Hood Has Light Bounce While Driving Resolution Needed (1 Viewer)

[zpilot]

My hood has had a Light bounce at the front of the truck and so far no luck with the following parts changed.

New OEM Hood Struts
New OEM Hardware for Hood Lock Mechanism
New OEM Front Left and Right Weather Stripping
Adjusted Hood Lock to Lowest point possible.
Hood Alignment Stoppers cannot go up anymore or it will cause hood not to sit flush.

Do I need to change the Hood Lock itself? 53510-60011

The Shocks on the Truck are also New OEM but I do have mud Terrains.

 

[TheBussman]

i wouldn't know unless i saw it happening but alot of times it's the foam that goes between the inner structure of the hood and the outer skin. A good body shop has something that will work best but a lot of people just shoot expanding insulation foam in there. Works but messy.

 

[Kernal]

Is it the whole hood or just the sheet metal "skin" that is moving?

When you close the hood is the sound like a vibrating metallic clang or is it a dull thud?

Did you replace the hood stoppers (they get squished down over time) or just adjust them upwards?

There are a couple of rubber side cushions for the hood, replacing those may make a small difference if old and shrunk.

If the skin (sheet metal) has come loose from the supporting frame (causing a metallic clanging sound when it's closed) one option is to use a specific NVH adhesive to stick them back together. AFAIK it's important to not use anything that shrinks (or expands too much) while curing or which turns rock hard.

Two examples:

Dual-Mix™ Flexible Urethane Foam | 39357 | SEM Products

Dual-Mix™ Flexible Urethane Foam is a two-component, urethane, expanding foam that stops vibration and dampens sound in most voids.

semproducts.com

https://www.3m.com/3M/en_US/p/d/v000179172/

Please talk to a paint and body expert for the correct procedure before doing anything.



Has the vehicle ever been in a front end collision?

 

[shocktower]

i wouldn't know unless i saw it happening but alot of times it's the foam that goes between the inner structure of the hood and the outer skin. A good body shop has something that will work best but a lot of people just shoot expanding insulation foam in there. Works but messy.

The proper way is pull the, blanket off and see if the ribs have separated from the skin, I'm betting on that is what has happened. So the correct way is pull the hood get the area of the skin and ribs should be contacting and clean between them, I'm going to use a Fein multi tool and scotch Brite attach to the reciprocating blade, and then put a cloth on a blade with wax and grease remover so I get the best adhesion . Some people have used a poly eurathane for glue them , I prefer the 3M automotive panel glue it's a 2 part strong adhesive, do this out on your lawn on a warm day and after re gluing the ribs to skin put a slight bit of weight to make it new again

 

[TheBussman]

I've seen people try to glue it together and it's always failed, I think it needs to be some type of slightly flexible foam that pushes between the 2 parts. I've seen one after it was done at a body-shop before and it looked like they got the same stuff the factory used.

 

[duece71]

IMO I would check the hood lock at the front and the actuating cable. Does the lever in the cabin feel loose when you pull it to release the hood lock to open the hood? Is the hood lock mechanism it self on tight?

 

[zpilot]

i wouldn't know unless i saw it happening but alot of times it's the foam that goes between the inner structure of the hood and the outer skin. A good body shop has something that will work best but a lot of people just shoot expanding insulation foam in there. Works but messy.

It not the actual hood skin separation from its sub frame but the actual hood nose bouncing a bit. I will be reinforcing the skin to frame once I replace my hood insulator. Thank you for your suggestion.

Is it the whole hood or just the sheet metal "skin" that is moving?

When you close the hood is the sound like a vibrating metallic clang or is it a dull thud?

Did you replace the hood stoppers (they get squished down over time) or just adjust them upwards?

There are a couple of rubber side cushions for the hood, replacing those may make a small difference if old and shrunk.

If the skin (sheet metal) has come loose from the supporting frame (causing a metallic clanging sound when it's closed) one option is to use a specific NVH adhesive to stick them back together. AFAIK it's important to not use anything that shrinks while curing or which turns rock hard.

https://www.3m.com/3M/en_US/p/d/v000179172/

Please talk to a paint and body expert for the correct procedure before doing anything.



Has the vehicle ever been in a front end collision?

