Rear Blocks Removed 2.0

[JCsTruck]

My appologies if I missed it, but did you re-use the stock shocks? Everything I've read says the 2WD shock are some 3/4" shorter. Do we know that at full bumpstop squish that the 4WD shocks don't bottom first? Plan to do this when/if my 157 arrives. Thanks.

Good question. The 2WD and 4WD are so similar with the only difference seemingly being that the 2WD has a 1-1/4” lower ride height and it is 200-300 lbs lighter. I really haven’t put much thought into the differences for the rear shocks up until you asked the question. I didn’t remove the rear shocks to do this job either because I didn’t need to.

Looking at the OEM part numbers from Ford they do list the 2WD rear shocks with slightly different part numbers vs the 4WD shocks. Looking at aftermarket shocks like Bilstein 5100 or Fox 2.0 and they also list them as different but they also indicate they are cross compatible with stock ride height.

I was not able to narrow the differences down really so I would have to assume that the differences have more to do with the valving of the shock for weight differences with the 4WD being tuned for the increased weight and maybe position too. Again, the 2WD bump stops are ~1.25 inches shorter than the 4WD bump stops so I would assume with that little difference the shocks should not bottom out.

In theory if the shock valving was different, then my ride should be less comfortable because the shock might behave as if there was a load in the bed of my truck (lower height) by stiffening up yet it seems more comfortable, so I’m not sure.

Conclusion: I would say under normal conditions you likely don’t need to replace the shocks. Whether they can handle the modified travel without bottoming out under normal driving conditions I guess only time will tell. I will need to monitor the truck and check for harsh impacts, clunking, or fluid leaks which could indicate bottoming out and report back here if they happens. I also don‘t off road or load the truck to near it’s maximum payload capacity, so considering this I will take a chance and leave the stock shocks for now. If you are the type that does push your truck to its limits then I would consider upgrading the rear shocks to a high qaulity aftermarket shock such as Bilstein 5100 or Fox 2.0 shocks specified for a 2WD vehicle.

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[honda250xtitan]

Thats actually Beuna Vista CO. Ill be around Peoria looking for good shooting and camping spots.

pretty much endless. bit busier during the summer time for the mtn areas. But winter time camping in the desert is severly underrated. Offroad during the day with the boys, camping and shooting in the evening.

 

[JumboJVT]

Thanks. I do sometimes load a pickup fully (firewood, crushed stone, etc) not real often. But it always seems even with a moderate load that there is some negative-G "feature" in the road (culverts that have been replaced with good, well-drained material surrounding them, when the rest of the roadbase is still frost-active are a favorite) that sneaks up and result in a hard bottom. Let alone a good old fashioned frostheave at speed.

I guess the question I would ask is why Ford would use two different shocks lengths if they're interchangeable? And since the payload ratings - minus the 4WD equipment - are basically the same for 2WD or 4WD of similar GVW, I'd expect not much difference in valving, total sprung weight at max. being very similar. But who knows?

Bilstein's, in my experiance with my current '16 Tundra, have signiciantly more bottoming resitance than OEM, which could explain the cross-compatibility they suggest.

I guess it won't be that difficult to figure it out: measure c-c at ride height, pull shock and measure compressed, measure axle to bumpstop (guess at how much it can compress) and do the math.

 

[slater]

Majority of the trucks in San Diego run the front higher than the rear...
Not terribly like North Carolina squat, just give it a slight pre-runner look..
This info might come-in handy when the time comes.
Plan on doing a 2.5" front spacer "level" & then reassess the situation.
If need be, pull out the block & install a shorter one if the reverse rake is excessive...

 

[Old Hat]

Lowering the rear (and changing to 2wd bumpers) will also make the driveshaft spline enter deeper into the trans. Did you check if this causes it to bottom out? Are 2wd driveshafts and/or yokes/splines different than 4wd? Thanks for the detailed write up.

 

[slater]

Lowering the rear (and changing to 2wd bumpers) will also make the driveshaft spline enter deeper into the trans. Did you check if this causes it to bottom out? Are 2wd driveshafts and/or yokes/splines different than 4wd? Thanks for the detailed write up.

Wouldnt be any different than lowering the truck which has been done since the start of time, without modifying the drive shaft slip yoke...

