New Box, Serious Juddering on N/S wheel under load. Any Ideas?

[Martin.]

Did an evening at Brands last night. All was good apart from this nasty juddering I was getting from the N/S wheel on any right hand corner. Speed I think is irrelevant, it was happening at Paddock, Druids and CC.

The best way to describe how it felt was as if the near side wheel was loose. I would have put money on something being loose down there. But nothing was when we came in to check. No play in anything and nothing visible. Another way to describe the feeling is. As if I had a semi slick on every corner and a budget tyre on that corner. It just wasn't happy under any load, when trying to push on too hard whist steering it would just under steer. It didn't feel very nice.

For reference, left hand corners, so load on the offside front wheel, were perfectly fine. Straight line on the throttle seems perfectly fine too.

Luckily had @AlexW @sonny172cup and @GrahamS with me for comfort and opinions/diagnostics.

From what I gathered, they think it's something to do with the drive shaft bottoming out. (correct me if I'm wrong lads)

But I thought I'd whack a post up on here anyway, just in case someone else had encountered this problem before or had any advice/suggestions. @NorthloopCup @BIGASH

I think next steps will be to take the shafts off again and inspect them and around the knuckles...

Other than that I'm lost. And a little gutted as the car felt awesome with the recent changes.

Another thing to note. When turning into a right corner, and the juddering starts, if I straighten up the wheels briefly mid corner the juddering goes away, until I carry on turning again.

Couple of pics, just because.

Oh and the gearbox is still leaking, even with that new seal in 😧

Cheers.

Alex loves touching this car.

Standing around head scratching..

 

[Cub.]

Mmmm.

I'm not saying it is the diff, but how aggressive is the gripper set up to be? And when were the plates / gripper last refurbed?

Also, did the gripper come out of porkies car? And if so, what driveshafts are you running - cup or non cup?

Both Mark and James will be better placed to advise, i'm largely guessing tbh!

 

[STEVE.M]

Is the tyre contacting with the arch liner(if not removed) or wheel arch at the front bumper side mounts?

 

[Martin.]

Mmmm.

I'm not saying it is the diff, but how aggressive is the gripper set up to be? And when were the plates / gripper last refurbed?

Also, did the gripper come out of porkies car? And if so, what driveshafts are you running - cup or non cup?

Both Mark and James will be better placed to advise, i'm largely guessing tbh!

James bought the diff new in March last year from memory. I think he said he did one race in it and then Porkie had it for a couple of track days.

If it was happening on all corners then I would have though diff, but the fact the left handers were completely fine/awesome makes us think otherwise..

I have 182 cup drive shafts. Although I believe there's not much difference apart from the dry side being one or two piece?

 

[Martin.]

Is the tyre contacting with the arch liner(if not removed) or wheel arch at the front bumper side mounts?

I've had issues with this before at brands. So I've cut out most of the bumper bracket and painted the edges black to show signs of contact. Which there doesn't seem to be much of now if at all.

 

[Martin.]

Not that I think this makes any difference. But I was running a 5mm flat spacer on the first session. We removed this when we came in, simply to do a bit of testing and trial & error. It did seem to help, but that may have just been in the mind.... As I have no idea how it would have made any difference.

Alex also tried shifting the engine assembly over to that side more. This also seemed like it might have helped. But it was also wet at this point now and it might have just been harder to notice, combined with not being able to push as much.

Who knows.

 

[sonny172cup]

Also happened on compression at the bottom of Paddock Hill, this would push the drive shafts in more... All 4 wheels was checked for fouling, only thing found was the Nimbus air deflector was slightly bent due to tyre hitting but that wasn't the cause of the noise.

Only real way is to drop oil and inspect NS drive shaft knuckles and inside of the knuckle housing for obvious signs of chaffing.

 

[STEVE.M]

Not that I think this makes any difference. But I was running a 5mm flat spacer on the first session. We removed this when we came in, simply to do a bit of testing and trial & error. It did seem to help, but that may have just been in the mind.... As I have no idea how it would have made any difference.

