Factory Torque Settings for Front and Rear Shocks

[parb]

Someone told me he kinda are softer and doesn't handle the highway as well as stock.. But I'm not sure I fully trust the source.
Can you confirm?

 

[Dokatd]

Someone told me he kinda are softer and doesn't handle the highway as well as stock.. But I'm not sure I fully trust the source.
Can you confirm?

I have Kings specifically to provide more firmness on the highway. They absolutely are and I don't have them dialed up. Plus, you can send them back to king to increase baseline valving.

 

[CountyV8]

I have Kings specifically to provide more firmness on the highway. They absolutely are and I don't have them dialed up. Plus, you can send them back to king to increase baseline valving.

When you say more firmness on highway is that with them set soft or hard on the adjuster

 

[Tenac]

I set mine to setting 4 on the highway drives flat and great feel. Off road I will take them too about 12 or 8 so they soften up and handle the bumps really well. I've never had adjustable off road shocks before or a set of Kings but WOW the eases to reach the knobs while I'm airing down is perfect. It allows me to have best of both worlds.

 

[Dokatd]

When you say more firmness on highway is that with them set soft or hard on the adjuster

When you set them on the more firm side, so I would say hard. I notoriously go with firmer shock setting. I have actually exceeded FOX valving specs on a few builds for customers in the past. I prefer a firm sure footed feel for sure.

 

[Ralphzim]

I took delivery of a set of King shocks. I watched the videos of a couple of installs. The instructions looked easy peasy. I'll start with the rear shocks because that seems the easiest. Off I go to the parking garage with the shocks and my Halfords socket/wrench set. Removing the wheel, easy. Removing the plastic shroud - bl00dy hell, fiddly as anything. Pulling on the plastic around the wheel arch to remove it feels uncomfortable up to the point where it just comes loose. Getting that lower shock bolt loose wasn't happening. I had to go back upstairs and get the Milwaukee ugga dugga. Wouldn't you know it the only size I needed wasn't included in the impact socket set I had. The Halfords 24mm socket did the job but it paid a heavy price. I got the old shock out and was feeling quite pleased with myself. Commence assembly! Erm, yea. This is when I realised I didn't have all the right tools. The bottle jack that comes with the Grenadier does a decent job of lifting the axle. Jack stands under the axle for safety but the little bottle jack wouldn't reach anything higher. The King shocks are pressurised and took my full body weight to barely start compressing it. There was no way my scrawny ass was going to be able to compress the shock to get it to fit in the shock mounting brackets gap. I didn't have a way to adjust the distance between the shock mounts. I ended up using ratchet strap to compress the shock. It worked but it was really fiddly. Not recommended.

I've got a digital torque wrench range 17NM to 200NM. I looked up the torque specs for the 16mm bolt. There is a 10 stamped on one of the nuts so I'm assuming that means grade 10. The chart said 302NM so the 275NM figure from the Ineos specs seems about right. I set the torque wrench to 200NM and I spent 20 minutes trying to get the lights to go green. I wasn't successful. I ended up with the jack handle on the Halfords socket wrench with as much effort as I could muster and I think I might have reached 200NM but no way was it anywhere near the expected 275NM.

I never give up so I finished installing the rear shock on the right side. I'm a believer in loc tight so I'm sure nothing will work loose. I'm off to Totaltools tomorrow to get the tools I need before doing the other three.

I enjoy working on the Grenadier. Every panel I take off or bolt I remove makes me feel like I know it a little better. It feels like it's going to be a long relationship.

This might be a bit late, but the easiest way to remove and fit the shocks is to jack up the body to allow the shock a full drop. Then jack up the axle until the the holes line up and you can remove the bolt easily or slide the bolt in.

 

[Glen]

It is so high as to strain credulity. There is no engineering reason for a shock mount torque spec of 275NM on the Grenadier, it is not an earth mover. It also exceeds the standard maximum torque rating of ~217NM (per Fastenal, but varies by source) for a M14x1.5 10.9 bolt with dry assembly.

Old thread, but this looks like another example of Ineos fastener torque specs that don’t make any sense. I just looked in the workshop manual and it does indeed specify 275 Nm for the shock bolts in two different places.

