making for a very tight fit, Good Luck
Andy
AS Douglas

If you DO drain / top up gearbox oil, it's NOT 20/50 on a 1500 - it's Hypoid EP80
20/50 is the 1275 and earlier 'box.
Steve Clark

Yes rad out. Mr Douglas is correct that the tail will need to be lifted to ease the rear mount back and up onto the rear x-member. I have in the past stuck my hand thru the g'lever apperture, to do the lift and to reconnect teh prop shaft, but be very careful not to get it pinched.

ASD also makes a good point that it may be easier to leave the manifolds attached, and dissconnect the choke, accelerator cable and the down pipe. (This wasn't an option for me as my long-LCB goes under the car, plus once my manifold studs are backed off they can be dissassembled with fingers).

JE
J E G Eastwood 1

Ah hah, Steve's point is right and it shows I haven't read the text very well, my info is for an A-Series g'box. Apologies. JE
J E G Eastwood 1

I've done in 8 hours, but that was my third time and not leisurely.

R
Richard 1979 1500

To answer the questions: the rad & surround comes out...

A
Anthony Cutler

***DISCONNECT BATTERY LEADS AND REMOVE BATTERY TO A SAFE PLACE*** Remove bonnet; drain coolant from radiator and engine block (by removing bottom hose)and remove rad (and both hoses)and cowl (fiddly/hidden and probably rusty four bolts); jam some rags in the water outlet pipes to prevent the rest of the coolant in the engine block from spilling out when the engine is eventually lifted; disconnect choke cable and accelerator cable at the carbs and tape the cables out of the way; disconnect fuel feed pipe at carbs and **SECURELY PLUG THE END OF THE FUEL PIPE** and tape out of the way; check that the fuel pipe is not attached to the top of the gearbox or bellhousing; remove small oil pipe next to oil filter (this pipe feeds oil gauge if the 1500 is pre '78) or oil pressure warning wire (post '78); disconnect end of starter motor cable and tape out of the way; remove engine mount nuts (two mounts, two nuts per mount); if oil cooler is fitted to car, remove oil filter and sandwich plate and tape all the pipework out of the way; disconnect coolant pipes that are connected to inlet manifold, prepare for coolant spillage.

Underneath car: release (one bolt) and tape out of the way the clutch slave cylinder, remove gearbox mounting bolts and propshaft bolts; disconnect speedometer drive cable from gearbox and tape out of the way; disconnect reverse light switch plug and tape out of the way; whilst underneath the car it's adviseable (but not essential) to drain the engine oil and gearbox oil; inside cockpit: remove gearleaver gaiter and actual gearlever.

The actual drivetrain removal is best done with engine/gearbox in one piece and, in all practicality, the removal process is a two man job.

Tie a rope around the tail of the gearbox and feed the rope through the gearlever access hole in the transmission tunnel. Man #1 standing in the car can then pull the rope upwards to prevent the gearbox flange jamming on the chssis crossmember when the drivetrain is being winched/hoisted from the car by man #2.

Use an engine hoist/winch that can lift to at least eight feet in height because you'll need to clear the bonnet slam panel (in front of/above where the rad was mounted).


You'll need to arrange the two lifting chains on the engine removal 'eyes' to be as short as possible AND in a way that the engine/gearbox is hauled out at quite a steep angle, I would say at least 45 or 50 degrees from the horizontal.

It's a shame that you don't live closer, I'd give you a hand!











A Hock

I've made a day of it usually. Of course the longest was when I upgraded to a 5-speed. that took a LOONG time because I had a case of the "while were at its" and ended up doing a minor engine rebuild.
S.A. Jones

Hey SA,

Thats always the case with me, while its out I might as well do this, and this, this to....Gee that was a fast $600

I got to tell ya, Im NOT looking forward to reinstalling the engine and datsun agian, was looking at that last night aand trying to figure an easy way of doing it. Just not possiable.

prop
Prop***The End in 2012

datsun 5 speed meant to say.

back to work, lunch is over...

prop
Prop***The End in 2012

Hi Also if your hiring in an engine crane check to see if it will fit between the front wheels the midget has a narrow track,you may also have to jack the front slightly to get the engine crane under the drop links to the anti roll bar,I have a clark one tonne crane and it does the job nicely,
Andy
AS Douglas

We did this a wee while ago but A Hock's description sounds spot on. We also replaced the clutch and release bearing while we were there. i got the alignment 'tool' from moss which made aligning the clutch a doddle. i replaced a fair number of bolts & nuts, just in case, especially the nylocs. replaced the propshaft bolts & nuts, the engine mounts, the mount bolts & nuts too. It took us a weekend but we'd only owned the car about a month and spent ages cleaning up the engine bay while we were there. We left the manifolds (and carbs) on and just split the downpipe from the exhaust manifold. Don't forget the engine earth strap - its amazingly strong! While the rad was off we flushed it out with a hose pipe - horrid brown yuk emerged for some time!
THe local MG garage reccommended just lifting it on the eye on the alternator bracket. i was sceptical of this but it worked a treat & tends to tip the engine to the correct angle to clear the heater shelf & the bonnet slam panel. a trolley jack under the gearbox tail was handy but I like the rope through the gear lever hole idea better.
Next time I reckon a day would do it easily but leave a weekend for your first time. don't rush it because its a fascinating insight into the innards of your toy!
Good luck,
-Craig
(Edinburgh, not Durham!)
C Robertson

Yeah, still not sure about the work I need to do on the datsun box someday. Clutches last only so long and the syncro in second gear is not so good these days. When it comes out the next time, chances are the block will go off to a machine shop to be rebored, a new head will go on, and i'll stick in a better cam.
S.A. Jones

Again thats for all the input guys. I've printed out a few bits off this topic to refer to. Now i know ill get the spares and then attempt to do it over a weekend, ideally im thinking over easter which then gives a monday "just in case"

Ive got a tubular manifold on the car, so Ill probably end up taking the carbs off, they shouldnt be too hard to get off as they have only been on a few months now.

I really have remove the cylinder head too, but I think ill get the gearbox in first!
D Tetley

Yeah, it will be easier to pull the engine with the head on. My dad used to attach one end of the chain for the engine hoist on a bolt that was plugging the air injection ports.
S.A. Jones

This thread was discussed between 16/03/2009 and 18/03/2009

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.