32 replies to this topic

[GraemeC]

Yes - he has the Metro double groove gearset and the primary variations in the drop downs

[JonnyAlpha]

 

@GraemeC ah didn’t know that, I have changed the Diff though from the stock 2.95 to a 3.44.
3.44 was the preferred ratio for intended driving but how will that be affected with one less tooth on the input gear?

Put the info into the guessworks calculator and see

 

http://www.guess-wor.../Tech/ratio.htm

 

 

I have, but I am never sure of the correct settings e.g. what Drop Gear ratio do I have 

I am running 10 Inch 165/70 Tyres.

 

So:

Tyre Size: 165/70 x 10

Drop Gear Ratio: 1:1 (Standard)?

Gearbox Type: Metro 1.3 HLE (Double groove A+)

3.444:1 18/62 (Most Mini's & post '84 Metro's)

 

Changing between Metro 1.3 HLE and MkIV Mini and Metro makes no big differences, however the Diff Ratio does:

Selecting a 3.44 which I now have gives this:

 

 

And going back to the 2.95 Diff gives this:

 

 

I am no expert, but it would seem (if I have the figure correct) that I should have stuck with the 2.95 Diff? The 2.95 appears to offer greater speed at lower revs?

Please tell me I am wrong!!!

[imack]

2.95:1 final drive will give you lower engine rpm for a given road speed compared with a 3.44 final drive, but the 3.44 will give better acceleration and in gear performance.
With only 4 gears you're always trying to to strike the best compromise for your needs.

[GraemeC]

Count the teeth on the primary gear and the input gear.  1:1 they will be the same (29 teeth each), other ratios will be as per the drop down on the Guessworks site - either an economy primary (30 teeth), an economy input (28 teeth) or both economy gears.

[JonnyAlpha]

Count the teeth on the primary gear and the input gear.  1:1 they will be the same (29 teeth each), other ratios will be as per the drop down on the Guessworks site - either an economy primary (30 teeth), an economy input (28 teeth) or both economy gears.

 

OK so looks like an Eco Primary (30 Teeth) and Eco Input (28 Teeth), and inserting this adjust the speed / rpm back up a bit e.g. a reduction in RPM per Speed 106 at 6000RPM:

 

 

So I should end up with a revvy / torquey / nippy Engine

[JonnyAlpha]

Quick question - the Diff cover on this Gearbox had these and these Locktabs.

It says in the MiniSpares page that they are listed on that they were only used up until 1982, so I take it that means I don't need to fit them?

 

This is a Gearbox from a 1989 Metro:

 

[nicklouse]

They were used when the studs and nuts were used. Dropped when bolts were used. Add thread lock to the fasteners.

[JonnyAlpha]

They were used when the studs and nuts were used. Dropped when bolts were used. Add thread lock to the fasteners.

 

Well that will save some money (if I have the bolts, as opposed to studs that is, I'm sure I do), although I may by new bolts anyway.

What type of ThreadLock? I have some Loctite 243 which I ordered for the threaded Oil Gallery Grub Screws. 

[NDT]

I have a rebuild kit so all of the bearings will get swapped out.

Where did you get your rebuild kit?

Minispares ones all claim to be out of stock.

[JonnyAlpha]

I have a rebuild kit so all of the bearings will get swapped out.

Where did you get your rebuild kit?
Minispares ones all claim to be out of stock.

Got mine from Guessworks, but more pricey but promptly answered questions and was really helpful.

http://www.guess-wor...argument=GW_Kit

[NDT]

Thanks - I’ll give him a shout in the morning.
I had hoped to get the box rebuilt over the long weekend.
Seems to be in good condition so I’m not sure about whether to go for the full rebuild kit. Bearings look unmarked for example.

[JonnyAlpha]

Thanks - I’ll give him a shout in the morning.
I had hoped to get the box rebuilt over the long weekend.
Seems to be in good condition so I’m not sure about whether to go for the full rebuild kit. Bearings look unmarked for example.

 

Have you stripped it already? I guess you could build it over a long weekend if you have everything ready? 

 

Check what you get in the rebuild kit as there are a few additional things I am going to have to buy such as:

 

DAM2377 Locktabs For Double Row Bearing Housing 

 

DAM4000 1st Motion Shaft Nut Locktab

 

DAM6140 Differential Pinion Locktab

 

You do get a new nut for the BellCrank (Gear Selector Lever Shaft) but you'll have to reuse the washer or buy one as it is not supplied.

In Johns kit he also supplies a Central Oil Pickup pipe.

 

There are plenty of rebuild videos on YouTube by Classic Mini DIY, MED Engineering and MiniMania, the MiniMania guy is a little brutal IMHO. You could also watch my ones  although though don't give you a detailed account, more of a 'this is what I did' diary.

 

You also need a Torque Wrench suitable for doing up the Pinion Nut on the Main Shaft - this is 150lb/ft so a large one is needed.

 

I have already had my DIff rebuilt, I got John Guess to do it as he was exchanging mine for a different ratio.  

 

Just waiting for a replacement MCB for my garage so I can get the Compressor running and clean up the casing before I can start the rebuild.

Edited by JonnyAlpha, 20 May 2020 - 12:38 PM.

[JonnyAlpha]

Iv'e done a first clean up of the gear box parts, I am using White Spirit. 

What do you guys recommend for cleaning everything up before the rebuild? Like I said I have done the initial clean with White Spirit and then Brake Cleaner or Thinners?

 

I don't have an Ultrasonic Cleaner or Dishwasher :-(

 

Also, I guess I can't order Layshaft Thrust Washer or Diff Shims) until I start the re-assembly and identify if I need any?

Edited by JonnyAlpha, 20 May 2020 - 06:29 PM.

[JonnyAlpha]

Resurrecting this thread to add some questions if I may.

 

So 2 years down the line and I am still building this engine / gearbox

The engine is now going to be Superchared, CR 8.5 @10 PSI, which according to Stuart Gurr should push out around 13ft/lb torque.

 

As a result of this change in direction and to account for the extra torque, I have now changed the Diff to a 3.1 and fitting a cross pin (currently being done by John Guess).

 

To achieve the correct acceleration v cruising speed with the 3.1 Diff, I needed to swap out the Eco Primary and Input Gears. I have sourced a 1:1 Helical Primary and Input Gear, but these are not double grooved and I was wondering if it is ok to use them with a double grooved Idler Gear? If not should I source an A+ Idler Gear (non double grooved)?

 

P.S. I have contacted Ac Dodd ref re-busing the Primary Gear.

 

 

[JonnyAlpha]

Here's the original Primary Gear: