Automatic to Manual conversion: Convert an Auto block for use as a manual (13 04 2003: Simon Dummett)

Basically, it is a case of getting the engine and subframe and swapping the
lot. It is possible to use the auto subframe if custom engine mounts are
used, but you'd also have to cut the wings as the auto subframe mounts the
engine further towards the front of the car.

You will also need: - a manual pedal box and clutch pedal - associated clutch workings ie clutch cylinder/pipes/arm - possibly a new speedo cable as the driver in the gearbox is different, IIRC

John Middleton who used to be on the minilist did this very engine swap.
Unfortunately his email address (horror_head<at>morka.freeserve.co.uk)/
website (www.morka.freeserve.co.uk) now appear defunct.

He did post a number of messages back in 99/00 regarding this swap; I'll
have a look tonite thru the yahoo/autox archives!!!

Yahoo! Minilist Archives: http://autos.groups.yahoo.com/group/minilist/messages but nothing found.

From autox... link.

Added 17 04 2003

To: "Mini-List"
Subject: Tech: Auto to Manual Conversion
From: "Shawn Sears"
Date: Mon, 15 Oct 2001 21:50:22 -0500

--------------------------------------------------------------------------------

Seems this question comes up quite often in the mags and I have had a couple
of people ask me if it could done. After calling around to a couple of
specialists who gave me enough vague info to almost do it I went ahead and
jumped in. Overall the actual conversion is quite simple. This particular
engine replacement was a total pratt though. Everything that could be a pain
was.

In addition to the normal engine replacement stuff the following is what I
did. Vehicle has test driven fine for 100 miles and is on it's way back to
the happy owner tomorrow.

After old engine is removed bolt engine mount up to the rear hole on the
passenger (radiator) side of sub frame and drill new front hole for mount.

Space between the new bolt hole and old bolt hole is quite small so I filled
the old one in with a welder and ground smooth.

Bolt new engine in place by securing mount on the drivers (clutch) side of
engine.

Use jack to keep engine in proper position and used punch to line up holes
for mount on passenger (radiator) side of sub frame and measure gap. It
should be approximately 1/2inch.

Fabricate spacer for mount. I used two pieces of flat steel 6 mils thick and
welded them together.

Install required pedals, gear change mechanisms and clutch cylinders.

Reverse lights/automatic safety switch if fitted. I relocated the reverse
light switch from inside the car onto the gear change mechanism under car
and bypassed the auto safety switch by splicing the two wires together.

I also had to convert the wring/solenoid from the prengaged to an inertia
starter so if anyone needs that let me know.

Bob in IDaho!!!...

I have 5, count them; 5 auto 1275 blocks and/or engines, 0, ( no need to count) manual blocks. In the US, Austin America auto engines greatly outnumbered the manual version.....Drilling and a small amount of lathe work on an adapter plat for the oil pump.

Gearbox, Linkage & Idler Gear Stuff

Overhaul, what to replace

You don't have to replace every shaft and bearing in the gearbox. That could get expensive. According to my engine rebuilder/parts supplier, A+ gearboxes don't wear anything like as much as the A boxes. Anyway, I would check carefully the big double row bearing in the center web, the cage falls out and the balls smack into each other.

The things that wear on the A box are the idler gear shafts and their bearings, the layshaft, laygear and their bearings, the double row bearing in the centre web, the first motion shaft and the mainshaft and the little bearing that goes between them. The gears themselves don't wear, except on the dogs where you engage, and likewise the things that do the engaging also wear. The thin needle roller bearings don't wear either, and you can reuse them so long as they aren't damaged (they don't have rollers missing or something). A bad A box could need replacement first motion shaft, mainshaft, layshaft and laygear...

The A+ box is supposed to be much better with most of the above problem areas are fixed (except notably the double row bearing).

