Insulating bonnet

[Tbaumer]

Removed the old bonnet insulation. As with everything on a 1986, insulation style is NLA - P#MUC9850 superseded to P#AWR4147. Cleaned the underside & carefully spread the gap between the framework & the skin, so an adhesive caulking (Vulkem) can be applied between. B-Quiet Ultimate to the panels & spots of caulk to make really sure the edges don't let go.

 

[Tbaumer]

You can see the difference in thickness & fastener layout at the front edge. What is the cut out in the insulation & metal tab for in the last pic?

 

[JimC]

It’s just so you can access the clip for the bonnet prop rod. Most newer trucks don’t have the scissor hood prop.

 

[chris snell]

What's the point of the Vulkem in between the frame and skin?

 

[RBBailey]

I think he may be trying to stop vibration on any parts that looked like they were separating.

I'm curious about your results -- do you notice any difference in noise? My current liner is in pretty good shape, but starting to show age. I was just going to use some heavy paint and DynaMat clone, but may go further if it might help.

 

[Tbaumer]

Of course - the bonnet prop rod. I would have realized it as soon as I went to put it on.
The Vulkem is just for possible vibration. I didn't see any signs of wear/vibration, but with a little gap already, I just made sure there wouldn't be any.
I can't tell you about improvements in noise because I am doing this all at the same time as an engine swap & I'm adding sound liner to the cabin side of the bulkhead.

 

[Tbaumer]

Put the bonnet on. The cut out & metal tab I was asking about is not the bonnet prop rod cut out.
It's this mystery cut out & tab in the pics.

 

[RBBailey]

I have the tab on the center area as well. I’m thinking I’m going to drill a hole in it to hang my work light from.

 

[JimC]

You have the scissor-type bonnet prop. There is another one that is just a straight rod. It stows by way of a little clip that attaches to that tab. I swear I’m not lying!

 

[Tbaumer]

Ha! I believe you. Spent way too much time again looking for the answer in all the wrong places online. So, I have the, way ahead of it's time in 1986, fancy "multi-prop capable bonnet".