Gear box oil recommendations

[Pedrokat]

Dear all...... last year i decided to change my gearbox oil.... i took the spec from hand book and went to the local motor factor and got 5 litres of MPM gl4 or what ever it is.....
Gear change was instantly nicer..... however the down side was the selector seal started leaking....
Ok well its 37 years old so i will change it.....
1 massive pain in the arse later its csrefully changed......
Yet it continues to drip........
Im wondering if the new oil is slighly thinner.....
I see no other reason for it to drip....
What brands/products are people using?
I think im going to get my spare box overhauled/inspected and new seals fitted but its an odd coincidence the change of oil and now it drips...
Cheers.
Peter

[LooLooSud33Spider]

Hi Pedro. Is this a sud ?
Here a snapshot from my Sud tech spec book (Alfa publication)

[Pedrokat]

Sorry yes a sprint .

[Veesix75]

I’m pretty certain I’ve got Millers CRX 75/90 in mine.

[dave.armstrong]

I used Castrol Syntrans Multivehicle 75w90 in mine.

[Pedrokat]

Thanks gents..... might try a different brand before i give up and swap the gearbox...... as on the whole it has no real issues.....except the drip... and it is just a drip...

[Spacenut]

I’m pretty certain I’ve got Millers CRX 75/90 in mine.

Ditto in mine. I've put over 2,000 miles on it since the rebuild and no leaks, from anywhere! Most unusual for the Green Machine not to be leaking from somewhere...

[Splant]

I've put comma 75/90 gl5 semi synthetic in and it's dripping out before I've even started it! So bought some old fashioned mineral 80/90, but just read in Haynes it needs hypoid? Is that right?

[rsfruitbat]

I was recommended by someone well in the know to put 175/90 in my competition gearbox.
I did it and no problems
Rsfruitbat

[NEG]

Our sprint leaks from the selector as well and that’s with normal Castrol EP80/90

[Veesix75]

I previously used the castrol oil referenced above when it was called syntrax, and I am defo using the millers now. I had no leaks / drips with either. I get some oil residue on the sump plate and every now and again nip the bolts up, but it’s a racer and getting stressed and hot every time it’s used.

When stood in the garage cold it’s leak and drip free, same when stood in the paddock post race.

[KevJTD]

A few years ago I went to Witham Oils & Paint for a look around and talk organised by the AROC, only at Lincoln so handy for me.
Great place, very informative, friendly approach with no BS. Got to have a look around the whole factory and see how oils are blended to produce the various grades and see how they are tested on site to make sure standards are maintained. Makes me realise I ought to support a local company more.
The guy doing the talk said if anyone has any questions or requirements then just phone them and they'd offer advice.
They can see oils from 1L up to huge barrels, no limit or minimum,
Might be worth a call.

Looking on their online listings you have to put 1983 to get a Sud on the listing, not really surprising seeing as they have all sorts to deal with not just cars but trucks, agricultural and JCB etc.

https://www.withamgroup.co.uk/

[alfadave]

So Withams recommend HP oil.
To answer Splant's question, are HP and Hypoid the same thing?

I think so, but I'm not 100% sure!

[Pedrokat]

Thanks All... it didn't used to leak..... i cant decide if its worth the Agro and cost to strip it all out again ... and to send my spare box to have all its seals changed..... at 37 years old its marking its territory!
If i top it up occasionally its probably fine....
But the drip annoys me.
Peter

[Splant]

Wished mine was like that, I did the gear change seal and had the left half shaft seal changed when the engine was out ,now it's the right half shaft! So it will contaminate the brake pads .

[Pete Jennings]

Yeah it's a pain really..... I had my engine and gearbox out a few years ago and could have had seals done then.... looking back I should have.... but there were no leaks...... so if it ain't broke......
Hard to know. Especially as seal replacement for half shafts needs special tools that seem hard to come by.... as I was considering doing mine...... hence now looking at getting my spare box overhauled

[alfadave]

I've just realised that Hypoid is a type of gearing......which requires EP oil.
Every day is a school day!

Just checked, and I've got 80/90 EP oil in......

[Pedrokat]

Today i checked my spark plug colours as its been running well for a couple of months now and gearbox oil level.... i was expecting nothing to come out when i removed the filler plug and was suprised to find a reasonably big puddle of oil came out..... good job i had cardboard on the floor of the garage .
Bearing in mind its been dripping lightly for at least 2 months and its still full perhaps i had slightly over filled it hence the leak... either way im probably worrying over it too much...
Peter

[KevJTD]

Are you sure it's coming from the gear change seal?
The gearbox breather is atop the rear plate, if it's overfull then it could be pushing oil out through the breather and running down the back plate, dripping off near the selector shaft...

[Pedrokat]

Yeah i know there is the breather up there... and yep fairly sure its coming from the seal.... but i clearly over filled it..although not by a huge amount.... it has been dripping here and there for at least 8 weeks..... yet it still ran out of the filler this am.....
It wasnt that much over. Perhaps a 3rd of a beer cans worth came out...so not over full enought to reach the breather vent.
Will clean it all off again and see what happens next.
Peter

[alfadave]

I contacted Withams Tech Dept.
They told me to use their Classic 75W/90 gear oil. Its spec covers GL4 and GL5
Ref CLSS 75W/90

Not cheap at £75 for 5 litres. Plus post I presume!

[KevJTD]

That sounds a tad expensive!

[alfadave]

Ordered 5 L of 75W/90 fully synth GL 4/5 from Smith and Allan on Ebay.

Ebay item 370753692415

A bit cheaper at £23.75