Hello new to GMC motorhoming

[Jack Keith]

Hi,

I’m looking for ideas in replacing my driver and passenger seats with more modern seats w/side seatbelts.

Does anyone have plans, pics, drawings, etc of what you did. At the onset I’m not a welder, but have access to so having new base, etc I could get done.

Thanks for your help,

Jack

 

[tmsnyder]

I put Honda Odyssey mid row seats in my SOB, and two pieces of 1.5 inch Unistrut installed laterally under the van seat and bolted down to the seat base put the seat right at the correct height.

 

[Christo]

Search the forum for “odyssey” for some ideas. Gmcrvparts.com sells a shoulder belt kit. Keep in mind that if you choose seats with integrated shoulder belts you’ll need to secure the seat to the coach frame because the existing pedestals aren’t strong enough. You don’t want to end up flying through the windshield still attached to the seat!

 

[dsmithy]

Jack, FYI, apparently Honda Odyssey minivans are a common conversion to handicap vans and the second row seats are a casualty of that conversion, which makes them fairly findable at a decent price. They also typically have armrests on both sides, are comfortable and a good size for our motorhomes. particularly if you want to retain the pivoting around to become extra living area seating. As Todd says, it takes very little tasteful butchery to adapt them to different bases. All this adds up to it being a common mod for our coaches. We did it about a decade ago and have been delighted with the seats ever since. They still look brand new.

 

[Richard RV]

Hi,

I’m looking for ideas in replacing my driver and passenger seats with more modern seats w/side seatbelts.

Does anyone have plans, pics, drawings, etc of what you did. At the onset I’m not a welder, but have access to so having new base, etc I could get done.

Thanks for your help,

Jack

Toyota Sienna reclining cockpit seats

<p>I was in Phoenix and saw that the guy that sold Honda seats was fairly local, so I took a run over there and came back with some Toyota Sienna seats. Â More money, but I think it\'s worth it. Â Way more comfortable, two armrests (mandatory), built in shoulder belt (mandatory) and they\'re...

www.gmcmhphotos.com

What I did was a fair bit more involved, and more expensive, than Honda seats on the existing pedestals, but it checked all of the boxes for me so I'm happy.

 

[sailor man]

Hi,

I’m looking for ideas in replacing my driver and passenger seats with more modern seats w/side seatbelts.

Does anyone have plans, pics, drawings, etc of what you did. At the onset I’m not a welder, but have access to so having new base, etc I could get done.

Thanks for your help,

Jack

These are very large Villa 6 way electric seats with 3 point shoulder/waist seat belts. The passenger seat is extra wide. The could have been rotated but they are just too large.

I removed the old pedestals and floor mounted seat belts.

I installed new 1/4" epoxied steel plates using the 9 original pedestal bolts and drilled 4 new holes to the Villa seats fasteners plus one for the electrical cable.

I bought these used seats on eBay for $1,500 each.
The seats go up and down, forward and back, tilted raise feet, all electrically.
I feel more secure because I have a full shoulder harness and I did not have to find a way to secure the shoulder harness to the side wall.
Because of the extra size, it is sometimes a bit more difficult to access the engine.

These plate and seat bolts for the steel plate do provide for th installation of lift nuts to provide strong lift points for block and tackle when needed.
We also installed large fender washers to prevent the bolts being pulled through the plywood floor for impact loads.
Since I could not find a showroom to see these seats before I purchased them, I went to Happy Days dealership near Orlando as a possible buyer of a luxurious and very expensive diesel pusher to try similar ones out. Since these seats are about $5,500 new, I took the plunge.

 

[Keith V]

I'm not a fan seats bolted to just the plywood. Doesn't seem too safe, the steel plats are definitely a good idea!.
I used Chrysler swivel and go seats, I used the stock Chrysler disconnect and made brackets that bolt to the floor crossmembers. This makes removing the seats quite easy.
I also got lucky and got cloth, very comfortable, I drove 2800 miles in them this spring and love them.

 

[Christo]

I'm not a fan seats bolted to just the plywood. Doesn't seem too safe, the steel plats are definitely a good idea!.
I used Chrysler swivel and go seats, I used the stock Chrysler disconnect and made brackets that bolt to the floor crossmembers. This makes removing the seats quite easy.
I also got lucky and got cloth, very comfortable, I drove 2800 miles in them this spring and love them.

Yeah, those bolts will pull right out in an accident.

 

[pvfjr]

Yeah, those bolts will pull right out in an accident.

