Hello guys,

My father's Favorit is again in some problems, there's front suspension noise when going uphill or when you accelerate hard.

Last year we changed all parts on both control arms (ball joints - 6U0 407 365, rear bushings - 115 422 291 and round bushings - 6U0 407 182). In the process I somehow swapped the control arms (left ended on the right side, and right one is now on the left) which shouldn't be a problem since that part (007 304 443) is interchangeable, plus I checked both of them for dents and none of them looked like it was dented or bent.

After that change there was a sound from the struts I believe every time when you would accelerate hard or going uphill. I assumed that the springs were toast since those are 30+ years old, so I bought Kayaba RA1152 (specification says that those are 360mm and my Haynes manual specifies 350mm for front springs length) to go with Kayaba 9330045 shocks which were installed two years ago. This didn't improve anything, so we tried to play with the pinch bolt and adjust the height of the strut in the knuckle, but that also didn't help (best position is when you pull the knuckle as much as you can on the strut). Note: gap between the top of the wheel and the wheel arch is now almost doubled with Kayaba springs.

We also tried to swap the struts in order to diagnose if one of them is faulty (once with old springs, and once with new ones), but still no luck. We even changed the driveshaft and CV joint on the right side (that side produced more noise) thinking that we might solve the problem.

Just to mention that all parts on the struts are new.

One more thing that I think it's important (and my father doesn't): when we were getting ready to change all control arm parts my father hit the curb with front right wheel and bent a wheel rim a bit on his way to the garage. Could that be the issue, that somehow differential or gearbox is damaged? (Gearbox oil was changed after that hit, and I couldn't find any metal shavings in the old oil)

I attached the audio when going up hill, hope that it's clear enough (note: noise disappears once the suspension settles down)

Any ides how to fix this issue?

You have a lot of things going on in your post, you need someone that knows about Favorit suspension, which is not me, but are you sure the noise is from the suspension, or underside of car, or front and not rear even.

Going up hill or accelerating usually transfers the weight to the rear, this could take some load off the struts possibly causing issue if they or other parts are not correct or fitted correctly but then another part f the engine of car might be the cause of the noise.

How much damage your father caused by hitting the kerb depends how hard he hit the kerb, if the front right wheel hit at an angle then it may dent the wheel without other damaged if the impact was light. You could try put that wheel on the rear better still as the spare to see if that changes the sound.

For the front springs I don't know if Kayaba are good quality now or not, you certainly do not rely on past brand quality or reputation, as you may know the quality of many new made parts can be low to be polite.

Haynes, like all databases including manufacturers, has errors and omissions so you do need to check and cross reference from other reliable sources that 350mm was correct.

You also need to check parts are correct before you fit them, wrong parts get sent, or they are wrong specification and/or build from manufacturer or supplier.

The height of the spring is just one dimension you also have to check the springs are the correct rate for your fathers car.

When you say the gap with the Kayaba springs has doubled is this from previously worn out springs fitted or is the car sitting too high from factory standard (a 10mm difference when fitted is nothing)?

Best way to check how the car sits is to park on level ground (car not loaded) and measure and record the distance on each wheel from the middle of the wheel hub to the lip edge of the wheel arch, this also compares side to side and front to back and even possibly diagonals. If you still have old worn spring and suspension on the rear then of course this will effect the readings and comparison to factory but is still useful for comparisons.

There will be posts and threads here about suspension if not factory figures.

Haynes may show "ground clearance" but unless it states from where to ground and load it might not help, figures could be from marketing brochures rather than technical measurements.

As there are so many names and terms that are interchanged rather than say which I put the need to make sure all the suspension parts match to each other and the car and all are fitted correctly.

I hope that helps a little generally.