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-   -   Subframe in situ: accessing arm bolts - advice please (https://www.the75andztclub.co.uk/forum/showthread.php?t=302884)

Blink 15th February 2020 06:48

Quote:

Originally Posted by BOZZ (Post 2793180)
... ARE you sure they not strenght bolts ? if they are you HAVE TO REPLACE them.

I'm not sure what you mean. If you're saying have I used the 8.8 grade bolts shown in the pic, the answer is no. I've used the correct 10.9 grade
FC112187A, M12x90 (15mm socket), nos 3 & 7 here.

Blink 15th February 2020 06:54

Quote:

Originally Posted by macafee2 (Post 2793154)
I've circled the two holes to use.
I have a "home made" extension that is 85mm long and a king dick extension that is 75/76mm long
with the 15mm socket added they are 111 and 97 mm

macafee2


Ok, thanks for doing that Ian. Can you remember which was the better fit, 111mm or 97mm?
  • The closest I can get to an 85mm extension is the Snap-on SXWK3 - that'll give me 105mm with my 15mm socket but the SXWK3 has the 'wobble end' thing.
  • Any of the 75mm extensions available on Amazon will give me 95mm with my 15mm socket.
  • Or I could try the Teng 63.5mm extension with a longer socket. :shrug:

macafee2 15th February 2020 07:22

Quote:

Originally Posted by Blink (Post 2793246)
Ok, thanks for doing that Ian. Can you remember which was the better fit, 111mm or 97mm?
  • The closest I can get to an 85mm extension is the Snap-on SXWK3 - that'll give me 105mm with my 15mm socket but the SXWK3 has the 'wobble end' thing.
  • Any of the 75mm extensions available on Amazon will give me 95mm with my 15mm socket.
  • Or I could try the Teng 63.5mm extension with a longer socket. :shrug:


97, the 111 was a bit of a fiddle. Also the 97 had the spring and ball bearing to keep the socket on. The 111 as it was "home made" was just a square end. The 111 will do, so if that is all you can get or something in-between it should be fine but then of course there is the thickness of your ratchet to consider, so the shorter one would be safer.

jacking the trailing arm up to re-torque may not put the suspension in the same position as it is with the car on all 4 wheels. I put the rear end onto ramps, the front was on ramps also

macafee2

Blink 15th February 2020 07:47

Quote:

Originally Posted by macafee2 (Post 2793254)
97, the 111 was a bit of a fiddle. Also the 97 had the spring and ball bearing to keep the socket on. The 111 as it was "home made" was just a square end. The 111 will do, so if that is all you can get or something in-between it should be fine but then of course there is the thickness of your ratchet to consider, so the shorter one would be safer.

Ok, I'll aim for 97mm for the extension bar with socket. I've got three 1/2 inch ratchets to choose from so I'll use the one with the slimmest head.


Quote:

Originally Posted by macafee2 (Post 2793254)
Jacking the trailing arm up to re-torque may not put the suspension in the same position as it is with the car on all 4 wheels. I put the rear end onto ramps, the front was on ramps also.

I thought about this yesterday and tweaked the height of the front blocks. It's set up now so that when the back end is just lifting off the rear blocks, the front end is still resting on blocks but the whole car is dead level (as checked with a spirit level under the mid point of the sills). Isn't that the same as having all 4 wheels on and resting on the ground?

Blink 16th February 2020 16:08

RAVE - trailing arm torque confusion
 
While waiting for Amazon to deliver a 75mm extension I thought I'd see what RAVE says about setting torque on the trailing arm bush bracket bolt (#6 here).

I've set mine to 100Nm off the car because the bolt is invisible when the trailing arm and bracket are in situ. Before tightening the bolt I angled the bracket to the position I thought it would be in when the weight is on the suspension, but it was only a guess.

This is what RAVE says on page 808 (Workshop Manual Service Procedures) underneath diagram M64 0112: 4. Position trailing arm bush bracket, align to marks on casing, fit bolt and tighten to 100Nm. Caution: Nuts and bolts must be tightened with weight of vehicle on suspension.

What marks? Which casing? The only marks mentioned are on page 807, where in the left column it says: 14. Reference mark trailing arm bush bracket to body to aid assembly and in the right column it says: 15. Align trailing arm bracket with reference marks and tighten bolts to 100Nm. These obviously refer to the three bracket-to-body bolts and not the single arm-to-bracket bolt.

