Growing up doesn't have to suck

[89Suburban]

I just got some new Bilstein 4600 B6 struts to match the rear Bilsteins I have. Just posting this for part number documentation and notes about the rear shocks.

Front struts, OEM replacement: 24-186926

Rear shocks, Jeep Cherokee XJ stock rear replacement: 24-010467
I'm using them as shorter shocks for my 4.5" drop

Belltech's specified shock for a 3"-5" rear drop is the 2410FF- 13.0" compressed, 20.5" extended.
The Bilstein 24-010467 is 13.01" compressed, 20.39" extended. It has a bar pin that will need to be removed, the bushing drilled out and the bolt sleeve/spacer from the original shock pressed in.

I've been running this shock with the stock Jeep TJ rear coils as my drop coils for over four years and about 35K miles now. I've towed 2,000+ miles and carried a few hundred lbs. in the cargo hold. I have Air Lift bags that I kept 6-9 psi in. Never a problem. With no air in the bags, the combo is a little too soft for handling but rides very comfortably. Upgrading the sway bars resolved the handling aspect while maintaining the great ride characteristics.

This is next on my list. I want shorter rear shocks to keep the lowering springs from dangling when the weight is lifted off them. I assuming the shorter shocks help with this? Do you still need to run the drop brackets with the shorter shocks?

 

[89Suburban]

@randeez yeah I would ask you but you lift sh*t.

 

[iamdub]

Do me a flavor and measure from the center of your hub to your fender arch. I wanna see how comparable our drops are

Fo sho. I have terrible memory. Text me this evening to remind me.

 

[randeez]

This is next on my list. I want shorter rear shocks to keep the lowering springs from dangling when the weight is lifted off them. I assuming the shorter shocks help with this? Do you still need to run the drop brackets with the shorter shocks?

the drop brackets correct some of the angle you get from dropping it, ive used them and not used them - dont really notice a difference honestly

@randeez yeah I would ask you but you lift sh*t.

it's a lot easier to work under lifted

 

[iamdub]

This is next on my list. I want shorter rear shocks to keep the lowering springs from dangling when the weight is lifted off them. I assuming the shorter shocks help with this? Do you still need to run the drop brackets with the shorter shocks?

There's more to it than that. But, basically, yeah. If the shock is too long, it'll be too compressed and in danger of bottoming out. But, it could have too much extension travel to allow the rear to droop too much and springs become unseated. I use the factory setup as my starting point. If I drop it 2", then stock shocks with 2" extenders will keep the travel just like the factory design. An inch either way doesn't make enough difference to be of concern, so 2" extenders on a 3" drop is fine. The shock will only have lost 1" of travel. Beyond that 1" difference is where things can start to get questionable if your springs aren't tall enough when unloaded.

I'd have to look up the compressed and extended dimensions of the OE shock and compare to the 2410FF or XJ shock to answer if the extenders are needed. Off the top of my head, I'd say they aren't, but don't hurt to have. I'm running them to ensure I have enough up travel cuz I'll never be jumping my Tahoe and fully extending the shocks. Compressing them is the much more likely possibility. This also ensures that the rear never droops enough to allow the springs to be unloaded.

Another way to limit droop is to have proper-length end links on the sway bar. Shorter ones (to match the drop) will limit the droop. But it's not quite as effective as having the proper shock length.

 

[89Suburban]

There's more to it than that. But, basically, yeah. If the shock is too long, it'll be too compressed and in danger of bottoming out. But, it could have too much extension travel to allow the rear to droop too much and springs become unseated. I use the factory setup as my starting point. If I drop it 2", then stock shocks with 2" extenders will keep the travel just like the factory design. An inch either way doesn't make enough difference to be of concern, so 2" extenders on a 3" drop is fine. The shock will only have lost 1" of travel. Beyond that 1" difference is where things can start to get questionable if your springs aren't tall enough when unloaded.

I'd have to look up the compressed and extended dimensions of the OE shock and compare to the 2410FF or XJ shock to answer if the extenders are needed. Off the top of my head, I'd say they aren't, but don't hurt to have. I'm running them to ensure I have enough up travel cuz I'll never be jumping my Tahoe and fully extending the shocks. Compressing them is the much more likely possibility. This also ensures that the rear never droops enough to allow the springs to be unloaded.

Another way to limit droop is to have proper-length end links on the sway bar. Shorter ones (to match the drop) will limit the droop. But it's not quite as effective as having the proper shock length.

I'm not worried about unloading the springs road wise, just when I put it up in the air on a lift. Or jack one side up. I know my springs will wobble unloaded, possibly not seating correctly in the top hats or on the isolator when reloaded.

