Gearbox Oil Change

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Telegram Sam
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Gearbox Oil Change

Post by Telegram Sam »

I'm told that to do an oil change for my 5-speed C/R SRi box means dismantling the drive shafts. Is there a way of partially draining the oil without the hassle of dismantlng? I want to top up what's there with one that Opie recommends for stiff gear changes (2nd, when cold).
'91 H-reg SRi "130" manual hatch 8-valve non cat with mods
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Envoy CDX
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Re: Gearbox Oil Change

Post by Envoy CDX »

Who the hell told you that? You'd never get all the old oil out that way.
Buy a new bottom pan gasket for the box (10-16 from Vauxhall), drop off the pan, (with a tub underneath)
Clean everything up, replace the gasket, bolt it all up.
Refill following the Haynes manual.

However, if you have stiff gears - look at your linkage first too.
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Re: Gearbox Oil Change

Post by Mk3alan »

I recently have changed the oil in my CDi box (and fitted drain, see my post)
I fitted the new gasket from Vauxhall which looks great with like an 'O' ring moulded around the inner edge - but it leaked!
All perfectly clean and torqued up correctly, I got hold of the earlier plain gasket and with a very thin application of blue hylomar it has been fine since.
Get the older gasket!

Alan
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Telegram Sam
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Re: Gearbox Oil Change

Post by Telegram Sam »

However, if you have stiff gears - look at your linkage first too.
The problem only occurs when I change down into second when the car is not warmed up which made us think that it was probably more to do with the oil spec than with the linkage.

Points re replacement gasket (+ reminder to use a tub!) noted, tks.
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Super89
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Re: Gearbox Oil Change

Post by Super89 »

Use Vauxhall gear oil. also what miles has your car done?
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Re: Gearbox Oil Change

Post by Telegram Sam »

229 K if you press me, including engine rebuild / overhauls. Under normal conditions I've got no moan with gear changes, just when cold, and the man from Opie recommended me an alternative oil that would or should address such situations.
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Robsey
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Re: Gearbox Oil Change

Post by Robsey »

Nothing against the man from Opie...

He is a salesman, so he is bound to recommend that you buy one of his products.
Apologies, but that is the cynic in me.

I am sure a complete gear oil swap would do the same trick.
Your original oil will be completely different after 20 years of shearing and mashing from the gears, and obviously the constant changes in fluid temperature.

Assuming that you use oil to the same or equivalent spec that Vauxhall supplied specifically for your car.
So apparently your gear oil should be -

Manual Transmission =
SAE 80 EP.
Vauxhall part number 90 188 629

Auto Transmission =
Dexron II type ATF.
Vauxhall part number 90 350 342
(Same as for Power steering).
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Re: Gearbox Oil Change

Post by Telegram Sam »

I'd be kinda shocked if the oil in the gearbox was as old as the car! I'll have to check but I'm assuming that when the engine was overhauled and rebuilt the gearbox oil was changed at the same time, by someone who knew what he was doing. If so then what's there should be very new-ish and up to spec. Worth checking though (manual transmission - automatics give me the willies)
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Re: Gearbox Oil Change

Post by Robsey »

Many people don't faff with the transmission oil because it is a messy job entailing the removal of the bottom cover plate and gasket.

I am sure that if a sump plug had been fitted, then many more people would change the oil regularly.
I have to confess that my Cav is still running on the gear oil that it left the factory with in 1994.

I have looked at the Opie site, and there are literally dozens of options for EP80 gear oil rated GL4.
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Re: Gearbox Oil Change

Post by Telegram Sam »

This is what the man said:
Originally the gearbox in your SRI was recommend an 80w that meets API GL4, as a modern upgrade I would have a look at the Redline MTL
http://www.opieoils.co.uk/p-1019-red-li ... 0-gl4.aspx
This has been well proven on fixing difficult shifts.
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Re: Gearbox Oil Change

Post by btcctroy »

