Did They Destroy My Frame?

aedwards56 · February 3, 2008

Took the 08 1500 Sierra Z71 ExCab into a local RV dealer for 5th wheel hitch. Warned the service manager not to damage the truck in any way as it is a lease. When I picked it up they said they couldn't find no-drill hitch rails so they installed their regular sliding hitch which means I now have three holes per side drilled into the frame under the hitch. I flipped out and they gave a huge discount for the mistake but it's not like they could "undrill" the frame.

Aside from that fact that GM will now crucify me if I try and return the lease (my research so far is showing holes in frame are considered extreme wear), another RV dealer in the area where I ended up buying the trailer is saying that the frame may be screwed. He says that it is hydroformed and cannot support being drilled. It needs to be "filled" at all the drilled points to prevent collapse. When I asked him what that meant and how much he said he wouldn't touch it... Anybody know anything about this? Is the second dealer correct? If so, what does he mean by filled?

Appreciate the response...

Zembonez · February 3, 2008

I've seen many bolt in fifth wheel hitches pulling large commercial loads over long periods of time quite successfully. The frame is supported by the hitch structure at the bolt holes. It's probably actually stronger at that point.

I'd get another unbiased opinion from another trailer or truck outfitter. Too many "old wives tales" exist in this business that have little or nothing to do with fact. A lot of shops believe "their way is the only way" and "any other way is just plain stupid". It's a common problem... Hell, look at ANY oil change thread ever posted here... Nuts from all camps will swear that they have the only answer.

As far as "hydroforming" goes it just means that the metal is formed in a hydroform press. It's simply a method of shaping the frame that doesn't use typical dies. Composition of the metal is a much more important factor. If the hitch they installed was one engineered for your truck, there is probably little reason for concern.

GasHog369 · February 3, 2008

Once you take the 5th wheel out and trade the truck in, they probably wont even know .. do u have a bed liner in there? That should camouflage the holes well. Also from the last 2 trucks i turned in to my dealer after leases , they never once looked in the bed when they did the walk around with me.

As for holes in the frame that they drilled... i highly doubt that a (what is it , 1/2" ? 3/4 " ?) hole will weaken the structure of the truck ... I know when i ran wires and air lines under my truck there were plenty of holes allready in the frame from the factory that technically did not have to be there.

pm26 · February 3, 2008

Holes can be drilled in the frames or structures without decreasing their strengths provided these holes are not drilled in high stress areas. Such holes are often drilled in frames for mounting of support brackets, , for mounting of skid plates, etc. The truck frame is basically a ladder frame with C channel (full box in higher stress areas) for sides and rungs. Typically, frames are made of A36 structural steel, meaning that the tensile yield strength is 36,000 psi. This is not considered a high strength steel structure. When you look at the cross section of a C channel, each drilled hole will remove some metal and make the effective area somewhat smaller, theoretically decreasing the strength. However, small bolt holes will not remove any appreciable amount of material.

As Zembones said, once you bolt the hitch to the frame, you create a bolted connection with the hitch rails actually strengthening the frame, as it is now more resistant to buckling and bending in that region.

If any repairs of the welded holes were desired after removal of the hitch, this can be done by using a plug weld technique.

jenricco · February 3, 2008

all these holes and holes topics are driving me nuts!

Zembonez · February 3, 2008

all these holes and holes topics are driving me nuts!

Well, Joey. It's a pretty short drive.

marko · February 3, 2008

Holey Moley!

Dana_15 · February 3, 2008

Once you take the 5th wheel out and trade the truck in, they probably wont even know .. do u have a bed liner in there? That should camouflage the holes well. Also from the last 2 trucks i turned in to my dealer after leases , they never once looked in the bed when they did the walk around with me.

As for holes in the frame that they drilled... i highly doubt that a (what is it , 1/2" ? 3/4 " ?) hole will weaken the structure of the truck ... I know when i ran wires and air lines under my truck there were plenty of holes allready in the frame from the factory that technically did not have to be there.

