Manual Gearbox with O/D

[Branyster]

Hi SOC members,

When I re-fitted the Stag manual gearbox and reconnected the O/D wires I expected to hear a Click when engaging the O/D.

How do I know if the O/D is working ?

Finding Gears in the Stag (especially 3rd) can be a pain. It's Like Stirring Porridge !

What would it Cost me for a Reconditioned Manual Gearbox & O/D ?


Regards, Nick Branson

[malc4d]

I believe the od only works when driving.

[Alanmax]

If you turn on the ignition (do not start engine) and select 3rd or 4th, you should hear a clunk as the od is switched on.

[Mike Stevens]

And when the gearbox is in 3rd or 4th. With the ignition on and in one of those gears, you should be able to hear the solenoid click.

Cheers,
Mike.

[Branyster]

YES - That is what I thought too. But I heard Nothing...

And when the gearbox is in 3rd or 4th. With the ignition on and in one of those gears, you should be able to hear the solenoid click.

Cheers,
Mike.

[Stagdad]

Take a direct live to the solenoid if it clicks there must be something wrong with the loom/inhibitor switch/gear knob switch/fuse. Just trace it back with a bulb starting with the fuse then I think it goes to the gear knob so see if there is juice getting to that then on to the inhibitor switch etc until you find the break. If it doesn't click with a direct live supply it's the solenoid that needs looking into.

[Lingen]

Nick. Like stirring porridge! You obviously like your porridge thicker than I do. If you can find the gears easily when the engine is not running, then I would suspect that the clutch is not releasing properly, which could be for all sorts of reasons. However, if it is always heavy, then probably the gear lever mechanism needs lubricating / checking, which is a pretty easy job that can be done by simply removing the centre console wood trim to get at it.
Although by modern standards the stag box is a bit agricultural, it is not all that bad. The biggest improvement I made to mine some years ago was to use engine oil in it in stead of EP90. And yes, I did check first with Miller's Oils, who recommended the change.
Mike.

[Branyster]

Hi Mike, That is Interesting about the Oil as I bought special synthetic or semi synthetic oil from Wards and put this in the Gearbox under Paul Smarts tuition. Paul commented on it as he uses Mineral Oil. I will look at the Bottle tonight and see what is called. Please can you tell me which Engine Oil and Grade you use in your Stag Gearbox which has Improved it's Use. Many Thanks Nick Branson

[V Mad]

Although by modern standards the stag box is a bit agricultural, it is not all that bad. The biggest improvement I made to mine some years ago was to use engine oil in it in stead of EP90. And yes, I did check first with Miller's Oils, who recommended the change.
Mike.

The use of non EP oil for gearboxes always concerns me a little. I also find the stag box is little baulky, but I think on balance I would rather play safe and keep to a gear oil. Here is some useful info on gear oils:

Gear oils are classified by the American Petroleum Institute using GL ratings. For example, most modern gearboxes require a GL-4 oil, and separate differentials (where fitted) require a GL-5 oil. It is important that purchasers check the oil against the vehicle manufacturer's specification to ensure it does not contain any aggressive chemicals that may attack yellow metal gear components, such as phosphor bronze.
API viscosity ratings for gear oils are not directly comparable with those for motor oil, and they are thinner than the figures suggest. For example, many modern gearboxes use a 75W90 gear oil, which is actually of equivalent viscosity to a 10W40 motor oil

[marshman]

The use of non EP oil for gearboxes always concerns me a little. I also find the stag box is little baulky, but I think on balance I would rather play safe and keep to a gear oil. Here is some useful info on gear oils:

I used to think the same way Chris but age and experience of many different "classics" have led me to the conclusion that you can put virtually anything in a gearbox ! The original Mini uses normal 20W50 engine oil for the gearbox and final drive (diff), My 1950's vanguard and my dads Peerless (same mechanics as a TR2/3) both have straight SAE30 oil - recommended because they are fitted with an overdrive. My Landrover with it's 5 speed LT77 gearbox has ATF - according to Russ BL had trouble with bits breaking due to the high viscosity of other oils in cold weather so recommended ATF. That box has now done over 100,000 miles and is still OK. many agricultural tractors use "universal tractor oil" for virtually everything - engine, gearbox and hydraulics - this is I think equivalent to a 10W40 engine oil. Most other boxes I tend to fill with an 80W90 Gear Oil

Roger

[V Mad]

I suppose I never had a real need to change from the original oil, so no need to try as such. But engine oil has such a different job to do, with all the additives like detergents etc. so I would tend to avoid it. The mini was designed to use engine oil, so they should have made sure it was compatible and suitable.

I wonder, did Triumph agents ever recommend a different oil for the stag or similar gearbox, and what do the current stag specialists like Wards, Robsport etc recommend?

[KOY 23]

I suppose I never had a real need to change from the original oil, so no need to try as such. But engine oil has such a different job to do, with all the additives like detergents etc. so I would tend to avoid it. The mini was designed to use engine oil, so they should have made sure it was compatible and suitable.

I wonder, did Triumph agents ever recommend a different oil for the stag or similar gearbox, and what do the current stag specialists like Wards, Robsport etc recommend?

Maybe they heed the advice of the Club Technical Advice Co-ordinator in post #7?

[Branyster]

This is the Gear Oil I was Sold. Millers TRX Synth 75w90 Full Synthetic - Is This OK ?Miller.jpg

[Lingen]

Nick. Back in 2005, at which time I had no workshop available, I had my gearbox overhauled and refitted by a local specialist, and was amazed at how light it was to use afterwards compared with any other Stag I had previously owned. The fitter mentioned that he had filled it with a good quality 20/50 oil which he assured me would be ok in the Stag, to improve gear selection, particularly in cold weather. I was not entirely convinced, so I phoned the advice office at Millers oils. They informed me that all good makes of 20/50 would now contain the necessary "EP" additives that at the time the Stag was being made, were only present in the heavier grades. They recommended using the lighter oil to achieve the result I was benefitting from. After 40k miles, my box, and overdrive, are still performing really well, and clearly no damage is being done by using the lighter grade of oil. The only downside has been having to wait a bit longer before engaging reverse, as there is less oil-drag to slow them down.
Mike.

[73stagman]

The different gearboxes mentioned all require different things from the oil.
There is no point in comparing the oil used in the mini engine / gearbox with a Stag setup because the Mini gear box sits in the engine oil sump. It is unique and so has unique requirements from the oil. Any more than you would compare an auto gearbox oil to a manual gearbox oil. The "oils" do different things.
Some gearboxes have always been "choosy" on which oil works best (My LT77 is a case in point and has had three or four completely different recommendations for oil from the gearbox manufacture.)
Manufacturers had to think about things like "cost" and "warranty" and "availability" and "serviceability" They also only had current technology when the cars were being built. In hindsight and as better or more accurately different oils were produced, people have found that different oils work "better" than some others in older gearboxes and engines.