I’d think it’s a pretty rare situation where you need to use fasteners at 100% of their proof load instead of just going up a size and torquing that to a standard 75% of proof load.

Fastener selection should begin with the shear and clamping loads required - based on a conservative loading like 75% of proof load - and then torques needed to create the required clamping force would be documented. I can’t even begin to speculate what kind of systemic error would lead to the situation of insanely high torque figures for multiple fasteners. Did anyone ever send a query to Ineos?

 

[TCMColorado]

Old thread, but this looks like another example of Ineos fastener torque specs that don’t make any sense. I just looked in the workshop manual and it does indeed specify 275 Nm for the shock bolts in two different places.

I’d think it’s a pretty rare situation where you need to use fasteners at 100% of their proof load instead of just going up a size and torquing that to a standard 75% of proof load.

Fastener selection should begin with the shear and clamping loads required - based on a conservative loading like 75% of proof load - and then torques needed to create the required clamping force would be documented. I can’t even begin to speculate what kind of systemic error would lead to the situation of insanely high torque figures for multiple fasteners. Did anyone ever send a query to Ineos?

Ignoring whether an M14 bolt should be torqued to 275Nm, the question is why does a shock bolt need the clamping force this would provide. I will be installing Koni shocks soon and the bolts will not be torqued this high.

 

[Glen]

. . . the question is why does a shock bolt need the clamping force this would provide. . .

It doesn't. And stupid-tight won't prevent loosening from vibration, if that was the rationale.

 

[Glen]

@Clark Kent posted an excerpt from the workshop manual in another thread here that describes how to align the front and rear axles. This procedure includes replacing the fasteners (12 of the 16 control arm connections, not including the upper control arm to chassis connections), a step where intermediate torque values are applied, then the vehicle is driven off then back on the ramp before a final torque of 110 Nm + 180° more is applied.

By saying to discard the fasteners (the only place I see this), Ineos is acknowledging that either their procedure is torque to yield or that it might get into that region. Torque to yield is for situations where you need extremely precise torque values, like compressing a gasket and holding down a cylinder head. It provides very little additional clamping force over the proof load of a fastener (some models actually show a steep drop to less force before the slope briefly goes to zero) once you exceed the elastic limits of the fastener. I’m struggling to understand why control arms would need either extremely precise clamping forces from torque to yield OR extremely high clamping forces at all. The fasteners are in a double shear loading - that’s about as strong as it gets. Extreme clamping forces shouldn’t be required.

I'd suspect there's something else going on here - like Ineos trying to solve a problem they don't quite understand yet.

Still no resolution to my inquiry of Ineos.

edit: modified the statement regarding clamping force for proof load vs elastic limits

 

[ryanjl]

Ignoring whether an M14 bolt should be torqued to 275Nm, the question is why does a shock bolt need the clamping force this would provide. I will be installing Koni shocks soon and the bolts will not be torqued this high.

What torque value did you wind up going with?

I agree that 275Nm is insane.

I am putting on Konis in a few days. I was watching the below video to get an idea of what's entailed in the job, and saw a comment that wrote King says 140 ft lbs, which equates to 190 Nm. I'm thinking that plus some blue loctite will be sufficient.


View: https://www.youtube.com/watch?v=GP9koq7hlyk

 

[TCMColorado]

What torque value did you wind up going with?

I agree that 275Nm is insane.

I am putting on Konis in a few days. I was watching the below video to get an idea of what's entailed in the job, and saw a comment that wrote King says 140 ft lbs, which equates to 190 Nm. I'm thinking that plus some blue loctite will be sufficient.


View: https://www.youtube.com/watch?v=GP9koq7hlyk

I went with the 200 Nm. I did not use loctite.

 

[ryanjl]

I went with the 200 Nm. I did not use loctite.

Incidentally, what setting did you put your Konis at?

 

[TCMColorado]

Incidentally, what setting did you put your Konis at?

I left the shocks at the factory setting. So far I have not felt the need to adjust them. But I will be likely be switching to Fox shocks later this season when my roof conversion and interior system is installed. With the increased weight I want easy adjustability to dial in the ride especially in combination with the highest spring rate factory springs (black markers) that will be going in as well.

