Why does my powerflex diff bush not sit as expected?

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Fixing a Z3 rear end that has had a harsh side impact through the rear passenger side wheel. Everything looks visually in line with a rebuild except I can't figure out this Powerflex diff bush where the diff seems to sit too far forward. Is this just poor bush design or is something more serious wrong with this car? I would like to take it for an MOT (UK test), is this a failure?
 

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Jack Ratt

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That looks ok to me. I believe that Powerflex diff bushes are made to a different design than manufacturers standard. Plenty of people on here have the same set up.
 

Lee

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Looks like that shunt you've had has caused it to pull the diff bush through, or try to at least.

You can also see a slight bend in the hanger where the bush attaches, I'm afriad that does look like the result of a hard impact.

Remove the bolt and allow the diff to lower so you can straighten it all out again and centralise the bush.

Do you have any more photos showing everything else? we might be able to see if anything else looks out of align for you.
 

t-tony

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And no it is not in itself an MOT failure.

Tony.
 

Pingu

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Something is definitely wrong.

I agree with @Lee about removing the bolt and seeing how the diff lines up naturally.

I'd check to make sure the diff is sitting correctly relative to the car. I wonder if the diff carrier has a slight (very slight) kink in it. You may be able to feel it over the top of the diff. It should feel the same on both sides.
 
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Looks like that shunt you've had has caused it to pull the diff bush through, or try to at least.

You can also see a slight bend in the hanger where the bush attaches, I'm afriad that does look like the result of a hard impact.

Remove the bolt and allow the diff to lower so you can straighten it all out again and centralise the bush.

Do you have any more photos showing everything else? we might be able to see if anything else looks out of align for you.
Something is definitely wrong.

I agree with @Lee about removing the bolt and seeing how the diff lines up naturally.

I'd check to make sure the diff is sitting correctly relative to the car. I wonder if the diff carrier has a slight (very slight) kink in it. You may be able to feel it over the top of the diff. It should feel the same on both sides.
Thank you for the replies. The diff doesn't naturally line up with the mounting section, in fact I had to raise the subframe slightly on its bushes to get the diff ear to fit within its mounting section.

I know that the metal insert for the bush is a good fit by itself within the mounting points so even if there is a slight bend it shouldn't be the cause of this issue.

@Pingu thank you for the advice, I will have a look and report back.
 

GazHyde

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You can clearly see in this picture that the diff hanger has deformed towards the left of the pic, which is why the bush has pushed out to the right (left side being the front of the car, and right being the rear).

Very difficult to make out any other deformation of the chassis, rear beam or swing arms from your pictures though.

upload_2019-2-28_17-35-29.png
 

Pingu

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The image of the diff carrier (IMG_20190228_142852) looks OK, but I agree with @GazHyde about the deformed "ear".

I'm wondering if the whole subframe has been pushed forward on the left mounting pivoting about the right hand mounting. I'd check the area where it is mounted to the body just in front of the left rear wheel.

You should be able to tell if something is wrong by measuring the distances between opposite wheels. I think that you will find that your LHR wheel is further forward than it should be.
 
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A few more photos. I'll measure some distances too around the subframe to check for movement.
 

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gookah

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that prop shaft looks a mile off centre....

I would say either the rear beam is bent, or the bell housing on the rear beam that holds the diff is bent, or both. Either way it would be a replacement rear beam to begin with.

Also how do the wheels look centred in the arches front gap/rear gap between tyre and arch,
compare each side,
 
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the Nefyn cat

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Got to agree with @gookah there, that prop looks way off centre, and @GazHyde too, that diff hanger looks all wrong too, as if the larger front part has bulged out, and the rear (thinner) part has followed it when the bolt was tightened. Are you anywhere near any of us who've got straight cars to compare it to?
 

Jack Ratt

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Find someone near with the same car, duplicate the photo's and then compare them
 
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Got to agree with @gookah there, that prop looks way off centre, and @GazHyde too, that diff hanger looks all wrong too, as if the larger front part has bulged out, and the rear (thinner) part has followed it when the bolt was tightened. Are you anywhere near any of us who've got straight cars to compare it to?
That's a good question! I don't think so? I'm in Warwick.

Thanks for summarising, I'm thinking replacement crossbeam and straightening out of the diff hanger when possible as these seem necessities, then a detailed alignment check to see if the subframe bolts have moved. The car has already had new control arm, diff plate, drive axle.

The twist in the tale is that I'm moving house on Sunday and tomorrow is MOT day followed by a 150 mile drive north on Sunday - there's nothing like throwing yourself in at the deep end :nailbiting:
 

Sean d

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I assume that the diff case snapped during the impact, if thats the case you can safely assume that a number of parts moved during the process, you could set the car on stands, use a plum line from various mounts and triangulate the measurements, it will become obvious immediately
 

Sean d

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That's a good question! I don't think so? I'm in Warwick.

Thanks for summarising, I'm thinking replacement crossbeam and straightening out of the diff hanger when possible as these seem necessities, then a detailed alignment check to see if the subframe bolts have moved. The car has already had new control arm, diff plate, drive axle.

The twist in the tale is that I'm moving house on Sunday and tomorrow is MOT day followed by a 150 mile drive north on Sunday - there's nothing like throwing yourself in at the deep end :nailbiting:
Before goiung anywhere I would get it laser aligned, they can't change anything but they can tell you if its dangerous
 

Sean d

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Might not help but this is when I was putting it back together
IMG-20180615-WA0010.jpg
IMG-20180615-WA0009.jpg
IMG-20180615-WA0008.jpg
IMG-20180615-WA0007.jpg
 
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