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Kristian

Front Vibration

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Kristian

Hi and thank you for my membership. 
I bought my kit back in 2017 and finalized the assembly spring 2018. Its a FW 175 bhp, Zetec 2.0l,.
Here is my pride.

pic1.jpg?psid=1&width=1064&height=798

 

Right after some driving I started to notice some vibration. As a rookie I started a long journey towards something I thought would be a quick fix.
Even when writing this I'm a bit tired of it but see you guys and your knowledge as a final solution and hope some of you could give me some advises.
I'm situated in Norway and we do not have local garages like you have. I would like to find a solution with your help.

 

This is what I have been doing so far:

  1. New rims
  2. New tires
  3. New rear axles 
  4. Sent the prop shaft for service and fixed
  5. Sent the diff (Mazda LSD) for service and check - all good.
  6. Sent the car on a rolling road to check the vibration
  7. Sent the car to two different garages - no clue and interest what so ever
  8. New rear brake discs
  9. New front discs
  10. New front hub from Siltech incl bearings (what a quality)
  11. Sent the brace discs to check for run out, 0,05 mm and reduced to 0,001 - straight as a...
  12. Countless of hours investigating the issue.

 

What I'm experiencing is that it vibrates at low speeds, around 30 mph. It shakes and I believe its in the front. At high speed it did use to vibrate as well until new hubs from Siltech was assembled.

 

When using a dial indicator facing the hub I read 0,14 mm and disc 0,18 mm. This is to much and gets even more when checking the rim. 0,7 mm run out on the rim.

 

This is the setup and figures. Since I have a new hub from Siltech I suspect the stub on the upright is gone?

 

pic2.jpg?psid=1&width=869&height=798

 

And my theory is that this error will expand towards any outer rim.

 

pic3.jpg?psid=1&width=604&height=798

 

  Any thoughts or experience? All comments, relevant of course, will be very much appreciated 🙂 

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Geoffrey Carter (Buttercup)

Hi. sorry I cant answer your questions but would love to see more pictures of your car. It looks really smart.

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Terry Everall - WSCC Competition Secretary

Could you please confirm that you have had the wheels balanced correctly and have not lost any weights whilst driving the car. Can you use your gauge to check rim alignment ?

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pistonbroke

Hi Kristian & welcome to the club . 

 

Sorry to here about your problems but you are probably in the best place for a solution . 

A bit more information might help us to track down the vibration ? 

For instance 

What speed range does it occur , is there one speed when it is worse than others 

Is it the same under power ? (acceleraion)  and power off ? (deceleration ) 

Do you get the vibration if free wheeling ( clutch depressed ) ?

Is it from the front or rear , lhs . rhs ? 

any other observations to help

does it effect the steering ?  any vibration from the steering wheel or gear lever or any of the foot pedals 

anything else you can think of ?

 

Finally congrats on the build , that looks a fine car :t-up:

 

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Kristian
7 minutes ago, Terry Everall - WSCC Competition Secretary said:

Could you please confirm that you have had the wheels balanced correctly and have not lost any weights whilst driving the car. Can you use your gauge to check rim alignment ?

Hi Terry, yes its been balanced. And yes you can use the dial indicator checking run out.

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Kristian
15 minutes ago, pistonbroke said:

Hi Kristian & welcome to the club . 

 

Sorry to here about your problems but you are probably in the best place for a solution . 

A bit more information might help us to track down the vibration ? 

For instance 

What speed range does it occur , is there one speed when it is worse than others 

Is it the same under power ? (acceleraion)  and power off ? (deceleration ) 

Do you get the vibration if free wheeling ( clutch depressed ) ?

Is it from the front or rear , lhs . rhs ? 

any other observations to help

does it effect the steering ?  any vibration from the steering wheel or gear lever or any of the foot pedals 

anything else you can think of ?

 

Finally congrats on the build , that looks a fine car :t-up:

 

 

Thanks Pistonbroke :)
The speed range is about 30 mph.
It vibrates when pushing clutch in and even setting the gear in neutral.

I believe its from the front but since the car is so little any vibration will be felt all over the place.
I feel a vibration in the steering wheel and see the arches vibrates more than I expect.

 

I suspect the stubs from the uprights since the dial indicator shows run out at the hub.
What is normal and accepted run out at the hub? 

