Noisey gearbox

[alanjesty]

Hi all
Last year I successfully swapped out my tired old engine for a recon unit and I got some great advice off the messageboard to help me along.
It's time now to turn my attention to the gearbox which makes a whining noise in first gear but only when I'm using the engine to brake. Other than that, the box is perfect!!
Is this a fault that I can fix myself if I take the whole box out, or better to get a recon. I would be keen to know what people think the problem might be.
Regards Alan

[panky]

They all whine in 1st so yours sounds normal. I wouldn't use 1st as an engine brake, nasty things can happen

[liammonty]

As above - it isn't a fault. It;s due to the straight-cut gears on first gear (same on reverse).

[bmcecosse]

And as above - never EVER use 1st gear to 'brake' the car.... In fact - best not to use any of the gears for braking - gears are for going, and brakes are for slowing....

[SteveClem]

Must be other things to do to the car to pass the time of day? The whine is part of the ambience, like the farting exhaust.

[les]

And as above - never EVER use 1st gear to 'brake' the car.... In fact - best not to use any of the gears for braking - gears are for going, and brakes are for slowing....

Apparently even driving schools teach people not to use the gearbox now! At least they still teach using indicators, something many experienced drivers can't get the hang of!

[amgrave]

Are modern cars fitted with indicators

[les]

Good question!

[mike.perry]

I don't wish to start off the engine braking saga again but when I am descending a steep hill with 7 in brakes and a trailer on the back I most certainly use my engine for braking. What about the rule that you should descend a hill in the same gear as you climb it?

[MarkyB]

the rule that you should descend a hill in the same gear as you climb it

Never heard of that one, which rule book is it from?

Didn't cars in the 20s and 30s sometimes use reverse to get up steep hills?

[bmcecosse]

The 'going down' hill idea is fair enough, although not really 'braking' - more 'maintaining a steady speed' - but NOT in 1st gear. Can't say it's very wise to be towing any sort of trailer with 7" front brakes......

[SteveClem]

Good question!

People seem to think indicators are optional these days. Best to assume the worst...

[alanjesty]

Ok, I will treat the whine as standard. That leaves me with the task of changing the oil in the gearbox as I dont know when it was last done. I'm told it needs 20w50 for some reason, (why not gear oil). If the old oil has been in there for some time (maybe years) there must be some gunge and foreign matter in the bottom, the question is, is there a way of flushing the gearbox before I put lovely fresh oil in it??

Regards Alan

[greendefender123]

Dont know why 20 50 was used. Tho its designed for it so carry on using it. They don't take much oil, so if you wanted to flush it out I would change it, then use it for abit then change it again.

[philthehill]

The correct oil for a Minor gear box is straight a 30 grade.
The reason a thicker oil is not used in a Minor gearbox is that a thicker oil i.e. EP gear oil is harder to wipe off the Minor syncho rings leading to difficult gear changes.
Remove the drain plug and see what gunge is found inside the concave drain plug. It may not be too bad.
It is a pity a Morris did not consider fitting a magnet into the drain plug as some manufactures do as that would catch any metal particles.

[liammonty]

The correct oil for a Minor gear box is straight a 30 grade.
The reason a thicker oil is not used in a Minor gearbox is that a thicker oil i.e. EP gear oil is harder to wipe off the Minor syncho rings leading to difficult gear changes.
Remove the drain plug and see what gunge is found inside the concave drain plug. It may not be too bad.
It is a pity a Morris did not consider fitting a magnet into the drain plug as some manufactures do as that would catch any metal particles.

Hi Phil,
I'm afraid that's not right according to the workshop manual, that states a multigrade oil should be used, as for in the engine (edition 14, PP2). Unless of course the car is an MM, in which case it should be EP oil. There is no recommendation for using a monograde for either the engine or gearbox, regardless of temperature, in either Minor 1000s or Series IIs. Granted there may have been before the advent of decent multigrades.

I think that the reason for not using EP oil in the box is due to the incompatibility of the additives in it which harm yellow metals.

To the OP - 20W50 will be fine

[philthehill]

liammonty
You are right in that wksp man section does allow for the use of Multi-grade oils but only at temperatures above 18 degrees C ( AKD 530H - Section PP - Lubrication - issue 9. page 58436) and which was the current Morris Minor workshop when Minors were still in production and which also covered the Minor fitted with the 10MA engine).
For temperatures below 12 degrees C a 10/30 grade oil should be used.
The top table of page PP2 Issue 9 shows that for the Morris Minor (Series 11) and Minor 1000 gearbox the recommended mono grade oils except for Esso 20W/30 are all straight S.A.E. 30 grade oils.
Therefore your statement that there is no recommendation for the use of a Mono grade oil is wrong.
EP oils may have changed but back then there were no nasty additives in the oil, whilst one of the current reason for not using EP in the Minor gearbox may be because of the nasty additives I can assure you that a Minor gearbox filled with straight EP oil with or without nasty additives will not allow a smooth gear change as the oil will not shift from the syncho cones it being a extreme pressure oil.
Not withstanding the above; as a grease monkey in a BMC garage in the 60s/70s when Minors were our bread and butter work; I have filled many a Minor gearbox with straight S.A.E 30 oil, mainly Castrol XL.
So I will stick with my statement that the correct oil for use in a Minor gearbox should be a straight S.A.E 30.
Whilst the above is correct I will concede that a current issue reputable multi-grade engine oil in the 20W/50 range is likely to do little harm to a Minor gearbox.
Phil

[liammonty]

HI Phil,

I'm not wanting an argument, but to state 'the correct oil is 30W' is misleading, as it is advice that was superseded in later manuals. I did say that it may well have been the case in earlier manuals (which I don't have access to), and it seems this indeed is the case according to your older version of the workshop manual. So what I said isn't 'wrong' - it's correct according to the later manual (AKD 530, 14th Edition, 1970, when I believe Minors were still in production), which recommends 20W50 for both engine and gearbox at 'all temperatures above -12 C'. This is the case for 803, 948 and 1098 engined cars.

I think my point is that it makes more sense to follow the advice of the later manual, i.e. to use a multigrade, rather than follow the superseded advice to use a monograde.

Regarding the EP, I wasn't disagreeing with you, but with todays' oils, the reason I gave is valid also.

I'm going to stop now, as this risks becoming extremely boring!

[dalebrignall]

my manual says 20/50 so that will do for me , i change it every 2 years clean oil cant do any harm .