Wednesday, June 20, 2007

Failing Fuso Santek.

Always the fact has been published that the Fuso Santek is a custom-made expedition vehicle.
Explaining why there have been issues like overflowing water tanks, short circuit in wiring, failing heating in truck cabin, lacking correct city water connection, missing sewer hose and other things.

All those issues have been corrected.

However, a new issue has come up today which is rather serious.
For a while it had been noticed that the Santek camper box on the Mitsubishi chassis was not really horizontal.
It was clearly off to the driver’s side.
This was mentioned to the chief engineer of Santek Trailers last Saturday.
He explained this was normal and that most trailers were not exactly horizontal.
The 6 heavy batteries are located on the side where the camper box was lower.
Therefore the conclusion was made that the explanation for being lower on one side was that one side of the Fuso Santek was simply heavier.

Today everything was well with the Fuso Santek.
A lunch stop was made in Catavina at noon and everything was fine with the Fuso Santek.
At 13.30 hours a stop was made for a nap and still everything was OK.
At 16.15 hours the town of Guerrero Negro was reached and before going to a trailer park, the local gasoline station was visited for fuel.
It was then noticed that the camper box was completely off.
Hanging sharply to one side.

An inspection was made.
The camper box is attached to the chassis on three points.
Two in the front and the pivotal one in the back.
The two attachments in the front are engineered by Santek Trailers.
To the chassis of the truck two square steel tubes are vertically bolted.
On top of these square steel tubes the camper box is welded.

The two square steel tubes are bolted to the chassis with four bolts each.
Each bolt secured by two nuts.
Tomorrow the exact diameter of the bolts will be measured but they look like 1 cm (0,39 inch) bolts.
It must be imagined that the weight of the camper box rests on those vertical square tubes and consequently on the 4 bolts.
Driving makes the weight invariable: the up and down movement goes also into the 4 bolts of each square steel tube.
For a while the process must have been going on that the bolts couldn’t hold the weight and were being bended to eventually break.
This explains why before the camper box looked like sagging.
If a close inspection were made at the time, the weakness of the bolts would have become clear.
It would have been seen that the bolts were bending being unable to hold the weight.
And this problem would have been avoided by replacing the small bolts by much larger ones.

Now the situation is that one side of the camper box is completely off.
Being totally unsupported.
Unclear is yet what damage this has caused.
It can be seen that the water pump is pushed on the battery bank of the truck.
And oil lines are pushed away by the square steel tube.

The holes where the bolts were are bend open wider.
In some holes parts of bolts are stuck.
Broken off and twisted.

For the moment the camper box is lifted up by a jack to be able to spend the night in the Fuso Santek.
Tomorrow a mechanic must be found in Guerrero Negro who can fix this problem.
This will take time and needs patience.

What is fortunate is that this happens in Mexico.
If this problem would have happened somewhere in the USA it would have been a very costly repair.
Because the Fuso Santek is lame: it can’t drive anymore.
It would have been unable to return to Santek Trailers for repairs.
A local truck repair centre in the USA would have needed to do the job at 85 $ (63 Euros) per hour.

It is clear now that on both sides larger bolts must be installed.
If it happened on one side, it can happen on the other side as well.
To install larger bolts, the holes must be drilled bigger.
How that can be done while the camper box is on the chassis is a question to be answered by Santek Trailers.

Is there now frustration maybe?
Anger perhaps?

A range of emotions is waiting to be expressed but for the moment they are waiting for a more expert technical diagnosis.
Tomorrow on this blog there will be a report of the exact size of the bolts and expert fervent and loyal blog readers will be requested to give their opinion in how far we can speak here of an engineering error.



steven said...

Poor workmanship , bad conception, "bricolage" this thing is a costly gadget, you would have been better off with Hackey's outfit, a Bigfoot bolted on the way he did . Good luck anyway.


PS, why don't you comment on the comments ???

Stephan said...

In one of the postings of the making of the Fuso you showed some pictures of the connection between chassis and cabin. I'm no engineer, so it went by. In retrospect: I've only seen sofar 4-point connections which seem much stronger.
Anyhow, I think you should have a third party have a look at the Fuso to make sure the rest is still OK.