So what the heck are they talking about on page 808? Have I missed something? :shrug:

And what the heck is diagram M64 0112? My trailing arm looks nothing like that. :shrug:

macafee2 16th February 2020 16:19

Quote:

Originally Posted by Blink (Post 2793577)
While waiting for Amazon to deliver a 75mm extension I thought I'd see what RAVE says about setting torque on the trailing arm bush bracket bolt (#6 here).

I've set mine to 100Nm off the car because the bolt is invisible when the trailing arm and bracket are in situ. Before tightening the bolt I angled the bracket to the position I thought it would be in when the weight is on the suspension, but it was only a guess.

This is what RAVE says on page 808 (Workshop Manual Service Procedures) underneath diagram M64 0112: 4. Position trailing arm bush bracket, align to marks on casing, fit bolt and tighten to 100Nm. Caution: Nuts and bolts must be tightened with weight of vehicle on suspension.

What marks? Which casing? The only marks mentioned are on page 807, where in the left column it says: 14. Reference mark trailing arm bush bracket to body to aid assembly and in the right column it says: 15. Align trailing arm bracket with reference marks and tighten bolts to 100Nm. These obviously refer to the three bracket-to-body bolts and not the single arm-to-bracket bolt.

So what the heck are they talking about on page 808? Have I missed something? :shrug:

And what the heck is diagram M64 0112? My trailing arm looks nothing like that. :shrug:

The head of the bolt for the upper arm is visible from under the car.
If you have already tightened to 100, I would loosen them off once you have the car on 4 wheels and then tighten to the correct torque.
If you have had the trailing arms off then I would suspect you will need to have the tracking checked


macafee2


ignore this post I did not see when I replied it was trailing arm, sorry

Kev75 16th February 2020 17:36

I think the referance marks is refering to marks made by the person doing the job made before dismantling?

Kev

Blink 17th February 2020 13:09

Quote:

Originally Posted by macafee2 (Post 2793581)
The head of the bolt for the upper arm is visible from under the car.

The upper arm bolt isn't the one referred to in the RAVE p808 text quoted in post 15. They're talking about the bolt that the secures the trailing arm bush to the toe-in adjuster bracket, represented by this blue dotted line.

https://www.the75andztclub.co.uk/for...a951a6d3b1.jpg

This bolt cannot be torqued on the car - it's impossible because the bolt head and the nut are completely covered by that flat plate on the bracket.

Quote:

Originally Posted by macafee2 (Post 2793581)
If you have already tightened to 100, I would loosen them off once you have the car on 4 wheels and then tighten to the correct torque.

I've already tightened the three blue bolts indicated below to 100Nm. They're easy to get at so I'll loosen them off and re-tighten once the weight is on the rear suspension.

https://www.the75andztclub.co.uk/for...a99dc35fe1.jpg

Quote:

Originally Posted by macafee2 (Post 2793581)
If you have had the trailing arms off then I would suspect you will need to have the tracking checked

Yes, the rear wheel tracking (via toe adjuster) and the front wheel tracking will both need to be done again.

This text on RAVE p807 is an attempt to get the bracket back on in exactly the same position as it was in before you took it off:

14. Reference mark trailing arm bush bracket to body to aid assembly.
15. Align trailing arm bracket with reference marks and tighten bolts to 100Nm.

It doesn't work because the reference marks I made around the bracket (before I took it off) got obliterated when I cleaned up and repainted the whole area with POR15.

Blink 17th February 2020 13:18

All of which brings us back to here:

Quote:

Originally Posted by Blink (Post 2793577)
RAVE page 808 (Workshop Manual Service Procedures) underneath diagram M64 0112: 4. Position trailing arm bush bracket, align to marks on casing, fit bolt and tighten to 100Nm. Caution: Nuts and bolts must be tightened with weight of vehicle on suspension.

What marks? Which casing?

Blink 2nd March 2020 15:08

Quote:

Originally Posted by Kev75 (Post 2793596)
I think the referance marks is refering to marks made by the person doing the job made before dismantling?

Kev

Sorry Kev - I missed your post.

The answer to your question is I don't know. :shrug:


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