Gearbox Whine 275 Cup-S

Hi Billy thanks for the mention

I still need to finish off the gearbox, but as mine is still going strong its not high on the priority list, my original gearbox lasted till 90+k miles (full Renault service history) I bought a gearbox off of Ebay as a stop gap and has lasted a long time now, still sweet with it running 388hp and numerous trackdays.

The only problem with the mk3 gearbox is it is very heavy, easy to strip though, easier than a mk2 box.

By looking at the inside the bearings Renault used were cheap ones and the newer the car the cheaper they are, sorry probably you didn't want to here that, the box i am building has the best bearings in it you can get, not a job i want to do too often.

 

I bought my 225 with a gearbox fault, it was jumping out of 6th gear, i had the guy next door to my workshop rebuild it as i also wanted a diff fitted (we helped each other out so didn't charge) but the parts were a lot of money, so i bought another box and he checked it, replaced the bearings and seals.
That gearbox was being punished a lot, forged 250 engine 320hp and 360ftlb of torque.
That box lasted a really long time, it was my track car did loads of trackdays with no problems.

I put Extralube ZX1 in my gearbox's and in my engines and that works very well.

 

What is this zx1 extralube?

I used to use slick to back in the day?

Is it similar?

Had a look online seems to make some big claims. Even suggests adding to the fuel? I find unusual that an oil additive is also a fuel additive.

 

Had the same issue on my Cup-S at 26k, it was a very faint whine. Was diagnosed as the diff by my local Renault dealer, fortunately mine was still in warranty! Glad you got sorted and fingers crossed your gearbox troubles are behind you.

 

Ironically the box in my 200 was sweet despite their reputation!

 

Intrigued to know how long the box would've lasted? It was still working fine as far as I could tell, just becoming increasingly noisy.

 

Are the gearbox and diff seperate parts? So what is whining the diff or the box?

When I see diffs advertised for focus rs or fiesta st they only seem to be £7 - 800.

Only experiance I have of a whiney diff was on an opel manta 30 years ago. Only noticed it when the stereo broke. Fixed the stereo. Problem solved.

 

I was told it was the diff but I'm no expert. Presume the diff is housed within the gearbox casing therefore probably making more sense to replace the whole thing? Taking the diff out of the gearbox housing I would presume is more labour intensive.
Never thought of just turning the stereo up to drown it out!

 

Sure ianplymouth can educate us!

 

Done my usual Xmas oil/filter change, done the gearbox oil aswell. Glad I regularly change after reading this. And yes, I got my right forearm covered in oil taking old filter off.

 

Most people probably straight piped the exhaust so can't even here the stereo!

 

Not sure fresh oil would have made a difference on such a young box?

 

Yeah, possibly. Just saying, that’s all. First changed my Gearbox at around 30,000 I think.

 

Definitely a good thing to do, I'll be doing mine for sure!

 

Last changed it 2 years ago, think done 2 or 3 trackday max since changed it last. Even though came out pretty clean can tell a difference on the shift. Cleaner,easier, smoother action so well worth doing for relatively easy job. Typically do about 10,000 miles a year unless I go on a big trip.

 

ZX1 is a friction eliminator, i used it years ago when QVC sold it.

Never used slick 50, so can't give any feed back

I used to use it when i raced lawnmowers ( yes i know ) Good crack, great bunch and a lot of drinking, whats not to like.
Anyway, we lost a couple of engines due to there not being an oil pump, there splash lubricated fine for a lawnmower at 3600 rpm and on the flat, but with ours were running 5-6000rpm and with the cornering the oil wouldn't splash enough, once we poured some ZX1 in we never lost an engine in two years.

Its good in diesels as it lubes the injector pump and the injectors, suppose it would still work in petrol engines.

 

The diff is in the gearbox, so it use's the same oil as the gears.

A Quaiffe diff for the Megane gearbox whether its mk2 or mk3 are about £700-800, they are the same as the ones fitted in the cup box's.

There is my strip and build of the mk3 gearbox on here, needs finishing though.

 

My gearbox wasn't noisy, it started crunching when changing into 3rd gear, got so bad i had to change from second to forth and changing down as well, then 4th started to crunch, so time to swap out the gearbox.

 

I change the gearbox oil every time i pull the engine out, if it doesn't come out to for a while then its annually, well it gets a hammering on track.

 

Exactly. I would change it annually if done more then 3 trackdays, this hasn’t happened yet but may well do in 2021 after the famine of 2020. Good/interesting post on the gearbox by the way.

 

3 trackdays i am looking at engine oil changes every 3 trackdays and gearbox oil changes annually or about 15 trackdays , well hopefully

Thanks about my gearbox post, will finish it off soon

 

So is a quaiffe diff better/more reliable than the originals?

 

I am sure there very much the same, why do you ask about reliability of an original diff, i have never heard of any problems with them.

I fitted a Quaiffe to my 225 as it didn't have one fitted and couldn't find a R26 one at the time

 

My gearbox whine was diagnosed as the diff being the issue which I appreciate I can't take as gospel from a non Rs specialist Renault dealer. Just interested too!

 

I would say its possibly the diff bearings, they are not part of the diff in reality, they just support it

There isn't anything inside the diff that can go wrong, Quaiffe give a lifetime warranty even in race cars

 

Ah right, cheers for that. Shame Renault don't do a lifetime warranty!

 

they would have gone bankrupt years ago if they had

 

When I opened my box up due to a whine, I found that the diff bearings had been changed previously at some point. SNR bearings were fitted in stead of the OE items. Meaning my box has been apart twice in 60k miles. Firstly for the diff and secondly (by me) for the short secondary shaft (3rd & 4th). Hopefully the full set of SNR bearings I fitted will last.

I think all in for me, including a press, two sets of pullers, oil, bearings, a new 4th, c clips, seals and baffles I was around £600 odds.... and a fair amount of head scratching, swearing and crossing of fingers.

Like ianplymouth mentioned, not a job I'd want to be doing too often. Took me a fair bit longer than anticipated. There are some pics and info on my project thread. It's a shame that the PK4018/9 seems to be soft and such a common issue.

 

How easy is it to get it in the gearbox? Post a couple of pics?

 

I hate this thread. Generally thought the meg was reliable.

This is starting to read like Scooby 2.5 failures, m3 v8 rod bearings, e46 boot floors and clio gearboxes.

It's like every car has a forum Achilles heal.

 

I wouldn't go that far!

Got my cup-s at 18k, now on 31k. Had no issues and fingers crossed that continues.

 

Guess it depends on previous owner mainly, 54,000 miles for me,bought a year old from Renault, 11,000 miles was a staff car for a year. Done nearly 10 trackdays with it, two 2,000 mile trips to South of France. Really no issues, regular servicing. Easily the best/most reliable car I’ve owned although was first nearly new car I ever bought.

 

I think if the driver has an understanding of mechanical sympathy, it'll increase the lifespan of the running gear.

At least a gearbox can be 1 for 1 swap.

 

Having some mechanical sympathy and understanding will help a great deal .

I managed to save my 225 (250) engine from seizing at Thruxton, coming from church to the chicane i heard a noise, dipped the clutch and coasted into the pits, let it cool down a bit and started the engine, ohhhh big noise.

Did manage to drive it Stonehenge before it got too bad to carry on, recovered home.

Stripped the engine and it as suspected, it had run a big end bearing, it was also ZX1 i really think that saved the conrod exiting the engine.