Alex also tried shifting the engine assembly over to that side more. This also seemed like it might have helped. But it was also wet at this point now and it might have just been harder to notice, combined with not being able to push as much.

Who knows.

The tapered grub screws that are supplied with Brembo discs sit proud of the disc,so any spacers fitted do not seat correctly?

 

[Martin.]

The tapered grub screws that are supplied with Brembo discs sit proud of the disc,so any spacers fitted do not seat correctly?

I'm sure they are flush on mine. The spacer sits flat against the hub face anyway Although I will check it.

But still had the issue when we took the spacer off.

 

[sonny172cup]

I did check this but was flush (reason i normally file mine down) as a matter of course

 

[Mini182]

I bet it's the short shaft making contact with the inside of the diff.

I've got a later cup subframe on mine so bolt holes are further out making it slightly wider, but I am still having to use a ph1 short shaft as anything else makes contact and knocks/judders on hard right turns.

 

[Martin.]

I bet it's the short shaft making contact with the inside of the diff.

I've got a later cup subframe on mine so bolt holes are further out making it slightly wider, but I am still having to use a ph1 short shaft as anything else makes contact and knocks/judders on hard right turns.

Hmm does sound like it could be similar to what you say.

Could the fix be as simply as changing shaft for a shorter one then? Any potential drawbacks from this?

 

[Mini182]

Hmm does sound like it could be similar to what you say.

Could the fix be as simply as changing shaft for a shorter one then? Any potential drawbacks from this?

Only doing it on hard right hand turns? Feels like a really bad vibration, like the wheel is loose? I bet you it's the short shaft being slightly to long.

ABS rings are different on the 182 cup shaft, don't think there is any other differences other than the fact it is 10mm longer than the Ph1.

 

[Martin.]

Only doing it on hard right hand turns? Feels like a really bad vibration, like the wheel is loose? I bet you it's the short shaft being slightly to long.

ABS rings are different on the 182 cup shaft, don't think there is any other differences other than the fact it is 10mm longer than the Ph1.

Another thing to note, it was in Porkies 172 cup and on James' race car with no issues. Wouldn't James at least have been running the exact same shaft as me...

 

[Kelv]

Martin, I am certain a shorter shaft will do more harm.

If we call your shaft mounting point at the box Point A, and the hub mounting point for the shaft Point B...

As factory, the shaft sits almost straight and level, with extreme lowering such as you have, you have changed the level between point A and point B, which in turn makes it a slightly further distance.
On that basis, your current shaft will now already be classed as too short for the job in hand, it's trying to reach a further distance than it's ever had to before.
If you now go for a shaft even shorter, you will be making the shafts work even harder.

This is what the bump steer correction hubs try to rectify.

 

[sonny172cup]

But an expensive fix Kelv...

We mentioned this yesterday, also regarding different subframes, shafts and even uniball sizes. Again nothing has been changed on your chassis that would make it different from another Cup

 

[Kelv]

Martin, take my hubs, it will cost you nothing more than time and getting dirty.
Give them a try on another track day and I'd put money on it fixing your issue.

 

[GrahamS]

I think this is a case of trying the cheapest things first. If the engine/box can be moved over a bit then that's the first trick. Second would be to try a shorter driveshaft as the shaft. Really Mart needs to look at the angle of the shaft to establish what's happening under compression and lock. Is it pulling the shaft out the box or pushing it further in. If the shaft was too short then the bump steer kit would make it worse!

 

[AlexW]

its shaft too long/engine too far to the N/S. Exactly as I said last night, and Exactly what I've had in the past.

Just need to find time/when I can be arsed to come down and fix it.

 

[Mini182]

I would be 99% sure that it's going to be that the n/s shaft is to long, it's has happened to me and I am running a very similiar set up to you. If you speak to gripper they are aware of it as well so it must have happened to other people.

