I had a subscription to ALLDATA for my '91 Ranger. Using ALLDATA I was able to find out why my A.M. radio reception was so bad. Didn't know there was an extension cable off the antenna which turned out to be corroded. The diagram I downloaded from ALLDATA clearly showed it--right behind the glovebox. ALLDATA's a valuable resource.

I was disappointed to see that the latest model year they cover is 2002. However, I never thought about TSBs carrying over to newer years. You'd think once they found the problem they'd correct it in later models. Go figure. They know about it and still don't fix it? That's not good.

 

Right. And how can they fix a body vibration problem with re-engineering the whole frame?

 

It's a lot cheaper for Ford to issue a TSB and band-aid repair, than to re-tool or re-design at the factory. Since TSB's are not recalls, only customers who complain will get the repair...if the vehicle is still on warranty. Most owners have no idea what fixes are available, because Ford doesn't exactly tell you. That would cost them money.

 

TSB's are not always problems to fix as well. Often they are just service tips to the mechanics if something isn't completely intuitive to disassemble, or an order in which to do something that isn't completley specified in the workshop manual.

-ii

 

Correct. Much like SSM's.

 

I meant to say "without" re-engineering the whole frame.

 

The only real way to really fix the vibration problem, as I see it (just a humble backyard mechanic, not an engineer), is as you say Jake01, to reengingeering the frame. Find the harmonic of the vibration, and change whatever dimension in the frame is creating it. Easier said than done, I'm sure. Ford certainly isn't going to replace everyone's frame!

That said, another way is to better isolate the frame from the cabin. That's also difficult, because when metal touches metal it creates a path for sound to travel. In the Navy, we take this very seriously. All motors, pumps, etc are shock-mounted and mounted on rubber pads to make it harder for the bad guys' subs to hear us. Heck, if someone paints a rubber mount by mistake, we have to scrape it clean, because the thin layer of paint creates a noise conduit from the motor to the ship's hull.

I probably went off the deep end here. Navy pun intended! In a nutshell; the stiffer you make the frame, the more chance for vibration to be transmitted from the road to the cabin, so more emphasis must be placed on cabin sound and vibration isolation.

 

An alternate way of understanding the approach to "fixing the problems" is to use a Software analogy. The software (truck in this case) is debugged as best as possible and then put on the market. As other bugs are sure to turn up, they are addressed by a "team" and the fixes found and upgrades realeased (service bullitens).

In the case of a physical item like the F150, the whole design is on computer, in 3-D, component by component, where it is digitally assembled. Simulated stresses can then be applied to the computer model to see how the "parts" perform - individually & together. For a needed fix they just go back to the computer models, try to simulate the problem and try to create a fix idea(s). Then these "ideas" are physically tested.

So, fixes can be found relatively easily. BUT, the flip or busines side to this is what does the MONEY say. The initial tooling cost money and they want it to pay itself off (make at least X amount of vehicles) before they do any major re-tooling. Provided the fix is easy to build into present (new) tooling then I would suspect that it's usually done pretty quickly. The fixes that require major re-tooling ($$$) are evaluated on a Cost vs. Benefit type of analysis - is it worth spending the money to re-tool or just keep going and hope for the best.

 

Ford is one of our customers. They've been using our CAD/CAM/CAE software for quite awhile. I'm wondering if the new F-150 was designed/simulated/built using our software? The entire suite of software products and services is known these days as 'PLM Solutions' or Product Lifecycle Management. GM, Nissan, Boeing and a bunch of others use it as well. Kinda neat.