What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[mikez71]

Heres where the supported one cracks.. Even cracked under the windshield! I want to put velcro felt under those 4 bolts, which were locktited from the factory, so its not clamping the plastic and it can expand and contract without binding.

 

[Doubeleive]

Heres where the supported one cracks.. Even cracked under the windshield! I almost want to b

View attachment 467319

what do you mean by supported one?

 

[mikez71]

The updated design with support ridges, I already had them I'm pretty sure. Will verify soon once I remove it completely.

 

[Doubeleive]

my thoughts on where those crack like that if I ever replace mine is to glue or epoxy Plastic sticks or something similar underneath those known weak spots as added support

 

[j91z28d1]

cracked dash is annoying. all they really needed to do was changed the plastic type up just a bit. add some more flex into the mix. better than the dodge bit ugh.


well no play in the wheel bearing this morning. cleaned up the oil/very thin grease. leave the center cap on and head out. we shall see haha. 24h till the TN mountain roads for a week.

 

[mikez71]

Old dash removed. Original from 2012.
Definately needs different material.

Someone showed a fiberglass dash on here, but one area by vents looked a little off..

 

[PG01]

12 years = 4380 days
new dash = $1000

For only 23 cents a day, you can help a chevy owner drive without a broken dash!

I am wondering if I should fill that area under my new dash with JBweld..
Will that prevent cracking or accelerate it? That crack is just over the airbag support bracket.
Amazing they crack in the exact same place, that they didn't fix it with their 'updated' design.

View attachment 467318

I wouldn’t jb weld it. Imo, it took my truck 12 years to crack….if I still have this thing in 12 years im doing something wrong…. Dont get me wrong, i bought it new and i love this thing but the rust is gonna take over soon…. It already started and its just gonna get worse….

The last rotted out plow truck i had was an ‘89 w250.. i put a motor in it before it got too bad but after that i always hated working on it because of the rust so i sold it in 2008ish.

 

[Sparksalot]

I wouldn’t jb weld it. Imo, it took my truck 12 years to crack….if I still have this thing in 12 years im doing something wrong…. Dont get me wrong, i bought it new and i love this thing but the rust is gonna take over soon…. It already started and its just gonna get worse….

The last rotted out plow truck i had was an ‘89 w250.. i put a motor in it before it got too bad but after that i always hated working on it because of the rust so i sold it in 2008ish.

If the truck already has cancer, why worry about the dash cracks?

 

[PG01]

If the truck already has cancer, why worry about the dash cracks?

Right!

 

[mikez71]

I've been looking at the cracks.. using Mental Element Analysis... Here's my dashboard install plan..

Leave all the upper bolts/screws very LIGHTLY snug. 4 windshield bolts, 2 defroster screws (rattles if loose), maybe 2 more airbag bolts (tightened them with spacing washers)
Put a layer of velcro fuzz above bolt holes.. possibly below also. Cushion it and let it slide.
Hog out the holes so there will be a little more room to shrink.. Old one was on the edge of some holes, and all were tight, not allowing any movement.

 

[mikez71]

I wouldn’t jb weld it. Imo, it took my truck 12 years to crack….if I still have this thing in 12 years im doing something wrong…

I've been doing something wrong for awhile, which is why I bought this thing with 200k miles..
And I'm not sure when I'll stop... Not with this dash obviously..

 

[Geotrash]

Fixin’ to pull our camper home with it. Gonna be a hot day today. Glad I made all those engine and cooling system mods to it a few years ago. Route 33 over the Blue Ridge between Luray and Shenandoah.

 

[Scrappycrow]

I am wondering if I should fill that area under my new dash with JBweld..
Will that prevent cracking or accelerate it? That crack is just over the airbag support bracket.
Amazing they crack in the exact same place, that they didn't fix it with their 'updated' design.

I would not use JB Weld at all, much less "fill" the area with it. You'll end up with different contraction/expansion rates simply due to different materials, and also different contraction/expansion between that area and adjacent areas, as the JB Weld fill would have thermal inertia due to increased mass.

What I do agree with is enlarging the mount holes and bolting them down in a manner to allow flex (I have successfully done this on mid-'80s BMW bumper covers). I would definitely use larger washers, because keeping the original size washer with a larger hole will mean more stress on the hole perimeter.

