Bilstein shocks wrong length? Looks too long for 6in lift...

[jbai332]

I recently purchased a full set of 5100 series bilstein shocks for my 1988 Blazer. When I went to install them they look way too long. My fear is that I will not have enough travel in the shock and it will bind/act like a bumpstop and limit my suspension travel.

The guy I bought the Blazer from thought it had a 6in lift but wasn't sure, and the leaf springs do not show specifications, so I do not know for sure. I ordered what Bilstein specified as the correct shock for the 5100 series Bilsteins (6inch lift, front and rear)...

This is what I bought:
Part #'s: Bilstein 5100 Series: (Front) 33-185552; (Rear) 33-185569

What is currently on the truck are some no-name shocks that are quite a bit shorter than the new Bilsteins. The rears look almost the same length, but the fronts are much longer and just seem way too long.

My question: When you raise the Blazer by the frame, and the wheels hang, should the extended length of the shock be more than a couple inches past the mounts? The front goes about 5 inches past, and on full compression only looks like it has about 2-3 inches of travel. What is the best way to determine my lift height and what size shocks are the best since I do not know if it is actually a 6inch lift?

Anyone have some helpful feedback? Much appreciated, thank you!

 

[jeff in co]

You might check your "eye to eye" measurement and then compare to Bilstein's website as a starting point. Their site is kinda screwy but the info is out there..... Compare with compressed and extended shock lengths.

I did the same as you, brought my truck into a shop asking how much lift I had (with 37" tires). The shop "thought" it had to at least be 4" and possibly 6". After going to 35's and replacing my fronts with 2.5" springs.....I find out I actually only had 2.5" lift. I guess it's just hard to tell sometimes.

 

[jeff in co]

33-185552

• Series:5100 Series
• Old Part Number:F4-BE5-6248-H5
• Collapsed Length (IN):15.91
• Extended Length (IN):25.93
• Body Design:46mm ID smooth body (Non-coilover)
• Boot Included:Black bellows
• Finish:Zinc plated
• Internal Design:Monotube
• Lower Mount Type:5/8" Eye
• Upper Mount Type:5/8" Eye
• Reservoir:No

33-185569

• Series:5100 Series
• Old Part Number:F4-BE5-6249-H5,F4-BE5-6249-H6
• Collapsed Length (IN):17.91
• Extended Length (IN):29.7
• Body Design:46mm ID smooth body (Non-coilover)
• Boot Included:Black bellows
• Finish:Zinc plated
• Internal Design:Monotube
• Lower Mount Type:5/8" Eye
• Upper Mount Type:5/8" Eye
• Reservoir:No

 

[Mkuhn138]

Measure your truck from mount to mount with the suspension at full droop. Then compress your suspension and measure at as close to full bump as possible.

If the shock is longer than the full droop while extended, and shorter than full bump when collapsed you will be fine. In your application the second scenario is the more important one - with a shock like a 5100 there is really no harm in running it too long, as long as you are not bottoming the shock out before the suspension bottoms out. You may run it compressed a few inches at full droop, but this has no effect on a non-bypass shock.

 

[jbai332]

Thanks for the feedback. I guess I will get under there and measure it eye to eye on full droop and fully compressed then figure out which shock would be the best fit. The way it is now, there is no way it would compress to meet the bump stops before it bottoms out on the shock.

Not going to take someones "estimated lift height" serious next time... lesson learned.

 

[goathearder]

This same thing happened to me when I bought mine. Guy told me it had a 6 inch lift so I bought 6 inch lift shocks. Turns out it had a 4 inch suspension lift and a 2 inch body lift so the shocks were too long.

The way I found out was measuring the lift blocks at the rear springs. If you have blocks that will be a pretty good indication of the lift height.

 

[jbai332]

Thanks for the tip! I will be doing some measuring tomorrow to figure this out. I think it also has only a 4inch lift.... looks like 6 though.

 

[Mkuhn138]

Where in San Diego are you?