Ken Norton - Image 66 Media said...

Boy, I bet THAT will give the Datastorm fits!

This type of system failure is to be expected. I've seen a number of highest-quality RVs with broken frames delivered to the dealers--when all they've had is less than 1000 miles from the manufacturer over smooth interstate.

The independant floating box method that was used for the "house" is still the best method for an expedition vehicle. Instead of broken/bent bolts, you could end up with a bent/broken chassis. Bolts are a lot easier to deal with. Chances are, the bolts selected were not of a sufficient grade and you need to go up to a harder bolt. Check the bolt head to see if they have the markings of being hardened. If not, you don't even need to mess with drilling, just replace them with better bolts.

:Don said...

I do not like to admit that I would be quite emotional about the Fuso failures as well. But, I try to practice a mantra of "life is 10% what happens to me, and 90% how I react". Might I suggest you always try to look at the Fuso as an Experimental Expedition Vehicle and that you are the test pilot for such an amazing machine (which you helped design)? If this were a plane, you would be required (in U.S.A.) to label it experimental.

Fred Wishnie said...

Most likely the bolts are too small, but another part of the problem may be that they did not use higher strength bolts. They are available in many grades.
I'm really surprised at this happening, because your application should not be heavy enough to really stress a truck body and suspension system.
You might want to have a qualified engineer evaluate the system and not just get the local mechanic to affect a quick fix.
Good luck,
Fred Wishnie

Al said...


I sent you some repair suggestions to


Robert Hill said...

Best of Luck,Robert

dhackney said...


Sorry to see that the revised forward pivot frame attachment design didn't turn out to be much stronger than Santek's original idea.

The lines being pushed by the square tube in your photo are not oil lines, they are wire looms (wire wrapped with plastic split loom). As long as none of them are putting stress on their connection points you will probably be OK there.

You are OK to drill out reasonably larger holes in the Fuso frame for larger bolts but DO NOT let the Mexican mechanic weld on the Fuso truck frame. Welding on the frame will permanently weaken the metal in the frame rails. Make sure they use Grade 8 bolts.

If you take out the original bolts and they are not stamped on the head with grade 8 marks (6 marks on the head), you will not need larger holes or bolts, just stronger ones.

On the brighter side, IMO you are correct in stating that it is good it happened in GN. The local guys there can fix anything that involves basic mechanical objects and systems. They are experts at improvisation with available materials. Second only to mechanics in India.

And BTW, the shop rate at the dealer is currently $125, so again, better there than in the US.



Michel used the same basic 3 point pivot frame design we used in our project. Santek did choose a different method to attach the forward end of the pivot frame to the Fuso truck frame and that is the current failure point.

The only major conceptual difference in the projects is that he had a custom camper box created to match his exact requirements while we settled for what we thought was the best built commercial product.

It is my understanding that this Fuso project was Santek's first expedition vehicle project. I don't think they fully appreciated what the stresses are and the type of roads you encounter in Baja. I do believe Michel and I both tried our best to communicate that to them. To their credit, I think it is very hard to make the jump from RV builder to understanding what goes on in a truck chassis when completely articulated crossing a wash.


Henk said...

Letting the weight of the camper-box rest on Bolts sounds like bad engineering. It Would have been best to rest the box on the Main-beams with a sturdy spacer and use bolts only to secure the box to these beams.
How did you select Santek to build your vehicle? The problems you had with it look like this is the first time the are building an expedition vehicle.

May be the would have been a better choice?

Hope you can get it fixed soon and good.

William said...


Two solutions come to mind to the problems you described in your recent blog entries.

First, rather than have the local mechanics drill holes in the chassis, see if they have replacement bolts. If they can't find them locally, the ask the Santek people to send bolts to you.

If these alternatives fail, tell me what size bolts you need and I can send them to you by UPS or Fed Ex.

Second, there's a forum for people who have the Datastorm equipment. It's at

The people who participate in this forum include several professional installers. They are good at diagnosing problems online. While you're in a town with an Internet Cafe, you should take advantage of this resource. I think they will at least be able to narrow down the source of the problem.

Let me know if there are ways I can help.

William Haven