 

[mikez71]

I would not use JB Weld at all, much less "fill" the area with it. You'll end up with different contraction/expansion rates simply due to different materials, and also different contraction/expansion between that area and adjacent areas, as the JB Weld fill would have thermal inertia due to increased mass.

That was my thinking as well, but I also thought the epoxy might still keep the plastic together, while stressing it minimally during expansion/contraction.
As to increased thermal mass, it might help if it could keep temps more evenly distributed.
Looking at where I want to re-inforce, it covers a large area, increasing my chances for failure and making a mess.

Enlarged all the front holes.

Something I just noticed, the metal dash brackets are floating about 1/8" off the mount (the airbag brackets), and tightening it down will pull the plastic down noticeably, right where they always crack.

After it's all lightly snugged, I'm going to put the right size washers between the brackets to keep it from pulling down on the dash.

 

[Just Fishing]

I was just looking at a new dash for mine.
Cracked right at the airbag corner and a fresh one above the instrument cluster.

About $1300 for a new gm dash.
Eventually I'll try and patch it, i also looked at some of those covers.
They hold on with double sided tape... eww

 

[Just Fishing]

My dash also made it a long time w/o cracking.
First crack appeared on the airbag corner last year.
We took it to oktoberfest and let the valet park it.
I noticed the crack the next day.
Second crack just appeared, i noticed it after doing yearly inspection.

I'm imagining that it went something like this "wow this one isn't cracked, *bang bang fist* oh there it went!"

 

[j91z28d1]

That was my thinking as well, but I also thought the epoxy might still keep the plastic together, while stressing it minimally during expansion/contraction.
As to increased thermal mass, it might help if it could keep temps more evenly distributed.
Looking at where I want to re-inforce, it covers a large area, increasing my chances for failure and making a mess.

Enlarged all the front holes.

Something I just noticed, the metal dash brackets are floating about 1/8" off the mount (the airbag brackets), and tightening it down will pull the plastic down noticeably, right where they always crack.

View attachment 467399
After it's all lightly snugged, I'm going to put the right size washers between the brackets to keep it from pulling down on the dash.

putting it in a bind and then sitting in the sun for years, definitely sounds like recipe for cracks.

for the other holes, if you can cut a metal tube the thickness of the plastic as a spacer and then use the fuzzy side of velcro top and bottom. I find it fixes rattles well and the adhesive holds it in place

 

[Just Fishing]

I have one of these that does an ok job melting metal tabs into plastic.
https://www.amazon.com/Upgraded-Plastic-1000PCS-Abrasive-Aluminum/dp/B0C8S2BV2N
this isn't the one I have, but they are all the same pretty much.
Mine is a 100w...

Handy for lots of things, especially 3d printing.
IIRC I bought it for my Jeep after someone hit it, I stitched the plastic fenders back together and slapped them back on.
worked great!

I'm figuring it will come in handy fixing my dash.


On mine I had to take it apart and drill vent holes for the electronics.
it overheated fast, now it works better, and I can cool it off quickly when it does a thermal shutdown on me by using some compressed air to vent through the tool.

 

[Pandabird]

I have one of these that does an ok job melting metal tabs into plastic.
https://www.amazon.com/Upgraded-Plastic-1000PCS-Abrasive-Aluminum/dp/B0C8S2BV2N
this isn't the one I have, but they are all the same pretty much.
Mine is a 100w...

View attachment 467433

Handy for lots of things, especially 3d printing.
IIRC I bought it for my Jeep after someone hit it, I stitched the plastic fenders back together and slapped them back on.
worked great!

I'm figuring it will come in handy fixing my dash.


On mine I had to take it apart and drill vent holes for the electronics.
it overheated fast, now it works better, and I can cool it off quickly when it does a thermal shutdown on me by using some compressed air to vent through the tool.

Solid recommend from me as well, these things solve a lot of headaches

 

[tuckerrnr1]

I remember years ago my father showed me how to use a standard two lead soldering iron to make tips for many different uses.

Every day I'm thankful for the knowledge ancestors gave me