Page 1 of 6

Gearbox woes

Posted: Tue Feb 05, 2019 6:58 am
by ndevans
Well, a day of triumph and failure.

After a bit of faffing, I got the engine out. However, purely as a result of my own negligence in failing to support the gearbox, and in failing to check I'd removed ALL the bolts on the bellhousing, I've managed to break the top RH bolt hole off the bellhousing. I suspect it may have been flawed anyway if it broke that easily.

On the plus side, the new DIY hoist worked a treat. Bit fiddly with chains everywhere, but it did the job with ease.

So I'm on the hunt for a replacement 1098 bellhousing. Is it an easy job to get the innards out and put them in a new bellhousing? And while it's out of the car, and apart, is there anything worth replacing?

cheers N

Re: Gearbox woes

Posted: Tue Feb 05, 2019 9:29 am
by kennatt
you may find its still ok to fit as long as the rest of the bolt holes are sound,I ran an mg b with one bolt missing(Same as no bolt hole) for years,some cars have tight access to these bolts and many a diy er deliberately leaves it off,obviously not a good practice but need must sometimes. I would have no issues using it as it is.

Re: Gearbox woes

Posted: Tue Feb 05, 2019 9:53 am
by ndevans
I suppose I could try glueing the offending piece back in and then drilling and tapping a plate over it, before reattaching.

Re: Gearbox woes

Posted: Tue Feb 05, 2019 11:43 am
by jaekl
The upper bolts have no load since the top of the case is in compression and the rest of the upper case takes the load. The alignment hole is important. Epoxy will work if the upper piece fits back in well. Using a back plate to set everything should be used.

Re: Gearbox woes

Posted: Tue Feb 05, 2019 1:56 pm
by RobThomas
TIG weld it back on? I repair a few ali Austin Seven castings with my little home TIG kit. Probably cheaper than the cost of a set of gaskets. Failing that, I have a spare gearbox case here with the gears still in (although knackered first/reverse gear). 10 miles west of cardiff.

Re: Gearbox woes

Posted: Tue Feb 05, 2019 2:34 pm
by ndevans
I can't weld. Thanks for the offer, I can get a spare bellhousing locally, but I'll bear you in mind if it falls through.

Is it getting the innards out and swapping them into a new bellhousing difficult?

Cheers N

Re: Gearbox woes

Posted: Tue Feb 05, 2019 3:25 pm
by les
Not so much difficult as requiring patience, there are a number of areas where you need to check clearances, and indeed dismantle and assemble in a specific order. I think I’m right in saying someone on this forum posted a rebuild guide, which I saved on my homepage but in trying to access this for you, found it no longer opened. A workshop manual would give some guidance.

Re: Gearbox woes

Posted: Wed Feb 06, 2019 8:15 am
by kennatt
if you aren't prepared to just refit it,take it and the broken bit to any metal fabricator,gearbox specialist or engineering firm and get them to weld the bit back on,it will a lot cheaper and quicker than finding another gearbox,and if you have never been into the innards of a box ,be aware that they are not for the faint hearted,thats why gearbox specialist charge a small fortune for rebuilding them. If you stick it on with any bonding it will be as strong as just fitting it as it is.The only thing you will achieve is cosmetic. As previously posted I used and mgb for years with one bolt at the top missing,it stripped the threads on refitting so I left it off.It does of course depend on how much of the bell housing has broken off.

Re: Gearbox woes

Posted: Wed Feb 06, 2019 8:07 pm
by biomed32uk
The rebuild guide was mine, I can't remember where it linked to now, possibly my dropbox ??.

Do we have a files area on here where it could be loaded to.

I personally would whip the box out, find a local engineering shop or someone with a TIG set and get them to weld it back on. I have a mate in the village that can TIG, and he loves doing little jobs lilke that.

Re: Gearbox woes

Posted: Wed Feb 06, 2019 9:47 pm
by les
Yes dropbox

Re: Gearbox woes

Posted: Wed Feb 06, 2019 10:19 pm
by Mark Wilson
The dropbox link wasn't working when I tried it. However.....

www.dorsetmmoc.co.uk/wordpress/tech_art ... ebuild.pdf

Bloody good guide too!

Mark

Re: Gearbox woes

Posted: Thu Feb 07, 2019 12:11 am
by ndevans
Mark Wilson wrote:
Wed Feb 06, 2019 10:19 pm
The dropbox link wasn't working when I tried it. However.....

www.dorsetmmoc.co.uk/wordpress/tech_art ... ebuild.pdf

Bloody good guide too!

