Anyone remove rear blocks?

[Zyvin]

Do you know if anyone has dropped rear end on Powerboost yet? Because I'm considering it on my 2023 Lariat Powerboost.

They make 2wd and 4wd powerboosts, so I don't see where there would be any difference in removing the blocks on a pb vs any other model.

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[Bryan Simon]

Put the max-trax 1” shackles on yesterday before the freeze came to town.
Not done yet, gonna remove the blocks next week. U-bolts on the way, along with the 2wd bump stops.

I have an extended cab 8’ box, and I gotta say: Even with slightly more than an inch drop, it was immediately noticeable as soon as I got in the truck.
Can see more of what is behind me now thru the mirror.

Block removal will bring me closer to a “level” truck.

Dont know what to say about the ease of this install. Everything I’ve read about it made it appear to be a 30 minute job.

Im inclined to think my rear hangers are about 1/4” too far forward.
had to remove tires, place a screw jack between the axle and bump stop and then get a long bar to force more of an arc to remove upper shackle bolt.

replacing with the new shackle was a bit easier as the upper bolt area of the shackle was the same size as the spring loop where the original was a bit larger.

I knew I wanted 2” down, but I was not about to cut bed braces, so, 1” shackles and then block.

 

[McGuyver]

I finally pulled the blocks out of my CCD truck. The shorter 2wd bolts were pricy so I just bought another set of long ones and cut 1 3/8” off. Threads looked to be just long enough but I put a couple of washers under each nut just to be sure. Keeping the 4wd bump stops, adjusted the headlights down a bit and everything is good so far.
I’ll hang on to the old bolts and blocks in case I want to re-install.

 

[KartRacer25]

 

[WhiteLightningnshitshadow]

Posting my 'block removal exercise' just FYI ....

As mentioned in a previous post I've got a 4WD 145" WB Supercab which uses a ~72" long 1-piece driveshaft from the tranny / transfer case to the rear differential (no intermediate support / U-joint).

After examining a 2WD 145" WB Supercab on a dealer lot I found that not only are the U-bolts shorter but also the bump-stops are shorter (presumably to allow similar total suspension travel without the blocks).

Back to my truck I carefully measured clearances and found the shorter bump-stops would still afford plenty of clearance along the entire driveline in a worst-case maximum-travel excursion.

I used my rotating laser-level (a construction-site tool) to determine the change in differential / pinion angle before and after removing the OE ~1.2" blocks (with full 36 gallon fuel tank, the truck resting on the wheels).

Within the limits of my measuring tools I could discern no change in the differential / pinion angle relative to the truck chassis line (bottom of the straight length of frame under the bed). IOW the differential is just 1.2" higher in the chassis with no measurable change in angle relative to the chassis. Based on this I've concluded that in my case the block removal slightly reduces the effective pinion-to-driveshaft angle at rest (the driveshaft is angled up going forward from the differential).

The PN's I installed are:
2WD U-bolts ML3Z*5705*A (quantity 4)
2WD Bump-Stops ML3Z*4730*A (quantity 2)

The resultant ~1.2" lower bed height directly over the axle obviously reduces the 'static rake' a corresponding amount. For me the benefit is reducing the minimum height of my 5th wheel hitch so my RV trailer now rides 'level' when loaded; when hitched my relatively light (for a 5th wheel) trailer increases my rear sag by slightly under 1" and decreases the front sag by an almost immeasurable ~1/8"~3/16". Those 'sag' dimensions did not change with the block removal.

So if I'm reading this right, your pinion angle actually improved? If it's more linear, does that mean there's potentially pressure from the driveshaft pushing on the pinion seal/bearings? Do you have the 1 piece drive shaft and mid length wheel base?


Anyone have the PN for the shim and guidance for install of the shim? Somewhat new to this. I want to try removing the block on my 2022 2.7 fx4 4wd. Is it better to remove the block or should I be looking at 1 or 2" shackles instead?

I wouldn't like to give up much in the way of payload honestly, but suspension travel is a little less important. Any qualified known impacts to either?

 

[Buyer2021]

So if I'm reading this right, your pinion angle actually improved? If it's more linear, does that mean there's potentially pressure from the driveshaft pushing on the pinion seal/bearings? Do you have the 1 piece drive shaft and mid length wheel base?

I am saying that the differential pinion angle is less without the spacer block both 'at rest' and at the extreme of suspension travel.

The vertical distance between a line through the differential pinion and the transmission shaft is reduced by 1.25", making the angle of the driveshaft connecting those two points less 'steep'. At the 'midpoint' of suspension travel (the point in the arc where the pinion-to-transmission tailshaft distance is shortest; i.e. the point where the line though the differential pinion and the transmission shaft coincide) is unchanged.

Yes, I have a single 1-piece driveshaft on my 145" WB Supercab with 6.5ft box.

 

[WhiteLightningnshitshadow]

I am saying that the differential pinion angle is less without the spacer block both 'at rest' and at the extreme of suspension travel.

