Oil gearbox change

[Le_Combattant]

Good news !

Oil servicing and inspection is scheduled next week. I'm waiting for tools to do the best job as possible.

Why an inspection ? Because since I own this car, in the 5th gear I have a whinning noise from 90 to 110 km/h.
On the 4th gear and at the same speed: nothing.

Two possibilities:

-5th gear's bearing
-5th gears

My gearbox is a Q200, and his code is "PED".
According to VW, oil capacity is about 2.1 L.

But due to the design of the gearbox and the location of the drain plugs, not all of the oil will be able to drain completely.

The drain plug is on the lower side of the differential.
The filling plug is on the opposite side but higher.

My question is the following one:

According to this gearbox schematic, can I remove this little cap in red (lower one) ?
This cap is a cover for the selector.
His location is on the lower side (just under the gear).

Two srews to hold it. But it cover also 4 holes (I don't know why) whiche gives an other acces to the inside of the gearbox and maybye, helps to drain even more oil.

[amer6R]

Whats the need to drain it bone dry?

[Le_Combattant]

Renew the entire oil.

Same as an oil servicing on the engine

[amer6R]

Maybe take a peek at this video?
https://youtu.be/9-hwC95USHw

[Le_Combattant]

You know what ?

I found this video few days before posting the last post haha but thank for the share.
This guy is good and explain well.

Plus, it's the same gearbox

[amer6R]

Can you take a syringe and small tube and fish it and suck out some fluid?

[Le_Combattant]

Well, here we are!

Finally the post on this damn oil change

Gearbox: 02T (5 gears)

Equipment:
-Socket/ratchet 1/2 (Bahco S240)
-Torque wrench (Bahco too )
-Febi 21829 oil
-Lots and lots of paper towels

Objectives: -change the box
-Inspect the 5th gear to locate the whistling (only on this gear)


The famous 02T gearbox

Beforehand I took the care to drive several kilometers in order to heat the oil of box to make it more fluid.
Favoring its evacuation.


Filling plug


Draining plug

I had taken care to choose a flat and level surface in order to not distort the filling of the box.
To my surprise, when I removed the filler cap, a significant amount of oil came out.


Oil that came out the filling cap

I then tackled the drain plug.
Its location does not help and forces to spread oil almost everywhere and this even with a huge funnel.

The mention "lubricated for life" makes sense lmao ! Especially since the gearbox oil smells extremely bad.

Nevertheless I managed to recover a certain amount.


However I was still far from the 2.1L theoretical (according to the official VW doc).
So I played on the temperature by running the engine (20min) to evacuate the rest.

After decanting in bottles, I get roughly between 1.7 and 1.8L of oil. Which is not so bad.


Old vs new


30 Nm for the drain and filling cap

Equipped with my 1L mini pump, I start filling.

The first liter is put without problem.
Second bottle, the overflow arrives at 1,5L. This is logical because from the beginning I had oil coming out of the filler cap as soon as it was opened.

I had to shunt the system: the creek :Red:

Placed at the opposite in diagonal (right rear wheel), I raised the car:

-A first time: I could put 0.3L before it overflows.
-A second time: I could put 0.3L before it overflows again.

Theoretically the quantity is correct. But as a precaution, I accelerated the pumping to "fill" the box before putting the filler cap back.

I prefer to have more oil than not enough.

It's an easy operation but it's still messy (and with its bad smells).
The oil change system is a pain in the ass, just like the filling system.

Why not just put a plug at the lowest level on the box and a filler plug at the highest?

The operation would be much easier:

-We empty the entire oil.
-We put back the exact quantity with a syringe/pump.

Just like an engine....

In the end I could not examine my 5th gears. Indeed to be able to have access to them it is necessary to dismount the wheel.
And to disassemble a wheel above a pit....I don't prefer to tempt the devil.

Especially since to disassemble the casing, you'll have to add oil. In short, a headache. Especially when you are not at home and with the minimum of equipment.

To conclude, gear shifts seem easier, smoother.
Only the reverse gear is sometimes capricious but nothing bad. Certainly an adjustment to be made concerning the gearbox linkage.

[amer6R]

Nice job!

[Le_Combattant]

Nice job!

Thank you !

[veteran]

Thanks for posting your update on this, Le_Combattant.

You appear to have performed this task in the yard of your local mairie - or maybe that building in the background is a school? Whatever, you seem to have had the convenience of a pit over which you could place the vehicle, that then enabling you to work underneath with some ease. Lucky you!

Along with maybe others in this forum, I think I said before that you were likely to remove less oil than you presumed, and it looks like that's certainly proven to be the case. Did you ever try removing the cover 6 , which you had circled in red, as you were proposing to do so in order to possibly get the last vestiges of dirty oil out of the gearbox? In the case of my 02T gearbox, that cover 6 is badly fitted and I've wondered for a long time whether gearbox oil leaks from around it. But I've been reluctant to disturb that little cover, for fear of it not sealing properly afterward.