Has a thud when closing it. Hood Stoppers are the original and cannot go any higher or it pushes the hood out of alignment.
Good suggestion on the rubber side cushions, I will see if those are available. I am sure the mud terrain tires aren't helping but suspension is OEM new and pretty smooth. Appreciate the suggestions.

The proper way is pull the, blanket off and see if the ribs have separated from the skin, I'm betting on that is what has happened. So the correct way is pull the hood get the area of the skin and ribs should be contacting and clean between them, I'm going to use a Fein multi tool and scotch Brite attach to the reciprocating blade, and then put a cloth on a blade with wax and grease remover so I get the best adhesion . Some people have used a poly eurathane for glue them , I prefer the 3M automotive panel glue it's a 2 part strong adhesive, do this out on your lawn on a warm day and after re gluing the ribs to skin put a slight bit of weight to make it new again

It not the actual hood skin separation from its sub frame but the actual hood nose bouncing a bit. I will be reinforcing the skin to frame once I replace my hood insulator. Thank you for your suggestion and steps on how to.

I've seen people try to glue it together and it's always failed, I think it needs to be some type of slightly flexible foam that pushes between the 2 parts. I've seen one after it was done at a body-shop before and it looked like they got the same stuff the factory used.

I agree, I think Shocktowers suggestion above on the 3M panel glue would be the proper type of adhesive or the likes. Thank you

IMO I would check the hood lock at the front and the actuating cable. Does the lever in the cabin feel loose when you pull it to release the hood lock to open the hood? Is the hood lock mechanism it self on tight?

Lever inside is solid with no slack. Hood Lock Mechanism has all new hardware and is tight. New lock mechanism is cheap, $50 so might as well change it I guess could be worn overtime adding to the bounce. Thank you.

 

[Hornd]

First Confirm Bumpers are Well Adjusted.
THey Black Rubber at Corners of Hood - Adjust them out then Lock the Nut

Next I filled the Gaps in Hood to Ribs with Minimally Expanding Foam, but you have to remove the Hood Insulator to Apply.

 

[zpilot]

First Confirm Bumpers are Well Adjusted.
THey Black Rubber at Corners of Hood - Adjust them out then Lock the Nut

Next I filled the Gaps in Hood to Ribs with Minimally Expanding Foam, but you have to remove the Hood Insulator to Apply.

Thank you, I will check the Hood Stopper adjustments.

 

[Hornd]

Thank you, I will check the Hood Stopper adjustments.

Hood should Pop up to Safety Latch after Hood Release is Pulled.
Keep adjusting them up till hood Springs Open.

 

[zpilot]

Hood should Pop up to Safety Latch after Hood Release is Pulled.
Keep adjusting them up till hood Springs Open.

I checked it, hood pops up to release perfectly. I’ll check the hood stopper adjusters. Thank you

 

[shocktower]

I deal with more than my own Land Cruiser 80 series and I thought it was the, rubber stoppers, and after looking at several other ones I went and replaced them on mine and a customer's and it's the separation of the skeleton and skin , I'd never use spray foam it's going to push bumps in your hood, and look bad I bought some 3M specific Automotive 2 part adhesive. When I replaced rubber bumpers I noticed nothing and was dissatisfied and knew it's the broken factory adhesive and the only way is clean it up by first using a solven and 3M scotch Brite, I'm going the route of using a multi tool and folding on both sides of blade and get ready for the proper way I'd probably clean with power purple and then the final cleaning with Wax and grease remover and then us the adhesive and weights to secure it evenly I would avoid the spray foam it's crap . Good luck with your own testing I'm going with quality products

 

[CharlieS]

I'd be a little bit surprised if SEM doesn't have an auto body adhesive made for that purpose.

 

[Kernal]

Dual-Mix™ Flexible Urethane Foam | 39357 | SEM Products

Dual-Mix™ Flexible Urethane Foam is a two-component, urethane, expanding foam that stops vibration and dampens sound in most voids.

semproducts.com

The topic is discussed in a lot of rebuilder forums:

that sticky stuff between hood skin and the under bracing ???