The vertical distance between a line through the differential pinion and the transmission shaft is reduced by 1.25", making the angle of the driveshaft connecting those two points less 'steep'. At the 'midpoint' of suspension travel (the point in the arc where the pinion-to-transmission tailshaft distance is shortest; i.e. the point where the line though the differential pinion and the transmission shaft coincide) is unchanged.

Yes, I have a single 1-piece driveshaft on my 145" WB Supercab with 6.5ft box.

Understanding the output shaft and pinion need to be parallel irrespective of the driveshaft, it sounds like you're getting that by simply removing the blocks. I guess the blocks must have some sort of shimming angle built in then.

 

[Buyer2021]

I guess the blocks must have some sort of shimming angle built in then.

Not in my case, the faces of my OE blocks are perfectly parallel to each other.

Determined by placing the blocks on a know true-flat surface, then a 48" long know true flat bar centered on top of the block, and carefully measuring the surface-to-bar distance at each end (it was equal). Even a slight angle / out-of-parallel would be apparent over that length, but none was observed.

That's not to say that other blocks (there are 3 versions / thicknesses used for different applications per the Workshop Manual) are the same. The WSM only distinguished between the three by a 'type' designation, does not provide dimensional specs for any of them.

EDIT - I found WSM section 205-01 Driveshaft, General Procedures, Driveshaft Angle Adjustment which does make reference to the use of shims to make that adjustment. Follwoing are some of the introductory notes to that section:

NOTE: Some vehicles may exhibit a drive-away shudder or vibration under moderate to heavy acceleration from a stop, especially when heavily loaded or when towing a trailer. It is important to confirm how the vehicle is driven the majority of the time (loaded or unloaded), as adjusting the driveline angle in one condition (loaded or unloaded) may result in a shudder or vibration with the vehicle in the opposite condition (loaded or unloaded).​

​

NOTE: Verify suspension is not modified from the original configuration. Aftermarket leveling kits and rear leaf spring shackle kits change ride height, which affects pinion angle and other critical driveline related operating angles. Vehicle must be at OEM specifications before accurate evaluation and diagnosis can be performed.​

​

NOTE: The driveline angle must be measured with the vehicle in the same condition as the concern (loaded or unloaded) to determine the amount of adjustment necessary to correct the condition.​

 

[WhiteLightningnshitshadow]

Put the max-trax 1” shackles on yesterday before the freeze came to town.
Not done yet, gonna remove the blocks next week. U-bolts on the way, along with the 2wd bump stops.

I have an extended cab 8’ box, and I gotta say: Even with slightly more than an inch drop, it was immediately noticeable as soon as I got in the truck.
Can see more of what is behind me now thru the mirror.

Block removal will bring me closer to a “level” truck.

Dont know what to say about the ease of this install. Everything I’ve read about it made it appear to be a 30 minute job.

Im inclined to think my rear hangers are about 1/4” too far forward.
had to remove tires, place a screw jack between the axle and bump stop and then get a long bar to force more of an arc to remove upper shackle bolt.

replacing with the new shackle was a bit easier as the upper bolt area of the shackle was the same size as the spring loop where the original was a bit larger.

I knew I wanted 2” down, but I was not about to cut bed braces, so, 1” shackles and then block.

I think I'm going to do the same. I just ordered the same Maxtrac 1 inch shackles which are quoted to drop 1.25. Add the 1.25 drop from the block removal and then subtracts a negligible amount from the 2.5 degree shims, and I think I might be just around 2.3-2.4" drop at the rear tire. My truck looks to have at least 4 inches or more of rake with the Screw 2.7 FX4 package, tow package, 5.5 bed.

I'll be pissed if these aren't compatible with my requirements to not cut any OE parts.

 

[Buyer2021]

I wouldn't like to give up much in the way of payload honestly, but suspension travel is a little less important. Any qualified known impacts to either?

Changes to ride height won't change 'payload' directly in terms of pounds capacity (that's a function of spring rate).

But anything that lowers the bed / frame / bump stop relative to the wheels / axle housing obviously reduces the suspension compression travel by an equal amount, and part of that travel is required to accommodate payload-induced sag; the degree to which that's important for your truck use is only known to you. If you never really load your truck maybe it's a non-issue.

Suggestion:

• Before doing any mod measure the at-rest clearance between the top of the axle housing and the bump-stop directly above. That's your maximum available suspension compression travel available to accommodate both load-induced 'sag' and road-induce bumps.
• Know that if you remove an x" thick spacer block that available travel distance will be reduced an equal amount unless you recover it by installing equally shorter bump-stops
• If you then install lowering shackles you further decrease that available distance and commensurate suspension travel in compression.
• You can't use bump-stops any shorter than those for 2WD pickups with no spacer blocks lest you risk conflict between the top of the axle / differential with the bottom of the bed / frame (which would be traumatic).

At some point in the lowering exercise you will suffer effective payload loss because the load induced sag will leave an insufficnet amount of travel to deal with road bumps / hazards without 'bottoming' on the bump-stops. Remember, the bump-stops are a last-resort vehicle protection device, no one wants to actually 'use' those, it's a hell of a jolt when you bottom-out that's rough on equipment and causes very bad momentary handling issues.