Also the driveshaft doesn't sit parallel from the factory it droops down slightly, so a lowered car (as long as it's not severely lowered) will push the shaft in even further not move it out. If you are running lot's of -ve camber this will be amplified. So you will need a shorter shaft not a longer one.

 

[sonny172cup]

Exactly my thoughts too, how much more camber did they add at the garage Martin?

 

[AlexW]

Camber wasn't changed, so its the same as it has been for a while, I think its a couple of degrees, poss 2.5, so not a massive amount, but all adds up obviously.

 

[sonny172cup]

Yea true. Heres a pic of martins NS drive shaft from a few months back, look any different from others?

 

[NorthloopCup]

As per my text Martin, I'm gonna say shaft bottoming out. Both James and porkie ran the hub kit so they benefitted from an additional 5mm of track width. That could easily negate the issue.

If you take the outer cv joint apart it should have a clip that's holding the cv in place. Remove the clip as this should allow your shaft to gain a bit more travel and should potentially prove the theory. When I say outer cv I'm meaning the one at the wheel end if your not sure. It's been a long time since I've looked inside one of the Clio cv joints though, so I could be talking bollox.

 

[AlexW]

@NorthloopCup Circlip is holding it in the CV, so it doesn't come out, the inside edge is part of the shaft, it's that, that would need removing so it would solve the issue.

Which would be a poss fix if a shorter shaft is not available.

 

[Cub.]

I also run the RC Kit, so would explain why I don't have the same problem either.

 

[Martin.]

Cheers chaps. Hopefully this will be it then.

Will strip it all down when I get a chance and go from there. Engine pushed over as far as possible, and a shorter shaft/ tweaked shaft if needed.

As said, camber wasn't changed recently, just the tracking checked and tweaked.

 

[Martin.]

@NorthloopCup Circlip is holding it in the CV, so it doesn't come out, the inside edge is part of the shaft, it's that, that would need removing so it would solve the issue.

Which would be a poss fix if a shorter shaft is not available.

I'm not going to try and understand that just yet. 😌

I also run the RC Kit, so would explain why I don't have the same problem either.

Does make sense.

If it hadn't been such an expensive last 6 months for me I'd just think f**k it, buy the RC kit. Be done with the issues and have a good upgrade at the same time!

 

[sonny172cup]

Surly this diff is meant for this car so should be made within the correct tolerances, I would speak to Gripper and ask there opnion, they may even ask for it and machine it out to allow for extra movement etc

 

[AlexW]

I guess its something that can't be avoided, as said above, they know about it anyway. I'd guess they say to fit a shorter shaft.

 

[STEVE.M]

A daft question maybe,
was everything hunky dory before you fitted a recon box?

 

[Martin.]

A daft question maybe,
was everything hunky dory before you fitted a recon box?

Never had any issues like this before no mate.

 

[Martin.]

I also run the RC Kit, so would explain why I don't have the same problem either.

On that note, didn't you have the Gripper long before the RC kit though mate?

And you didn't have problems with shafts before then?

 

[Cub.]

On that note, didn't you have the Gripper long before the RC kit though mate?

And you didn't have problems with shafts before then?

That is true. I have had the gripper for about 2 years, and it's been out once for a replate.

I have had the RC kit for 3 months.

I've not had any problems with the shafts, or the gripper, and no juddering....

Something isn't right here. Will it do it on the road? If so, welcome at mine on Sunday. Has the dual purpose that you get to see what a supercharged 1*2 does?

 

[Martin.]

That is true. I have had the gripper for about 2 years, and it's been out once for a replate.

I have had the RC kit for 3 months.

I've not had any problems with the shafts, or the gripper, and no juddering....

Something isn't right here. Will it do it on the road? If so, welcome at mine on Sunday. Has the dual purpose that you get to see what a supercharged 1*2 does?

Yeah that's concerning.... Hmmm

I'll have to try and test it on the road. Need to top up my box oil and sort that leak out too.

Thanks for the offer mate, would have done. But I've been ordered to help the old man do a job of clearing out a house this weekend. Before the new people go in.