Looking for new seat that has shoulder strap on the seat.

[bowtieman4life]

I had a 2001 chevy that had the shoulder harness connected to the seat. Do any of you know if it will fit? Also, does anyone know of someone selling this type of seat?

Thanks,

[ChevyDude]

They fit..yes they do. Try Ebay.

[2low72]

Also do a search for Envoy or trailblazer not sure if they fit but they have the seat belt your talking about

[Yukon Jack]

Here's my thread on installing 40/20/40 seats from a 99 Silverado in my 69 K20. Definitely mounting them as shown in the last pic. http://67-72chevytrucks.com/vboard/s....php3?t=130006

[bowtieman4life]

Thanks guys

[StingRay]

Every time this kind of topic comes up I post the same kind of warning. Our series of trucks were NEVER intended to have seat belt type loads imposed on the seat mounting. If you have ever seen the kind of carnage an integral seat/belt set up can cause on a floor actually designed for them during seat belt pull testing you'd all think twice about just bolting such a seat in place. At the very least some kind of mounting must tie into the floor at the rear of the cab where seat belts would normally attach (for each seating position)and the front will need significant strengthening to not have the seat simply submarine through the floor in a front end collision. For true bucket seat trucks the floors have front stiffening and they don't even have integral seat belts. I believe the whole point to all of this is to get adequate seat belts is it not? I'm not trying to be harsh but I do this stuff for a living and I keep seeing this topic come up with few having any reguard for their own lives or their passengers health or safety. If any of you are planning to install your seats like in that last pic in Yukon Jacks link don't I reapeat don't let anybody you love ride in the seats next to you ever! In an accident the mounting of the seat could well be the cause of their deaths. I am a Mechanical Engineering Technologist and a part of my job is developing seat and seat belt mounting for the RV's our company builds. I say all of this with great concern and with real experience.

[72CSTC5]

StingRay do you have any suggestions or recommendations on how you could go about reinforcing the floor in order to make these seat installations safe? I was planning on putting in convertible Chrysler Sebring bucket seats in my Blazer. Maybe I could build a crossbrace connecting both of the rocker boxes underneath that would tie in to the floor where the seats would mount. What do you think?

[TEXAS 68]

Stingray,I was think about the same thing, do you have any sugg or have you tried any type of reinforcement you could reccomend?

[StingRay]

I have't put any real thought to a solution but I'd start with bracketry that ties into all or most of the seat and seat belt mounting at the rear of the cab. Those mounting points in unison are designed to handle seat loads and three sets of seat belts. Use em all and the engineering is pretty much done. I'd be damn sure the cab was healthy and rot free back there as the very first thing. For the front I'd start with GM 69 and up floor bracing for buckets and try to build up from there. Any seat ( other than a stock bench or 67-68 cst seat) that does not bridge the width of the front floor from stock mounting to stock mounting even without integral seat belts should have front floor stiffening. Note I said stock. Any other bench not using stock holes will require some kind of load spreading plates or gussetry to the cab floor. Any cab with holes at the hump or a high hump that is not well attached will have significant weakness across the floor in front of the seat. I suspect that trying to bridge a low hump cab rocker to rocker under the floor would be awfully tight on a low hump cab with certain transmissions. A high hump cab is probabbly a different story. Each cab/trans/seat could well be a different solution. Reinforcement above floor and load spreading gusset plates below are probably the best option at the hump and at the drivers and pass seats every thing could be below floor. If you can tuck structure underneath into any of the shapes stamped into the floor then great. Take advantage of what ever space you can. What ever you all end up doing please do it with an understanding of the potential consequences in a worst case scenario.