Strip down

Stripping a box... (From memory, so correct me if i'm wrong)

• Remove the Diff

• Remove the speedo housing and drive gubbins

• Engage gearbox into two gears by fiddling with the selectors (disengage the selector shaft from the levers)

• Try and get that b*stard 3rd motion shaft nut off. Remove pinion gear

• Ideally remove the first motion shaft nut & gear, but not necessary if you are just changing baulk rings or something. If you want to change 1st motion shaft bearing, then you have to do remove this nut now while the gearbox is still in two gears

• Remove Laygear & Oil pickup pipe

• Gently, with a suitable drift (Soft ally) tap the 3rd motion shaft towards the 1st motion shaft.. Out pops the 1st motion shaft!! No need for a puller!!!

• The awkward bit.. Move the 3rd motion shaft as far as you can towards the flywheel end. Now try to get a small drift and drift the 3rd motion shaft bearing out, away from the flywheel end. Tricky

• When that is out, the 3rd motion shaft can be removed.

And as per Haynes... Reassembly is the reverse procedure to dismantling LOL!

Wear, differences between A and A+

"I'm told that the only parts to wear on the A+ are the baulk rings and the big double row bearing. What about A?"

A is a different story. These wear the layshaft and bearings and the gear where the bearings run on it. They wear the little bearing between the main shaft and the first motion shaft and the surfaces it runs on. It also wears the idler gear bearings and the first motion shaft nose bearing. Expect to replace all these bearings, and possibly the main shaft and first motion shaft if the wear on the little bearing is bad. You might be alright with the first motion shaft big bearing, there is supposed to be some play there.

Gear linkage, roll pin alternative

A 40mm M5 bolt and NYLOCK nut instead of the roll pin works just as well and is a hell of a lot easier to get in and out!

Gear ratios

MINIS FROM 1982-84 (all synchro)

ALL MINIS 1984 TO 1989 (12 inch wheels)

Gear ratios, 998cc gearboxes

I've been doing some research on 4 synchro gearboxes and maybe listers will find this useful as well as maybe offering any corrections.

Some applications identified but not all combinations were ever used, however chart allows you to pick the best combination for your needs and also to identify the different types.

Obviously then the old gearbox is the closest ratio so the one to use (with final drive to suit) if you can find a good one.

Starting at flywheel end gears go:
Lay transfer, Third, Second, First (straight cut)

A) Older type gearbox from 1970 to 1981 used on 998 850

B) Mid range 1981 to 1983

C) Later type 1984+

Idler Gear Thrust Washers Part Numbers and Sizes

Thank to Peter Kay for this!

The April edition of Mini Magazine has an article on measuring and
setting Idler gear endfloat. It also list the part numbers and sizes of
all available thrust washers for both original and 'A' plus boxes.
Since it may take quite a time before this mag is available in Aus. I
have copied the relevant details below:

Pre-A-plus, 0.750in. dia. pin, thrust washer 0.130 to 0.131in. - 22A 1545

Pre-A-plus, 0.750in. dia. pin, thrust washer 0.132 to 0.133in. - 22A 1546

Pre-A-plus, 0.750in. dia. pin, thrust washer 0.134 to 0.135in. - 22A 1547

Pre-A-plus, 0.750in. dia. pin, thrust washer 0.136 to 0.137in. - 22A 1548
Pre-A-plus, 0.750in. dia. pin, thrust washer 0.138 to 0.139in. - 22A 1549

A-plus, 0.875in. dia. pin, thrust washer 0.130 to 0.131in. - DAM5914

A-plus, 0.875in. dia. pin, thrust washer 0.132 to 0.133in. - DAM4822

A-plus, 0.875in. dia. pin, thrust washer 0.134 to 0.135in. - DAM4823

A-plus, 0.875in. dia. pin, thrust washer 0.136 to 0.137in. - DAM4824

A-plus, 0.875in. dia. pin, thrust washer 0.138 to 0.139in. - DAM4825

Added 21 Dec 2002

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