You didn't say what youwere working on, but you've got to have a really light touch when your sanding on panels like that. You do not want to "bond"...

www.jalopyjournal.com

 

[Broski]

I deal with more than my own Land Cruiser 80 series and I thought it was the, rubber stoppers, and after looking at several other ones I went and replaced them on mine and a customer's and it's the separation of the skeleton and skin , I'd never use spray foam it's going to push bumps in your hood, and look bad I bought some 3M specific Automotive 2 part adhesive. When I replaced rubber bumpers I noticed nothing and was dissatisfied and knew it's the broken factory adhesive and the only way is clean it up by first using a solven and 3M scotch Brite, I'm going the route of using a multi tool and folding on both sides of blade and get ready for the proper way I'd probably clean with power purple and then the final cleaning with Wax and grease remover and then us the adhesive and weights to secure it evenly I would avoid the spray foam it's crap . Good luck with your own testing I'm going with quality products

View attachment 3660451

While I agree with what you’re saying.
I don’t think the power grab is the proper adhesive.

 

[oilbrnr]

Here's what I just did a few weeks ago to address the lack of rib to skin gap filler. Nice to have the oil can go buh-bye as I cruise down the Interstate at 85. (well, the first part of that statement is true...). Sounds like your corner bumper posts need to come up or the latch down.

80 Series Hood - Insulate or Don't Insulate?

My insulated hood liner is about shot after only 27 years. In our climate is it better to not have the liner? I'm sure I'll hear more engine noise but curious what others have done. Thanks.

forum.ih8mud.com

 

[mudgudgeon]

I deal with more than my own Land Cruiser 80 series and I thought it was the, rubber stoppers, and after looking at several other ones I went and replaced them on mine and a customer's and it's the separation of the skeleton and skin , I'd never use spray foam it's going to push bumps in your hood, and look bad I bought some 3M specific Automotive 2 part adhesive. When I replaced rubber bumpers I noticed nothing and was dissatisfied and knew it's the broken factory adhesive and the only way is clean it up by first using a solven and 3M scotch Brite, I'm going the route of using a multi tool and folding on both sides of blade and get ready for the proper way I'd probably clean with power purple and then the final cleaning with Wax and grease remover and then us the adhesive and weights to secure it evenly I would avoid the spray foam it's crap . Good luck with your own testing I'm going with quality products

View attachment 3660451

Also a bit hesitant on the PowerGrab.

There's two part polyurethane seam sealer glues made for structurally bonding metal panels in auto body manufacturing and repair 3m, Sika, Wurth, SEM

I'd also be really wary of using a toothbrush (aka, oscilating multitool) between ribs and hood skin.
I think it would be easy to do damage, to much friction, or too much force you could damage the paint on the top skin or put dents in it.

Have a look here

2 Part Seam Sealer | Adhesive and Bonding | Chemical Product | Wurth USA

www.wurthusa.com

 

[TheBussman]

Dual-Mix™ Flexible Urethane Foam | 39357 | SEM Products

Dual-Mix™ Flexible Urethane Foam is a two-component, urethane, expanding foam that stops vibration and dampens sound in most voids.

semproducts.com

The topic is discussed in a lot of rebuilder forums:

that sticky stuff between hood skin and the under bracing ???

You didn't say what youwere working on, but you've got to have a really light touch when your sanding on panels like that. You do not want to "bond"...

www.jalopyjournal.com

Yea that looks like the best stuff to use, expanding insulation foam has been seems to be very unpopular here but it is proven for over 10 years and still going strong (customers done it themself) and can be done clean as you want it to be. Does not bulge the hood at all (use minimal expanding foam) Defiantly don't use glue or seam sealer seen it fail many times one was a customer took it to a body shop and paid hundreds to have it done and only lasted a month or so. don't really need to go crazy with cleaning as the foam is mechanically locked into place anyway.

 

[oilbrnr]

Problem with the two part solutions, at least in the case of 3M, you need to buy their proprietary application gun, which ain’t cheap.

 

[zpilot]

Some updates/progress.

I adjusted the driver side (The problematic side) Hood Adjuster up high so I could see the misalignment when hood was closed knowing I have contact and a starting point. I incrementally adjusted down in half turns, locked the nut and closed hood gauging it going down towards alignment. So far on my drive to work I would say it seems better but need more road time to check. If this works out, I will replace the Fender/Hood cushions and Hood Bumper adjusters and repeat this with these new parts.