gearbox removal?

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mark t4
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gearbox removal?

Postby mark t4 » Fri Aug 08, 2014 2:00 pm

Hi

i just wondered how long it would take someone who is ok with spanners etc to remove and re fit the gearbox? (948cc)

thanks

mark

philthehill
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Re: gearbox removal?

Postby philthehill » Fri Aug 08, 2014 2:14 pm

So long as you do not have any problems it should take no longer than 45min.


mark t4
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Re: gearbox removal?

Postby mark t4 » Fri Aug 08, 2014 2:17 pm

Thats great thanks for the quick reply

les
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Re: gearbox removal?

Postby les » Fri Aug 08, 2014 3:36 pm

Phil, you and Roy really should get a job as pit crew in F1. :o


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Re: gearbox removal?

Postby philthehill » Fri Aug 08, 2014 6:12 pm

Les
If I was in a formula 1 pit team it would be done in 10min. :D

The time is predicated on experiencing no problems and just for removing and replacing the gearbox.
Putting all of my old work study practitioner /production manager/job assessor/processer hats on and breaking the job down into the various elements I would not expect a qualified person with the right equipment to take any longer.
If when the gearbox is removed and extra work is found that will have a completely different bearing on the job and the time taken to complete.
Scrabbling around underneath a Minor without the tools/equipment and knowledge it will I agree take much longer.
Phil


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Re: gearbox removal?

Postby simmitc » Fri Aug 08, 2014 6:51 pm

I think that 45 minutes is optimistic for the average owner. Yes, in a workshop with all tools to hand, four post lift, and everything working, and an assistant to hand, it might be achievable. For the average owner working on the ground with minimal tools it's going to be a lot longer:
Disconnect battery.
Drain gearbox oil.
Jack up rear of car, place on stands, remove prop shaft - at least one bolt really tight.
Lower rear of car.
Remove gear stick gaiter and stick.
Depending on preferences, remove gearbox cover and therefore seats.
Raise front of car and place on stands (optionally, do this first and then also raise rear of car, but it depends on what stands one has available).
Disconnect engine steady bar to allow engine to tip downwards.
Remove starter motor.
Disconnect clutch linkage.
Support box and engine
Remove gearbox cross-member - at least one bolt probably seized, so definitely need to remove gearbox cover to get to cage nuts. worst case, remove master cylinder to gain access for repair.
Remove all bolts holding bell housing to engine back plate - top two may be difficult to reach. Fine if you have an open ended ratchet, otherwise may require many small movements of spanner.
Lower engine and box.
Slide box back, taking care to not break the top of the bell housing by catching it on the steering rack, and also to not hang the box on the input shaft/clutch. Great care needed, the box is heavy.
Fit new box - a reversal of the above.

OK, that's not precise, but gives an idea of what is needed, and what might happen. I suggest that for the average owner with DIY facilities, you should allow a day and be pleased when you manage 4 hours. I believe that it is important to set the correct expectations, and most owners won't have years of experience to know the short cuts and have the correct tools to hand.

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Re: gearbox removal?

Postby bmcecosse » Fri Aug 08, 2014 10:03 pm

Ahhh - no! The question was simply about removing/refitiing the gearbox.... That would imply everything else had been done beforehand - and all that was needed was to unbolt the gearbox -remove it - replace another and fit/tighten the bolts.. The gearbox change is a hateful /awkward job - especially refitting without damaging the clutch assembly. I would certainly allocate a full day if I had to change the gearbox on my Trav - that being the kerbside to kerbside time covering ALL the work required.
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Re: gearbox removal?

Postby kennatt » Sat Aug 09, 2014 7:48 am

I'm with roy here, unless the box and engine are out of the car then maybe 45mins,with the engine still in the car, well who knows,it can take 15 min to get the shaft to enter the clutch without causing damage.From start to running again,half a day at the min.

philthehill
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Re: gearbox removal?

Postby philthehill » Sat Aug 09, 2014 10:41 am

A couple of tips to make the job easier.