 

[FaaWrenchBndr]

Very well thought out and documented…well done Sir

 

[FaaWrenchBndr]

Lowering the rear (and changing to 2wd bumpers) will also make the driveshaft spline enter deeper into the trans. Did you check if this causes it to bottom out? Are 2wd driveshafts and/or yokes/splines different than 4wd? Thanks for the detailed write up.

Son in Law looked at that when he took his blocks out of his ‘22
Slip yoke position changed about 1/8”

 

[Old Hat]

Son in Law looked at that when he took his blocks out of his ‘22
Slip yoke position changed about 1/8”

Thanks for confirming my thoughts. It seems prudent to not only check, but clean the dirty/rusty outer portion of the slip yoke that will now be sliding into the seal.

 

[Dakar09]

Slip yoke is just that...a slip yoke. 1/8" is nothing in the grand scheme of things on a vehicle designed to tow or go off-road. Should you tow as heavy with the rear blocks off? Probably not. Will it damage the truck? Probably not.

The main concern is the driveshaft angle changes, which are negligible with a drop this minor.

My opinion is you're overthinking it. It's not "slamming" the rear of the truck, it's not a Carolina Crouch (or whatever that crap they do down South is called). And likely less dangerous to the driveline than lifting the vehicle an inch or more.

I'll put on my flame suit now...

 

[FaaWrenchBndr]

Slip yoke is just that...a slip yoke. 1/8" is nothing in the grand scheme of things on a vehicle designed to tow or go off-road. Should you tow as heavy with the rear blocks off? Probably not. Will it damage the truck? Probably not.

The main concern is the driveshaft angle changes, which are negligible with a drop this minor.

My opinion is you're overthinking it. It's not "slamming" the rear of the truck, it's not a Carolina Crouch (or whatever that crap they do down South is called). And likely less dangerous to the driveline than lifting the vehicle an inch or more.

I'll put on my flame suit now...

I agree with your thoughts. The rear blocks are what an inch and a quarter? Many trucks are gonna sag that much when a trailer is on the hitch. Nobody has any thoughts about the slip yoke in that situation.

 

[JCsTruck]

I’m happy to report that the truck has no driveline issues or vibrations. It rides and drives very nice actually. No issues with the stock shocks either which are the original shocks that came with the truck.

 

[National Superbike]

I’m happy to report that the truck has no driveline issues or vibrations. It rides and drives very nice actually. No issues with the stock shocks either which are the original shocks that came with the truck.

I don't think you would notice any problems unless you are towing something with a heavy tongue weight or have the bed loaded. The problem with the shocks is that they could bottom before you hit the bump stops- especially since you put the shorter stops in. The shocks and stops are designed to work together. I'm probably going to put the Bilstein B6 4600's on my truck since it is quite bouncy and wallows around corners. The stock shocks are pretty under-damped.

 

[Buyer2021]

Just FYI / FWIW ..... Billstein gives the collapsed length of their F150 5100 shocks as

4WD = 17.52"
2WD = 16.97"
(difference = 0.55")

Given the shock mounting angle that means the fully-compressed vertical suspension-travel difference is on the order of ~3/8".

Could be wrong but I don't think either fitment is going to cause a real-world problem whether on 4WD (with spacers) with long bump stops or 2WD (no spacers) with short bump-stops.

I know that with 15k miles on my 5th-wheel towing rig (see signature block) with 4WD 5100's, 1.25" spacers removed, and short bump-stops installed .... I've not yet encountered a 'bottom-out' of anything. But my rig's damping composure is certainly much better than OE.

Your opinion or experience may differ, No Worries!

So, you may ask, why did I remove the spacer blocks? Because with my specific trailer / hitch / rig-setup that allows an ideal level-stance for my trailer when towing.

 

[JCsTruck]

I don't think you would notice any problems unless you are towing something with a heavy tongue weight or have the bed loaded. The problem with the shocks is that they could bottom before you hit the bump stops- especially since you put the shorter stops in. The shocks and stops are designed to work together. I'm probably going to put the Bilstein B6 4600's on my truck since it is quite bouncy and wallows around corners. The stock shocks are pretty under-damped.

I towed my bass boat with bed loaded with gear and rear seats also loaded with gear and my wife with me to Maine from Massachusetts (~115 miles one way) and had no issues. It was very smooth actually. I took the boat to the boat launch twice over the last two weekends and had no issues.

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