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MG MGA - gear box

My '57 A g/box will be the death of me. Its' always been nochy to 2nd and was stiff in all gears after an o/h last year. It settled after a while and was liveable. Now after sitting for two months it is vertually un drivable. Nearly impossible to get into second and hard to shift to 3rd and 4th. I bleed the clutch again and can select 1st and reverse cleanly. But I can change gears ok if I don't use the clutch ? ? ?. The clutch was replaced at G/B O/H. The G/B is quiet in all gears and needed only a 2nd syncro and a lay shaft. I never ever want to remove the engine and box again. To old and stiff, me that is ! If necessary, can the G/Box be removed from the rear by cutting a cross member and welding it up again ??. I used to do that on V 12 Jaguars to get the Auto box out without pulling the massive engine. Six hours instead of two days. Thanks Sean
P S will the origonal G/Box ever be any good or am I flogging a dead horse ?
S Sherry

Sean,

The gearbox can be removed backwards but it is quite a procedure which is presumably why the manual says it can't be done. (The manual is telling lies).

You have to remove the gearbox cover and this is sandwiched between the chassis and floorboards and is the longest job. A lot will depend on the state of your floorboard fixing bolts. So, out must come the seats, carpets and all the front floorboards. Then the gearbox cover. From the engine bay the toe board support plate has to be undone and swung out of the way. It is hard to remove as there is wiring through it.

Undo the rear gearbox mount and with a jack under the back of the engine lower the back of the engine/transmission as far as possible. Watch out for the fan hitting the radiator. You might need to remove the fan.

At least now the engine/gearbox fasteners are easy to get at. You just have enough room to pull the 'box out backwards under the tubular cross member.

It is several years since I did this and didn't take notes so I have probably forgotten something but it is definitely possible without cutting and welding.

Malcolm
Malcolm Asquith

Sean, pull the engine out first, it's not that difficult, and with the engine out of the way the gearbox will come out dead easy. Only the mounting bolt and the cluth slave cylinder have to be removed. You can then lift the box out yourself (unless you are a back sufferer like me). Oh don't forget to undo the speedo cable as well.

Frank
F Camilleri

Sean,

I wonder if your clutch is overthrowing' i.e. going beyond the point of maximum release. This can happen if the relationship between the clutch cover and the release bearing is wrong. Has the G/B been modified with a wrong front cover that has a different pivot for the release fork?

Second gear is known to be notchy because the syncromesh wears out. But if it's a problem on all the gears now, maybe the selector rods are at fault.

If the clutch is defective, you'd be getting graunching noises rather than stiffness. Stiffness is more about components not lining up properly or not engaging as smoothly as they were designed to.

What really baffles me is your comment about changing gear without the clutch. How can using the clutch be worse than using no clutch? I suspect something was assembled wrong in the overhaul.

Regards

Malcolm
Malcolm Eades

Out of interest what oil are you using?

CP
Colin Parkinson

I was wondering that Collin. When I got my car, some clown had put hypoid oil in the gearbox. It was stiff as hell, stank when it got hot and synchro didn't work third to second. I changed the oil to 10/40 and gradually it freed off and the synchro started to improve. After about 500 miles I changed the oil again to get out the last traces of hypoid oil and now, 6,000 miles later, the gearbox is fine!
Lindsay Sampford

Sean,
I don't think the clutch is the problem. Your sliding hubs are not sliding on the main shaft. A clutchless shift will reverse the torque load on the hubs and sometimes eliminates the binding. It probably isn't a shift rail or fork issue because it involved both the 1-2 and 3-4 fork.

Most common cause is lack of oil. oil contamination, or an incompatible oil/oil additive pitting/galling the surface. Try overfilling your tranny with the slickest oil you can find. If this helps drain back to standard levels.

Unfortunately, there is no cure without pulling the transmission.