[moneyguru]

Originally Posted by StingRay

Every time this kind of topic comes up I post the same kind of warning. Our series of trucks were NEVER intended to have seat belt type loads imposed on the seat mounting. If you have ever seen the kind of carnage an integral seat/belt set up can cause on a floor actually designed for them during seat belt pull testing you'd all think twice about just bolting such a seat in place. At the very least some kind of mounting must tie into the floor at the rear of the cab where seat belts would normally attach (for each seating position)and the front will need significant strengthening to not have the seat simply submarine through the floor in a front end collision. For true bucket seat trucks the floors have front stiffening and they don't even have integral seat belts. I believe the whole point to all of this is to get adequate seat belts is it not? I'm not trying to be harsh but I do this stuff for a living and I keep seeing this topic come up with few having any reguard for their own lives or their passengers health or safety. If any of you are planning to install your seats like in that last pic in Yukon Jacks link don't I reapeat don't let anybody you love ride in the seats next to you ever! In an accident the mounting of the seat could well be the cause of their deaths. I am a Mechanical Engineering Technologist and a part of my job is developing seat and seat belt mounting for the RV's our company builds. I say all of this with great concern and with real experience.

I have read you REPEATEDLY make this statement and fully agree.

I happen to know about an accident involving a 69 Chevy truck, the truck was rust free and clean BUT had custom seats installed in it. The Seats were installed by drilling holes and using wide fender washers on both sides of the floorboard and as shims.

Upon impact bolts ripped lose and it wasn't pretty. The driver (sole occupant) survived but had a long hospital stay.

DO NOT....I repeat... DO NOT make the same mistake.

If you must have non-factory seats please listen to StingRay and research what needs to be done to provide for your safety.



StingRay, my question for you is would it be safest (while trying to be simple) to build a bracket for the seat that bolts into the factory seat and seat belt points? By doing so you don't weaken the steel by drilling holes and take advantage of the strength that was built into thet cab.



Does this idea make sense to anyone?

[StingRay]

At the back yes. At the front the issue is that any seat loads applied to the floor in non stock mounting points can be an issue. When you add the shoulder harness to the mix it applies a direct forward load that will translate into a force (or moment) rotating the front of the seat down through the floor. Hence you and your passengers will become very intimate with the dash and steering column. The floor was never meant to survive that kind of downward force even when gusseted for 69 and up buckets. Keeping the factory B pillar mounting for the shoulder harness and staying away from the seats with intregal belts can drastically alleviate the issues involved in mounting a non stock seat. When ever you are making modifications to something where life and limb hangs in the balance and real life is going to be the first and possibly the last test that mod will ever see you just can't make it too strong. Even with an engineering background most of this stuff is gut instinct and then a pull test tells the ultimate truth. There are way too many unknowns in the vehicle structure and the complex shapes the brackets can take to be able to engineer for certain first time performance without a zillion dollar computer and a cyber model of the vehicle you are working on or else just plain overkill in your design.

[GreyHoundSteve]

I have also seen integrated seatbelt seats rip through the floor but i have seen it on vehichles designed for these types of seats. In the same pile up i also saw a shoulder harness break loose from its pillar mounting and the lady in that car smashed her face up pretty good and that was also on an untampered vehicle.

The bottom line is, be careful when you install ANY SEATS including factory seats on these old trucks. I am installing 02 trailblazer seats and have taken extra precations by welding large plates on both sides of the floor.

Here is a list of seats that have the seatbelt integrated in them:

99-04 Chevy-

Blazer
Tahoe
Suburban
Silverado
Avalanche
trailblazer

Cadillac-

Escalade
Srx
Cts
Esv
Ext
Deville
Seville
V-series

97-03 Ford-
F150
F250
Superduty

01 Dodge-
Ram 1500

00- 04 GMC-
Sierra
Yukon 00-02 jump seat/center console
Canyon
Envoy

Oldsmobile-
Bravada

Buick-
Rainier
Park Avenue

Saab-
9-7x

Happy hunting.