 

[ryanjl]

I left the shocks at the factory setting. So far I have not felt the need to adjust them. But I will be likely be switching to Fox shocks later this season when my roof conversion and interior system is installed. With the increased weight I want easy adjustability to dial in the ride especially in combination with the highest spring rate factory springs (black markers) that will be going in as well.

Was the Koni factory setting stiffer than the stock Sachs units?

 

[TCMColorado]

Was the Koni factory setting stiffer than the stock Sachs units?

A bit softer.

 

[Glen]

@TCMColorado - Can you or anyone else identify the thread pitch of the upper and lower shock bolts? A number of posts in this thread (including mine where I comment on other posts) imply the shock bolts are M14, but now that I have access to the Ineos parts listing, I see they are M16 x 90. If someone can identify the thread pitch and verify Class 10.9 (standard or coarse pitch is 2.00 mm, fine pitch is 1.50 mm), I can run some calculations to make an informed comment on the published torque value of 275 Nm.

I suspect the bolt is Class 10.9 M16 x 1.50 mm x 90 mm, and if that's the case, I can show that 275 Nm is a very reasonable torque spec.

 

[ryanjl]

Not sure if I have the appropriate size in my thread checker string, but, if so, I can check when I swap my shocks sometime in the next few days/this weekend.

 

[TCMColorado]

@TCMColorado - Can you or anyone else identify the thread pitch of the upper and lower shock bolts? A number of posts in this thread (including mine where I comment on other posts) imply the shock bolts are M14, but now that I have access to the Ineos parts listing, I see they are M16 x 90. If someone can identify the thread pitch and verify Class 10.9 (standard or coarse pitch is 2.00 mm, fine pitch is 1.50 mm), I can run some calculations to make an informed comment on the published torque value of 275 Nm.

I suspect the bolt is Class 10.9 M16 x 1.50 mm x 90 mm, and if that's the case, I can show that 275 Nm is a very reasonable torque spec.

I just now checked. The shock bolts are M16 x 1.5 class 10.9.

I still question if 275Nm of of torque is necessary to produce an appropriate clamping force for these bolts even if it is within the spec of the M16 fastener.

 

[Glen]

My calculator output investigating the Ineos front and rear shock bolt parameters is attached. Ineos specifies 275 Nm torque for these Class 10.9 M16 x 1.50mm x 90mm bolts.

Use this data at your own risk: I am not a doctor, lawyer or engineer.

Here are some highlights:

• Applying 275 Nm (203 lbs ft) takes the bolt to 64% of the proof stress during install and results in a minimum preload in service of 42.4 kN (9,536 lbs).
• For a target 60% of proof stress, you could apply an initial torque of 80 Nm then advance the nut ~ 35°. This would provide 50.1 kN (11,261 lbs) of minimum preload in service. (kN data not shown in the attachment.)
• For a target 57% of proof stress, you could also just apply 277 Nm (which is ~ the spec of 275 Nm). Notice the Von Mises stress at target torque is at 536 MPa, well below the proof stress of 830 MPa for the M16 bolt.
• You could torque this bolt to 425 Nm and still be just under 100% of the proof stress of the bolt during install. (Output not shown, and to be clear, DO NOT DO THIS!)

You'll often see torque tables with a 70% or 75% figure at the top of the table, although many tables omit data for fine pitch threads like the 1.50mm here. Torque tables also can't account for the joint material, bolt length or joint shape as we're approximating here. Here is a fairly comprehensive set of torque tables: link. You'll notice they are using 75% of proof stress, a common standard (vs another common standard of % of 0.2% yield load that I use), and that the data is consistent with my calculator output. The 70% - 75% figures account for torque scatter – uncertainty in how the torque relates to tension due to factors like variations in friction and accuracy of the torque wrench – and it also usually ensures the Von Mises stress remains below the yield point during tightening.

So . . . I'd be fine with Ineos's torque spec of 275 Nm for the shock bolts. It's probably in the neighborhood of 60% of yield to leave some headroom for other loads on the bolt – in this case the shock bolt also sees shear loads from the shock pushing and pulling on the bolt vertically.

This number - 275 Nm - does intuitively seem high to me too, but then I don't usually deal with big M16 bolts either. Hopefully this information is helpful.