Especially with the seatbelts anchored to the seats rather than the aluminum frame members like the OEM design. This leverages the momentum of both the passenger and the seat both against the anchor bolts.

No doubt, the steel plate will do a tremendous job of reducing stress concentrations where the seat is anchored to the wood. Even so, I would personally add some ductile reinforcement tying the seat into the frame members somehow. Ductility is your friend in a dynamic situation--helps keep peak impulse forces from exceeding the fracture point of the materials. Wood and composites don't do well with that, but metals do.

 

[mech0001]

My coach has steel straps to which the seat assemblies are bolted. I would consider that the minimal requirement.

 

[sailor man]

View attachment 15377
View attachment 15379
View attachment 15380
These are very large Villa 6 way electric seats with 3 point shoulder/waist seat belts. The passenger seat is extra wide. The could have been rotated but they are just too large.
View attachment 15378
I removed the old pedestals and floor mounted seat belts.
View attachment 15381
I installed new 1/4" epoxied steel plates using the 9 original pedestal bolts and drilled 4 new holes to the Villa seats fasteners plus one for the electrical cable.
View attachment 15382
I bought these used seats on eBay for $1,500 each.
The seats go up and down, forward and back, tilted raise feet, all electrically.
I feel more secure because I have a full shoulder harness and I did not have to find a way to secure the shoulder harness to the side wall.
Because of the extra size, it is sometimes a bit more difficult to access the engine.
View attachment 15383
These plates and seat bolts for the steel plate do provide for th installation of lift nuts to provide strong lift points for block and tackle when needed.
We also installed large fender washers to prevent the bolts being pulled through the plywood floor for impact loads.
Since I could not find a showroom to see these seats before I purchased them, I went to Happy Days dealership near Orlando as a possible buyer of a luxurious and very expensive diesel pusher to try similar ones out. Since these seats are about $5,500 new, I took the plunge.

If you take a closer look at the bolts, the 4 seat bolts are larger than the (12) bolts that fasten the steel plate. The front (3) bolts in line are fastened through a chassis "strap/plate" that is welded to the chassis. That means that at least these bolts are actually fastened to the chassis. These (12) bolts fastened the original pedestal to the chassis.
I intend to investigate it further, but I believe that GM actually bolted the pedestals to the chassis and the plywood ws just a "spacer".
It is clear that the steel plate is bolted to a steel strap that is welded to the chassis.

In the above view, you can see the end of the front to back steel strap between the chassis and the side to side steel strap.
The original steel pedestal is a serious structural element that was directly bolted to the chassis. I just substituted a structural steel plate for the welded pedestal and used the original structural elements that GMC designed.
The (3) smaller bolts in the rear, running front to back are fastened to the steel plate and the strap that is welded to the chassis.

The rear line of (3) bolts is at the rear edge of the cockpit floor where there is a steel channel that appears to a steel cross channel welded to the chassis. The rear plate bolts are through this channel.

These bolts are the seat bolts. The 3 rear plate bolts appear to be through the channel behind the seats.
All of the fasteners are stainless steel, so corrosion is not a factor.

I was worried about the water damage to the plywood in this area. Instead of replacing the plywood with Coosa Board as Jim Bounds recommends, I treated all of the plywood with penetrating epoxy. I often do this when I am restoring a history building. I might do the thing to the underside of the plywood. The treated original plywood is now far stronger than it was when installed. It is now waterproof.

Your fears about the plywood floor are not justified.

Since the steel plate I installed is actually not depending on the plywood for structure. The new steel plate is actually fastened directly to the chassis as was GM's seat pedestal with (12) bolts.
As you can see from these blow ups, the plate bolts have fender washers and locking washers.

 

[Tybalt39]

I'm not a fan seats bolted to just the plywood. Doesn't seem too safe, the steel plats are definitely a good idea!.
I used Chrysler swivel and go seats, I used the stock Chrysler disconnect and made brackets that bolt to the floor crossmembers. This makes removing the seats quite easy.
I also got lucky and got cloth, very comfortable, I drove 2800 miles in them this spring and love them.

Hello Keith,

Would you by any chance have a drawing showing the dimensions/spacing of the OEM pedestal mounting holes into the deck? I'm having a customer seat base built and I want it to mount into the same structure as the original seats. Otherwise, I'll put some bolts into the original holes and place a piece of cardboard on top to create a template this weekend. I don't have the original pedestals and the current seats are bolted into the plywood.....