Hope this makes sense,
Bill
Bill Eastman

Thanks to all. Oil is 20/50 mineral.I agree that the problem is most lightly to be a miss assembly some where when I replaced the syncro ring. And I also don't understand how the box shifted quite well without the clutch. With the clutch 2nd gear will not engage , it is like pushing against a brick wall. Plus I don't understand how it was quite reasonable and after standing two months and this problem surfaces.I'm going to bite the bullet and pull the gear box out the back,
as on reflection it has never been right after O/H.
Finally please comment on the 1-2 shift , can I expect it to be reasonable ?? I don't recall the old Morris
( Mogwog ) boxes, both pre war and post war,not being ok. Thanks Sean
S Sherry

Thanks to all. Oil is 20/50 mineral.I agree that the problem is most lightly to be a miss assembly some where when I replaced the syncro ring. And I don't understand how the box shifted quite well without the clutch. With the clutch 2nd gear will not engage , it is like pushing against a brick wall. Plus I don't understand how it was quite reasonable and after standing two months and this problem surfaces.I'm going to bite the bullet and pull the gear box out the back,
as on reflection it has never been right after O/H.
Finally please comment on the 1-2 shift , can I expect it to be reasonable ?? I don't recall the old Morris
( Mogwog ) boxes, both pre war and post war,not being ok. Thanks Sean
S Sherry

Sean,
I had my g'box overhauled by a local expert last year and I replaced all the bushes and pins on the clutch arm plus new clutch plate and overhauled pressure plate. It is now great to use (engine and g'boxed removed) so it is possible (1600 MGA but with early model 1500 G'box) - hope this gives you some encouragement!
Mike
Mike Ellsmore

I did the cockpit strip-out about 5 years ago to access the gearbox (type 9 in my case). Never again. Taking the engine out is by far the easiest option in my opinion.

In his description above, Malcolm did not mention that the handbrake and tunnel bulkhead frames also have to be removed. In all, a total nightmare. Took me all day to strip it all out, whereas I can get the engine out in less than 2 hours without hurrying.

Steve
Steve Gyles

Before you do something you might regret I would just like to add the following.

My Gearbox is a bit stiff when changing gear, especially second to third where it needs a "little" nudge to get it out of second. :)

This is caused by the gear lever and extension being very tight. When I did the gear lever and extension about 7 years ago and then made everything tight I though it would work free. Maybe it has a little but not as much as I expected, maybe one day I will try and free it up.
Bob Turbo Midget England

Has anyone used the factory competition method of altering the gearbox tunnel so that it mounts on top of the floorboards?
Metal has to be trimmed from around the bottom edge of the tunnel and the flange restored. The handbrake mounting also requires considerable modification.



Mick
M F Anderson

Thanks for your advice Steve, sometimes the cure is worse than the decease. Does anyone know of a mechanic who works week ends in Sydney ( Paid ) to pull the engine ? Me as the Go For ? Not necessary to know the car, I've done the job before.
Another thought do I dump the box and fit a five speed, Is it a lost cause . Thanks Sean
S Sherry

Sean, I loved your "cure is worse than the decease"
Sounds as if your gearbox is dead and way beyond any cure!
But if you really meant to say "cure is worse than the disease" then there is hope for it after all!!

Im sure you can get the box fixed somewhere in NSW for far less than a 5 speed conversion.
Colyn
Colyn Firth

Sean..I would say dump it for a 5 speed ...but for good positive reasons ( ie 5 speed is a delight to drive with ). I did the conversion a few months ago and it is lovely and precise and improved the engine speed v road speed vfuel consumption v hills v everything performance for the car ..even with the standard engine. I always found the original MGA box to be by far the worst aspect of this beautiful car with such good handling characteristics. It felt like I was stirring a bowl of one week old cold porridge ( my Scottish Grandma used to make that goo so I know what that feels like )and the looseness of the stick with its ball engagement tip meant you often have to feel around to find the gear location.. ( the 5 speed has a fork end for driving the gears ).
Neil Ferguson

Sean,
just to show that I can sometimes offer practical advice I thought I would share with you my experience on this subject.

