New Wheels & Tyres Fitted - Now Massive Vibration Under Braking

[350wedge 13]

I swapped my standard 1.6 alloys for a set of 1.9's yesterday and now something is causing a massive vibration under braking which is clearly not a good thing. Driving on a motorway at 70-80 is fine, no issues pulling to one side and no vibrations indicating wheels are balanced. Its purely under braking that a severe pulsing comes up through the brake pedal and the car does shake quite badly.

 

Checked all the usual suspects, wheels seating properly, nuts tight, balance weights still on, tyres fitted correct way round, discs and pads secure (also brand new!). Old wheels back on again and its fine.

 

The new tyres are 195/50/15 so while they have the same rolling radius as the old wheels they are just that bit wider.

 

The wheels are freshly refurbished and are 100% straight and true, no damage or buckling.

 

Can only think tracking might be slightly out which with the extra width of the new wheels is magnifying the issue??

 

Has anyone fitting the 1.9 combo on a 1.6 had to have the tracking re-done when swapping wheels??

 

Any other ideas??

[welshpug 1,666]

it wont be the tracking.

 

was the mating face kept clean of paint/powder coat? it is going to be a balancing issue of some kind.

[350wedge 13]

The surfaces are pretty clean, as I say wheels are seating perfectly. There are no balance issues at motorway speeds, its only under braking.

[kyepan 291]

check the discs are seated, sounds like one is on the piss, most cars are missing the little locating screws because they've all rounded or been snapped off/ drilled out.

worst comes to worst take them off and check they've not been warped, or some crap has fallen behind them.

[350wedge 13]

check the discs are seated, sounds like one is on the piss, most cars are missing the little locating screws because they've all rounded or been snapped off/ drilled out.

worst comes to worst take them off and check they've not been warped, or some crap has fallen behind them.

 

I'm fairly sure the discs are on ok. New screws are fitted, the discs and pads have been on less than a week and are bedding in nicely.

 

When I have my standard 14's on there the problem goes away, its just with the new wheels on.

 

I'm going to check everything again at some point this week, nothing obvious jumps out though...

[welshpug 1,666]

has to be the wheels or tyres if the issue goes with 14"s back on.

[BlueBolt 156]

What tyres did you put on the new wheels? Are they the same as on the old? Were they new or new-to-you??

[350wedge 13]

Tyres are brand new Falken ZE-914's. Old tyres on the 14's are Pirelli P600's on the front and Khumo on the rear

[dcc 855]

are the tyres on the rims the wrong way.

[350wedge 13]

I've checked that, tyres are all fitted correctly the right way round.

 

There is no rotation direction marker but inside and outside are printed on the relevant sides.

[dcc 855]

only thing I can suggest is they are sawtoothing, but its hard to tell even if they're infront of you.

[jeremy 71]

Personally I would swap either the fronts or the rears back to the originals then vice versa and see if you can narrow it down by process of elimination. I would also notify the company who supplied/fitted them, and ask their advice too.

[TooMany2cvs 65]

See if it's just one wheel, and if so which.

 

Put a pair of the old 14" on, with a pair of the new ones. Try that combo front, try it rear. If those new ones are good, then try the other pair of new ones. Front, rear. When you've got a pair with the vibration, swap one wheel with the other pair. Helps if you just identify which of the four wheels is which - write an A,B,C,D on the mounting face - then keep track of which combos are coming up good.

[350wedge 13]

I tried the combo's of new and old wheels which at the time made a bit of difference but not cured completely (other than also killing my back!!).

 

Then I sanded clean all the mounting faces and re-attached all the new wheels with the old 1.6 wheel bolts, hey presto problem solved. Well 99% anyways but pretty acceptable. Can only think something was stopping a wheel from seating properly but that doesn't explain why the problem was only under braking. Surely if a wheel was out of alignment it would have created a vibration of some sort.... oh well....!

 

Just received a band new set of short headed bolts so they will be going on to replace the 1.6 ones too....