Gear box oil compatibility

[Smithfire67]

Hi peeps

Can I mix penrite hypoid 80w 90 GL-5 with Halfords 80w 90 GL-5 gear box oil?

Seems like they should be mixable but I'd like to be sure.

Many thanks

Clive

[RobH]

Both GL5 - not recommended for TR boxes. GL4 is the recommended stuff ( there is disagreement about this however ). You shouldn't use hypoid oil in a gearbox either, it's too slippery and the operation of the synchromesh will be affected. That is for hypoid back axles. 

 

 

Edited September 10, 2023 by RobH

[Smithfire67]

52 minutes ago, RobH said:

Both GL5 - not recommended for TR boxes. GL4 is the recommended stuff ( there is disagreement about this however ). You shouldn't use hypoid oil in a gearbox either, it's too slippery and the operation of the synchromesh will be affected. That is for hypoid back axles. 

 

 

Unfortunately, according to the receipts, that's what's in there.....would you recommend I change it?

Clive

[RobH]

Personally I would drain and re-fill with plain gearbox oil ( I use Penrite GB 40) but that is just my opinion.....others may differ. 

[RogerH]

Hi Clive,

 I would also drain, then fill with something a little better.

I use  Penrite GB40 and it works well.

Others use EP 80/90  but I would not.

Try and get a GL4 spec oil

There is lots of controversy about the best oil to use  But if you go as above you will not be far wrong.

 

Roger

[Smithfire67]

40 minutes ago, RogerH said:

Hi Clive,

 I would also drain, then fill with something a little better.

I use  Penrite GB40 and it works well.

Others use EP 80/90  but I would not.

Try and get a GL4 spec oil

There is lots of controversy about the best oil to use  But if you go as above you will not be far wrong.

 

Roger

Thanks Roger

[TimG]

Pete Cox recommends Penrite GB30 for non O/D boxes & GB40 for O/D boxes. GB30 in my non O/D box.

[Lebro]

GB40 in mine   just sayin !

[Smithfire67]

I have a 59 3a o/drive.....so GB40.

Thanks

[Smithfire67]

1 hour ago, Lebro said:

GB40 in mine   just sayin !

Also, do you know the capacity of the sump?.....gonna order some GB40 this morning!

[Smithfire67]

Just now, Smithfire67 said:

Also, do you know the capacity of the sump?.....gonna order some GB40 this morning!

Sorry meant gearbox....not sump! DOH!

[RobH]

2 litres with an overdrive. 

[Smithfire67]

1 minute ago, RobH said:

2 litres with an overdrive. 

Thanks Rob

[Deggers]

Hi Clive,

Like others here, I'm running GB40 in my o/d 3A box as well.

Here are two notes from the original TR factory service manual :

Lubrication: With an overdrive fitted it is inadvisable to use hypoid gear oils as these may be detrimental to the operation of the unit.

Draining: There is a drain plug fitted to the overdrive unit, and when draining the gearbox it is necessary to remove both the drain plug on the gearbox and the drain plug on the overdrive unit.

Incidentally, if you don't already have a copy, consider bagging yourself a TR Service Instruction Manual for the glovebox. Definitely a worthwhile investment (as well as a good read), with original copies readily available on eBay for around thirty pounds.

Note that later editions will state on the cover "Incorporating Supplement for TR3 Model", as below.

Cheers, Deggers

[Smithfire67]

1 hour ago, Deggers said:

Hi Clive,

Like others here, I'm running GB40 in my o/d 3A box as well.

Here are two notes from the original TR factory service manual :

Lubrication: With an overdrive fitted it is inadvisable to use hypoid gear oils as these may be detrimental to the operation of the unit.

Draining: There is a drain plug fitted to the overdrive unit, and when draining the gearbox it is necessary to remove both the drain plug on the gearbox and the drain plug on the overdrive unit.

Incidentally, if you don't already have a copy, consider bagging yourself a TR Service Instruction Manual for the glovebox. Definitely a worthwhile investment (as well as a good read), with original copies readily available on eBay for around thirty pounds.

Note that later editions will state on the cover "Incorporating Supplement for TR3 Model", as below.

Cheers, Deggers

Thanks Diggers

[ianc]

Unless you want a mess on the floor, don't try to put all 2 litres in straight away - it takes quite a while to ooze its way to the overdrive.

Put about 1.5 litres in, go for a drive, making sure you use the overdrive, leave the car to cool down, then top up - but slowly!

Ian Cornish