Help Sizing Bilsteins

[RottenBanana]

Hi Folks,

My shock measurements are as follows:

Front - 19" stud to eye
Rear - 19.75" eye to eye

Since the MS2020 from Duff won't work, I'm looking at Bilsteins. How do these part numbers look?

Front - 33-230450 (14.3" col. x 22.9" ext) 360/80 valve

Rear - 33-186542 (15" col. x 24.5" ext) 255/70 valve


The truck is running a Deaver 4.5" (F) and 3.5" (R) lift, and is primary driven on the road. The parts are likely an old setup from Wild Horses, with white bodied shocks. The springs are linear, and considering changing them to a 3.5" progressive. Likely Duffs just because I've liked their parts in the past.

Thanks in advance!

 

[1969]

If you’re looking at replacing the springs, I would get the matching set from duffs.. not buy shocks now and springs later.

 

[RottenBanana]

If you’re looking at replacing the springs, I would get the matching set from duffs.. not buy shocks now and springs later.

Duffs says I am outside the range of their MS2020 as it's Static Measurement is 17.25". Waiting to hear back from them about if the 3.5" springs would put me into spec, but their email wait times are long.

 

[1969]

Can you post some pictures of how your suspension is set up now? Do you have factory shock and coil mounts?

 

[RottenBanana]

Sure, I'll grab some in the morning.

Duffs Bump Steer Eliminator kit, and stock shock mounting locations. Only modification there are the Duff lower spring retainers.

 

[RottenBanana]

Some quick pics...

https://imgur.com/a/ib4dB1y

 

[ba123]

I'm not sure you're doing the Duff's measurements correctly. I have a 3.5" lift with a 1" body lift and the 10" was right for the front and the 9" for the rear.

And I think the shocks are great so far, btw.



Use the guide here to measure: https://dufftuff.com/wp-content/uploads/2020/01/shockmeasure.pdf

***EDIT: maybe because of the stud to eye part and they only have the one?

 

[RottenBanana]

I would have thought they would work too, but Duffs says no. What is your front measurement?

 

[ba123]

I would have thought they would work too, but Duffs says no. What is your front measurement?

I think the problem, which I didn’t realize on your first post, it that you’re running the stock front mount. Looks like they only have one option for the eye to stud

If you get rid of that and put the Duff towers you’re good I think.

 

[lars]

I think the problem, which I didn’t realize on your first post, it that you’re running the stock front mount. Looks like they only have one option for the eye to stud

If you get rid of that and put the Duff towers you’re good I think.

^^^this.

Swapping the OEM stud-type towers for any brand of tower that accepts an eye type shock opens up a ton of shock options.

 

[RottenBanana]

Will the Bilsteins listed not fit?

 

[Broncobowsher]

Hi Folks,

My shock measurements are as follows:

Front - 19" stud to eye
Rear - 19.75" eye to eye

Is that compressed, extended, or ride height?

My typical check for the front is to remove the front springs and jack the axle up as far as it will go. Might have to make adjustments to the bumpstops in order to pull that off. That gets compressed length. Find a shock with a slightly shorter compressed length (to make sure you never bottom it out) and looks at the extended length. Set the axle at that distance. Is it possible? Is everything happy? Is ride height reasonably close to the middle of that range? If so, you found your shock. If not, oh this gets into a can of worms.

The rear, this is about the same but you need to leave the springs in. How to get compressed length with leaf springs still installed? Measure axle to bump stop gap. Measure straight up that amount. You need 2 tape measures, and a second person is handy. One tape measure goes straight up that distance. second tape measure measures from the top mount to that point in space. This is where a second person holding that tape straight up and that is the only task comes in handy. Now you have compressed. Droop? Unbolt the shocks and carefully jack the frame watching brake lines and the like. At some point you also need to watch CV angles to make sure you don't get into a bind. The last set of rear shocks I did this way I had to limit full droop because the CV wanted to bind. I left the U-joint off the diff and rotated the driveshaft until I reached minimum angle and made sure the diff was slightly higher than that.

 

[nvrstuk]

Doing it right takes time. I spent over a week just simulating full articulation for EACH AXLE with a floor jack and determining shock angles and placement.. I drew a full sized drawing on a sheet of plywood showing all my axle measurements, DS angles (to make sure there's no binding), full movement stuff and droop to determine the correct travel and mounting location at the bottom and top. Then like bowser said, is this ride height?

This was for a custom axles in my example but I did the same thing when using the stock D44 and 9" (less the full scale drawing) but moved stock shock location mounting points to make sure everything worked for the shocks I was wanting to use.

There is so much more to it. Like already mentioned, change that mount so you have some viable shock options. Good luck, you'll get it.

 

[lars]

Will the Bilsteins listed not fit?

I won't comment on whether they'll fit, looks like the steps to confirm that are pretty well laid out in posts above. My comment about shock towers that use a through bolt instead of a stud only has to do with the fact that there are a lot more shock options with eyes at both ends than with a stud at one end. And it's pretty easy for anyone with some fab skills to install new towers. Having options is just about what if you want to try something different eventually (that would be me, for example).

That said assuming the ones you listed fit, I think you'll be happy with the valving you specified. I ran Bilsteins with the same valving for several years. Still have them in the back, only changed the fronts out because I.. ahem.. started driving harder.

 

[nvrstuk]

Wait till that new tranny is in Lars... THEN you'll start driving harder!

I ran that same valving with bumpstops in Bilsteins for a decade. NEED bumpstops for anything more than easy cruising but that valving & shock work well.