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Shudders when enginebraking 
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Post Re: Shudders when enginebraking
Hi Harold,
Just a thought, is there any looseness in the in the left side of the steering rack, early mini racks had an oil soaked felt bush as the as the bearing on that side, which used to have wear quickly later mini racks were fitted with a nylon bush that was much better, the other end of the rack was assembled with shims and had spring loaded saddle bush that could become worn but was not too hard to re-assemble with less shims to take up the wear, try to see if any movement when holding the inner ball joint which is covered by the rubber gaiter.
Yep I watched the F1 practice, I'll in front of the TV later :wink:
John


Sun Jul 24, 2016 4:18 am
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Post Re: Shudders when enginebraking
Hi John,
Don't know about that, do you mean radial or axial movement ?
Try it with all parts assembled and with wheels on the ground?

Was a wet qualification right?
Wasn't able to see it, but will watch the race this afternoon.

Harold


Sun Jul 24, 2016 8:40 am
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Post Re: Shudders when enginebraking
Hi Harold,
Look for any movement between the rack and the housing, up/down & front/back, early Mini racks with the oil soaked felt bush they used to wear quickly. later nylon bushed racks lasted much longer, I don't think you can tell which rack you have from outside, but was possible to upgrade early racks to the nylon bush.
Super Max had his usual tussle with Kimi, this is becoming a regular feature, the oldest and youngest drivers going head to head.
John


Sun Jul 24, 2016 3:16 pm
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Post Re: Shudders when enginebraking
I will take a look at that soon, thanks.

Miki and Max had a nice battle (again)
Miki and his successor :wink:
For the rest not a very exciting race.
Hoped Max would do better, maybe next race

Harold


Sun Jul 24, 2016 5:21 pm
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Post Re: Shudders when enginebraking
Hi Guys,

Before my Holidays my Coupe had it's MOT.
Only thing wrong was a tear in the right steeringarm-gaiter.
After replacing this it got through.
A few small holes in the exhaust and a bit of oilleakage were no MOT-failures.
The mechanic of the Subaru-garage where it had it's MOT, diagnosed that there was a little play in the left steering-knuckle.
This could explain the vibration I feel in the steeringweel when driving 80km/h and faster.
So I replaced them and alligned it again.
I also checked al front suspension-bolts and nuts an tightened some a bit.
I went for a testdrive and experienced that the vibrations are not gone but seem to kick in later, at aprox 100 km/h.
I had my wheels balanced before my Holidays, this didn't help.
@John: I checked for looseness in the steeringrack, but don't feel any.
Could having it alligned on a 3d alligningmachine help to cure the vibrations or do I have to get the vibrations out before having it professionally alligned?
Dont think it has warped brakediscs, I don't feel extra vibrations when braking. Any ideas what to check now?

Cheers
Harold


Wed Aug 31, 2016 9:40 am
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Post Re: Shudders when enginebraking
Hi Harold, I don't think its an alignment problem, its not pulling to one side when accelerating or braking, as its only a vibration and now at a higher speed it has to be something out of balance, or a slight looseness allowing a movement to cause the vibration when you go above 100kph does it remain the same, get worse or stop vibrating?
All very strange
John


Wed Aug 31, 2016 10:07 am
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Post Re: Shudders when enginebraking
It doesn't pull to the right or left, when driving faster than 100km/h the vibration gets worse. didn't dare to drive faster than aprox. 130km/h


Wed Aug 31, 2016 10:39 am
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Post Re: Shudders when enginebraking
Hi Harold,
Had your car been standing for a long time before you got it? if you lift the wheels off the ground and roll them do you have flat spots are the tyres round?


Wed Aug 31, 2016 11:39 am
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Post Re: Shudders when enginebraking
The former owner used it quite often, so I don't think the tyres have flat spots.
In my garage it gets moved often enough too.
I think it started somewhere after replacing lower arms / tie-bars with adjustable ones and replacing the suspension with Hi-Lo's.
I don't recall it vibrating before that.
I remember that when I was fitting the lower arms, the steel sleeves in the rubbers were not a very tight fit over the lower (bend) pin, there is a bit of play, is this usual or should it be very tight?
Also the washer on the pin was not very tight in the hole in the subframe (Aprox a mm play). I should fit new ones.

Just trying to find a cause...


Wed Aug 31, 2016 12:49 pm
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Post Re: Shudders when enginebraking
The sleeve on the inner lower arm bush should not be loose in the rubber bush, I've not replaced for many years, but if I remember correctly pressed the sleeves in with a vice after lubing them with washing up liquid, if the washer is loose, get one not loose, we are looking for no possible movement.
John


Wed Aug 31, 2016 2:37 pm
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Post Re: Shudders when enginebraking
John,
The steel sleeve is not loose in the rubber, but the sleeve fits over the pin with a small amount of play.
New bushes on an old pin, maybe the pin is a bit worn and has become a bit thinner in time
The washer is not very tight in the hole in the subframe whitch it falls into.
Again not a lot of play, I wonder if an original washer (if this isnt?) will fit any better. Should it be real tight?
The less movement the better probably,


Wed Aug 31, 2016 6:34 pm
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Post Re: Shudders when enginebraking
Harold,

If John's suggestion doesn't fix the problem have you checked the balance of the rear wheels -- they can sometimes drive a vibration in the 90-100kph range. Before you ask I've no idea why!

Steve


Wed Aug 31, 2016 6:35 pm
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Post Re: Shudders when enginebraking
Why Steve?? :wink:
I had all my wheels balanced, should be allright
I feel the vibrations mainly in the steeringwheel, it would surprise me if that comes from the back.


Wed Aug 31, 2016 6:40 pm
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Post Re: Shudders when enginebraking
Harold you better check those rubber bushes and lower arm pivot pins or don't exceed 95kph :lol:
john


Thu Sep 01, 2016 7:14 am
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Post Re: Shudders when enginebraking
I will fit new pins, washers and nuts, I hope this will help.
Or avoid highways and never drive too fast on 80km/h-roads... :lol: :lol:
Never really checked the top arms, what is the best way to check them for play?


Thu Sep 01, 2016 7:38 am
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