Hi guys

Just wondering, I've recently bought a mark 2 Cooper S gearbox. What should I do to the gearbox thats pretty cheap beside put a central oil pick up in it?. What mods would make the gearbox more reliable??

Cheers

Has it been reconditioned or is it used?

A new MiniSpares cross pin (4 pinion) diff. Failing that, I'd fit a competition diff pin and 2 new spider gears in the diff.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

At the moment it is used with fourth gear missing several teeth.

I was going to buy a kit from minispares to rebuild the gearbox which included berings etc, and gaskets.

I was also thinking about making up a oil feed layshaft

What do u reacon??

only things i have done to mine are bearings, oil pickup, Fred Sayers LSD conversion with new diff pin, spider thrust bearings with the tabs (needs slight mod to the hemisphere to fit), new layshaft (Heritage MG - proper hardness, the only one to get).

you may also need new synchros, but i hear that finding good second hand ones is a better option than new ones.

In all excluding the LSD conversion i would have spent about $400 on parts, but the price of Freds LSD is comparable to the cross pin diff that the good Dr mentioned.

cheers
michael

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

Hey again

So basically put the following in

Central oil pick up
Cross pin diff
New bearings and layshaft(as surgested by mickmini)
and new or close synchros

Its that all you would recommend??

Thanks guys for all your help!

Cheers

If you don't know its history, replace all 6 springs in both synchro hubs. They get weak with age, then the synchro baulk rings don't work properly even if new.
I'd inspect all the other bearings- replace ALL needle bearings, and the others if worn, noisy or damaged.
Diff bearings usually outlast all the others, as they are big and run slow.
Check the nose of the mainshaft for any damage where the needle bearing runs. if it's flaky or worn, get another mainshaft.
<edit> check the selector forks for wear or damage, if more than .035" side play on the synchro sleeves I'd get new or better forks.
Clearance new was .015" I believe.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

If you want a center oil pickup I have one for sale.
Brand new, never used.

My gearbox was rebuilt but the centre oil pickup didnt get used.

Peter.

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Click here for the Turbo Conversion Thread!

Thanks
but I made one up previously as i knew i was going to rebuild a gearbox within the next year or so.

Thanks anyway.

Which teeth are missing from "Fourth Gear". Are the teeth missing from the synchronizer hub, the first motion shaft or what? Fourth gear is direct and doesn't use any gear teeth. The only teeth for this gear are the teeth that lock the mainshaft 3/4 synchro hub and the first motion shaft together.
Whatever the teeth are missing from requires replacement.
Since its a 4 synchro box also check the 1/2 synchro hub assembly fit on the main shaft. Its a poor design in this area and results in excessive wear between the main shaft and the hub assembly. When wear occurs here the synchro hub assembly tilts when you engage 2nd gear and can cause broken synchro hub teeth on 2nd gear or if its really bad you may not be able to engage 2nd gear at all.
Its worth noting that the only difference between a MK2 S box and a non S box is the laygear and the first motion/input gear. All other gear parts are the same. (Except for the diff ratio and Hardy Spicer output shaft bits)
As the Doc says check the selector forks for wear, replace all needle rollers on the layshaft and the mainshaft spigot and fit a new layshaft even if it looks OK. This is not a part to gamble with.
The 1/2/3 gear mainshaft needle rollers dont seem to wear much as they effectively dont carry any load, they just allow the mainshaft gears to turn on the shaft when that gear is NOT engaged. When that gear is engaged there is no movement between the gear and the mainshaft so the bearing isn't doing anything. Some of these bearings have a plastic cage and the split one sometimes gives trouble. The rollers can fall out. If in doubt replace anything that looks even remotely worn. Pulling the power plant out and stripping down the gearbox because you used a doubtful part isn't worth the small amount of cash saved.
Definitely fit a centre oil pickup if you intend to do any sort of "Spirited Driving".

Hope this helps.
Regards
RonR

I dissagree about centre oil pickup.

On the dyno yesterday the oil pressure dropped up to 15psi when revving the engine as the minispares centre oil pickup can't "pickup" oil fast enough through the tiny strainer at the end of the pickup pipe. This is clearly evident and does not happen to cars fitted with a standard strainer and pipe.

If you fit a standard strainer and pipe, just fill the engine to full level and ensure that it is always full and you will never come across oil starvation problems. If you plan to race then fit a custom made racing centre oil pickup which has the pickup end cut at a large angle to increase the pickup area and mesh area.

If I rebuild this engine I will piss off the centre oil pickup for sure. 15PSI loss at full revs (6500rpm) is massive and can cause bearing/trust/cam/rod dammage if it starves of oil due to lack of volume of oil... This is especially when it starts to get clogged up with metal and gunk.

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Lillee - 1969 Morris Mini K

The current Minispares centre pipe is the one under discussion here, the previous design ones DO work well.
Current ones are a horizontal pipe sucking in the end, and gauze is small too.
The good old ones are blanked at the end, and cut away underneath.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

The 3rd and 4th synchro hub is destroyed, as with the laygear. The input gear was also destoyed, as with the input shaft drive gear. So basically everything past thrid gear it destroyed. The support bearing seemed to have dropped a few ball and chewed through most of the gears. I havent dismantled the box yet, but i know the 3rd and 4th synchro is gone. It is a Cooper S box, as I have check the teeth on the gears, the diff and the number on the from of the box. Hahah I i got the box for $50 from U PULL IT haha

cheers

The Mk2 S gearset is the same as a Mini K except for the 1st motion shaft and cluster gear.
Likewise most Oz rodchange boxes have same gears as a K, but reverse is different.
You can still buy S 1st motion shaft and 22G1040 cluster new.

If you find the S 1st motion shaft scarce, grab a DAM3167 1st motion shaft (used on 1275GT in UK) and use it with the 22G1040 cluster, and an A+ mainshaft.
Difference is only the mainshaft nose bearing is 18mm not 14mm. Stronger. I have run one in my car for 13 years now.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.