BD Steering Brace
01-15-2009, 11:11 PM
#31
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The more I read about these braces, the more I think it's a good idea. The front end is naturally heavy. Bearings always last longer when mounted in double shear. A shaft just hanging out there in the air with all that weight hung on it is bound to fail - sooner rather than later.
I looked at all the ones mentioned above. One of things that caught my attention was the general design. My amature engineer brain believes that things should be braced in at least two dimensions.
PSS has a square bar, with mounting tabs welded on to each end. That's good, it should be pretty strong. But, the sector shaft plate is a long flat plate welded to the bottom of the square bar. It then extends from in front of sway bar to the sector shaft. That's kind of a long reach. No bracing at all.
DSS appears to be the same thing.
The advantage to these two are that they're inexpensive, and can easily be braced with some flat stock and a MIG welder.
Defiant is a flat stock, with a bent L bracket to hold the bearing. It appears to be significantly differant than the other two, in that the flat stock sits under the sway bar, and not in front of it. The L bracket, though just hangs there, and is not supported by anything. I know they developed this part. But even with additional bracing it just doesn't appear to be that strong.
The last is the DT ProFab. Round stock instead of square. Sits in front of the sway bar like the square ones. But, the extending bracket is curved, and braced in two dimensions; three if count the curve of the bracket. Although it's a little more expensive at $175, it appears to be the better made part. With the curves I would expect it to be a little stronger than the first three, even with additional bracing added to them.
I am clearly an amature, and I admit I don't know a lot about these trucks. Does this make sense? Or, am I over thinking it (again)? I admit I have a nasty tendancy to over-engineer anything I make. Everything I make ends up stronger (and heavier) than it really needs to be.
I looked at all the ones mentioned above. One of things that caught my attention was the general design. My amature engineer brain believes that things should be braced in at least two dimensions.
PSS has a square bar, with mounting tabs welded on to each end. That's good, it should be pretty strong. But, the sector shaft plate is a long flat plate welded to the bottom of the square bar. It then extends from in front of sway bar to the sector shaft. That's kind of a long reach. No bracing at all.
DSS appears to be the same thing.
The advantage to these two are that they're inexpensive, and can easily be braced with some flat stock and a MIG welder.
Defiant is a flat stock, with a bent L bracket to hold the bearing. It appears to be significantly differant than the other two, in that the flat stock sits under the sway bar, and not in front of it. The L bracket, though just hangs there, and is not supported by anything. I know they developed this part. But even with additional bracing it just doesn't appear to be that strong.
The last is the DT ProFab. Round stock instead of square. Sits in front of the sway bar like the square ones. But, the extending bracket is curved, and braced in two dimensions; three if count the curve of the bracket. Although it's a little more expensive at $175, it appears to be the better made part. With the curves I would expect it to be a little stronger than the first three, even with additional bracing added to them.
I am clearly an amature, and I admit I don't know a lot about these trucks. Does this make sense? Or, am I over thinking it (again)? I admit I have a nasty tendancy to over-engineer anything I make. Everything I make ends up stronger (and heavier) than it really needs to be.
good analysis!
I agree the DT being more rigid at the bearing mounting point but the chance of its bearing surface being perfectly square with the steering gear box is pretty slim IMO. If both the gear box and steering brace are not square with each other then you end up loading the sector shaft
If these two systems are not perfectly square you would have to loosen up the steering box to allow it to float and relieve any loading of the sector shaft then re-tighten. Im not sure if thats even possible?
On the other hand, the DSS or PSC with a cantilevered tab hanging out like a diving board will conform and square up with the sector shaft and steering gear box? At the same time the square tube design will tie the frame together and firm up the frame in this area. The square tube is strong enough to not twist and keeping the torsion twist to a minimum the frame is now stronger?
I think the key here is to shear support the sector shaft but not let that support do more harm then good.
01-16-2009, 12:22 AM
#32
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good analysis!
I agree the DT being more rigid at the bearing mounting point but the chance of its bearing surface being perfectly square with the steering gear box is pretty slim IMO. If both the gear box and steering brace are not square with each other then you end up loading the sector shaft
I agree the DT being more rigid at the bearing mounting point but the chance of its bearing surface being perfectly square with the steering gear box is pretty slim IMO. If both the gear box and steering brace are not square with each other then you end up loading the sector shaft
So maybe the smart choice would be to start with PSS or DSS part. Install it. Make sure it's perfectly square with box. Then weld in some braces.
I would expect that the bearing would accept a certain amount of mis-alignment, like a rod end does. That would allow for wear and small changes and errors in truck production. But you would want to keep it at a minimum. Maybe that's the secret of the ProFab part - a better bearing????
01-16-2009, 07:04 AM
#33
Chapter President
You are over-thinking this. I can only speak for the DSS/PSC design...in practice, they are very strong and slightly over-built for the application. The materials used to support the bearing produce zero deflection to the naked eye at the pitman shaft and the steering box and frame also produce zero deflection with the brace installed. When taking the application into consideration for the design of the shaft support components, you should remember that this part is not intended as primary support for the pitman shaft - that is still the job of the box, itself. The brace is there to add secondary support to the lower most portion of the shaft to simply reduce the potential for deflection where a moment *could* exist under high load and to also preserve the life of the box. I have had a DSS on my last two trucks and they certainly perform their function as advertised.
Also, the bearing mounting plate is designed to allow the bearing assembly to float into perfect alignment with the pitman shaft until the bearing bolts are torqued down. It is really a very simple design but allows for perfect alignment of the bearing while taking into account varying tolerances of different trucks.
Also, the bearing mounting plate is designed to allow the bearing assembly to float into perfect alignment with the pitman shaft until the bearing bolts are torqued down. It is really a very simple design but allows for perfect alignment of the bearing while taking into account varying tolerances of different trucks.
01-17-2009, 01:24 AM
#36
Registered User
Not the prices that others have found, but here is a place selling three of them.
http://www.vulcanperformance.com/category-s/161.htm
http://www.vulcanperformance.com/category-s/161.htm
01-17-2009, 07:56 AM
#38
After reviewing the three basic designs, I gotta say looks like Defiant is the way to go.
Did you see the threads with a member reporting the steering box literally almost breaking off his '04, requiring the dealer to weld the frame? Not even off-roading the truck? I think some Dodge engineers need to go back to school.
Did you see the threads with a member reporting the steering box literally almost breaking off his '04, requiring the dealer to weld the frame? Not even off-roading the truck? I think some Dodge engineers need to go back to school.
01-17-2009, 09:02 AM
#39
Registered User
Thread Starter
Well I bit the bullet and ordered the one from polyperformance.com. Once I get it bolted up I'll let yall know how I like it. Thanks for all the input.
01-17-2009, 05:39 PM
#43
Registered User
01-17-2009, 05:47 PM
#44
Registered User
Yes the ones that lower the sway bar... Just wondering if the bracket itself (that holds the bearing) would be in the way of the lowered sway bar... It's hard to picture it without looking under my truck... know what I mean?
Dss