I have removed an engine/gearbox on my drive as one unit using just a tripod bought from a motorist discount shop and a chain lift. I have also removed the engine on its own which was easier to lift once I got the gearbox fixing bolts out. I managed both without any help so dont be worried about attempting it.
Im sure someone in one of the MG clubs will let you know where to get the box fixed once you get it out.

My car has a 5 speed ford sierra gearbox fitted and it definitely makes the engine less fussy at motorway speeds but then again, so would fitting a higher ratio diff. Also it does have synchromesh on 1st gear but once on the move I never use 1st gear again so it is not so much an advantage.

The best thing about the 5 speed is that I can use all the performance of the engine through the gears as MG intended but the still have an overdriven 5th gear for quieter motorway driving.

So, if you need a new gearbox then consider the 5 speed conversion, but repairing your own box is likely to be less expensive.

It kind of depends what you want from your car when you drive it.

Best of luck with the gearbox

Colyn
Colyn Firth

I would agree with Neil that the gearchange is superb with the sierra 5 speed, more like operating a switch than a gearbox, even on 1st gear.
It also will probably last the life of the car.

My car was already fitted with the 5 speed and a 4.3 diff gearbox when I got it and I would definitely recommend it. But if I was fitting it new myself I would have specified slightly higher ratio 1st, 2nd and maybe 3rd gear also.

I find that with my tuned 1800 engine I tend to only use 3rd 4th and 5th gears once I am on the move. I think that fitting higher ratio 1st, 2nd and 3rd would make them more usable when on the move. Maybe fitting a slightly higher diff would improve this for me.

Colyn
Colyn Firth

Neil, did you use the local kit and a Japanese box. If so were there any hassles ? thanks Sean
S Sherry

Sean..got the total kit ( recon. standard ratio gearbox, new supprt for box,new shift, clutch housing etc etc ) from Hi-Gear in Uk and given the good exchange rate it was great value...and all well made. I did have some peripheral hassles..all the big tasks like lift out and in ,alignent etc went well using cheap lifting frame ex Supercheap and a leveller( total about A$250 for both ). Dont have my files with me and only have 500mb brain memory but recollect about A$2600 all up and excellent service from Hi-Gear. I did keep some notes about the hassles during the job and wrote a thread many moons ago ...repeat below...in summary the best investment I have made in my MGA since buying it 21 years ago...transformational and a very logical change...

"For those of you who do a job like this once per lifetime and also dont have friends who share their love of oil and grease I have made a few notes below on some of the areas that gave me problems/delays/frustration and sometimes bloodloss.
The whole job stretched over 10 days and I averaged about 3hrs a day but included other car jobs whilst I had access..so about 24 to 26 hrs on the kit incl reverse light etc.
Lessons..
1) Get good quality and high stands..I went cheapo and got a clearance of 35cm and struggled like I was in a straightjacket. Your life for a long time is downunder...You need another 5 to 10cm.
2) The exhaust to manifold connection is held by three short pathetic brass nuts that go round if they are coughed on. It took me three days to get one of them off. I wanted to replace with Barneys idea of two ss nuts but could not get in time ( I live in a metric world ) but managed to get long brass ones.
3) Get a special sleeve removal tool for getting the existing spigot ( brass sleeve ) out of the rear of the engine .
4)The speedo angle drive was a nightmare.. it had to go on with the gearbox in near final position as it is vulnerable and flimsy. I spent 2 hrs using needle pliers tryng to get the spring washer in place before going and buying spring loaded special pliers..even then it was a struggle and I hacksawed grooves in the plier pins to get them to hold the eyes of the washer.
I also followed recent advice on the BBS and filed off a lot of material off the corner of the drive to increase the clearance inside the tunnel.
5) I prewired the reverse switch ( see pic on recent thread ) and it ended up with about 5 mm of clearance inside the tunnel and was easy to install and connect ..I fitted a Moss unit under the rear bumper and wired it up and works well and looks natural.
6)The lower of the two starter bolts bottomed out on the new bell housing and needed 2 thick washers..I had not trial fitted this bolt outside car during trial mating of the engine and box.
7)Hi-gear recommend removing and 'locktiting' two bottom bolts (on the bell to box flange ) and part of the new support assembley after installation of the latter..but they could not be withdrawn as a transverse section of the car is in the way...so I just made sure they were truly tight and will check after a few weeks ...
8)Avoid a backstep...I had removed the distributor cover during engine removal and during re-installation I bolted up the starter to find the rear metal clip of cover had been trapped behind the starter so ..
9) The gear lever did not interfere with the existing cover cutout but the offset bar underneath is too close to the underside of the cover and hits the cover whilst it tilts... I had bought an MGB boot as per HiGear recommendation and so I cut out the hole to an oval as per the bottom profile of the MGB boot and also raised the whole cover about 2mm by inserting a hard rubber seal strip between it and the tunnel.
The end effect..once carpeted.. is very like the original.
10) I read all about the horrors of oil filling the gearbox so I dug amongst my old boat gear and came across the 500cc syringe ( see pic) . With the wheel off you can get this in horinzontal and the plastic pipe into the box and fill without a mess. The box took about 1.3 litres. So with this method there is no need for more tunnel holes. I also find it relatively easy to screw in the plug using an allen key from underneath.

