Gearbox oil options

[osta]

I recently changed my gearbox oil to Red Line MT90 75W-90 GL4 expecting great things in terms of smoother gear changing based on the many reports about this oil but I have to say I've not noticed any improvement, if anything I would say it's slightly worse than the previous gearbox oil. I'm debating whether I should live with it and see if things stay the same or get better or change the oil again. I was therefore wondering if anyone had other suggestions on gearbox oil that might be worth a try.

[Mazda Mender]

Don't you just love the interweb....
I have used the red line, which is this all singing and dancing oil which gets up early makes you breakfast and a brew ready for you mad day ahead, and never felt any difference, the heart of advertising....
Which gearbox/diff are we talking about here?
M-m

[Lazza]

I've used the same Redline in all 3 of my MX5s and it has made a noticable improvement on all of them, especially the '98 Mk1 1.8 5-speed which was typically tight & clunky, especially 1st to 2nd but improved a lot after the oil change. On my current Mk2.5 6-speed it made very little difference but it felt great before so there would be nothing to notice. On our old Mk1 1.6 5-speed track car the gearbox had a number of "issues" and MT90 definitely made it better for a while (until it died altogether).

So really I'd say, it depends on how your gearchange felt before and what you were expecting from it.

[osta]

I have MK1 1.6 whose gear change is not bad but a bit clunky and stiff especially changing up from 1st to 2nd. I'd hoped the Red Line would make things a little smoother and enable a faster gear change but I'm still finding I have to slow changes down a bit as I did previously. I guess at the end of the day it's all hearsay and there's not much hard data to prove the stories that tend to go around. I'm currently looking at changing to Ford's 75w90 GL4 transmission oil which many people seem to say is better than Red Line for MK1s but I guess it's all a gamble when all's said and done.

[drumtochty]

Osta stop wasting your time with oil. You have changed and it made little difference.

You could replace the clutch slave cylinder that may make a difference but maybe not. They tend to go a bit soft after some years but not all of them do.

You could make sure there is turret oil in the change turret in this case any oil will do. It may make a difference.

You could replace the gear shift boot package available from a number of vendors.

You could change this bush
http://www.mx5parts.co.uk/gearlever-nyl ... p-696.html

You could loosen the frame behind the gearbox and retighten it.

All these may make a small difference.

In some cases, some cars just have a notchy gearchange end of story.

[osta]

Thanks for the advice. I think the annoying but also intriguing issue here is the part that different oils play in improving a car's performance (or not!). If it's the case that one oil is no different from another then why doesn't everyone just go for the cheapest. Although a lot of the evidence and reports seem anecdotal and subjective there must be something happening, other than coincidence, when somebody changes their oil and notices an improvement. At the same time I realise that I could waste a lot of money for no real benefit, but that seems to me a natural consequence of any hobby, which the MX5 is for me. So back to my original question - any other suggestions other than Red Line?

[Mazda Mender]

You are reading in to deep with all the oil crap on the interweb, leave it now and as Eddie says try new upper and lower gear shaft boots and slave, turret oil and then look at other things.
M-m

[osta]

To add fuel to the fire and to undermine my own arguments about lack of objective research into the qualities and benefits of different oils I stumbled across this document that some people might find of interest. http://www.goodsenseoil.com/G2457-GearOilWhitePaper.pdf

[Mazda Mender]

Not interested in a debate over oils, tyres, roofs, marks , enging size, drilled and grooved disks . 14 degree timing because it gives 700 bhp more etc, stop reading the internet 90% of it is just sh*t , most of what you are reading is hear say passed along and changed, or has been done for a look only (form) rather than performance (function), as you get more into it you will see all these can of worms being opened up across everywhere.
We will not bull sh*t on here, you will only get honest straight advice, like the posts above in this thread and we pride ourselves on that for too many years of us all fettling and spannering on these pocket rockets and we share all that free because of the passion to help fellow owners, and are here to make sure you get the right advice, to get the right parts at the right price ,from the right co's and how to trust with your pride and joy if that needs to be the case other than that we we help in guiding you in the ways to do it correct, safe in the easiest way.


Lazza and Eddie have whacked the nail on the head big time, just remember how old that box is and unknown history, changing some of the bits above could solve it, but on the other hand it could not, but they are the things to try first that are your cheapest options.






M-m