Apparently the previous owner replaced the gearbox shortly before I bought the car last year. I noticed in February that the gearbox was leaking oil slowly from that bolt. It was finger tight so I torqued it up and it seemed to stop the leak until a couple of weeks ago. Bolt is on tight now but still seems to slowly leak oil. (not much but enough to mark the drive and form a small pool in the under tray). Any ideas what that bolt holds on and how I could fix the leak? Gearbox model number is 02T 301 252.

Edited 16 June, 20214 yr by JoeF

It looks like the drain plug, the trouble is, to fix it you need to remove it which means draining the gearbox and it might have been overtightened cracking the casing.

It holds the reverse gear idler shaft....

 

Edited 17 June, 20214 yr by TMB

Seems they used two different bolt sizes, so you'd need to know which one you have. Unfortunately, I can't find any info on which of the two bolts were used on which box, but you could always try the lower of the two torques and see if it stops leaking (as long as the rubber seal is ok).   Screw   for reverse shaft support    M6 - turn 5 Nm and 90° (part number N 90929102).    M8 - turn 25 Nm and 45° (Part number N 90972701).   always replace

Here's a pic of the smaller size bolt.....

Edited 17 June, 20214 yr by TMB

For info - the gearbox fill and drain plugs are near the differential.

 

 

The type of plug used can vary....

 

 

Dunno, I've never messed with the gearbox oil because it isn't necessary, if that isn't a drain plug then can it be removed to change the seal without draining the gearbox oil or does my point seem reasonable and we're getting hung up on semantics?

Does the gearbox take standard 75w90 semi synthetic?

2 hours ago, JoeF said:

Does the gearbox take standard 75w90 semi synthetic?

 

ETKA says the oil is part number G 060726A2. It is indeed 75w90

On 17/06/2021 at 03:06, TMB said:

For info - the gearbox fill and drain plugs are near the differential.

 

 

The type of plug used can vary....

 

 

Looks like I have the bolt in figure 1. What size spline is it?

Edit: You are talking about the drain and fill plugs, rather than the leaky bolt? Or are you?

 

If the drain/fill plugs then M16 XZN with a hole in the tip, by the looks of it e.g. : BGS 4357 Vielzahn Nuss Bit XZN M16x100 Bohrung Getriebe AUDI A3 A4 A6 3357 T3023 | eBay

 

This bit "3357 T3023" matches the VW part number of the tool which is given just alongside those two images in the workshop manual.

 

If you mean the leaky bolt's head instead, then it'll be an M6 or M8 XZN bit depending on which bolt you have out of these two options TMB posted upthread a bit, I guess:

 

M6 - turn 5 Nm and 90° (part number N 90929102).

M8 - turn 25 Nm and 45° (Part number N 90972701)

 

 

Edited 18 June, 20214 yr by Wino

edited into previous

 

Edited 18 June, 20214 yr by Wino

2 hours ago, Wino said:

Edit: You are talking about the drain and fill plugs, rather than the leaky bolt? Or are you?

 

If the drain/fill plugs then M16 XZN with a hole in the tip, by the looks of it e.g. : BGS 4357 Vielzahn Nuss Bit XZN M16x100 Bohrung Getriebe AUDI A3 A4 A6 3357 T3023 | eBay

 

This bit "3357 T3023" matches the VW part number of the tool which is given just alongside those two images in the workshop manual.

 

If you mean the leaky bolt's head instead, then it'll be an M6 or M8 XZN bit depending on which bolt you have out of these two options TMB posted upthread a bit, I guess:

 

M6 - turn 5 Nm and 90° (part number N 90929102).

M8 - turn 25 Nm and 45° (Part number N 90972701)

 

 

Thanks I meant the fill plug. 

 

Approximately how much oil does it take? I may as well change it all as it will be pretty old. 

 

Should I fill it as much as it will take or is there a max mark?

Fill until it starts to trickle from the fill hole.

 

https://workshop-manuals.com/skoda/fabia-mk1/power_transmission/gearbox_02t/gearbox_mechanicsoperation_constructiondiff./inspecting_gear_oil/

Edited 18 June, 20214 yr by TMB

Your gearbox holds 2 Litres from empty.