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-   -   Rear subframe & arms - installation questions (https://www.the75andztclub.co.uk/forum/showthread.php?t=299310)

Blink 17th September 2019 14:24

Rear subframe & arms - installation questions
 
QUESTION 1

Is it possible to fit the rear subframe with the upper arms already bolted onto it (but not torqued up)? I ask because I just tried a dry run off the car and I can see that lining up the upper arms to get the bolts in will be a lot trickier if the subframe is already on the car.

The lower arm bolts can be seen from underneath but the upper arm bolts can't - so I'd rather put the subframe on with the upper arms already attached. The lowered exhaust might be in the way though.


QUESTION 2

How much lateral movement should there be between the upper arms and the subframe when the arm bolts are tight? (But not fully torqued)

I'm getting some play between the arm bushes and the bolts - i.e. the arms can swing a little in the arc shown by the arrows below. Shouldn't they be fairly immovable relative to the axis shown by the dotted lines?

https://www.the75andztclub.co.uk/for...0ea82a3cf0.jpg

Hope that made sense - it's difficult to describe in 2D.

KWIL 17th September 2019 15:24

As this is one of my future jobs, I would expect some movement at this stage of the assembly, as the final "fixed" point is determined by the other link, the trailing arm.

It should be noted that the final torque must be applied with the vehicle weight on the wheels so as to not compromise the resilient bush's life

clf 17th September 2019 15:45

Build it up on the ground and lift it with a trolley jack, using the threaded bar (the tip from another post) to help you guide it I to position. I would suggest you using two bars rather than the 4, as this will allow you a little 'wiggle' movement.

Keep an eye on cables and pipes when lifting.

I didn't have access to a four post lift, nor ramps, so when mine was fitted, nuts and bolts were fastened just tight,then torqued with both hubs jacked up until you could just see the weight of the car lifting from the axle stands.

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Blink 18th September 2019 09:03

Quote:

Originally Posted by KWIL (Post 2762906)
As this is one of my future jobs, I would expect some movement at this stage of the assembly, as the final "fixed" point is determined by the other link, the trailing arm.

It should be noted that the final torque must be applied with the vehicle weight on the wheels so as to not compromise the resilient bush's life

Yes, after I posted the above, I suddenly realised that the lateral movement would be stopped by the connection to the trailing arms.

Good point about torqueing up with the weight being on the wheels - I'd have missed that! Have you got a list of relevant torque settings btw?


Quote:

Originally Posted by clf (Post 2762910)
Build it up on the ground and lift it with a trolley jack, using the threaded bar (the tip from another post) to help you guide it I to position. I would suggest you using two bars rather than the 4, as this will allow you a little 'wiggle' movement.

Keep an eye on cables and pipes when lifting.

I didn't have access to a four post lift, nor ramps, so when mine was fitted, nuts and bolts were fastened just tight,then torqued with both hubs jacked up until you could just see the weight of the car lifting from the axle stands.

Did you put the lower arms on too while it was on the ground?

I've got a couple of Duratool D00324 dollies I'm hoping use to slide the whole thing under. I can bolt them together with two wooden crossbeams so they can be any length. The only thing is they're 120mm high and I don't know if the exhaust is going to be in the way.

I've got a metre of 12mm threaded bar - I'll cut two pieces off that to use as lifting aids. It still means a short lift by hand though - to get the bars through the subframe bushes. Or does it? Maybe if I put them through the bushes first, before the whole caboodle goes under the car. Can't get my brain round that one without actually seeing it. :}

clf 18th September 2019 10:02

Quote:

Originally Posted by Blink (Post 2763038)
Yes, after I posted the above, I suddenly realised that the lateral movement would be stopped by the connection to the trailing arms.

Good point about torqueing up with the weight being on the wheels - I'd have missed that! Have you got a list of relevant torque settings btw?




Did you put the lower arms on too while it was on the ground?

I've got a couple of Duratool D00324 dollies I'm hoping use to slide the whole thing under. I can bolt them together with two wooden crossbeams so they can be any length. The only thing is they're 120mm high and I don't know if the exhaust is going to be in the way.

