Gearbox oil

[Carba1984]

Hello, I've been looking at my manual and it doesn't indicate how to change the gearbox oil. I have been reading that there can be above and below, what is the best way to do it? How is it done? Can I use the same differential oil? I have used Castrol 75w140.

Thanks 

[Josef]

Assuming a small chassis Triumph here! There is a drain plug at the bottom of the gearbox, and a filler to the right hand side. To gain access to the filler you need to remove the gearbox cover. The original oil spec is EP90, I’ve used 75w90 before now on the recommendation of Overdrive repair services. The most important thing is to pick a GL4 spec oil as this is compatible with the yellow metal synchro rings. The oil you’ve got there will probably be a bit too heavy regardless.

[johny]

Agree however I would never remove my cover just to top up gearbox oil - its a bit fiddly but perfectly ok to do it in situ....

[dougbgt6]

Get it off!!!    And cut an access hole/flap so you don't have to take it off again.

Manual says EP 90 oil for gearbox and diff, so probably best to use EP 90? 

Doug

Edited August 30 by dougbgt6

[Carba1984]

Is it impossible to do it from under the car?

[68vitesse]

14 minutes ago, Carba1984 said:

Is it impossible to do it from under the car?

No, topped mine up recently, Vitesse 2L, using an oil syringe similar to this but I do have a pit in my garage.

Regards 

Paul 

 

[Pete Lewis]

it can be done from underside but you need long fingers its a good fiddle 

making access into the tunnel is a good idea and once done you make this an easy job.

The synchro will not cope with 140 oils  far too heavy .

as said stick to a EP90  GL4   for gearboxes   ............140  GL4 in the Diff is good 

overdrives if fitted are designed to work on engine oils ( often used by many car makers) but 

as the   small chassis gearboxes are the weak point  Triumph stick with EP90 and   Laycock Overdrives 

gave a dispensation that its ok to use and has been for the past 50 years 

there are modern GL5 oils that are yellow metal safe but you need to read the spec with care.

on truck production when renault took over ordered a change from GL4 to GL5 and we had Diffs with disintegrated

thrust washers cost a fortune wrecking previously sound Diff design     so yes this matters . 

Pete

 

Edited August 30 by Pete Lewis

[DVD3500]

4 hours ago, Pete Lewis said:

it can be done from underside but you need long fingers its a good fiddle 

.....

Pete

 

My usual comments about when things could be misunderstood if you walked by and only heard that part of the conversation..-.

[Colin Lindsay]

7 hours ago, Carba1984 said:

Is it impossible to do it from under the car?

No but make sure the engine is cold as a hot exhaust is very difficult to work around!!

The filler plug is on the opposite side to the clutch slave cylinder. You can see it in this photo, just behind the bellhousing. It's an 11mm / 7/16 square plug and once loosened you can remove it with fingertips. All you need then is an oil can with a long tube that can be wiggled up between the chassis rails and into the gearbox and the oil pumped in until it overflows, allow to settle then replace the plug. It can be awkward to reach and especially to replace, but not impossible.