- My model of MX-5 is: na eunos 1.6 ex auto now 5 sp
- I’m based near: __ulster
- I’m looking for technical help or recommendations on: __ 5sp transmission V 6 sp trans, o/a strength noise, syncro stengths
Hvaing done a lot of research and read almost everything i laid my hands on the general feeling i got was the 5sp was had utility wagon pick up box origins, was strong beautiful change, decent ratios for sports car, then i bought 2, had one cleaned up and fitted it to the car all the work farmed out to a friend a f/time mechanic who also serviced and fettled 5’s for guys who competed in them… my thoughts since putting it over a few hundred miles is that whoever said they were strong had a nice change weren’t noisy had never driven mine, or any decent Japanese 5 speed box rear drive car… not being satisfied i spoke with a local box fettler, he knew me from years back when i competed, i had his opinion on them as well and its not printable on here, nor was he keen to tackle a check over on my spare unit they’re a ballix to build he claimed. I’d like to hear what you guys think who are way more familar with 5’s than me…w
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MX5 five speed box takes some beating and apparently works very well on an auto conversion, 1.6 and 1.8.
There must be something wrong with the box you have fitted as 95% of us with MK1/MK2 are driving around with these and no issue. I have a mate who has just done this conversion, 1.6 auto to 5 speed manual and over the moon with it; seems to be better to drive than the standard 115bhp manual car.
I cannot comment on rebuilding an MX5 five speed box as they are still cheap enough to buy as a unit and I think are likely to outlast the car they are fitted to from new.
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As regards the better than OE 5 sp statement one could perhaps tie that down to the autos claimed better torque, i’ll agree that so far my choice of box is likely a wrong 'un, however that chat i had with the chap who used to do my gti golf gearboxes his words of warning were that the chaps he fettled for were lucky if the syncros lasted one rallye event…and the event maybe had 16 /20 of them out there ,that didn’t give me much succour… anyone else have a comment ?? w
The Standard 5 and 6 speed boxes cope well in forced induction cars, so your small amount of extra torque will make no difference. They are a strong box no matter what your " expert" says.
Has your box been standing around getting rusty before you got it?
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strong convictions here, my expert runs a successful business for over 30 years and has vastly more experience around transmissions than you or me, when i hear what you say i wonder if you’d have the same conviction on a good conclusion if your friend said you’re fine you’ll last another 20 years and your heart specialist says your time here is limited unless you have surgery, personally i know whom i would listen to… the man who works with the stuff daily…
.as to whether it sat around God alone knows… I know we drained the old lube and put in new stuff when we were fitting it… THE SYNCRO WAS FINE FOR 20 MILES then crunch every change over 10mph…don’t ask about the gear change quality…i surely cannot be the only chap out there with these issues…
I’m not a heart specialist.
But I have been around these cars for over 20 years and had a forced induction car with 200 bhp and no gearbox problems. A friend also has a FI car (for 17 years) with 230 bhp and no gearbox problems (including many track days)
If you are so convinced your expert is right, why ask the question?
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OK i hear you , that personal experience counts, i have nearly 35 years experience, why are you rattled over my query, yes, before i spoke with the ‘‘expert’’ i would have probably agreed with the general consensus from my research and general forum chat, i’m not convinced about his views this guy is good and i am left wondering why…I just didn’t want to haul the box out and fit something again very cheap for a 5sp box at 50 or less and be right in the mess again and basically thats what was coming across from him… I do try to be dispassionate around machinery… but if it can stick hard driving with nearly double the power, chances are this second box will sort the issues… thanks for your input, will
The 5 speed box is a good strong gearbox but is it does need the correct oil to function. The 75W/90 GL4 is the way to go, do not allow anyone to convince you that GL5 is better! it is too slippery for the synchronization used in the Mx5 box and will cause you problems. Personally I use Redline MT90 and don’t forget to renew the turret oil as in the 5 speed it is lubricated separately.
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Interesting, these mx5 boxes origin in a Jap pick up truck wouldn’t normally direct anybody to anything sophiscated in its requirements for a special lube in the gear box, however i’ll look into those mentioned when I refit with the other box as the girning and off power overrun noise tells this one is on its way out…w
Before doing anything else I’d check the clutch operation/clearances.
Don’t know much about the early cars but on the MK 3s the pedal free play can make a big difference to gear changes— lots of posts about this over the years.
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More like a failing slave cylinder on a mk1/mk2 but I trust this has been ruled out.
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Usually ends in divorce!
guys guys, this is a first few months after a full rebuild on everything except the power unit, that is on hand at present, and in my 35 odd years experience i know when a clutch isn’t clearing. i have no issues seeking first or reverse,even at high t/over… however as mentioned they, the gear changes are far from the slickness that so many spout about, so after being straightened out on here it would appear the first box i had fitted is just a very poor example and must have had a very hard life before i bought it… thanks anyway…w
You want a 5 spd MK 2/2.5 box and is the box the fit with the lowest mileage you can get, stronger box than the MK 1 unit, do not fit a 6spd,that would be a bad move, did you also fit a LSD ? 4.1 is a nice mix, but also off a MK 2 or Mk 1 , do not fit a fuji diff, but you must be aware that the 1.6 auto is down on power any way to the standard 1.6 manual regardless of fitting a manual box to her.
M-m
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hello, yes, its a mk2 box… yes, when we had the first drive after insertion i realised we had a diff and a tight one, spun the car like a dime, maybe previous owners fitted one why in an auto?? cause its not that noticeable ,the car may be down on power but not really an issue as this one has a lot of torque its pulling 3rd from a standing start no problem at all, plus the planned power upgrade is with a rebuilt head off a low mileage 1.6 same era and later the short motor off same unit,maybe coming up around 10/1 honed and reringed, strange you say the mk1 box being secondary to the later ones as the diff guys around N Ireland say otherwise according to the biggest 5 breaker this side of the Irish sea…they rave about the 2nd and 3 rd gear… the ones they use and break mostly…w
There is also someone over in Ireland who rebuilds the Fuji diffs, so the old issue of problem and them scrap now seems to have been dealt with.
Quite a few reckon the Fuji, when working properly is better than the Torsen 2 but then again quite a few reckon a lot of things and sometimes its tosh.
Auto with a limited slip diff, surely absolutely pointless?
Did you change the gearshift turret oil and did you check the state of the nylon bush in the gear selector? 5speed turret oil is separate from the box oil and may have drained out if the box has been stored on it’s side previously.
As previously stated I left the heavy end of the transfer to a friend [ complete with every piece of paper i could find detailing what needed sorted] a time served young chap who does bits and pieces for several younger friends with 5’s who do these small rallyes , hillclimbs and sprints I perhaps assumed he knew all about the ins and outs of the boxes doing clutches etc… i did ask him about that and had a non committal reply that may have something to do with the unslick changing feeling…it was transported sans oil to me, stored on its bellhousing vapor cleaned on its side and bellend… and filled with whatever oil he uses in the ones he works with…just wondering could the slip have been OE… agreed i never felt a slip when i drove it before i started to rebuild and i covered a few hundred K’s… it has bolt in half shaft arrangements. w
Not really a special oil just the one that is recommended and in its best form.