Drivetrain Help Please
 

Hi all,

Any help or advice would be greatly appreciated!!.. So a couple of weeks ago I may have dropped my clutch knowing that my dif and gbox were week and with a fresh dif and gbox on hand I wasnt too concerned for the consequences...

Basically I launched dropping the clutch at about 4k in my turbo and there was a loud clank like a metal on metal clunk?! I have put the new dif in first of all as I first thought maybe pinion gear but this has not helped the clanking. While idling the car sounds as normal and I can engage any gear without any unusual feelings in the gbox.

So now the car is up on stands still and before I remove the gearbox I am thinking of picking up a driveshaft and trying that first before needing to replace the box(want to get on the road!)? At the moment while driving once I have any load on the car it will clunk loudly feeling and hearing it through the gbox tunnel especially uphill and this can happen in any gear but most obvious while taking off and after shifts.. How much play is too much in a driveshaft when the car is placed in gear? At present I can hear a tiny knock when I try to move the driveshaft around while the gbox in engaged - maybes moves a couple of mm.

Sorry for the long winded call for help.

Cheers guys

Let me be quick to say "Hahahahaha!"

How are your motor mounts ?

I have to admit they have never even been looked at in my 3 months of ownership... The car has passed local WOF inspections without anything being said... Could one hard launch of thrown out the engine mount causing these crazy loud clanking metal on metal sounds?


Cheers mate

I agree, I'm an idiot as one of the things I knew I had to do when buying this project was to strengthen the driveline and all bushings!

Lmao sixshooter!!

Does it make the noise when you are coasting in neutral? If it does, the drive line could very well be the problem. If it doesn't, engine or clutch related. The only reason I ruled out the trani is because you said it makes the noise in any gear, I'm not quiet sure that it would do that, But i've been wrong before...

Sure, if they were already old, worn, and tired it's quite possible. Have you looked at the position of the motor to see if it is even sitting properly? Also, does the shifter look like it's oriented properly, i.e. 1-3-5 are all where they normally should be? I've seen where mounts completely broken free, which allowed the motor to shift out of it's normal cradle position and get hung up all crooked on the remaining lower halves of the mounts. Still drove fairly ok until you got any load on the motor, and then it would clank around a bit and cause the shifter to be off (1 was where 3 had been, 3->5, 5 rubbing right side of tunnel opening, etc.). May not be your problem, but it's sure easy enough to check for.

Nope it doesn'd make the noise when coasting in neutral.

So I have now replaced the engine mount that was in question, although it looked well on its way out all it did was quieten down the idle of the car and make it alot easier to pinpoint where the sound was coming from.

So basically now when in gear on axle stands if I accelerate and then let off throttle and quickly accelerate again I can phisically see the tail end of the gbox shake and rattle - it almost sounds like a bearing or something that is turning off its axis pehaps? The driveshaft seems to be in good nick after expecting it after removal. Currently I am removing the gbox once I manage to get my downpipe off and hopefully get my spare one in soon!!

If it was clutch would I not have felt something through the clutch pedal or biting point etc? Also in regards to the engine she idles sweet and in neautral freely revs etc and sounds as shoudl?


The motor is sitting correct as far as I can see and the lever was in the same position as my other mx5s so guess that isn't the problem.

Thanks again guys :vash2::vash2:

Did you snap one of the PPF bolts that holds the trans in place?

Sounds like you're taking it apart anyway, so I'm sure you'll find it...

Nope didn't snap any bolts, I have replaced the diff and those bolts were fine and same with the transmission bolts in the PPF.

The sound to me pretty much sounds like it is coming from around where the slip yoke sits into the transmission but the slip yoke seems to be fine... This makes me think gbox... i really hope it isn't clutch or flywheel as these are both uprated and never had any issues at all before,

I highly doubt it is the clutch from your description. When the transmission is out and on the ground, spend a few minutes turning it over by hand in different gears. If it feels smooth (i.e. the transmission might not be the problem), it might be worth unbolting the pressure plate while you are in that far to look at it and the disk. At the same time, turn the differential by hand and see if there is any gravel back there. You'll also be able to inspect the driveline carefully if you haven't - do that before you pull the tranny.

Drive shaft U joint?

I think I will unbolt the pressure plate and flywheel as while in there I think it may be a good idea to do the RMS which I just picked up.

I have only just fitted a new diff two weeks ago and haven't actually driven since then so can't be that(She turns sweet as)

So anyway the transmission came out lastnight after a while of swearing and cut fingers - definately getting a 2nd set of hands when I put it back in!

The sound was definately most prominent coming from the tail end of the gbox - if it was related to the pressure plate or flywheel would I hear these noises coming from there? Also what problems should I look for with these?

Cheers mate

Unfortunately the u-joint only moves the way it should do, would have been delighted if it was just my U joint..

I was going to suggest you take a good look at the PPF. A couple years ago I took a quick turn and when the backend stepped out a heard a loud pop. After that I'd get a clunking sound and a vibration. I eventually found a crack in the PPF right where one of the bolts goes into the diff.

https://www.miataturbo.net/attachmen...ine=1390855609

That may not be your issue, but it's probably work taking a look at while you're in there.

Thanks for that mate, will go over the PPF with a fine comb once I get home.

What type of diff is in it? Here is what my clank noise was. It only made noise under acceleration.

https://www.miataturbo.net/attachmen...ine=1391272999

Hey there,

Em it has a vlsd but I have actually just put a fresh one out of a low ks car until I can find a bigger torsen rearend. My gbox is currently sitting on the garage floor waiting to go in. Once I get her driving again I will upload a video...

If it's not the gbox the only thing it could be is the driveshaft although all ujoints seem sweet etc?

Cheers

Sorry for such a late reply people.

Just an update - my baby is back on the road. Turns out the new gbox I then put in only affected me having a smoother shift! But guess I now have a spare gbox to look into rebuilding with stronger internals.

So after the Vlsd n gbox done I then found a little more play than I would like coming from the ps axle inside cv so I replaced that too and am now back on the road!

I still have a bit of driveline noise Coming from the ppf so I need to look into adjusting it over the weekend:)

I took a few pics but am on my cell atm but will get them up when on the desktop site.

Thanks again