How did you install your floor hump? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**71CHEVYSHORTBED402** · 08-20-2020, 07:51 PM

They take a rubber gasket. I believe GM used body seal along any glaring cracks between the floor and hump, and sprayed with the hump bolted on. Sound right?

Is there are better way or sealant? Personally I don't care if it's finished on or off the cab floor, just need to account for it.

Thanks

**Curtb1971** · 08-20-2020, 10:33 PM

I've used weather strip caulking strip made by 3m otherwise known as "dumb dumb" after everything is painted. The high humps have a nice channel that it lays in and you can go around the bolts. It fills the gap areas good and smashes out of the tight areas. If you ever need to take the hump off the dumb dumb stays pliable and doesn't dry

elorenzof · 08-21-2020, 10:46 AM

Quote:

Originally Posted by Curtb1971

I've used weather strip caulking strip made by 3m otherwise known as "dumb dumb" after everything is painted. The high humps have a nice channel that it lays in and you can go around the bolts. It fills the gap areas good and smashes out of the tight areas. If you ever need to take the hump off the dumb dumb stays pliable and doesn't dry

I agree with Curtb1971, i use this stuff as well, I used it also to seal my factory A/C housing stuff under the dash when i took it out and cleaned it up. If it gets too hot it is hard to use / peel off the paper, so i keep one in my Freezer im my garage so its still easy to use. Gets harder but still stays pliable frozen.

57taskforce · 08-21-2020, 10:48 AM

I used 2 layers of butyl tape stacked on top of each other on mine.

**71CHEVYSHORTBED402** · 08-23-2020, 02:41 PM

Thanks for the replies. I took a note there was a gasket underneath, but I didn't note a description. Since I no longer have it I'm assuming it was a sealant. That said, what is the "Adapter assembly" piece they're referring to in the manual, page 68? It's #3.

Andy4639 · 08-29-2020, 04:29 PM

My 67 ramp truck hump is self tapping screws with some foam I got at work they use for insulation. I cut a 2" wide pattern out to fit the hump. Then bought 2 floor mates at Home Depot to cover the floor with.

BRL · 08-29-2020, 05:32 PM

Quote:

Originally Posted by Andy4639

LWB trucks rule, if you don't think so measure your SWB!:

...no they don't, but my Stepside comes really close!

Dang it you guys, I didn't even know there was a replaceable hump.

So when I switched from a column shift 3 speed manual, to a floor mounted 3 speed auto stick, I cut a big ol' hole in the hump for the shiftier.

The thing didn't even have a reverse lock-out, and one day I came to a red light, and a 2-liter bottle flew off my old bench seat and...SCREECH!

...that Turbo 350 tranny is still hanging in there all these years later...AMAZING.

So I put a B&M ratchet shifter in its place, and kind of patched the hole.

Now all I really need is a tiny hole for a shifter cable.

So where do you get a transmission hump, just in case I want to undo my messup someday?

Oh BTW, I do carry a fire extinguisher, have for years, just hope I never have to use it.

**71CHEVYSHORTBED402** · 08-29-2020, 05:46 PM

They sell humps on-line. don't know how good, but there's a Youtube of a guy installing one have he cut out the floor, he seemed happy with it.

**'68OrangeSunshine** · 08-29-2020, 06:33 PM

You can make your own gasket out of a thick bead [3/8''] of RTV. Squirt it out on the outside rim of the floorpan, and set strips of wax paper over the RTV, then put your hump cover on lightly. Start the bolts but do not torque them home. Let it set up overnight. In the morning, if it hardened, peel off the wax paper and secure the bolts.
I posted this exact same advice some years ago, but I dunno where old threads go.

Hey Andy, tell us more about the diamond tread stuff on your cab floor. I think I like your deal. Maybe post a new thread about it, otherwise We'll be accused of wilfull and flagrant hijacking.

Andy4639 · 08-29-2020, 07:59 PM

Quote:

Originally Posted by 68OrangeSunshine;8799928]You can make your own gasket out of a thick bead [3/8'

of RTV. Squirt it out on the outside rim of the floorpan, and set strips of wax paper over the RTV, then put your hump cover on lightly. Start the bolts but do not torque them home. Let it set up overnight. In the morning, if it hardened, peel off the wax paper and secure the bolts.
I posted this exact same advice some years ago, but I dunno where old threads go.

Hey Andy, tell us more about the diamond tread stuff on your cab floor. I think I like your deal. Maybe post a new thread about it, otherwise We'll be accused of wilfull and flagrant hijacking.