1. Use a old front portion of a Minor prop-shaft (Pt No: 17H3894) inserted into the end of the gearbox (after removing the prop-shaft) so you do not loose any oil. Cable tie it in place to keep it there.

2. Use an old first motion shaft (Pt No: 22A141 or 22G171) to ensure that the centre plate is accurately centred. This will eliminate any miss alignment and make mating the gearbox to the engine a once only job.


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Re: gearbox removal?

Postby bmcecosse » Sat Aug 09, 2014 12:29 pm

The problem is that you can't get a 'straight run' at the clutch with the gearbox - even when the engine is lowered to the max at the rear - the steering rack means the box has to go in twisted to the side and even then it's a struggle - supporting the weight on your arms and twisting etc - all while trying to be v careful to not damage the clutch springs and so on. It's definitely pretty much the 'worst' mechanical job on a Minor...
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mark t4
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Re: gearbox removal?

Postby mark t4 » Sat Aug 09, 2014 4:32 pm

I am starting to think this could be a load of hassle and not as straight forward as it first looked!

Thanks again guys for all the input :)

Mark

millerman
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Re: gearbox removal?

Postby millerman » Sat Aug 09, 2014 4:37 pm

IF you have a sensible engine crane is it not be easier to lift the engine and box as one unit?

mark t4
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Re: gearbox removal?

Postby mark t4 » Sat Aug 09, 2014 5:23 pm

Hi i have just been thinking that :)

bmcecosse
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Re: gearbox removal?

Postby bmcecosse » Sat Aug 09, 2014 7:54 pm

It may well be...although I have done the gearbox swap before - when I had no access to a hoist.
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kennatt
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Re: gearbox removal?

Postby kennatt » Sun Aug 10, 2014 8:19 pm

when I did my ser 11 last year I did it from inside the car,after removingv the trans mission tunnel covers.Still hassle,why are you doing it by the way,is it necessary for some problem :-?

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Re: gearbox removal?

Postby andypocock » Sun Aug 10, 2014 11:46 pm

I always pull the box out on it's own. I certainly wouldn't consider removing the engine to change a box or a clutch. Mind you I do have a 4 poster, I'm getting too old for all that laying under cars stuff.

One thing I didn't see mentioned was to remove the heater valve / tap. Without this in the way the engine will tip a lot more which helps greatly but do check your engine mounts afterwards if you have given them a good stretch.

I'd reckon to have a gearbox out and on the bench in under an hour but then I have the right tools and I've done it lots of times.

Andy

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Re: gearbox removal?

Postby bmcecosse » Mon Aug 11, 2014 9:09 am

And you have a 4 post lift....... It would take me an hour just to get the car securely held off the ground enough for me to get under to start undoing... And yes - heater valve removed helps.
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philthehill
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Re: gearbox removal?

Postby philthehill » Mon Aug 11, 2014 9:16 am

When you lower the back end of the engine put a piece of ply between the cylinder head and the bulkhead cross member. Saves the paint and alleviates the possibility of a dent.
Undo the top two bolts of the bell housing/rear engine plate before you lower the rear of the engine. In fact remove them as the first job after disconnecting the battery.


mark t4
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Re: gearbox removal?

Postby mark t4 » Mon Aug 11, 2014 9:13 pm

I am removing the gearbox to replace the clutch because it has run out of adjustment and the bite is quite low

also the gearbox was changed only a few years ago by the last owner (via a garage) as she had owned the car for 15 years
and killed the old one!! she told me that the replacement box had always crunched from 3rd to 4th and when she questioned the garage they said some moggies did :roll:

It has a release bearing noise too! ie rumbles when clutch pedal is released but quiet when pressed altho i didnt think
the carbon thrust bearing would do that?

les
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Re: gearbox removal?

Postby les » Mon Aug 11, 2014 9:20 pm

---so reckon on it taking you anything from 45 minutes to a full day Mark! :D -- allow even more if, like me, you care to clean all the bolts and stuff before assembly.



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