Diffs, boxes and sumps.

Tail Docker

Thought I'd bang up a thread about a recent purchase, a plain jane front wheel drive Transit 2.0. Nice clean van, service history from main dealer stamped up to date, all g.

I have a habit of giving new purchases a mega-service before putting them to work, it's sort of a standing joke amongst my mates. I change all the fluids and filters, etc etc.

So, anyway, according to Henrys crowd, these have a sealed for life gearbox and it isn't a service item, much the same as for the RWD ones and their diffs - also "sealed for life"..."just need a top up every now and then Sir."..

I ignore that, and if it doesn't have a drain plug, I drill one in, tap a thread and put a plug on, regardless. In this case though, the gearbox did have a drain plug and a filler..so I drained the "oil" and what came out (bearing in mind this van has only 50k miles done) was diluted watery filthy yellow p1ss water..not even close to resembling oil. I flushed it through with 5 litres of cheap engine oil to get the rest of the gritty, dirty muck out of it and refilled with 15w40 engine oil - I use it in all the van boxes and change it with the engine oil at every service as a matter of course. Never had a gearbox go yet either, despite lad telling you how "mad" using that oil is..

The same applies to rear diffs - usually on purchase I whip off the entire rear diff cover and give them a good clean out, usually they are full of crud and watery muck, I then drill and tap in a thread and plug and refill with diff oil. Filled for life me butt.

Any of ye do similar and did the muck that came out ever make ye wonder what manufacturers are thinking of with "filled for life" boxes of cogs? I follow the same course of action with our 4*4s as well.

visual

Sealed for life = will last until warranty expires and maybe little bit more but by that time you're on your own with a need for very expensive part

O.A.P

Yes I pulled the gearbox sump off my 15 year old astra .cleaned it all out ,resealed it and filled it with fresh gear oil.
I will soon have 200000 miles done on that 1.4 engine and I firmly believe its only because I service it myself and know how to mind a machine.

Tail Docker

O.A.P wrote: »

Yes I pulled the gearbox sump off my 15 year old astra .cleaned it all out ,resealed it and filled it with fresh gear oil.
I will soon have 200000 miles done on that 1.4 engine and I firmly believe its only because I service it myself and know how to mind a machine.

The Missus had the same car, an estate that did 295000 without missing a beat and still drove tight. The ECU died in the end - caused the "no-fuel fault" and I couldn't be bothered fixing it.

As an aside, I always use an engine cleaner additive in the oil before changing it - I let them idle for 30 minutes with it in the sump, it dissolves the sludge if there is any, frees up sticking rings and breaks down lumps that would clog the oilways. I get called nuts for doing this too, but I reckon it helps engines reach big miles. Vans we run have hit 500,000 on this regime without much more than clutches and brakes etc.

CJhaughey

Sealed for life depends on the expected life of the vehicle.
100,000 is probably what they will be expected to do in their working life then they get chopped in for a new one.
Its a load of balls tbh and I am a firm believer in oil changes for all mechanical parts.
The new stuff has long service or no service intervals because fleet buyers want to have low running costs after initial purchase.
The downside is that stuff is worn out after the warranty is over, 2nd buyer beware!

CJhaughey

Interesting about the 15w40 as gearbox oil, most 4 stroke motorcycles use oil to lube the engine, clutch and gearbox. 15w40 is pretty much the same viscosity as 75w 90 gear oil.
Sounds like a good strategy.

Tail Docker

CJhaughey wrote: »

Interesting about the 15w40 as gearbox oil, most 4 stroke motorcycles use oil to lube the engine, clutch and gearbox. 15w40 is pretty much the same viscosity as 75w 90 gear oil.
Sounds like a good strategy.

Dunno tbh, but a good mate runs all traffics, the ones with the shyte 'boxes - he's a mobile agri mechanic and the vans get dogs abuse - he does the engine oil in the gearbox thing and changes it every service(7k) with the engine oil - again, no gearbox failures... so I asked why, he explained, and I followed..his yokes have giggle mileage on them too, all over 200k.