 

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Ian Kinder (Bagpuss) - Joint Peak District AO

Wow, what a journey, you've on and well done for being so loyal and patient. Lesser men would have lost interest/walked away or sold the problem on.

 

As above, does it stop when you put the clutch in? A friend had a rear tyre not seated correctly on the rim and this caused the steering to vibrate at certain speeds and much time and effort was spent focusing on the wrong end of the car!

 

Have you checked that you've not got a broken or faulty engine or gearbox mount?

 

Can the problem be re-produced on a rolling road (chassis dynometer), this would at least help identify if it's the front or rear end of the car.

 

Have you spoken to Siltech about the run out on the stubshaft?. I'm sure you know they make nice uprights too! If the stub shaft isn't mounted perfectly in the upright. I'd be looking in this location.

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Kristian
41 minutes ago, Geoffrey Carter (Buttercup) said:

Hi. sorry I cant answer your questions but would love to see more pictures of your car. It looks really smart.

Thanks, I see if I have more pictures :)

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pistonbroke

From your reply  I think you can eliminate the drive train and assume the fault is there regardless of engine speed RPM so rule out engine mounts etc . 

You say Prop shaft is OK and diff checks out 

What about wheel bearings could possibly be one of those binding ?

Assume you have checked with the road wheel jacked up for any rough sounding bearings or any play 

Have you swapped wheels around front to rear and noticed any difference ?

 

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Kristian
5 minutes ago, Ian Kinder (Bagpuss) - Joint Peak District AO said:

Wow, what a journey, you've on and well done for being so loyal and patient. Lesser men would have lost interest/walked away or sold the problem on.

 

As above, does it stop when you put the clutch in? A friend had a rear tyre not seated correctly on the rim and this caused the steering to vibrate at certain speeds and much time and effort was spent focusing on the wrong end of the car!

 

Have you checked that you've not got a broken or faulty engine or gearbox mount?

 

Can the problem be re-produced on a rolling road (chassis dynometer), this would at least help identify if it's the front or rear end of the car.

 

Have you spoken to Siltech about the run out on the stubshaft?. I'm sure you know they make nice uprights too! If the stub shaft isn't mounted perfectly in the upright. I'd be looking in this location.

Hi Ian, yes - a bit heavy to stay focused all the time after all this time and money. But I'm not a quitter 💪

I tried a rolling road. What a disappointment. The rolling road vibrates even more than my car and was a failure.

Is there a way to verify that my upright is straight?  Siltech didn't supply me with the upright its a Hispec.

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Ian Kinder (Bagpuss) - Joint Peak District AO
1 minute ago, Kristian said:

Hi Ian, yes - a bit heavy to stay focused all the time after all this time and money. But I'm not a quitter 💪

I tried a rolling road. What a disappointment. The rolling road vibrates even more than my car and was a failure.

Is there a way to verify that my upright is straight?  Siltech didn't supply me with the upright its a Hispec.

 

Others have had manufacturing issues with the Hispec items. Some have found that when the bearings where pressed into the hub, they scrape a small piece of aluminium off, which then sits under the bearing housing. This then makes it out of true and causes issues.

 

There's a diagram here of the upright and stub shaft.

 

http://www.hispecmotorsport.co.uk/cortina-uprights.html

 

I'd be taking the stub shaft out and looking for issues in the areas arrowed:

 

image.png.9c137e6dfb4263d2eae46a5b6e7455ea.png

 

You could put the stub shaft in a lathe to check for run out.

 

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Kristian
3 minutes ago, pistonbroke said:

From your reply  I think you can eliminate the drive train and assume the fault is there regardless of engine speed RPM so rule out engine mounts etc . 

You say Prop shaft is OK and diff checks out 

What about wheel bearings could possibly be one of those binding ?

Assume you have checked with the road wheel jacked up for any rough sounding bearings or any play 

Have you swapped wheels around front to rear and noticed any difference ?

 

Bearings are new from Siltech so I think they are ok. Also swapped front with rear. No run out at rear.

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pistonbroke

Even new bearings have been found to be faulty , so worth you checking them out , otherwise Ian might have the answer above ?

 

 

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pistonbroke

You can check this thread 

 

 

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Kristian
Just now, pistonbroke said:

You can check this thread 

 

 

It was because of this thread I bought new hubs from Siltech 👍

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