Here is the thread with it.

http://67-72chevytrucks.com/vboard/s...68#post8799968

saxart · 08-30-2020, 07:28 AM

I used this on mine and it's worked great. I've had that cover off a couple of times since and it's never come loose.

https://www.menards.com/main/hardwar...252-c-3624.htm

BRL · 08-30-2020, 10:12 AM

Yes I like that diamond carpet as well, great idea! Seems I'm always spilling some liquid on the floor.
Thanks for the information.

08-20-2020, 07:51 PM	#1
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,148	How did you install your floor hump? They take a rubber gasket. I believe GM used body seal along any glaring cracks between the floor and hump, and sprayed with the hump bolted on. Sound right? Is there are better way or sealant? Personally I don't care if it's finished on or off the cab floor, just need to account for it. Thanks __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring the truck from ground up. With assys, the guide accts for 1000s details, OEM identifications & part numbers, written in short order. 700+ images of assm., illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025

08-20-2020, 10:33 PM	#2
Curtb1971 Senior Member Join Date: Feb 2014 Location: Erie Colorado Posts: 1,007	Re: How did you install your floor hump? I've used weather strip caulking strip made by 3m otherwise known as "dumb dumb" after everything is painted. The high humps have a nice channel that it lays in and you can go around the bolts. It fills the gap areas good and smashes out of the tight areas. If you ever need to take the hump off the dumb dumb stays pliable and doesn't dry __________________ 1971 LSX "Bonnie" build thread http://67-72chevytrucks.com/vboard/s....php?p=8026381 paypal is curtbarton1971@yahoo.com

08-21-2020, 10:48 AM	#4
57taskforce All about them K’s Join Date: Jun 2014 Location: Farmington, New Mexico Posts: 6,257	Re: How did you install your floor hump? I used 2 layers of butyl tape stacked on top of each other on mine. __________________ Tyler '57 3100 http://67-72chevytrucks.com/vboard/s...d.php?t=813888 '72 K20 Cheyenne http://67-72chevytrucks.com/vboard/s...d.php?t=662879 ‘69 K10 SWB http://67-72chevytrucks.com/vboard/s...d.php?t=805206 '98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6" lift 315/75/16's ‘87 IROC-Z all original 50K mile survivor TPI 305 IROC Blue ‘10 Camaro 2SS/RS Aqua Blue Metallic #93 -version 2.0 Last edited by 57taskforce; 08-29-2020 at 04:37 PM.

08-23-2020, 02:41 PM	#5
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,148	Re: How did you install your floor hump? Thanks for the replies. I took a note there was a gasket underneath, but I didn't note a description. Since I no longer have it I'm assuming it was a sealant. That said, what is the "Adapter assembly" piece they're referring to in the manual, page 68? It's #3. Attached Images __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring the truck from ground up. With assys, the guide accts for 1000s details, OEM identifications & part numbers, written in short order. 700+ images of assm., illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025

08-29-2020, 04:29 PM	#6
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: How did you install your floor hump? My 67 ramp truck hump is self tapping screws with some foam I got at work they use for insulation. I cut a 2" wide pattern out to fit the hump. Then bought 2 floor mates at Home Depot to cover the floor with. Attached Images __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

08-29-2020, 05:46 PM	#8
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,148	Re: How did you install your floor hump? They sell humps on-line. don't know how good, but there's a Youtube of a guy installing one have he cut out the floor, he seemed happy with it. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring the truck from ground up. With assys, the guide accts for 1000s details, OEM identifications & part numbers, written in short order. 700+ images of assm., illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025

08-29-2020, 06:33 PM	#9
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,089	Re: How did you install your floor hump? You can make your own gasket out of a thick bead [3/8''] of RTV. Squirt it out on the outside rim of the floorpan, and set strips of wax paper over the RTV, then put your hump cover on lightly. Start the bolts but do not torque them home. Let it set up overnight. In the morning, if it hardened, peel off the wax paper and secure the bolts. I posted this exact same advice some years ago, but I dunno where old threads go. Hey Andy, tell us more about the diamond tread stuff on your cab floor. I think I like your deal. Maybe post a new thread about it, otherwise We'll be accused of wilfull and flagrant hijacking. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

08-30-2020, 07:28 AM	#11
saxart Registered User Join Date: Aug 2012 Location: St. Croix River Valley, WI Posts: 795	Re: How did you install your floor hump? I used this on mine and it's worked great. I've had that cover off a couple of times since and it's never come loose. https://www.menards.com/main/hardwar...252-c-3624.htm __________________ Meet "Old Roy": http://67-72chevytrucks.com/vboard/s...d.php?t=707801

08-30-2020, 10:12 AM	#12
BRL Registered User Join Date: Jun 2014 Location: Tahuya WA Posts: 522	Re: How did you install your floor hump? Yes I like that diamond carpet as well, great idea! Seems I'm always spilling some liquid on the floor. Thanks for the information.



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