Tail Docker

Although I have to say, I find electrical faults with more modern yokes to be the biggest issue and the hardest to fix. Any of ye find that? What's the most challenging thing ye find to repair? Wiring faults rot my brain.

tomwaterford

Tail Docker wrote: »

Although I have to say, I find electrical faults with more modern yokes to be the biggest issue and the hardest to fix. Any of ye find that? What's the most challenging thing ye find to repair? Wiring faults rot my brain.

AFAIK a good wiring diagram while can be hard to track down is worth anything....I always found the card/circuit boards on so many thing are ***** for rusting...if wiring diagrams for these were readily available it would be great...just solder and wire across/bridge the rustgap

Slideways

CJhaughey wrote: »

15w40 is pretty much the same viscosity as 75w 90 gear oil.
Sounds like a good strategy.

LOL.

You do know that the numbers have a direct correlation to the viscosity of the oil?

Where I work we change all final drive oils every 250hrs which is about once a fortnight or less.

I wouldn't put engine oil in a gearbox. IF I was to do it I would use a synthetic gear oil like Enersyn EPX 320 and change it about once every 25-30,000 k

CJhaughey

Slideways wrote: »

LOL.

You do know that the numbers have a direct correlation to the viscosity of the oil?

Correct but the SAE rating for engine oil and gear oil are entirely different things.
Engine oil uses the SAE J300 index while Gear oil uses the SAE J306 index.
75w Gear oil has a Kinematic viscosity of 4.1 Centistokes at 100ºC max
15w Engine oil has a Kinematic viscosity of 5.6 Cst at 100ºMax
In real terms this means they are very close in viscosity at 100ºc

BTW The oil you referred to is rated at 33Cst at 100ºC thats a big difference in terms of viscosity, you might find it hard to shift gears when its that thick.

Slideways

CJhaughey wrote: »

Correct but the SAE rating for engine oil and gear oil are entirely different things.
Engine oil uses the SAE J300 index while Gear oil uses the SAE J306 index.
75w Gear oil has a Kinematic viscosity of 4.1 Centistokes at 100ºC max
15w Engine oil has a Kinematic viscosity of 5.6 Cst at 100ºMax
In real terms this means they are very close in viscosity at 100ºc

BTW The oil you referred to is rated at 33Cst at 100ºC thats a big difference in terms of viscosity, you might find it hard to shift gears when its that thick.

Fair enough. I'll hold my hand up and admit I didn't know that.

The Enersyn always was pretty fluid when I was using it, I wouldn't have thought it would have been that much of a viscosity difference.

It seemed to handle the extreme abuse it got here with ease so that's why I'd be included to recommend it.

Tail Docker

Most "gear oil" is generally just shorter string molecules that resist the chopping action of gears meshing for longer than engine oil would. BUT, if you change the engine oil you used in the gearbox more regularily..the "chopping action" doesn't make much difference, if any, and you get a smoother box and nicer gearchange too. Fresh 15w40 beats scaggy gear oil hands down all day every day, regardless.

101sean

The LT95 gearbox/transfer box in my 101 uses 20W50 engine oil. The transfer box half was originally specced as EP90 but as the seal between the two often goes LR changed the spec as the gearbox oil pump won't last long pumping EP90.

CJhaughey

I think the motto is change it regularly and you should have no problems.
I have never heard of a cars engine or gearbox wearing out from too many oil changes but plenty of the latter.
I fitted a Fumoto valve to speed up changes and while it might seem to only save a few seconds as opposed to undoing the sump plug it actually makes the job faster because there is no chance of dropping the bolt into the oil and you don't need another tool.
It drains slightly slower but I am happy with the convenience.
I have theory that hot engine oil is someway magnetic, I can't count how many times I have dropped a ratchet or socket and its ended up in the drain container full of hot oil.

Slideways

Haha, you drop a bung at any stage it will always find a container of oil..

I haven't taken a bung out in ages. All our machines have evac fittings that you clip a vacuum on to.