Gearbox oil level

[mowjoe]

Hi

My 51 plate 1.9 tds has done 110,000mls now, bought it at 80,000 but never checked the gearbox oil level. How is this done and is there an oil change period as I don't see it in my book?

MJ

[tdigolf]

there is a 17mm allen key bolt under the starter motor and one on the bottom of the box you drain it from the bottom of the box then fill it up untill it comes out of the hole under the starter motor it takes about 2 and half litres chances are it wants some in i have just changed mine and its much better (1999 golf tdi) what alot of people dont realise is that the gearbox oil can evaporate over time leaving the box low on oil...

[tornadored7]

Hi MJ,

A gearbox oil change is similar to an engine oil change. The front of the car must be raised, and the fill hole and the drain hole must be opened, the oil drained, the drain hole closed and finally an oil refill without overfilling (however there is no gearbox oil filter).

BC (BigCol) wrote an excellent HOW TO on this;

"How To" Passat B5 B5.5 Audi A4 and A6 gear box oil change

Although BC's how to refers to a Passat/Audi A[4,6] gearbox, I have seen a similair configuration on a 130 PD Bora (ERF Gearbox), i.e. fill and drain plugs based on M16 Security Spline keys.

Before performing the oil change, a warm engine and gearbox may be useful to improve oil flow draining.

1) Opening the Fill then the Drain Plugs

The fill plug will be at a higher level than the drain plug. It is imperative that the (upper) fill plug can be removed, before attempting to open the (lower) drain plug, otherwise the gearbox will be drained potentially without being able to refill with oil.

To avoid accidently dismantling/damaging the gearbox clearly identify the fill and drain plugs and do not touch/loosen any other plugs or nuts.

I am uncertain as to whether the gearbox plugs have a;

• 17mm Allen key (i.e. as used on the Golf MK3 gearboxes)
• or a M16 Security Spline

but as previously mentioned have seen the latter M16 Spline fitted on a 52 130 PD Bora (ERF Gearbox).

The M16 Security spline is VW tool 3357 and has the following alternatives (thanks BC);

• Draper 63476
• Sealey SX107
• Laser 2493

2) Draining the Gearbox

Once the top fill plug has been removed, place an oil tray (~2.3 Litres) underneath the drain plug and unscrew the drain plug.


3) Filling the Gearbox

Close the drain plug and carefully torque to the required specification, according to the type of drain plug key used;

• M16 Security Spline: 45Nm
• Allen Key (Hex socket): 30Nm

Then fill the gearbox with oil, this poses a minor challenge since the fill hole is horizontally mounted, filling needs to be done sideways!

Perhaps the best method for this is to route a small length of clean hosing from the top of the engine bay, down into the gearbox fill hole. With a suitable funnel connected to the top of the hose, filling is then achieved by gently pouring oil into the funnel (from above).

VW specify that gearbox oil should be filled to the lower edge of the filler hole (which should equate to ~2.3L).

However, if the front of the car is raised on car ramps, this may result in slight overfilling ? Should the car be lowered for the filling process ?

With the oil sufficently filled, the forementioned torque specifications should be observed to refit the gearbox fill plug.


Questions:

Q1) At what interval should the gearbox fluid be changed ?
While VW may adopt a filled for life attitude (with intermediate oil level checks and top ups), personally I would change at around every 70K/80K miles and am planning to do this soon.

Q2) Which Gearbox oil should be used ?
Personally I would fill with the correct 75W90 gearbox oil sourced from a VW/Audi dealer, since certain other gearbox oils have reportedly caused issues.

Crasher recommends the Redline MTL Gearbox oil, but this is comparatively expensive.

Q3) If the front of the car is raised to ease access to the gearbox will this result in the gearbox being overfilled ?

I'm not sure. Can the gearbox be refilled with the car on level ground ?
Restricted access to the fill plug is likely to be the main issue when refitting the fill plug.

TR7

[tornadored7]

Update:

After checking a Golf MK4 2002 GT TDI 130 (ASZ) engine with an ERF gearbox, the gearbox oil fill and drain holes were actually 14mm Allen keys (unlike the Golf MK3 17mm Allen keys).

Figure 1 below, more clearly illustrates the corresponding 14mm Allen key Gearbox Oil Fill and Drain locations (yellow text).

Note; Picture has been taken from underneath the car at an angle (having removed the engine undertray), with the rear of the car projecting towards the bottom of the image.



Fig.1: Gearbox fill and drain holes (Click to enlarge ...)




TR7

[bpunkgttdipd10]

Hmmmmm, don't have any gear box problems, and don't want them in the future, so wondering if I should check gear oil as it approaches 60,000 miles.

Maybe can get them to check that on Friday whilst it's on a ramp for alternator pulley replacement then that's another box ticked before it's declared fit to take on next 60,000 miles...