Telegram Sam wrote:I'd be kinda shocked if the oil in the gearbox was as old as the car! I'll have to check but I'm assuming that when the engine was overhauled and rebuilt the gearbox oil was changed at the same time, by someone who knew what he was doing. If so then what's there should be very new-ish and up to spec. Worth checking though (manual transmission - automatics give me the willies)
I'm not being funny but when you had the engine overhauled why would they check the gear oil. It's not part of the engine rebuild, other wise it would be listed as an engine and transmission overhaul. 2 separate things.
The gear oil needs draining and refilling with ep80-90. Like Robesy states the oil would have broke down not lubricating the parts the way it was deigned to
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Re: Gearbox Oil Change

Post by Super89 »

Is the cavalier gearbox oil not still used in nearly all modern vauxhall cars?
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Re: Gearbox Oil Change

Post by Super89 »

Anyway I would stick with genuine GM oil. Mine feels better after I changed it a few weeks back. The mileage your gearbox has done might need a quick refurb.
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Re: Gearbox Oil Change

Post by Telegram Sam »

I'm not being funny but when you had the engine overhauled why would they check the gear oil. It's not part of the engine rebuild, other wise it would be listed as an engine and transmission overhaul. 2 separate things.
That was the query that was in the back of my mind.

I'm sure that the oil was changed say a few years ago to the proper GM one. The question is, how frequently should this be repeated and if I am experiencing the symptoms I've described if there is a case for varying the spec at all?
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Re: Gearbox Oil Change

Post by Telegram Sam »

I fitted the new gasket from Vauxhall which looks great with like an 'O' ring moulded around the inner edge - but it leaked! All perfectly clean and torqued up correctly, I got hold of the earlier plain gasket and with a very thin application of blue hylomar it has been fine since. Get the older gasket! Alan
Anyone know the part number to avoid getting the new-style gasket? If not I'll put a query on the parts number sub-forum
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Re: Gearbox Oil Change

Post by Super89 »

I got mine from GPS and its not leaking. Think mine was the old type too

My gearbox is the F13 so might not be the same..??
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Re: Gearbox Oil Change

Post by Telegram Sam »

Sod's Law says that it won't be the same. But I suppose that someone competent like Autovaux / GPS should be able to identify it if I can't supply them with the correct part no myself for the 5-speed close ratio box (I forget the F number).
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Re: Gearbox Oil Change

Post by Telegram Sam »

Rings a bell though I'd be happier if one of the experts could confirm this - and/or tell me where to get the old part number from!
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Re: Gearbox Oil Change

Post by Telegram Sam »

Last time I had a look it was covered with Rustbuster underseal like the rest of the underside.
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Re: Gearbox Oil Change

Post by Envoy CDX »

Box markings are on the top of the box near the gear selector.
Gasket part number I would need to check up on (EPC isn't installed at the minute).
GPS / Autovaux should be able to get you the correct part if you give them your reg number - usually all they need really.

As for box oil, if the box was rebuilt, then yes. But you've never mentioned (that I can recall) a box rebuild to me in our chats - and if so, there is no guarantee that GM box oil was used.
There has been an occasion where I used the Halfords equivalent and my box was a nightmare for gear changes - swapped it back out for the standard GM stuff and it was like a different box!
Don't ask me why - just seems to be a different grade of goo! :)

But pretty sure it will be an F16 Close Ratio box as above.
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Re: Gearbox Oil Change

Post by humbucker »

Envoy CDX wrote:Don't ask me why - just seems to be a different grade of goo! :)
Pretty much all GM fluids are of excellent quality.
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Re: Gearbox Oil Change

Post by Telegram Sam »

I think the gb oil was changed some years ago without the box being rebuilt. I don't know if Searles would have touched the box when they had the engine there.

I will approach Autovaux re an old style gasket for the F16 box on my reg and see what the reaction is

I just wondered if within GM oils there was one or more whose spec would be particularly suitable for a sticky-when-cold 2nd gear situation?
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Re: Gearbox Oil Change

Post by planetc »

They introduced a modified oil spec roughly 1993, supposedly to help with poor cold shifting. The part no ended 0998 if I remember correctly.
"No the temperature gauge doesn't work........
we've driven 150 miles today........
the heater went cold last Thursday........
they check the level when it's serviced don't they?"
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