Shock Length and Travel - Ford Ranger Forums

sawred · 02-24-2005

I have been looking around for possible new shocks for after upgrading the rear. Does anyone have stock measurements of what the compressed length is?

What seems to be odd is I have seen some people on ORR suggest the 5100 10" travel shocks for the rear and some shocks like the 5150 only go up to 14" travel. What confuses me is how do we only have less then 10" travel? Or is it 10" plus the compressed length added to get the total travel of the suspension, but that would then be the extended length.

What have people used in shock lengths for upgraded rear suspensions? Like adding a 2" AAL or 3" blocks or even those that might have added deavers in the rear.

Obviously the best way to do this is to setup the rear and then measure, but that would leave my truck off the road (and not in the good way) until I got the new shocks. Or could i ride with the OE replacements one and just keep to the road, essentially not running the suspension through its cycle and therefore not overextending, or trying to overextend the shocks.

sawred · 02-24-2005

Found this website:
http://www.off-road.com/toyota/travel.html

Quote:

COMPRESSED DIMENSION

To figure the compressed dimension, take an eye-to-eye (stud-to-stud) measurement with the truck at rest. From this dimension, subtract the distance between the bump stops. This is your nominal compressed dimension. It is also a good idea to go at least 1/2" shorter to allow for bump stop compression.

This method assumes the shocks are mounted vertically and the axle also moves vertically. In cases other than this, the shock movement will generally be less.

If possible, shock measurements should also be taken with the axle at full compression to ensure dimensions are correct. This can be done by twisting up the suspension on a ramp or obstacle, or articulating the suspension by some other means.

EXTENDED DIMENSION

Next, jack up the vehicle, or somehow twist it up, to see how much droop you get (with the original shock disconnected). It may also be helpful to disconnect your sway bar as well.

On leaf spring suspensions, you may see the maximum droop as the point where you run out of spring/shackle length and the axle cannot drop any further. Or.... you may have other limiting factors such as tire interference, spring bind, etc.

Get an approximate length from this and then start checking for shocks of the appropriate length in a shock vendor catalog. You may find a shock that matches your range well or you may have to go through a few iterations of comparing available lengths and your travel movement, and possibly consider modifying your existing shock mounts to maximize your shock travel.

Those two are pretty straight foreward, that's what i expected those numbers to be. But then travel is say only 10" with those 5150s in the previous post. Is that supposed to be impressive?

92 Ranger · 02-24-2005

well im not to sure but i dont think that it would be safe riding around like that.. if you just got some bigger shocks like worn out ones untill you get the aftermarket ones you should be ok... i wish i hadnt thrown out my old shocks i had shocks for a 4 inch suspension lift and they were worn out but good luck

n3elz · 02-24-2005

If you get some longer ones, you may want modified bump stops to keep the shocks from being the bump stops. Longer shock bodies (required for longer shafts) can decrease your up travel. Just something to think about.

sawred · 03-03-2005

Quote:

Originally Posted by n3elz

If you get some longer ones, you may want modified bump stops to keep the shocks from being the bump stops. Longer shock bodies (required for longer shafts) can decrease your up travel. Just something to think about.

Yeah I've been noticing that. I guess that is why guys run bed cages to compensate for that. It raises the upper mount to regain the otherwise lost uptravel.

I went out today and measured the shock length when the truck sits normally and found the eye to eye distance to be 20.5". I then measured the bumpstop to the stop on the block (by the way, the block is a 2" block) to be about 4.125". Oh and the bumpstop itself is about 2.125" tall.

I first thought the compressed length would be 20.5-4.125=16.375, but then realized the shocks are mounted at an angle and not straight up and down so this calculation is not applicable. So it seems I will have to get some flex to measure it at compression to know for sure, aside from trying to apply some trig. But I think the geometries and the swing of the axle makes it a bit complex. Besides, getting the actual measurement under full compression would be certain to give me the correct compression length.

SuperGildo@RRP · 03-03-2005

you need to remove your shocks and go to a ramp of sorts and test it there, that will give you your true compressed and extended length.

Edit: but be VEERY careful, i rode around without shocks for like 2 weeks and if you dont drive very slowly over bumps or bumpy areas you WILL lose control, make sure you take them off test them and put them right back on.