First winter in the MX5 and I notice the gearbox is a bit stiff and notchy when cold first thing… I know this is commonplace with nearly all cars as it’s not the first time I’ve experienced it, however out of good practice I’d like to do an oil change on the gearbox.
And on that note, what oil grade and brand would you all recommend?
And is the job itself a DIY one? I’m aware that a fluid pump is required, and to make sure the refill plug comes out before undoing the drain plug… but other than the basic precautions, anything else I should be aware of, or any useful tips?
There are plenty posts on here re the best oil to use so the search button is your friend.
This is a self help forum and it is expected you will help yourself first by using the search button.
If you do not have access to a lift stop wasting your time and pay the local garage £30 to change it for you unless you love crawling under a car on axle stands.
I did look first but I couldn’t find anything conclusive… It took me more time to look and find nothing than it took to just ask the question and hope someone can post a quick answer…
And regarding the ramp, If I can save a few £££ by doing something myself then I will, but thanks for your help
If it’s the 6 speed then they are notoriously notchy when cold.
There are quite a number of threads regarding this, as well as adjusting the free play on the clutch pedal.
I wouldn’t bother with the free play adjustment though, as in my opinion, it made no difference.
As for changing the oil, Castrol Syntrans 75W90GL4, seems to be favored, and whilst changing the oil may have a small improvement, it’s by no means the miracle cure you might be looking for.
You will need to get it up on ramps to remove the shielding etc.
Loosen the filler plug before removing the drain plug… if I remember correctly you’ll need a 22 or 24mm socket/ring spanner.
You’re probably aware already that gearbox oil usually comes in 1ltr bottles with a very short spout, without a pump of some sort, you’ll need to extend this spout by about 2 feet.
With the car on level ground, the spout extended, and the passenger door open, you’ll be able to sit in the car with the bottle between your legs and squeeze like mad.
It’s easier if you warm the oil first.
Then get it back up on the ramps to tighten the filler plug and refit the shields.
The job will take about an hour and half, due to faffing with the ramps, shields and the laborious task of squeezing the oil.
I recently changed my G/Box oil and used Castrol Syntrans 75W-90 fully synthetic, I got it from Opie Oils, and it certainly helped to improve my notchy 6 speed box but it is still there so not a total cure. Did the Diff at the same time as it was a quick job to do once the car was lifted and level.
Well to be honest mine is the 1.8 5 speed so the notchiness probably isn’t nearly as bad as yours. Even if I didn’t much improvement, I’d have the peace of mind knowing it’s all been done and I don’t need to think about it again.
Although the more this thread goes on, I’m beginning to wonder whether I can do this myself on the driveway or not
So all in all, 2 litres of oil would be around the £25 mark, a pumping tool might be another £15 or so… Anything else? Any consumables? I might just spend the money and have it done at a garage really but at the end of the day it’s just an oil change… In the words of Jezza, ‘How hard can it be?!’
The only difficult part was getting the car lifted and level on a slightly sloping driveway, other than the oil just a drain plug washer (plus another litre of oil and washer if you do the Diff).
I was quoted £25 by a local garage to change the G/Box and Diff oils (got the price just in case I couldn’t get her lifted and level) and that was with me providing the oil, but it turned out okay and as I was doing the brakes and a few other bits at the same time I never went that route, so it might be worth checking with a few independents local to you.
My post refers to the 6 speed re turret oil, it does take a little.
The 6 speed takes over 2 litres but your 5 speed will be ok with just the 2 x 1 litre bottles.
I bought a suction pump from Machine mart, less than £10 if I remember. It does the job but leaks as you are pumping the oil in, it’s ok for a 2-3 oil changes but not something I would like to use on a regular basis, but I don’t need to, job done.
I tackled this job from the left side of the car as of course that’s where the plugs are. I got the car up on that side on axle stands, yes it is a faff raising and lowering the car but easier with a trolley jack jacked up on the sills.
I’m 62 yrs old and shouldn’t be crawling around under cars these days but feel a sense of acheivement at DIY and that goes for most jobs whether in the garden or home.
Thankfully not everyone is unwilling to help give a straightforward answer, otherwise what’s the use of an Owners’ Club Forum (or for that matter, an Owners’ Club)?
I found that the standard type of extendable spout on gearbox oil bottles fits securely into a piece of (standard size, half inch i.d.) plastic garden hose. I had a spare length of this, which is now used just for this purpose. We changed the gearbox and diff oils on my son’s Mk2 a few weeks ago, before the weather turned cold!
^^^ Yep that’s a method I used on my Mk1/Mk2. Feed the hose down from the engine bay and let gravity do it’s bit.
If you’ve ever tried and done that method on a Mk3 then great. I failed to find a route down from the engine bay to gearbox for the hose. Not saying impossible, just saying I wasn’t successful.
But I do feel routing through the engine bay might be difficult…
So I feel like I have a good enough idea of how to go about the actual process now, but the refill and drain plugs are a concern… I’ve read some horror stories about them shearing off and all sorts because they are made from what resembles cheddar, apparently.
Has anyone got any experience of this? By the looks of mine, I feel confident in saying it doesn’t look like it’s been touched since ever, at least that’s attitude I’m gong to take!
