Custom Rear Strutrods and SBLs(56k... no way)

[operdot]

Strut Rods:
I was rebuilding my rear suspension this summer. Upon removing and inspecting the rear strutrods I found a problem. The shank that holds the rubber bushings in place had a nominal diameter of 18mm, however on one of the rods from my car I measured 10 mm diameter . This was a no-no in my book . So the day I found this I started designing new strutrods. Basically made a quick CAD model, structural analysis, cost analysis, and a bill of materials. I ended up using the following
Hexrod:
Rockwell Hardness - C39,
Tensile Yield Strength - 163ksi

Bolts:
Thread - 18mmX2.5mm
Class - 12.9
Rockwell Hardness - C39
Tensile Yield Strength - 174ksi

The Bolts and the hex rod where cut at a 45 degree angle to take advantage of the maximum in plane shear stress. Once I cut these I welded them together using mig spray arc transfer. I really wanted to do a tig root pass, but I did not have the correct electrode and filler.

I incorporated three nut locking features. Just as a comparison military aircraft applications only require 2 locking features.
1) Threads themselves
2) Nylock nuts
3) Cotterpins

 

[operdot]

Sway Bar End Links:
For some reason every sbl I install in the rear I end up snapping. So I was really fed up with that and just decided to make my own, pretty much the same process as above accept I did not cut the bolts/rods at a 45 degree angle.

 

[firebat45]

Stock swaybar endlinks suck... I snapped a brand new one installing it, the nut was barely tight. Your endlinks look super strong, but how much do they weigh in comparison?

Same with the strutrods - they look like they'd weigh almost twice as much as a stock one. I'm not trying to put down what you did, I'm just wondering if they're kind of overengineered.

PS: Your car looks nice and clean underneath!

 

[SuperHO]

holy crap! nicely done! gonna tackle the rear control arms next, since they now look incredibly obsolete under there?

 

[operdot]

Your endlinks look super strong, but how much do they weigh in comparison?

Same with the strutrods - they look like they'd weigh almost twice as much as a stock one. I'm not trying to put down what you did, I'm just wondering if they're kind of overengineered.

PS: Your car looks nice and clean underneath!

There is no weight gain in the sway bar links, because they are much shorter than most aftermarket ones you can buy. The pound or 2 gained in the strutrods, does not compare to the functionality gained by any means. So the weight is not an issue, besides I do not track this car, it is my daily driver and I simply do not care if I gained a pound or 2. Just care about the reliability of it.

And thank you, I've worked ******* this car... its got lots and lots of hours in it.

holy crap! nicely done! gonna tackle the rear control arms next, since they now look incredibly obsolete under there?

The control arms will hold for now, but eventually I plan to make adjustable ones probably after I do extensive bodywork....

 

[SHO Continental]

I could have just grabbed you some new Strut Rods from a rust free car out here in Cali... or even out of the parts from the rust free low mileage '89 I just parted out. From the yard it wouldn't have been more than $10 for both.... just saying. :swing:

 

[operdot]

I could have just grabbed you some new Strut Rods from a rust free car out here in Cali... or even out of the parts from the rust free low mileage '89 I just parted out. From the yard it wouldn't have been more than $10 for both.... just saying. :swing:

Why? I have a set of rust free ones laying around?

 

[K-Dawg]

What do those endlinks do when you load the suspension?

For the strut rods, I think I would have rather put the hex rod on a lathe.

 

[Phoenix]

I had the same issue with mine. But I found a good cheap way to do it.

I welded the crap out of it , in the place where metal should be , you know to add metal in that area , then I buffed the welds till I had a good dimention (and round).

I really like it man , good job.

 

[operdot]

Let me just make it clear that I made these rods to be on the safe side, because they are such an important part of the suspension system, and the stock ones did not inspire confidence in me.

What do those endlinks do when you load the suspension?

They pretty much resemble the stock links, but the geometry is a little altered. The Stock ones involved a bending moment which superimposed extra tensile stress on each link. What I did is line up the hexrod to be in a vertical position, and relieve a some of the bending stress. The main point is that they are made out of strong steel, and the cross-sectional diameter is greater.

For the strut rods, I think I would have rather put the hex rod on a lathe.

The hexrod I'm using is really strong. Once you get into that level of heat treated steels, its becomes really expensive to do any king of milling operations. However it is possible, what you could do is to use a grinding lathe, another option is take the heat treatment out of it, lathe and then heattreat again.

Even welding is not the best choice, because no matter what it will re-ogranize the micro-structure of the material. Ideally you weld first and then heattreat. I managed to retain as much of the heattreatment as possible by following a Time-Temperature-Transformation map. But it is relieved somewhat.

I really like it man , good job.

Thank you :wave:

 

[K-Dawg]

I've never heard of a strut rod failing, at least not when you don't want them to.

 

[operdot]

Fine you got me

The MAIN reason is I wanted to have some fun with my welder....

 

[K-Dawg]

:wave:

 

[luigisho]

Anyone who goes through that much work for an old Taurus gets a tip of the hat from me. It looks really clean underneath for a car that old from the northeast.

 

[hawkeye18]

Fine you got me

The MAIN reason is I wanted to have some fun with my welder....

Well there you go. Nobody can fault you for that!

 

[LOUDSHO92]

Nice job on the rear strut rod.

Interesting job on the endlinks though I think this is a better way of loading them: Endlinks.

 

[operdot]

Nice job on the rear strut rod.

Interesting job on the endlinks though I think this is a better way of loading them: Endlinks.

Thank you, I agree that is a better way of loading the endlinks and the swaybar. However I could not afford the 215$ tag.

P.S. I ended up building mine for 25$

 

[GR8WYT]

Nice work! I'm always intrigued by what Mech Eng's can come up with when faced with a challenge.

Any other "issues" on your car that you have designed fixes for?

 

[operdot]

Nice work! I'm always intrigued by what Mech Eng's can come up with when faced with a challenge.

Any other "issues" on your car that you have designed fixes for?

Why of course!

I reinforced my subframe and used hockeypucks as mounts, custom front and rear motormounts, engine brackets(3.2 conversion), custom equal volume exhaust. I also have a modified cable shifter that works better (for me at least) than a rod shifter.