I've got a metre of 12mm threaded bar - I'll cut two pieces off that to use as lifting aids. It still means a short lift by hand though - to get the bars through the subframe bushes. Or does it? Maybe if I put them through the bushes first, before the whole caboodle goes under the car. Can't get my brain round that one without actually seeing it. :}

I built it complete, to be able to lift it onto the threaded bars. But I used the 4, which made it quite awkward as it would stick on them as it rocked on the top of my trolley jack. That's why I say to use only 2. Once raised to the chassis, you can then attach the hubs to the arms. There will be a fair bit of movement in the hubs and trailing arms to allow you to do this.

When you first remove the sub frame (old). Support the trailing arms or hubs to save damaging the bushes. I used a spare set of axle stands for this and bungee cords when it came to assembly. It will all be very obvious when you come to do it

I have a pdf at home of all the torque settings if no one has them before.

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clf 18th September 2019 19:37

1 Attachment(s)
here are the torque settings for around the car (page 6-26 for rear suspension)

Blink 19th September 2019 08:49

Quote:

Originally Posted by clf (Post 2763049)
I built it complete, to be able to lift it onto the threaded bars. But I used the 4, which made it quite awkward as it would stick on them as it rocked on the top of my trolley jack. That's why I say to use only 2. Once raised to the chassis, you can then attach the hubs to the arms. There will be a fair bit of movement in the hubs and trailing arms to allow you to do this.

When you first remove the sub frame (old). Support the trailing arms or hubs to save damaging the bushes. I used a spare set of axle stands for this and bungee cords when it came to assembly. It will all be very obvious when you come to do it.

I was planning to remove the old trailing arms & hubs before the old subframe comes off - I've got brand new trailing arms & hubs to go on.

Quote:

Originally Posted by clf (Post 2763152)
here are the torque settings for around the car (page 6-26 for rear suspension)

Aha, that's exactly what I wanted - thanks Alan. :}

clf 19th September 2019 08:58

Quote:

Originally Posted by Blink (Post 2763236)
I was planning to remove the old trailing arms & hubs before the old subframe comes off - I've got brand new trailing arms & hubs to go on.



Aha, that's exactly what I wanted - thanks Alan. :}

Dont fit the hubs until the subframe is in, there will be extra weight rocking about, and you will have enough space to fit those anyway.

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Blink 19th September 2019 09:48

Quote:

Originally Posted by clf (Post 2763238)
Dont fit the hubs until the subframe is in, there will be extra weight rocking about, and you will have enough space to fit those anyway.

Ok, so it's this order:

1. Remove old calipers, discs, backplates
2. Remove old trailing arms & hubs
4. Remove old toe-in adjustment brackets
4. Remove old subframe inc upper & lower arms and rollbar

Sort out underside of floorpan - clean, paint, wax

5. Fit new subframe inc upper & lower arms and rollbar
6. Fit new toe-in adjustment brackets
7. Fit new trailing arms & hubs

Sort out calipers

8. Fit new backplates & discs
9. Refit calipers

Bleed brakes! :}

clf 19th September 2019 10:10

Quote:

Originally Posted by Blink (Post 2763245)
Ok, so it's this order:

1. Remove old calipers, discs, backplates
2. Remove old trailing arms & hubs
4. Remove old toe-in adjustment brackets
4. Remove old subframe inc upper & lower arms and rollbar

Sort out underside of floorpan - clean, paint, wax

5. Fit new subframe inc upper & lower arms and rollbar
6. Fit new toe-in adjustment brackets
7. Fit new trailing arms & hubs

Sort out calipers

8. Fit new backplates & discs
9. Refit calipers

Bleed brakes! :}

I didn't do the trailing arms and.hubs etc. But yes that would the way I would do it.

Remove the rear bumper too (tip, remove rear lights also, as these can be easily damaged when removing the bumper, and it is 6 easy nuts for them). Loosen the shock tops too before lifting the car, also.

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