Just for your consideration, Have Fun!

 

[WhiteLightningnshitshadow]

Changes to ride height won't change 'payload' directly in terms of pounds capacity (that's a function of spring rate).

But anything that lowers the bed / frame / bump stop relative to the wheels / axle housing obviously reduces the suspension compression travel by an equal amount, and part of that travel is required to accommodate payload-induced sag; the degree to which that's important for your truck use is only known to you. If you never really load your truck maybe it's a non-issue.

Suggestion:

• Before doing any mod measure the at-rest clearance between the top of the axle housing and the bump-stop directly above. That's your maximum available suspension compression travel available to accommodate both load-induced 'sag' and road-induce bumps.
• Know that if you remove an x" thick spacer block that available travel distance will be reduced an equal amount unless you recover it by installing equally shorter bump-stops
• If you then install lowering shackles you further decrease that available distance and commensurate suspension travel in compression.
• You can't use bump-stops any shorter than those for 2WD pickups with no spacer blocks lest you risk conflict between the top of the axle / differential with the bottom of the bed / frame (which would be traumatic).

At some point in the lowering exercise you will suffer effective payload loss because the load induced sag will leave an insufficnet amount of travel to deal with road bumps / hazards without 'bottoming' on the bump-stops. Remember, the bump-stops are a last-resort vehicle protection device, no one wants to actually 'use' those, it's a hell of a jolt when you bottom-out that's rough on equipment and causes very bad momentary handling issues.

Just for your consideration, Have Fun!

Great point. I'll see how this pans out. Someone else brought up a really good point about the increased leverage a longer shackle provides against the springs. This would effectively alter the spring rate and further lower the max load, but might make a slightly softer ride.

Airbags might be the way, but I'm totally foreign to those.

 

[Bryan Simon]

Not in my case, the faces of my OE blocks are perfectly parallel to each other.


That's not to say that other blocks (there are 3 versions / thicknesses used for different applications per the Workshop Manual) are the same. The WSM only distinguished between the three by a 'type' designation, does not provide dimensional specs for any of them.

mine were not parallel .
If I recall, about .070 difference between front and rear. ( maybe a bit more)
they were also directional for 157” and 145” pickups.
my pickup is a 164” wheelbase, and the blocks were oriented for 157”.
thick end to the rear, moving the pinion down.
My thinking was removing the blocks and raising the rear eye of the spring, would accomplish the same thing as the ever so slightly tapered blocks

I recall seeing 3 different blocks, I guess for different applications.

At any rate, lowering just a bit did actually make the truck feel a bit heavier in the rear. does not seem so “hoppy” on a washboard or gravely surface.
But, keep in mind that mine is an 8’ box SuperCab.
Just a bit of weight transfer going on as the front came up about 5/8”

 

[WhiteLightningnshitshadow]

Changes to ride height won't change 'payload' directly in terms of pounds capacity (that's a function of spring rate).

But anything that lowers the bed / frame / bump stop relative to the wheels / axle housing obviously reduces the suspension compression travel by an equal amount, and part of that travel is required to accommodate payload-induced sag; the degree to which that's important for your truck use is only known to you. If you never really load your truck maybe it's a non-issue.

Suggestion:

• Before doing any mod measure the at-rest clearance between the top of the axle housing and the bump-stop directly above. That's your maximum available suspension compression travel available to accommodate both load-induced 'sag' and road-induce bumps.
• Know that if you remove an x" thick spacer block that available travel distance will be reduced an equal amount unless you recover it by installing equally shorter bump-stops
• If you then install lowering shackles you further decrease that available distance and commensurate suspension travel in compression.
• You can't use bump-stops any shorter than those for 2WD pickups with no spacer blocks lest you risk conflict between the top of the axle / differential with the bottom of the bed / frame (which would be traumatic).

At some point in the lowering exercise you will suffer effective payload loss because the load induced sag will leave an insufficnet amount of travel to deal with road bumps / hazards without 'bottoming' on the bump-stops. Remember, the bump-stops are a last-resort vehicle protection device, no one wants to actually 'use' those, it's a hell of a jolt when you bottom-out that's rough on equipment and causes very bad momentary handling issues.

Just for your consideration, Have Fun!

Thanks! I just took delivery of the truck. Maybe it's the 200lbs of gas in the tank, but it doesn't look near as bad as the pictures. I might try to do just the blocks and see what I can get away with. I certainly have the flat blocks after looking.

My thinking is removal of flat blocks does absolutely nothing to change pinion angle, so shims shouldn't be required if the goal of setting pinion angle is a parallel trans and pinion. I don't think the linearity of the driveline, which is now more aligned than before, would be a negative attribute right?

Super great info in the thread, I just want to confirm the system of thought here.

 

[TXBJJ]

I put my blocks back in. That said , 2WD U bolts are for sale. I paid a ridiculous price of 170 for them.
I'm asking for 100 in the DFW (Texas) area.

 

[Buyer2021]

I put my blocks back in.

No worries but curious what your XLT wheelbase and what you didn't like about the mod?

GLWS of bolts

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