[StingRay]

Good point Steve. Considering that vehicles designed for these types of seat and seat belt loads have failures just imagine how bad it could be for something just cobbled together

[moneyguru]

Originally Posted by StingRay

At the back yes. At the front the issue is that any seat loads applied to the floor in non stock mounting points can be an issue. When you add the shoulder harness to the mix it applies a direct forward load that will translate into a force (or moment) rotating the front of the seat down through the floor. Hence you and your passengers will become very intimate with the dash and steering column. The floor was never meant to survive that kind of downward force even when gusseted for 69 and up buckets. Keeping the factory B pillar mounting for the shoulder harness and staying away from the seats with intregal belts can drastically alleviate the issues involved in mounting a non stock seat. When ever you are making modifications to something where life and limb hangs in the balance and real life is going to be the first and possibly the last test that mod will ever see you just can't make it too strong. Even with an engineering background most of this stuff is gut instinct and then a pull test tells the ultimate truth. There are way too many unknowns in the vehicle structure and the complex shapes the brackets can take to be able to engineer for certain first time performance without a zillion dollar computer and a cyber model of the vehicle you are working on or else just plain overkill in your design.

OK StingRay I think I get it...and it makes sense.

The weak point is the FRONT mounting point of the seat because there isn't enough strength there to prevent the seat from pivoting on the rear mount and force the front of the seat down...right?

With this being the case even creating a "bracket" out of flat steel that combines all of the factory mounting points won't prevent this pivoting action unless you also strengthen the front. right?

So if a "bracket" was built that combined all the factory mounting points that went in the cab....AND a similiar "bracket" was built out of flat steel but went under the cab floor this would spread out the stress over a larger area.

Now it wouldn't be as strong as factory built because it still depends upon the relatively thin steel that the floor is made of. But it would provide alot more strength than drilling holes.

Am I on the right path StingRay?



I wish I could draw up my idea for everyone to critique......

[StingRay]

I doubt flat steel under the cab is going to do much. It will help prevent pull through of bolts only with forces acting upwards (unless well welded). Stiffness is a function of dimensions. Take an 8' 2 x 4, bridge a gap with it flat and jump on it. Then try it with it vertical. Way stiffer isn't it. The same 8 SQ in of wood will be equally strong in tension no matter what the dimensions but in bending or compression the dimension and the orientation of the dimension will dictate stiffness. For integral seat belts on the drivers and pass seats I'd try to tie some structure that has some real stiffness built into it into the floor support Z section that runs for and aft between the cab supports. It has lots of dimension and could even be stiffened up by boxing it in or sistering tubing to it. For the middle seating position I wouldn't know where to start right now but with a little effort anything can be figured out. Personally I will not be putting seats with integral belts in any of my trucks. I only have laps in my driver and am no worse off (probably better) than a cobbled together integrel set up. I know my laps and seat mounting will hold. When the new cab finally goes on it will be with 3 point belts installed into factory mounting locations that are clean and rust free. The seat will be a 67-68 CST seat. Plenty of options exist for the 3 point type belts using stock mounting points.

For reference does anybody have a good pic of the underbody 69 and up bucket seat floor gussets? If so please post it.

[Dick Dale]

Sting Ray, who would you talk to to do a competent install for these seats?

[Yukon Jack]

Stingray, thank you for all the insight. The last thing I want to do is make something worse rather than better. Your info shows how a novice can misunderstand how something should be done. I thought the important thing was using something below the floor to reinforce each attachment point but I definitely see now with your info why the force is actually placed on the front seat brackets pushing through the floor with the intergrated seat belts.

Thanks for taking the time to bring this issue to my attention!

[StingRay]

Dick Dale that is a good question. If you know any mechanincal engineers, race car builders, older fabricators or machinests they will all have good perspectives on what it will likely take to not break. Make sure you advise them on the reason for beefing up the mounting and make sure some math gets done on what the loads are likely to be. Get an engineering or physics guy to crunch a few numbers for you. Loads will be based on decleration, total mass of occupants and seats, mounting points and distances from mounting points to belt positions and seat/occupant center of gravity.

One useful trick can be to make bracketry that allows isolation between the cab and the frame but limits the amount of defelction of the floor downward by the use of a foot so to speak that touches the frame after the cab floor deflects say a quarter of an inch.

You live in Indiana. Elkhart is full of Engineers that do this stuff all of the time and companies that do nothing but seats, seat bases etc, etc. With a little luck maybe you can Find somebody that works for Atwood or Isringhausen.

Jack no problem. I hope I'm not sounding holier than thou it's just that the same topic just keeps coming up again and again and I'm worried some day I'm gonna read somebodies obit here because of it.

