checking/filling gearbox oil

good morning

this weekend I will be checking/filling my gearbox oil on an 07 jimny . I have not done this before , are there any tips ? thanks in advance

My only experience with gearboxes is with ones associated with helicopters but the principles are the same!

Part of the process with draining and refilling helicopter gearboxes was to get the oil hot; we actually did what we called "a hot drain & flush".
This involved getting the gearbox oil up to operating temperature then draining it while it was hot.
(Removing the filler-cap before draining allowed the thinner (hot) oil to rush out quicker bringing with it as much debris as possible).
The g'box was then refilled and the process repeated.

Finally the g'box magnetic plug was inspected and/or cleaned or replaced and fitted with with a new seal/gasket, and the g'box refilled with new oil; job done.

A bit extreme I guess; we have cars not heli's, but if you haven't done the oil for a long time a flush might well be good a good idea particularly if you find particles on the plug.

Other tips...
Wear the right correct PPE - some eye protection and disposable gloves - oil can be very nasty stuff.
Know the quantity you're expecting to come out and have the correct sized container! Be aware of it being hot!
Have rags paper or other absorbent materials at hand if you have a drama and miss the container!
Fit the plug with a new seal BEFORE filling the g'box!
Make completely certain you refill the g'box with the correct quantity of the correct oil, ad fit the filler plug

Someone here mentioned that a Redline oil helps with g'box selection issues but I don't have details of which oil exactly.


Sorry if some of this includes the teaching of egg-sucking, but you did ask :laugh:

You need a 10mm square toll to remove the filler plug. It is a real pig to get to and the space between the plug and the transmission tunnel only allows a shart length tool to get in there.

I have a number of 10mm square tools and I will be doing a how to early next week and wll show the tools that will not get in there.

Make sure you can undo the filler first before the drain plug, I normally hold a tube while my mechanic pours it in from standing beside the jim and let gravity do the work

Quantities and spec are in the wiki Forecourt section if you need then

thanks for the replies ; with regards to putting in the new oil ; is there a knack ; or does the new oil container have a built in spout .

sorry for the daft questions but I have never replaced gearbox oil and because its to dangerous for me to do it out side my home I was going to drive to Halfords ; buy the oil and fill the level in their car park (with a blanket underneath for spills) so ideally I want to go fully armed

Wouldn't advise doing it at halfords,
If you're not able to do it at home I would recommend a garage do it then it is also there responsibility to recycle the old oil once they have finished.