On re-filling, I'm not sure whether there was much point in trying to get another 0.3 litre in. Surely, unless the gearbox is off the car, with the filler hole facing skyward, any extra oil you might try to put in while the gearbox is still on the car is going to dribble out again immediately? But maybe if you were able to raise the car on that filler plug side sufficiently, you then managed to get a little extra oil in? But you'd have then had to have quickly re-fitted the filler plug. Another thought is that if you over-fill the gearbox you eventually might have gearbox oil seeping out from around the seals of the gearbox output couplings (eg.from around those brown rusted coupling situated to the right and just above the filler plug, in your picture). When the car is in gear and each front wheel is turning, I think the bearings of each output coupling simply need to dip into the oil, rather than all the bearings being always submerged in the oil (if you see what I mean).

I'm surprised that the old oil had a terrible smell. I've never noticed that before when changing the oil in the gearboxes of previous cars of mine. When I put new oil into my own Polo's 02T I was not aware of any bad smells, but hey that might have been just because the oil I was taking out hadn't been in the gearbox all that long. Or maybe the smell is something to do with the special additives that are put into the oil by the manufacturer, maybe additives that get smelly when the oil gets well-used over time?

I found that care was required when refitting the filler and drain plugs, as getting the thread crossed in either case could prove disasterous. And when you removed the filler and drain plugs, did you find any signs of thread sealant having been used at the factory? Those plugs have tapered threads, BTW.

Now that you've done the changeover of the oil, do keep an eye open for any leaks as time goes by and you continue to use the car. Watch out for signs of oil on the ground after you've parked the car overnight or for longer. If your Polo has a removeable plastic undertray, you'll find signs of oil on the normally unseen surface of that if you've got a leak. Let's hope you haven't though, and that all will be well, going forward. A leak is the problem that now plagues me, and determining exactly from which point or place the oil is actually coming from is very, very difficult (as ultimately it all just collects and drips from the very lowest point on the gearbox).

[Le_Combattant]

Hi Veteran, thx for your feedback too !

I performed the oil change in my school. The building you've seen is the main one. It's an old castle from 1660.
And yes there is a pit over. Not the best one to be honest, but enought to work under the car quite nicely.

"Along with maybe others in this forum, I think I said before that you were likely to remove less oil than you presumed, and it looks like that's certainly proven to be the case. Did you ever try removing the cover 6 , which you had circled in red, as you were proposing to do so in order to possibly get the last vestiges of dirty oil out of the gearbox? In the case of my 02T gearbox, that cover 6 is badly fitted and I've wondered for a long time whether gearbox oil leaks from around it. But I've been reluctant to disturb that little cover, for fear of it not sealing properly afterward."

Yes I tried to remove this little cover (I even bought the right sealant to replace the old one) but...I couldn't.
I was stock in position thanks to the orignial sealant so I didn't try too much.

"On re-filling, I'm not sure whether there was much point in trying to get another 0.3 litre in. Surely, unless the gearbox is off the car, with the filler hole facing skyward, any extra oil you might try to put in while the gearbox is still on the car is going to dribble out again immediately? But maybe if you were able to raise the car on that filler plug side sufficiently, you then managed to get a little extra oil in? But you'd have then had to have quickly re-fitted the filler plug. Another thought is that if you over-fill the gearbox you eventually might have gearbox oil seeping out from around the seals of the gearbox output couplings (eg.from around those brown rusted coupling situated to the right and just above the filler plug, in your picture). When the car is in gear and each front wheel is turning, I think the bearings of each output coupling simply need to dip into the oil, rather than all the bearings being always submerged in the oil (if you see what I mean)."

When I removed the filling plug, some oil gets out. I attached a picture of this oil quantity.
Maybye 0.3l, I don't know.

It's now a week ago I've performed the oil replacement and no leaks at all.

According to many peoples, gearbox oils smells bad. Why ? I don't know.

"I found that care was required when refitting the filler and drain plugs, as getting the thread crossed in either case could prove disasterous. And when you removed the filler and drain plugs, did you find any signs of thread sealant having been used at the factory? Those plugs have tapered threads, BTW"

Nothing about thread sealant. I took care about them and clean them correctly.
Both torqued at 30Nm and no leaks.

But I will keep an eye open and will check under the car and on ground if there is any leaks.

[2226]

I would presume the usual way is to refill with as much oil as was taken out.
You won't get all the oil out since the drain plug is higher up.

But job well done.

Here in South Africa we don't need those pits ... we just park the car over a pothole. Big enough.

[JiSingh1]

Also in this case.. did you ever know if part 6 in the diagram can be removed to drain the oil too, or not? Otherwise I see no reason for it.

As I've stated in my posts, my new (used) gearbox is too damn notchy and sticky, and I am hoping it's just the linkage and the oil. Cheaper for me to tackle it at home and save £70 or whatever on labour so if i can just remove that part then it'll help, lol.