Correct amount of oil for seven gearbox

[JonE]

so - 4 speed - you don't worry a jot about the perceived glut of oil there as others have worried over? Do you think possibly the first RP handbook was thus a misprint, not being revised from the earlier 3 speed up to 1.25 pint? That might explain the discussion...

[Ruairidh Dunford]

I have not experienced any problems with my method, I cannot speak for others.

[Reckless Rat]

Four speed crash (not synchro) - filled to the bottom of the filler plug threads, or even a bit lower. Works for me.

[JonE]

ok, well I'll post the think to Alan, Vince and Dave's notes anyway. From reading everything above, on an old gearbox, I'm going to go with the 7/8" under.
http://pub25.bravenet.com/forum/static/s...9&cmd=show

[Steve Jones]

I use the engine dipstick for a three speed box and fill to just below the threads of the filler hole in a four speed box.

I have always used this method, never ever measured the amount going in and never ever suffered any issues.

I hope it works for you too.

Moi aussi. 

Worked for over 30 years with no problems. 

Steve

[John Mason]

I have Ruby with 4 speed box. If I am in any doubt I drain off and measure the amount that comes out. Then refill with new oil. What is the cost of a drop of oil compared to a gear box overhaul.

John Mason

[Ruairidh Dunford]

I understand the logic in that but would not be keen to apply the method today as Last year, for the first time ever, I decided to entrust my local garage to service my new (to me) modern car.

It came back with new oil and filters etc.

After about 40 miles the low oil light came on - I just about had a heart attack.

Turns out that they did not know how to use the electronic dip stick and simply measured what they had removed - which was less than the amount it should have had in it. I used a friend’s machine to read the dipstick properly and added nearly a litre more before it showed full.

I was terrified that the engine had been damaged because is was not very responsive - turns out the car knew it was low on oil and prevented the engine from performing to protect itself. Apparently it would have shut itself down completely if it detected and threat of damage.

[JonE]

I have Ruby with 4 speed box. If I am in any doubt I drain off and measure the amount that comes out. Then refill with new oil. What is the cost of a drop of oil compared to a gear box overhaul.

John Mason

John - as well as Ruairidh's point about not really knowing whether the amount is correct in the first place, your logic is counter to the point of the thread, which is supportive of the "standard" level being potentially a greater risk to oil contamination than "using a bit less", most likely in less well maintained engines...?

[Colin Morgan]

Recently I have had to check my Ruby 4-speed 2-sync gearbox oil level every few of days because of a slight weep from the drain plug.  For many years it has been running at a level 19mm below the top of the filler plug hole, and this seems to successfully have avoided a recurrence of clutch slip.  I understand from the above posts this corresponds to about 1 pint in the box, though I haven't measured it.  

I am checking the level from the top of the filler hole using a tyre tread gauge.  When this is adjusted to just touch the oil I know the distance down to the surface, which is otherwise hard to see.  If the level is a bit low, an egg cup full of oil brings it up a couple of mm.

Colin

[JonE]

Colin's measuring method has just given me an idea for a very "little" version of the Austin petrol dip stick... with a mark for 7/8" (22mm) and 19mm distance-to-surface perhaps.. Watch this space!