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5 speed gearbox ? help


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#1 scrapy

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Posted 07 September 2004 - 11:24 AM

Ok i know this subject has been touched every now and then but i really need someone to put this into English for me. Please. All the topics i have read have a lot of people just throwing in comments that don’t really help. so please someone help me.
I have a 1989 mini 998cc standard it’s just done 51,000 miles and the gear box is on it way out. i love driving the mini but the gearing is sooo wrong (for me) so i have decided i really want to put a 5 speed box on there. I haven’t a lot of money so i cant pay thousands. A few people have said to me to look into getting a gearbox of a metro?? Will this work?

So i need someone to advise me on what gearbox i can get the best place to get it and how much i am looking at. Depending on the cost i will probably get the clutch done to so some help on that would be appreciated.

Please someone help me

#2 minimadjonesy

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Posted 07 September 2004 - 11:38 AM

take a look at the VmaxScart website! His 5 speed boxes start at around £800 and if you give him a call he will also be happy to chat to you about the alternatives!

#3 Guess-Works.com

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Posted 07 September 2004 - 01:39 PM

Quite simply there are no "Standard" built 5 speed boxes which will fit an A series engined Mini.

Metro's with 5 speed boxes are attached to K series engines and will not fit. Other Austin cars with A series engines Maestro's, Montego's etc, had the gearbox on the side of the engine, the more familary fwd configuration ( and the engine turned round for thos who wish to know ), so are also not worthy of consideration

You will need an Aftermerket built box, of which there are many.

The other way of looking at this is, what's wrong with the gearing....? is the Final drive too long or too short, gears not close enough together.. ??

Maybe your answer is a different set of ratio's which will certainly workout cheaper than that extra gear !

:P

#4 scrapy

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Posted 10 September 2004 - 12:49 PM

Cheers for the advice spoke to a few people and decided i wont be able to get a 5 speed gear box. But i do like what guesswork said about the gear ratios. Im not very up on the gearbox side of things so ill try and explain this as best as i can. :grin: basically i think my gear box is knackered so im going to have to sort it. what’s the best thing to do?. get my current one reconditioned or buy one already done? :dontgetit:
The problem i was having with the gears is that there is just too big a gap between 3rd and 4th so how would i go about changing this? Im not trying to get it to go faster top end just improve on the smoothness of getting there

Cheers for your patients :grin:

#5 Guess-Works.com

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Posted 10 September 2004 - 01:25 PM

For gear ratios ( and probably a bit of an over the top explanation ) see topic explain about the gearbox on the "Mini Chat" forum, but in summary the only way to shorten the gap from 3rd to 4th, is a Close ratio box...

There are a few ways this can be done...

1. be a jammy git as I was the other week and get an engine with a cr box on the bottom ( sorry ! ), you'll find them on the bottom of 1275GT's and coopers ( that's pre 73 cooper's not the later models - not sure on this so please correct if wrong )

2. You can get a gearset which consists of a new laygear and 1st motion from such places as Minispares for less than 100 quid, (minisport have one for 95 )which basically turns your existing ratios into a CR set, but with this you'll still have to re-build the box, which again rebuild kits ( which include all required bearings etc ) are available. According to Minisport they're about 180 quid, which I personally cannot believe is right, I'm sure I got all the bearings etc for mine for about 70 ?

3. Buy a reconbox with a CR set in it.. ( 430 quid Minisport )

4. Go the whole hog and get a straight cut CR box.. (if you don't mind the whine - and the loss of money )

#6 Dan

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Posted 11 September 2004 - 09:04 AM

Also remember that using a CR box moves all of your ratios closer to fourth, making first gear longer and giving slighly less acceleration through first in the process. The genuine S (only Cooper S had the 4 synchro CR box, not regular Coopers) and GT set will have a first gear most similar to your current A-Plus gear set and is probably the set youe are looking for. These boxes are rare though now, and there are one or two problems. Firstly if you find the laygear and first motion shaft for this set as a kit they can't be used with your A-Plus gears because they have different tooth pitch and profile. So you'll have to buy the box complete, but since they are rather old I can't say whether they'll fit a 998. There did used to bo two different gearbox castings for large and small bore but I can't remember when they standardised the case.
So you may need to use one of the later CR gearkits available as tuning parts. These are nice close boxes but do tend to have a first gear closer to your current second (your current first gear is 3.6, and second is 2.2. The kits here are using a first gear of 2.5.). Try using second instead of first for a couple of days to see if you like it. But don't do it for very much longer than a few days, 'because second is fragile enough in a Mini.
One more thing, when buying a recon box remember that all the bearings and seals needed cost around £200. Even the big companies that do hundreds of gearboxes a year can't get them much cheaper. MED think that it is very amusing that some companies advertise recon boxes for about £150. And they laughed out loud (in front of me) when they took apart my box that was 'reconditioned' by Minispeed (Byfleet) for about that price. The box had lasted less than 10,000 miles. They showed me a bearing that they removed from it which Minispeed claimed had been replaced. The part had been out of production for about 8 years when they said they put it in new.
Alway pay properly for a gearbox, I learned the hard and expensive way.

#7 Guess-Works.com

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Posted 11 September 2004 - 11:29 AM

To rebuild a gearbox ( not differential ) you will....

Replace the following...

Layshaft Needle roller (small)
Layshaft Needle roller (large)
1st motion bearing
1st motion needle roller
Baulk rings
3rd & 2nd Gear bearing
1st Gear bearing
3rd Motion shaft bearing

You MAY need to replace....

Layshaft
3rd motion shaft
1st Gear journal
Thrust Washers

You should consider replacing..

Idler Bearings
1st Motion nose bearing ( you will probably break this removing it )

And you should also consider a Central Oil Pickup, while you pulling it apart.

You will also need a Gasket set...

The MUST replace list should be less than 100+vat ( Shop around ! )

The MAY NEED TO list will depend on fit and wear ( more than likely you'll have to replace the layshaft < 20 quid ), and you're unlucky if you have to replace the 3rd motion shaft and 1st gear journal.

As Dan has said, MED probably supply the best rebuild gearboxes, no doubt, and you pay for it, not only are you paying for the bits by the high cost of their skill and expertise. They did the machining on my engine, and the quality was superb, and that is only gained by years of experience.

I've also had an 'also rand' recon box which cost me 110 quid, in which they had not bothered to change the bualk rings, which is unforgivable.

I do my own now...

#8 Guess-Works.com

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Posted 13 September 2004 - 12:53 PM

Hoorah... Minispares is back online... links...

A+ rebuild without diff
A+ rebuild with Diff

Pre A+ (14mm) without Diff
Pre A+ (14mm) with Diff




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