Vauxhall 4 Speed & Overdrive Oil Change

Post by MattA24 » Subscribing Member » Fri Sep 07, 2018 1:06 am
Joined: Wed Jan 15, 2014 9:06 pm
Posts: 195
Hola,

Just to check, what's the best way to drop the oil out of the Vauxhall 4 speed box? Is there no better way than just popping the bottom cover off? (That sounds like a recipe for oil EVERYWHERE.)

If I do pop the bottom cover off, is there any springs or ball bearings or whatever to try and catch?

Also, I recall reading somewhere sometime that the overdrive unit runs in common oil with the gearbox. Or am I talking nonsense? If I'm dropping the oil should I pull the bottom cover off the overdrive too?

Cheers!
Matt

Re: Vauxhall 4 Speed & Overdrive Oil Change

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Post by Phil Bradshaw » Club admin » Fri Sep 07, 2018 1:56 am
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3669
Remove bottom cover to drain transmission unless cover has a 1/2-inch AF square head threaded drain plug at the edge (CA or FC Victor 4-speed cover).

When installing cover align reverse pinion for fork to engage collar on pinion -

Image

(Striking lever peg in view doesn't engage with anything in neutral.)

Drain overdrive by removing its sump. There is a screen filter behind a threaded plug: requires a special tool to unscrew the plug which has two holes in it, often chisel damaged...

TS862 manual for Laycock J-type overdrive on its way to your Library folder: expect email with link. :thumb:
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Vauxhall 4 Speed & Overdrive Oil Change

Post by MattA24 » Subscribing Member » Fri Sep 07, 2018 2:07 am
Joined: Wed Jan 15, 2014 9:06 pm
Posts: 195
Darn with the gearbox still in the van, I can't imagine a way to get those covers off without getting oil absolutely flipping everywhere, particularly because the liquid gasket the cover us stuck on with means it won't come off gently!)

Ah well :lol:

Does refilling the gearbox refill both, though? :?:

Thanks for the bedtime reading! :geek:

Re: Vauxhall 4 Speed & Overdrive Oil Change

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Post by Phil Bradshaw » Club admin » Fri Sep 07, 2018 2:20 am
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3669
Glue shouldn't be a problem: transmission bottom cover probably will need a nudge anyway to free the two locating dowels from the main casing.

A feed bowl or similar wide container propped on house bricks should catch all the oil (2.4 litre or so if full to start with). Lay some cardboard down to catch wayward drips.

Aim for the rear of the bottom cover dropping first, to hang on the front two bolts so that the oil drains rearwards, sort of: some nearly always comes out sideways.

Once oil starts running out go take a break, remove cover when it's just dripping.

Filling the transmission fills the overdrive eventually (it has its own little pump): need to top up after a test drive to make up for oil taken by the overdrive.
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Vauxhall 4 Speed & Overdrive Oil Change

Post by Robin from France » Subscribing Member » Thu Sep 13, 2018 8:20 am
Joined: Thu Jan 02, 2014 2:17 pm
Posts: 76
Hi folks,

this is great help, because I'm about to change my gearbox / overdrive oil too after ten years and forty thousand kilometres it must be time.

What grade of oil should I use? I initially filled it with SAE 40 monograde oil, as recommended by I don't remember who. Is this suitable or should I use something thicker.

When hot, the overdrive is occasionally slow to engage, and the box needs topping up every year.

Robin

Re: Vauxhall 4 Speed & Overdrive Oil Change

Post by MattA24 » Subscribing Member » Thu Sep 13, 2018 9:00 am
Joined: Wed Jan 15, 2014 9:06 pm
Posts: 195
Hi Phil,

Got the covers off with a bit of shoving. The technique used was to envelop the bottom of the gearbox in a binbag, then shove at the cover through the bag. :thumb:

All for naught really because there was only a dribble in there! :?

Robin, the recommendation for the Vauxhall 4speed is SAE90 (or 89w90) but it should be to the old GL1 specification, not to the modern GL4/5 specification. The modern stuff has EP additives that people claim will errode your synchros!

Re: Vauxhall 4 Speed & Overdrive Oil Change

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Post by Phil Bradshaw » Club admin » Thu Sep 13, 2018 10:54 am
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3669
For the Vauxhall transmission GM specify API GL-1 (GM4753-M, MIL-L-2105A) without EP additives which 'can contribute to corrosion and wear of yellow metal components' (e.g. sychromesh cones, brass face thrust washers).

My guess is that it's something to do with 1960s design (Victor F series, CA van) that only changed significantly about 1980 (modified syncromesh - identifier is cones for 1/2 speed larger diameter than 3/4 speed; earlier cones are all the same size).

Slow overdrive engagement may be due to sticking relief valve, sticking solenoid valve, blocked screen filter or a combination.
Robin - PM on its way: new upload to your Library folder. :thumb:

Only once a year for topping up the transmission is good going for a Vauxhall transmission.
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Vauxhall 4 Speed & Overdrive Oil Change

Post by Robin from France » Subscribing Member » Thu Sep 13, 2018 11:03 am
Joined: Thu Jan 02, 2014 2:17 pm
Posts: 76
Thanks both,
I'd better get some thicker oil then!

Robin

Re: Vauxhall 4 Speed & Overdrive Oil Change

Post by MattA24 » Subscribing Member » Thu Sep 13, 2018 11:10 am
Joined: Wed Jan 15, 2014 9:06 pm
Posts: 195
Phil, I've never found a satisfactory stockist of non-EP oil. Have you?

Also, I've heard others say on other forums for other old cars with yellow metal that it's not really an issue because the EP additives have got less potent since GL4 first came out, and it's not worth worrying about. What's your take?

Cheerio!

Re: Vauxhall 4 Speed & Overdrive Oil Change

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Post by Phil Bradshaw » Club admin » Thu Sep 13, 2018 2:24 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3669
Dunno: not enough data.

If I was running a CF with Vauxhall transmission then I'd know already (a) where to get non-EP oil and (b) whether GL-4 will do ... :)
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

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