 

[KidWgn]

the drop brackets correct some of the angle you get from dropping it, ive used them and not used them - dont really notice a difference honestly

what you’re correcting with the drop brackets is the geometry during the compression stroke and rebound stroke. They are, in fact, important.

There's more to it than that. But, basically, yeah. If the shock is too long, it'll be too compressed and in danger of bottoming out.

You also have to factor that a shock has a working “range”. It isn’t effective through its entire range of motion. If you start a shock 50% compressed, it may only have 20% of its effective range left

 

[iamdub]

You also have to factor that a shock has a working “range”. It isn’t effective through its entire range of motion. If you start a shock 50% compressed, it may only have 20% of its effective range left

And I feel Bilstein would have more engineering in their design than Belltech. But, who's to say BT doesn't have a top-name shock manufacturer build their shocks and they just paint 'em silver and slap their stickers on 'em? Their Street Performance shocks and struts are pretty good, just tuned too "sporty" for what I want.

 

[randeez]

And I feel Bilstein would have more engineering in their design than Belltech. But, who's to say BT doesn't have a top-name shock manufacturer build their shocks and they just paint 'em silver and slap their stickers on 'em? Their Street Performance shocks and struts are pretty good, just tuned too "sporty" for what I want.

KW is the parent company of belltech, IE they have coilover product lines from from 1k-10k
although i think they just let belltech do whatever they want

 

[KidWgn]

And I feel Bilstein would have more engineering in their design than Belltech. But, who's to say BT doesn't have a top-name shock manufacturer build their shocks and they just paint 'em silver and slap their stickers on 'em? Their Street Performance shocks and struts are pretty good, just tuned too "sporty" for what I want.

All of these companies manufacture a handful of shock lengths, and just change the ends to fit the application. This is where researching valving profiles comes into play, and knowing the shocks' effective range. Atomic Fab was a huge help with the Viking shocks, and you can order them by length and effective range.

 

[iamdub]

KW is the parent company of belltech, IE they have coilover product lines from from 1k-10k
although i think they just let belltech do whatever they want

I forgot all about that. Good pernt.

 

[iamdub]

All of these companies manufacture a handful of shock lengths, and just change the ends to fit the application. This is where researching valving profiles comes into play, and knowing the shocks' effective range. Atomic Fab was a huge help with the Viking shocks, and you can order them by length and effective range.

I just happened to have the XJ shocks on hand from a past project and the dimensions matched the BT drop shock so I rolled with it. I've tested it for about 35K miles now and am satisfied. Especially for what it cost.

 

[iamdub]

5K service (oil change and tire rotation) last night. Catch can had the expected 2 oz. Drain plug magnet had about the same iron on it as last time. Engine might be eating itself and the clock is ticking. It's been a hard 30K miles.


230K badge of honor:

I also noticed my next project. I'm sure this is my fault:

The output seal has been like this for a while. But, now that I gotta do the pinion seal, it only makes sense to pull the shaft once and do both at the same time.

 

[iamdub]

Took some measurements to get an idea of the drop from under-mounting the struts.


Control arm is right at 1":

The bar pin on the new Bilstein strut is right at 1/2" thick. This means the strut will sit 1.5" lower. Wouldn't this equate to nearly a 3" drop? Just to try to get half-assed numbers, I eyeballed the lower control arm from the center of the ball joint to the center of the pivot bushing to be 17". The center of the strut mount is about 7" inboard from the center of the ball joint. If it were half way (8.5"), then it would yield a 2:1 (200%) ratio, meaning a full 3" drop from the 1.5" difference. Since it's 7", or 41:100 (41%) of the 17", does that mean it'll only drop 82% of that 3", making it a 2.46" drop?

I'd like to know what to expect before I build the new struts. I have some ~5,000-mile struts from a '22 Sierra. I wanna use the top plates/mounts. They have a spacer built into them that's about .25" thick. If undermounting the struts yields a 2.5" drop, then that built-in spacer would put me back at the ideal 2" drop (approximately). I'd have the same drop I have now but with full OEM strut travel. Any further drop or reduction of drop could be easily fine-tuned in as small as ~3mm increments by adding a custom-thickness spacer (high grade washers?) under the control arm or on top of the top mount.

 

[kbuskill]

Took some measurements to get an idea of the drop from under-mounting the struts.


Control arm is right at 1":

View attachment 424137


The bar pin on the new Bilstein strut is right at 1/2" thick. This means the strut will sit 1.5" lower. Wouldn't this equate to nearly a 3" drop? Just to try to get half-assed numbers, I eyeballed the lower control arm from the center of the ball joint to the center of the pivot bushing to be 17". The center of the strut mount is about 7" inboard from the center of the ball joint. If it were half way (8.5"), then it would yield a 2:1 (200%) ratio, meaning a full 3" drop from the 1.5" difference. Since it's 7", or 41:100 (41%) of the 17", does that mean it'll only drop 82% of that 3", making it a 2.46" drop?