Mark
Thanks for that, most informative. I think I'll have a go at swapping the innards into a spare bellhousing, I think it's within my abilities. I may still get the broken bellhousing repaired and keep as a spare.

Cheers N

Re: Gearbox woes

Posted: Thu Feb 07, 2019 8:59 am
by kennatt
good luck with the rebuild :-?

Re: Gearbox woes

Posted: Sat Feb 09, 2019 12:20 am
by whyperion
Post Here, or a new thread ?
Anyway
948cc Smooth Case Gearbox. Model Year 1960
What has happend. Sent to my local garage to change the Clutch ( I Got a 948cc Plate from Moss). They did not use the plate as the entire release bearing / pressure plate and driven plate were knackered (I have the remants still overfilling my lock up garage to take to Fleetway as a possible spare rebuild). At the garage chap stated that the operating arm spring between the chassis pivot and clutch pedal offset (Charles Wares Part ref 26 was too tight (too strong - causing the pressure plate to float on the driven plate and wear the release bearing - the mileage the unit had covered since its previous build I am not certain as I cannot recall if it came with the replacement engine or was one I had fitted about 40,000 miles previous. I had recently replaced the clutch operating mechanicals with a new kit from Moss and looked dead the same as the one I had taken off before - in particular matching the manual the ends of the spring are hairpinned back to line up with each other (similar spring operates the throttle butterfly return to the exhaust clamp bracket but that is offset 180degrees so I dont think i muddled up and the return spring from the bellhousing hole and operating fork hole I dont think is over-critical for the set up.
Question is was the chap from the garage correct in his diagnosis ? As slipping clutches go , this was not too bad and I was replacing it faster than the previous time when I could not get up the multi-storey ramps without someone getting out and pushing , so I was surprised at the amount of dis-integreation of the pressure plate.
Anyway they sourced a new , matched to chassis number, QH branded 3 peice kit and fitted it. However since fitting I have extreme difficulty selecting gears and I think the amount of free play in the clutch pedal is too great - but If i depress the pedal the drive does seem to disengage, but the gears cannot be quietly selected (other than 4th if I change without operating the clutch - which is not easy in London traffic !). Additionally I think they, or a previious garage, has filled the gearbox with EP90 gear oil - assorted forums seem unclear as to if (modern) gear oil is detrimental to gearbox operation or has no significant effect either way compared to SAE30 or similar (would one use SAE5-50 in preference nowadays anyway ?).

Would adjusting the free play actually make a difference to the ability to select gears (as it appears to crunch for me even when engine turned off), or has the set-up of the presssure plate been done incorrectly - I note that there should be a slight final gap on between the trust bearing fact and the spring operating yoke ( pressure ring?) of the pressure plate ?

Finally the rubber spacer that (part 28 in Ware's Catelogue- which I have always seen as unobtainable) is missing from the clutch pedal - is this critical and if so , is there a particular dimension for it - I have an old truck mud flat of suitable rubber that I could cut to size, and what is a good glue to attach to the metal of the clutch pedal ?

Re: Gearbox woes

Posted: Sat Feb 09, 2019 8:17 am
by kennatt
absolute load of rubbish/ the only way the friction plate can float/?????or be released from the pressure plate and fly wheel is when the clutch pedal is pressed and pushes the release bearing onto the pressure plate to free up the plate.The stronger the pedal spring is the less chance there is of the bearing getting anywhere near to the pressure plate , So I don't know what this :mechanic.... is talking about.Adjust the clutch on the mechanism just alongside the engine so that there a small amount of free play on the pedal before you feel that you are now about to push the bearing onto the pressure plate basically you will feel the resistance on the pedal,I forget the free play gap but so long as there is some free play the clutch should be ok The only way the bearing could be against the pressure plate without pushing the clutch down is if a VERY strong spring was fitted to the linkages but put on to pull the linkage the wrong way ,can't see how that could be done because its obvious which way round the spring goes don't think it could be fitted the other way ,not long enough to reach an anchor point. Would have to be an extremely strong spring to free up the friction plate,but suppose it could keep bearing in contact with the pressure plate and cause rapid wear its called a bearing but has no moving parts its just a ring of carbon and would soon wear out like this. But who knows.

Re: Gearbox woes

Posted: Sat Feb 09, 2019 8:20 am
by philthehill
If the clutch linkage has not been adjusted correctly the thrust bearing can constantly press on the pressure plate and cause wear to both the release bearing and pressure plate.

The clutch pedal must be up against the underside of the floor before adjustment is undertaken.

If the clutch pedal/linkage is correctly adjusted the spring will work correctly - the spring is not too strong - that strength is required to pull the pedal back up against the underside of the floor.