The big jobs ( engine removal etc etc ) all went well and this site and the Hi-Gear instructions were great.
...and the car is transformed..precise, positive gear changing and no crashing into 1st. Recommend the conversion to everyone !! "






Neil Ferguson

Neil you are worth more money ! One last question.
Did you have the kit and G/Box sent out ? ?
If so did you use Air or Sea freight
Thanks again Sean
S Sherry

Sean..
airfreighted it out and it was quick and very very cheap and units came well packaged ( always want something NOW once I've decided). There have been some good comments by other guys recently on various threads about how to avaid the 10% GST on import( VAT.. Oz equiv.) . I attach another old thread on the costs of the unit and transport etc.

" Bruce...A painful comparison...
...Peter Gamble packaged the kit in uk ,sent to airport using airport transfers tunbridge wells,exported and had the whole thing transported to Melbourne..a distance of 14000km ..for 188 UK pounds( equiv to A$360 approx).
...The monopoly airport parasites then took over and got it the last 400m for me to pick up for A$585 ( incl A$266 tax..the rest FEES )...I even had to load it myself in to my car ..
Luckily the Oz dollar exchange rate still worked for me and the total cost of about A$3100 was still well below a Moss Uk or US purchase of the same kit for about A$3500 plus transport and tax and and.....prob A$4500 all up.
Too many middle men adding zilch but getting a cut!!
Good luck...."
Neil Ferguson

An MGA gearbox in good condition is nicer than the later MGN all synch box. It should shift easily. There is certainly something up with yours, though I wouldn't venture what it might be.

I second the 'pull the engine and gearbox together' group.
Bill Spohn

A heaty thanks to all for detaied advice. Now that I understand all the facts , decision time The last comment by Bill pushed me to sort the origonal box. The problem was self inflicted wounds ! Ouch ! Sean
S Sherry

Sean, I live in western Sydney and have an engine crane that could be lent for a day or a weekend if you are interested. I may even be available to give a hand if need be, though no guarantees as work is busy and I have a midget with the engine and gearbox on the floor in the garage at the moment. Send me an email if you like at andrewdotfraserattransgriddotcomdotau.

Cheers,

Andrew.
AndrewF

Thanks for your offer Andrew. I have access to an engine crane and a friend and I have done a deal , he will help, Today, to pull the engine and g/box and I will rebuild his T. F. diff. Let me have your email and we can keep in touch Thanks Sean. P.S. I'm in Hunters Hill
S Sherry

This thread was discussed between 02/07/2010 and 21/07/2010

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