I'd like to know what to expect before I build the new struts. I have some ~5,000-mile struts from a '22 Sierra. I wanna use the top plates/mounts. They have a spacer built into them that's about .25" thick. If undermounting the struts yields a 2.5" drop, then that built-in spacer would put me back at the ideal 2" drop (approximately). I'd have the same drop I have now but with full OEM strut travel. Any further drop or reduction of drop could be easily fine-tuned in as small as ~3mm increments by adding a custom-thickness spacer (high grade washers?) under the control arm or on top of the top mount.

While I have never taken all the measurements and done the "maths" I know that Rough country sells what they advertise as a 2" drop kit that comes with grade 9 hardware AND a .25" spacer to go between the control arm and strut bar. That .25" spacer, in theory, should add .5" of drop but again I never cared enough to take measurements when I did it.

I just bought the hardware without the spacer from Rough Country and combining that with the Belltech 2" drop spindles assumed I had APPROXIMATELY a 4" drop up front.

I know you are very precise (read anaI) about your measurements though, so keep us posted.

I always figured, what is a 1/4", give or take, amongst friends... lol

*** EDIT ***
I forgot how woke this forum has gotten with the nanny system that censors everything. Turns out you can get away with spelling AnaI if you spell it with a capital i at the end instead of an L, so take that nanny state.... lol

 

[OR VietVet]

5K service (oil change and tire rotation) last night. Catch can had the expected 2 oz. Drain plug magnet had about the same iron on it as last time. Engine might be eating itself and the clock is ticking. It's been a hard 30K miles.


230K badge of honor:

View attachment 424127


I also noticed my next project. I'm sure this is my fault:

View attachment 424128


View attachment 424129


The output seal has been like this for a while. But, now that I gotta do the pinion seal, it only makes sense to pull the shaft once and do both at the same time.

I have seen the same seepage stain at my output seal but no drops out of the holes on the rubber sleeve. Fluid level stays good. I agree though to do both while shaft is out BUT, it looks like the pinion seal is just seepage too, unless the pic of the stain is after wiping away the wet.

 

[89Suburban]

I'm getting the itch to swap my struts back under the arms again to get another 2" of drop. This shit is addicting. Damn you people. Which also means the rear will have to go lower at some point as well.

 

[Geotrash]

I have seen the same seepage stain at my output seal but no drops out of the holes on the rubber sleeve. Fluid level stays good. I agree though to do both while shaft is out BUT, it looks like the pinion seal is just seepage too, unless the pic of the stain is after wiping away the wet.

I'm in the same boat but unless I see drips, like you, I'll let it ride.

 

[iamdub]

I somehow missed all the following replies.

While I have never taken all the measurements and done the "maths" I know that Rough country sells what they advertise as a 2" drop kit that comes with grade 9 hardware AND a .25" spacer to go between the control arm and strut bar. That .25" spacer, in theory, should add .5" of drop but again I never cared enough to take measurements when I did it.

I just bought the hardware without the spacer from Rough Country and combining that with the Belltech 2" drop spindles assumed I had APPROXIMATELY a 4" drop up front.

I have that same hardware kit- "720BAG3". RC's drop kit including the spacer being advertised as a 2" drop is where I'm confused. Without that .25" spacer, I should be around a 1.5" drop with just the undermount.

I'm a visual learner. I swear I once found an online suspension visualizer where you could mark pivot points and link lengths and it'd show the degree and distances of change at any chosen point along the link. I couldn't find anything this time.

I know you are very precise (read anaI) about your measurements though, so keep us posted.

I always figured, what is a 1/4", give or take, amongst friends... lol

Not many record empirical data so when I'm elbows-deep, I like to be thorough. Also, when you're at the bleeding edge of being too low for driving without much concern, .25" can be a lot.

*** EDIT ***
I forgot how woke this forum has gotten with the nanny system that censors everything. Turns out you can get away with spelling AnaI if you spell it with a capital i at the end instead of an L, so take that nanny state.... lol

I use Windows special characters (search "Character Map") to sneak past the nannies.

Example: Aņal

 

[iamdub]

I have seen the same seepage stain at my output seal but no drops out of the holes on the rubber sleeve. Fluid level stays good. I agree though to do both while shaft is out BUT, it looks like the pinion seal is just seepage too, unless the pic of the stain is after wiping away the wet.

It was just as I found it. No drips. But, I don't expect it to get better.