Why torsion bars?

[hoser]

Yeah, I know what you mean.

It's power tilt/telescoping steering though. The telescoping feature is kinda nice if you don't match the "average Joe" bodily dimensions. But yeah, it's just one more thing to break.

Variable ratio steering comes on all US market '03+ 100's.

 

[tabraha]

WOW!!! 408lbs difference in similarly outfitted 100's with all 408 being on the front yeah I'd say that's significant.

 

[hoser]

Tad, I think you're correct, but also remember that a lot of folks out there really load up the roof, which will put some load on the front axle, though again, still most on the rear.

And don't forget when you hit the brakes, a LOT of that weight in the rear transfers to the front wheels.

 

[NMuzj100]

But EL_3grab brings up a very interesting point: Why don't we see problems in the middle eastern countries or the rest of the world for that matter?

I imagine the language barrier has a lot to do with that. I did see the ARB A-arm kit on an arabic language site but couldn't read any of it. El3_grab and siglo aren't much of a sample.

 

[farinvail]

Isn't a t-bar a more durable spring than a coil? It will handle more cycles before failure or decrease in spring rate. Could that be why?

 

[Jim_Chow]

That's one thing I mentioned in an earlier reply. Coils are the cheapest to replace, but they fatigue the quickest. Personally, I like leaf springs...no funny rods/arms to hold the axle in place...good 'ol fashioned 19th century (or earlier?) technology. I know the pioneers used them on horse-drawn buggies, stage coaches, covered wagons, etc.

 

[dclee]

That's one thing I mentioned in an earlier reply. Coils are the cheapest to replace, but they fatigue the quickest. Personally, I like leaf springs...no funny rods/arms to hold the axle in place...good 'ol fashioned 19th century (or earlier?) technology. I know the pioneers used them on horse-drawn buggies, stage coaches, covered wagons, etc.

And they're easier to bush-fix.

 

[calamaridog]

I was thinking at the time if I could get rid of the torsion bars and use coilovers, I can use a Marks Adapter crawler gears - the 100 Series can't use this said crawler gears because it goes where the torsion bar are (towards the rear of the vehicle) - I would also have to modify the floor and gas tank too but .. that's another thread in itself - Slee has photos of the install on the Short Bus so you can see the modification needed to do this.

Damn! Great minds think alike


As far as the IFS goes, it works pretty good for what I use it for. And Toyota has won the production class every year since 1998 with the torsion bar IFS Land Cruiser and will probably be racing the same thing this year with the same result.

As far as the diesel IFS goes, they obviously forgot to overengineer the set up for the extra weight and so they are having problems. Real shame there.

Would I prefer a coil over shock set up? Damn straight, but I understand why they didn't come that way.

 

[Tinkerer]

Isn't a t-bar a more durable spring than a coil? It will handle more cycles before failure or decrease in spring rate. Could that be why?

Properly engineered and manufactured springs will last as long as the engineer wants them to, regardless of spring type (coil, torsion, leaf, whatever).

Springs that fail early (sag, break) do so because they are not engineered properly for the design paramters and design life of the system (the application in the vehicle, in this case), or because of defective manufacture, or some combination thereof.

Torsion bars do have that advantage of being able to adjust height, both at initial assembly and also if they sag over time. That, and space/packaging constraints, are usually the reasons they are used in automotive applications, as far as I know.

A semi-related note: I had to replace springs recently in a 10 year-old Schwinn stair stepper. They failed because of fatigue crack propagation, probably related to corrosion that started underneath the chrome plating near the failure region. These springs should have outlasted the stepper, if done properly. The replacements are not plated...gee, I wonder why? Shame on Schwinn. (They probably saved a couple of bucks and figured that most people would not keep & use the stepper enough to cause them to fail...)

 

[calamaridog]

A semi-related note: I had to replace springs recently in a 10 year-old Schwinn stair stepper. They failed because of fatigue crack propagation, probably related to corrosion that started underneath the chrome plating near the failure region. These springs should have outlasted the stepper, if done properly. The replacements are not plated...gee, I wonder why? Shame on Schwinn. (They probably saved a couple of bucks and figured that most people would not keep & use the stepper enough to cause them to fail...)

So you let the equipment rust but it's somehow their fault?

 

[Tinkerer]

So you let the equipment rust but it's somehow their fault?

We're drifting...

The equipment was used in a correct application. The springs are actually inside the mechanical enclosure, so nothing I did had anything to do with their early failure. (Other than the fact that I actually used the machine more than a few times, over the years, unlike 99% of exercise equipment purchasers in the USA.)

Chrome plating is porous. It allows moisture and air to reach the substrate steel - and traps them there, causing corrosion. It is NOT a very good corrosion preventive treatment for steel. (Take a look at chrome-plated steel objects like automotive bumpers that are exposed to air & moisture over time...the chrome plating develops bubbles, with rust underneath.)

You don't see chrome plating on OEM automotive springs, do you?

A better way to limit corrosion of the spring steel is by better specification & control of the metallurgy (which costs more both in design and manufacture stages). Sometimes, a spring can be kept coated with grease or oil, to help limit corrosion (but not in an exposed automotive suspension application, usually). Sometimes, other surface treatment types can be used with some success in limiting corrosion - but not chrome plating.

With a mechanical element like a steel spring, once corrosion starts it propagates more rapidly with more mechanical deflection cycles, and the resulting cracks that start propagating spell early failure for the spring. Very important to never let corrosion start at all, in a steel spring. Using cheaper spring steel and chrome plating for corrosion resistance are poor design decisions - unless the designer doesn't care if the spring fails prematurely, which sometimes happens at companies more concerned with short-term profit than with building high-quality product as a long-term business model. (You know of 3 other such companies, that used to be known as The Big Three, but are now becoming just The Three, as their market share contracts over time due to customer dissatisfaction with their prevailingly shoddy products.)

The new replacement springs for the Schwinn stepper are coated with a light coating of anti-corrosive stuff, like a sort of grease. No chrome. (Schwinn probably realized their error in using cheap chrome-plated springs when they had a high warranty failure rate from commercial customers.)

(And talk about a ripoff: The retail cost of four springs from Schwinn/Nautilus worth a few bucks apiece added up to almost 10% of the original cost of the entire stepper.)

Have we beaten that horse to death yet?