1HD-FTE Viscous heater bracket

[l3n0x]

Hello Again!

I have a last question (for now) I've asked it before in other threads, but perhaps this will get more attention.

In order to take off the intake I had to remove the viscous (or power) heater mounting bracket (red circle):

It is secured to the head ( I think, maybe one goes into the block ) with 3 long, I think 8mm bolts (blue circles in image above):

I can't for life find a torque value for these 3 bolts in any of the FSM's, so was wondering if somebody knows the value? For now I've done it up to 19.6Nm (as most bolts on the head uses this value), but it would be a bad day if any of it came undone (a belt is pulling on the assembly), and to be honest I think the 19.6Nm is a bit low for it - but also don't want to snap it or strip a thread.

Thanks in advance!

 

[Towpack]

If there is no specific torque given for these bolts, there should be a table of bolt types and markings with appropriate settings near the front of the FSM.
Bolt strengths range from 4T to 11T. The table shows bolt types (flange etc...) and the different markings and what they mean.
Eg....a hexagon flange bolt with no markings is 4T which in M8 =14nm (10lb/ft)
A hexagon head bolt marked with 4 short lines is 8T which in M8 = 29nm (22lb/ft)
It’ll make sense when you see it.
This is from the 1HD-FT FSM.

If you’re that concerned about them coming loose you could always use a dab of non permanent threadlock.

 

[l3n0x]

If there is no specific torque given for these bolts, there should be a table of bolt types and markings with appropriate settings near the front of the FSM.
Bolt strengths range from 4T to 11T. The table shows bolt types (flange etc...) and the different markings and what they mean.
Eg....a hexagon flange bolt with no markings is 4T which in M8 =12.5 nm (9lb/ft)
A hexagon head bolt marked with 4 short lines is 8T which in M8 = 29nm (22lb/ft)
It’ll make sense when you see it.
This is from the 1HD-FT FSM.

If you’re that concerned about them coming loose you could always use a dab of non permanent threadlock.

Yeah I've seen that table, it's just I'm not sure if it matters if the bolt is screwed into iron or into aluminium.. Because one torque value could be okay for one and strip the threads from the other I think.

 

[Towpack]

I think that’s taken into consideration on the design specs. You wouldn’t specify an 11T M8 bolt if it’s screwing into soft alloy, more likely a 4 or 5T.

 

[l3n0x]

I think that’s taken into consideration on the design specs. You wouldn’t specify an 11T M8 bolt if it’s screwing into soft alloy, more likely a 4 or 5T.

That makes sense! Thank you very much!

 

[l3n0x]

Okay, so it's a 10T M8 bolt & according to the FSM that means 38Nm, or 42Nm because it's Hexagon flange bolt. I don't think this is right & pretty sure that would strip the threads out of the cylinder head (alloy). I now went for 29Nm, but this already feels like it's on the edge of pulling the threads..

I'm out of ideas.. Don't want to strip the threads, don't want the assembly to fall off.. Meh.

 

[l3n0x]

These are the bolts in question:

2 of them (circles) go into the head, one of them is attached to the timing case.

These 3 bolts hold this whole assembly to the engine:

And these are the bolts:

4 lines & a dot

Soooo.. That's what I have..

 

[l3n0x]

Okay, I went back to 19.6Nm & hope for the best.

 

[jibberjabber]

Okay, I went back to 19.6Nm & hope for the best.

If it makes you happy, just put some red Loctite on the thread and tighten to 19.7Nm, then stop worrying, and spend the time cleaning you engine.

 

[jibberjabber]

Okay, I went back to 19.6Nm & hope for the best.

If you are really worried about them coming out.
I tell you what else you could do, drill a small hole through the head of the bolts (flat to flat) then pass wire (perhaps stainless steel) through them from one to the other, then they can't rotate.

 

[l3n0x]

If you are really worried about them coming out.
I tell you what else you could do, drill a small hole through the head of the bolts (flat to flat) then pass wire (perhaps stainless steel) through them from one to the other, then they can't rotate.

Good idea, thank you!

 

[l3n0x]

Interestingly enough the (new) belt that drives the aircon and the viscous heater started to squeal today. I thought that the bolts came lose, but that's not the case. I've tried to adjust the belt, but the adjusting screw is behaving strange - it wants to come out of its bracket as I tighten the nut on the idler - which it didn't do before.