My regular readers will know that my "Chevissan" is a "noise polluter". I'm slowly quietening it down.
The latest effort is to insulate the front passnger area. I'll do the bonnet next. I had a word with Marlin Seals and Insulation in
Fremantle - they're in the phone book. They do ships' engine rooms and the like. Mark, the guy there, certainly knows his stuff. I have no connection with the company BTW.
I paid $175.00 for 2 sheets of differing sound insulation materials. The first is for the passenger area & is about 5 mill thick consisting of a foam layer, a layer of barium ( ya can't use lead anymore, it's illegal) and a layer of protective vynil. The barium barrier absorbs and kills the sound energy.
When fitting this stuff, you have to ensure that the Barium/foam barrier does not touch the steel of the floor pan or bulkhead/firewall. the technical term for this is "decoupling". You should make every attempt to plug all holes and crannies - damn near impossible without ripping the whole dashboard out. Alas, when I ripped out the seats, consoles, gear levers and existing floor matting, the Nissan felt insulation came out as
well, stuck to the back of the carpets. So I had to fit some polyester fibre to floor before putting down the barrier material. I got lucky here as my next door neighbour gave me a huge roll of the stuff that he found on the side of the road on his way home from night shift.
It was a bugger of a job all round, but
well worth it. I can now listen to the radio at 100 kmh!! It's not "Rolls Royce quiet" by any means, but it's very much improved. I'll be doing the rear passenger area in a similar fashion. This should be a much easier job as I have no back seats at all in the "Chevissan".
The next job is the bonnet. The sound insulation for this bit is different to the inside stuff. It's about 30mm thick and includes the same barium layer. Hence its less dense but has the same Db sound insulation qualities.
This should make a big difference to the sound levels at traffic lights etc. "Cos right now it's quieter when moving than it is when stopped!!
If you do have to remove any of your seats for any reason be VERY careful when replacing the
seat bolts. They are a fine metric thread (pitch 1.25mm) and strip very easily if not lined up properly. The extra thickness of the barium barrier throws the bolt/hole alignment out by a long way. You have to cut a fair bit of the old carpet out around the
seat mountings.
I took a chance on one bolt and thought "that feels passable" and it chewed it up. I haven't stripped a thread for 25 years!! I usually have a good eye for these things. I had go & buy a 10mm by 1.25 tap to clean it up. Cost was $34.00. Bummer!!
If you think yer truck is noisy, I'd recommend this stuff. It certainly makes a difference. And it's not that expensive either. Just a bit time consuming and awkward. But once you've done one , ya know where the traps are.
In fact I might start doing this as a business!! Nice little earner for a retired old bloke like meself.
Take Care,
Bilbo