Gearbox oil...

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Skyguyz
Posts: 145
Joined: Sat Jun 01, 2019 6:53 pm
Location: Las Vegas, NV. USA

Gearbox oil...

Post by Skyguyz »

I now have the miles to do the first gearbox oil change of my 75 Suzuki GT750. I have 20w/40 "Break-in oil" now and it's time to drain and start regular oil changes. *I know not to trust the little oil screw for volume and use about 2200ml for the amount to fill. I have done a search here of recommended gearbox oil here and oddly enough, I can't find a link to this? (*I am sure this posting will garner plenty of links.) As per the Suzuki manual, I'd think I should use a non-synthetic 20w/40 oil. The internal seals and clutch are suseptable to premature wear using synthetic oils.

Problem is, I can't seem find a fully non-synthetic 20w/40 oil to use??? I live in the states and although some brands sold in the UK would be fine but would be unavailable here in the USA. So, what major brand that would be available here should I consider using?


Thanks in advance as always,

Sky

PS: I have started the repair of my second GT750. More to come on the one later.



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Alan H
Posts: 12104
Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: Gearbox oil...

Post by Alan H »

It's just a case of looking around really. I had a similar issue a few weeks ago, but you need a 'proper' old style automotive supplier rather than one of the 'modern' ones. Ebay may be your friend. Item 352818824468 or similar.
Or even ask one of the aircraft mechanics who sorts out older piston engined aircraft?
Proof that four strokes are over complicated
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canaletto5
Posts: 5228
Joined: Tue Jul 23, 2013 8:43 pm
Location: Derbyshire

Re: Gearbox oil...

Post by canaletto5 »

Skyguyz wrote:I now have the miles to do the first gearbox oil change of my 75 Suzuki GT750. I have 20w/40 "Break-in oil" now and it's time to drain and start regular oil changes. *I know not to trust the little oil screw for volume and use about 2200ml for the amount to fill. I have done a search here of recommended gearbox oil here and oddly enough, I can't find a link to this? (*I am sure this posting will garner plenty of links.) As per the Suzuki manual, I'd think I should use a non-synthetic 20w/40 oil. The internal seals and clutch are suseptable to premature wear using synthetic oils.

Problem is, I can't seem find a fully non-synthetic 20w/40 oil to use??? I live in the states and although some brands sold in the UK would be fine but would be unavailable here in the USA. So, what major brand that would be available here should I consider using?


Thanks in advance as always,

Sky

PS: I have started the repair of my second GT750. More to come on the one later.



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Castrol 20/50 conventional would be fine. https://www.castrol.com/en_us/united-st ... tab_20w-50
barney01
Posts: 3118
Joined: Wed Sep 26, 2012 7:33 pm
Location: Prestatyn.Wales

Re: Gearbox oil...

Post by barney01 »

I'm sure if you search over there you will find this
https://www.ebay.co.uk/p/Castrol-1925-7 ... YcQAvD_BwE
NO SMOKE .......NO POKE
teazer
Posts: 1035
Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Gearbox oil...

Post by teazer »

Aahh.... Not another oil question. ;) We all have our favorites and in reality, almost any oil is probably better than the stuff that Suzuki used back in the day.

My preference for all street 2 stroke transmissions is http://prohondaoil.com/vital-fluids/transmission-oil/

It's designed for transmissions with wet clutches and that's what's in my RZ350 and GT750s. I have even used it a TZ or two and it's as good as anything else I have used and the price is reasonable. It's 80/85W which is rated differently than engine oil, so don't think that it's really thick. It's not. It's about 20-30wt.

https://www.bobistheoilguy.com/viscosity-charts/
Skyguyz
Posts: 145
Joined: Sat Jun 01, 2019 6:53 pm
Location: Las Vegas, NV. USA

Re: Gearbox oil...

Post by Skyguyz »

Thanks to all who replied. There are always many choices but after considering the options I went with Bel-ray Gear saver. It had the best reviews and best results for wet clutches.


*I must be getting old. I use this in my Kawasaki H1 and had excellent results in my Kawasaki H2

Again thanks for the responses,

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