The spring (Pt No: AAA1626 (MOSS)) is fitted between the engine back plate and the end of the release arm.

There is an additional spring (Pt No: 1G5999/803cc/948cc - AAA531/1098cc) which helps pull back the pedal see link for details.

https://www.moss-europe.co.uk/shop-by-m ... minor.html

The rubber gasket on the clutch pedal is a anti-draft/crud gasket and can be made out of any suitable rubber product.

You must be able to press the clutch pedal down 3/4" before you feel the release bearing engage with the pressure plate.

If you do not have the clutch correctly adjusted it can be difficult to engage gear.

The gearbox oil is a straight 30 or 20/50 engine oil. Not an EP oil otherwise it makes it hard for the synchro rings to clear of oil and some EP oils can eat the non steel gearbox internals.

Re: Gearbox woes

Posted: Sat Feb 09, 2019 8:24 am
by martin418
a definite no to ep90 gear oil it must have engine oil sae 30 or 20/50 , i find it hard to believe a garage should not be able to find out what oil it should have , this needs draining and flushing asap

Re: Gearbox woes

Posted: Sat Feb 09, 2019 8:54 am
by Nickol
Under the Basis that trust is good but control is better.

I am no expert on ...clutches or anything really but I have installed one. The operating mechanism on the MM is very mechanical, i.e. has quite a few moving parts and pieces that fit into Nylon or rubber bushes. Unless brand new, These tend to wear and can make the linkage mechanically sloppy such that even fully depressing the pedal does not operate the release arm enough to disengage, hence the crunching of gears. first gear is unsynchronised anyway.

The best way to btain the free Play if you are doing it on your own is to raise the car ( supported on a lift, Axel stands or ramps ) and from underneath pull the pedal down with your Hand as far as it will freely go. I am not strong enough to pull the pedal such that the clutch will disengage so the movement you get is the free Play. This can be easily measured for the required 20 mm and adjusted per the Manual. While you are there enjoying lying on your back on a cold floor, inspect the mechanisms for wear. To do this it is probably a good idea for someone to depress the clutch pedal from inside the car so you can inspect the workings. Look for immediate and uninterrupted movement of the release arm as soon as the pedal is pressed beyond the free movement. If not there is a mechanical fault somewhere.

Re: Gearbox woes

Posted: Sat Feb 09, 2019 11:20 am
by whyperion
The clutch pedal must be up against the underside of the floor before adjustment is undertaken.

As I am a wimp I tend not to work upside down and take out the cover plate floor anyway - but I can match it up with the brake pedal and rest of floor by eye.

Originally I fitted everything back with a new mechanism ( slop out of the bearings and the twin plate holes assembly) including a s/h clutch pedal as the shafts had totally welded themselves together , but made no adjustments to the position of the rod nut as I was not changing the clutch on the engine- that only got top end work. Given that I had adjusted the clutch rod nut in 1985 last and the vehcile had not done that much mileage since- and any wear would not cause excess thrust bearing and pressure plate addtional wear as I did not adjust it out - if anything the clutch would just slip - which it had started to do, but I was surprised by the disintegration amount which implied the rod mechanism was 'adjusted too much' if I read thinks correctly.

Phil gives overall the clearest explanation of proper set up. but I am still slightly worried what the reported 'defect' with some new BB/QH badged units actually is, hence I hoped to use Fleetway units having got the driven plate, but they moved to Guildford (Dunsfold) so I could not walk to them to pick the other bits off the shelf.

Nikol - just a note that the MM (series 1 effectively) has the Morris (8?) Set up of engine and gearbox and the set up of that slightly differs on the free play from the Austin Drivetrain that is common to the Minor (Series 2?) and definatley Minor 1000 and Austin A30 (Hmm I'm saying that - the A30 never had an Hydralic System did it ?) .

"I find it hard to believe a garage should not be able to find out what oil it should have". But most non-specialists dont bother - its only when they have been messing about after one has booked it in for a (Proper) Service that the bill comes in with EP whatever and one is made to feel like an idiot for telling them to take it out and put correct oil in it - I think most dont like doing things like read manuals - with the demise of Austin Rover my local Sri Lakan guys are actually the best - but they are incredibly booked up and the last older chaps locally have retired over the past three or four years - I will be teaching two chaps (young ones who like their cars , fast and new and old and interesting) when I actually get round to emptying the car out and getting time to drive it down to them , they are happy for this.

Re: Gearbox woes

Posted: Mon Feb 11, 2019 6:56 pm
by ndevans
Regarding garages not knowing simple things like what oil to use in the gearbox-the answer is to leave a manual on the passenger seat, and tell them to refer to it if in doubt.