I agree, they don't get all that technical. Worst case scenerio is they refuse to take the lease back, you buy it outright, then trade it in somewhere else.

J45p3r · February 3, 2008

In my 2003 Z71, the previous owner had installed a 5th wheel. When I bought it they had removed it and left bolts through the rails that look to be welded in. Truck is still on the road, hasn't collapsed yet, and I've had 8,000lbs on the receiver hitch before. I don't know if the 2008 frame is different, but I'd say not to worry about it.

redvett · February 3, 2008

There is one rule about leasing, never lease if your going to exceed the mileage of the lease & if you modify or customize the vehicle. Its not yours its the lease companies, and you will pay pay pay for anything they deem abuse or wear.

Buy your vehicles for that purpose.

mes · February 3, 2008

all these holes and holes topics are driving me nuts!

O

jenricco · February 3, 2008

all these holes and holes topics are driving me nuts!

Well, Joey. It's a pretty short drive.

lol

superjim · February 3, 2008

EvansDad,

I don't think you have anything to worry about as far as damage to the frame. As others have said, it is probably stronger where the hitch is bolted in, than it was before.

If you are worried about big charges when you go to turn it in, there are several ways to probably bypass that.

What I would probably do when it is time to turn it in.... after taking the hitch out, I would take it to a GOOD welder and have him fill in the holes in the bed.

DO NOT WELD ON THE FRAME.

Grind it SMOOTH and have a bedliner sprayed in it. The holes would be undectable unless you got up under the truck and were actually LOOKING for them and the new bedliner would make it LOOK GOOD.

An even cheaper way... just put in one of the dropin plastic / rubber bedliners to cover everything up.

Jim from Texas

SLESierra · February 3, 2008

I would not guess at this considering I cannot find the upfitting of a fifth wheel hitch to a 1500 series truck.

What GM Says

http://www.gmupfitter.com/publicat/2007_BB...nstructions.pdf

Section 2 — Frame

Hole drilling, welding, modifications, or alterations to the frame assembly are the responsibility of persons performing these operations.

These same individuals assume complete responsibility for frame assembly, reliability, performance after alterations and compliance to

applicable FMVSS requirements.

The following procedures and specific precautionary instructions are recommended for proper installation of special bodies and/or

equipment on GM frames. Failure to follow these recommendations could result in serious damage to the basic vehicle.

Flanges

Do not drill holes in frame flanges.

Holes

Holes to mount brackets, supports, and out-riggers must be drilled in the vertical side rail web with the following restrictions:

• Material between edge of hole and inside of upper or lower flange must not be less than 37 mm (1.50 in.) for HSLA

• The minimum edge distance between any two (2) holes must be larger than twice the diameter of the larger hole.

• No holes should exceed 20 mm (0.75 in.) in diameter.

• All holes should be drilled in the frame using appropriate drilling practice and safety precautions.

Or you can call the Upfitter Integration hotline at 1-800-875-4742

or fill out the form here

http://www.gmupfitter.com/hotline/index.jsp

fbachman · February 3, 2008

Aside from that fact that GM will now crucify me if I try and return the lease (my research so far is showing holes in frame are considered extreme wear)...
Appreciate the response...

My experience with lease-returns (I've leased one or two over the years, have a standard finance on my present one) is that they really don't look at them that closely.

I HAVE heard horror stories from folks that return leased vehicles and get nickled and dimed to death, but they are few and far between.

Bottom line is THIS: If you return it, and look to take something new off the lot, they will leave you alone, unless there are agregious cosmetic faults and/or you are WAAAAAAAY over on mileage.

For now, and some time to come, it appears--- the customer is in the driver's seat. It's not like vehicles are flying off the lot. They are selling vehicles, but nowhere near what they were, or would like to be.

The bed liner is a good idea. I wouldn't lose any sleep over it.

Now, to the question regarding the reduction of strength of the frame, I am not the person to answer that, as I don't know.

I can't imagine that three holes will destroy a frame --- but I do not have expertise in that arena.