Seat mounting, seat belts, steering, suspension, frame and door latch integrity are all very serious issues and all too often are not considered with the respect and attention they require when modifying a vehicle.

Safe truckin everyone

[GreyHoundSteve]

I think stingray is right about if you really want to do it the absolute right way but lets face it .... we arent driving around 40 year old trucks because safety is our #1 concern.
The way i look at it is like this : (and i may be dead wrong here) If the original seat belt holes will work and the cab mounting bolts will theoritically work then it shouldnt be too hard reinforcing the area you plan to mount your seat to.

I didnt employ any nasa engineers when i did mine. I just figured out where the seat needed to be mounted and took two large peices of 1/4 steal and sandwiched the cab floor welding them both in place.

In my experience its usually the mounting bolts that break in a hard collision and not the vehicles floor but i wanted to be extra safe so i renforced the cab floor anyway.

I'm sure if you turned a team of automotive safety engineers loose on one of these old trucks they could find hundreds of things they would change but use your best judgement on these things and you should be alright ..... if your still woried then buy a Volvo ..... thats what my wife and daughter ride in.

[StingRay]

[GreyHoundSteve]

Originally Posted by StingRay

lol honestly sting, have you seen the bolts that hold these cabs on and the shape of some of these trucks that are on the road? I'm just trying to keep things in perspective.

You bump someone in a parking lot and youll save a tooth by having a shoulder belt but if someone crosses a median on the highway its not going to matter how much time or money you spent on mounting that seat. Use your head when mounting your seats and you should be okay, thats all im saying.

[jamis]

Originally Posted by GreyHoundSteve

I think stingray is right about if you really want to do it the absolute right way but lets face it .... we arent driving around 40 year old trucks because safety is our #1 concern.

You hit the nail right on the head........Its always better to always do your best with any modification. But we often find we tend to draw a line between looks, function, comfort
and safety. Lets face it these trucks don’t stop, steer and you wont survive a crash as well as in a late model. A four point harness tied to a roll cage, a helmet, on board automatic fire suppression and a scuba system in case you live near water is safe but who would drive around with all this stuff….so our comfortable side wins and we look for other alternatives to securing our selves to this 4,000lb of mass heading for a disaster….well a robe would be comfortable but not much help…… so we must look for that gray area we hope will satisfy all our demands and hopefully we wont loose our lives with the decision we make. I'm getting comfortable bucket seats with regular lap belt and not a roof to save my scull during a rollover.....but what the hell...I still feal safer then on a bike...

[72skytop]

Okay. If I use the same seat belts and convert my factory bench 1971 cheyenne to factory 1971 buckets...Will everyone be safe or is there a difference in the floor of a bench truck verses a bucket? If so, what is the difference and can it be altered?

Thanks for all your input. I know we have taken this way too far. But we live in hyper sensitive times I guess. Too many people trying to look and feel too good for too long a time....

[GreyHoundSteve]

Originally Posted by jamis

You hit the nail right on the head........Its always better to always do your best with any modification. But we often find we tend to draw a line between looks, function, comfort
and safety. Lets face it these trucks don’t stop, steer and you wont survive a crash as well as in a late model. A four point harness tied to a roll cage, a helmet, on board automatic fire suppression and a scuba system in case you live near water is safe but who would drive around with all this stuff….so our comfortable side wins and we look for other alternatives to securing our selves to this 4,000lb of mass heading for a disaster….well a robe would be comfortable but not much help…… so we must look for that gray area we hope will satisfy all our demands and hopefully we wont loose our lives with the decision we make. I'm getting comfortable bucket seats with regular lap belt and not a roof to save my scull during a rollover.....but what the hell...I still feal safer then on a bike...

Amen to that. I can drive anything with four wheels and feel safe after owning a bike ..... talk about danger, even a slow bump will send you to the hospital but again .... if doesnt keep me from riding.

[Dick Dale]

I actually do drive with scuba gear in case i fall in the big lake (Michigan). And if you live by water, no need to keep fire gear. Just drive into water.