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How do I sort the suspension on my new STX?


Strelok

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Bought a 1990 STX this weekend http://www.therangerstation.com/forums/showthread.php?t=177079

Previous owner said it's got a 4" lift, I don't see any spacers on the body but the axles seem pretty low. Stickers on the window say Rough Country N2.0, so I presume those are the shocks.

Going down the road, you can't even feel little tiny bumps or cracks or anything like that, but hit a one inch deep pothole and the whole truck shakes. Driving through San Francisco where the roads are shit rattles your teeth. I'm seriously worried about cracking the dash and my interior panels because they're all old and brittle but in mint condition.

I don't know the first thing about 4x4 suspension yet, but I know I want a softer ride. The primary use for this truck is hauling motorcycles, so I'll probably never have more than 600lbs in the back or in a trailer.

Secondary use is camping, and I wanna be able to fly down shitty dirt roads without breaking shit. I'd also like to fit 33's because I think it'll look better and the clearance doesn't look very good for such a high truck.

Can anyone point me in the right direction with what I need to do to this suspension to make it comfy and offroad worthy?







 


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Yes, it has definitely had the axles moved farther away from the frame.

Suspension tech here: http://www.therangerstation.com/how-to/suspension-and-body-lifts/

I would remove all 4 shocks(disconnect one end) and see how the springs are working

The springs set the ride, shocks can make ride worse, but not better, so see what you have to work with.

Springs are rated for the weight of the vehicle on that axle, if you have a 3,000lbs spring on a 2,000lbs vehicle it will have a stiff ride, not enough vehicle weight to hold springs down, so spring can't absorb a bump, it just pushes vehicle up since there is not enough weight to hold it down
That happens on most pickup trucks rear springs, to get 1/2 ton rating springs have to be rated for that, an extra 1,000lbs, so empty bed means stiff ride.
Answer to that is overload leaf springs added to CORRECT rated leaf spring, overload leaf doesn't touch the frame until bed load gets enough weight added, so good ride empty and still has same load rating

It is popular to add larger springs but that comes at a price if they are for use on heavier vehicle

In your case smaller bumps are probably being absorbed by the tires, when larger bump comes along the over sprung suspension transfer deflections to frame and YOU, might as well put steel bars in place of the springs, lol.
So pop off the shocks and see how vehicle bounces, should bounce easily if you weigh over 150lbs, if it doesn't then you are over sprung.

Shocks are there to stop springs from continuing to bounce after hitting a bump, dampers, you can also get shocks that slow the deflection of springs, and these can make ride stiffer, users choice.
 
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BlackBII

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What psi are your tires at? That can make a difference as well if they are too high.

Most aftermarket ttb coils are rather stiff, like 4-500 ppi stiff. Skyjacker's are a little softer. Getting rid of the stacked blocks would be a good idea too.

Is replacing the coil and leaf springs something you'd consider doing?
 

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Yes, it has definitely had the axles moved farther away from the frame.

Suspension tech here: http://www.therangerstation.com/how-to/suspension-and-body-lifts/

I would remove all 4 shocks(disconnect one end) and see how the springs are working

The springs set the ride, shocks can make ride worse, but not better, so see what you have to work with.

Springs are rated for the weight of the vehicle on that axle, if you have a 3,000lbs spring on a 2,000lbs vehicle it will have a stiff ride, not enough vehicle weight to hold springs down, so spring can't absorb a bump, it just pushes vehicle up since there is not enough weight to hold it down
That happens on most pickup trucks rear springs, to get 1/2 ton rating springs have to be rated for that, an extra 1,000lbs, so empty bed means stiff ride.
Answer to that is overload leaf springs added to CORRECT rated leaf spring, overload leaf doesn't touch the frame until bed load gets enough weight added, so good ride empty and still has same load rating

It is popular to add larger springs but that comes at a price if they are for use on heavier vehicle

In your case smaller bumps are probably being absorbed by the tires, when larger bump comes along the over sprung suspension transfer deflections to frame and YOU, might as well put steel bars in place of the springs, lol.
So pop off the shocks and see how vehicle bounces, should bounce easily if you weigh over 150lbs, if it doesn't then you are over sprung.

Shocks are there to stop springs from continuing to bounce after hitting a bump, dampers, you can also get shocks that slow the deflection of springs, and these can make ride stiffer, users choice.
I'll pop the shocks off this weekend maybe and see if I can get a video.

What psi are your tires at? That can make a difference as well if they are too high.

Most aftermarket ttb coils are rather stiff, like 4-500 ppi stiff. Skyjacker's are a little softer. Getting rid of the stacked blocks would be a good idea too.

Is replacing the coil and leaf springs something you'd consider doing?
Depending on cost yeah, I want this truck to be nice.
 

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Disconnect the front swaybar and see if that helps. You could temporarily disconnect one side and test.
 

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Not quite sure what is being said up above... Shocks have a bigger bearing on ride quality than pretty much any other part of the suspension. Springs would be a somewhat-close 2nd.

My suggestion would be a set of Bilstein or KYB shocks... Or if they're within budget, Fox 2.0 shocks would be my top recommendation (get the remote reservoirs if you like going fast on dirt). I have those on my BII and they beat pretty much everything else hands down for ride & handling.
The front shocks will need to be approx 19-20" long (fully extended length), and the rears need to be approx 28-29" to fit a 4" lift (you may need to consult the shock's specification chart to find the lengths, many application sheets typically only give stock-height fitments).

Remove the stacked rear blocks (keep just the OEM block with the bump-stop extension on it), and throw a set of Skyjacker #FR34 leaf springs on it. That should help fix up the rear. Or you could go with #FR36 springs and ditch the block entirely, though the ride might be a bit harsher (higher-arched spring)

For the front, you might consider Skyjacker coil springs pt# 136 since you have a Supercab truck (the bigger cab's heavier weight makes it sit at about 4.5" lift with those coils).

Lastly, I see your steering linkage isn't quite inline with your axle... dropping that down a bit (Skyjacker pt# FA600 drop pitman arm) should help the handling a good bit (reduced bumpsteer), as well as extending the life of your tires.

Nice score for sure. Looks like you got the good Dana35 front axle (which it should also have the BW1354 transfer case). Lots of gear ratio & locker options are available for it if you choose to go down that road. :cool:
It's possible you might even have the M5OD trans as well (I think I saw a stick in one of the pics in your other thread)... best trans Ford ever put in these trucks, and '90 was the only year 4x4 I've ever seen it behind a 2.9L.
 
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Strelok

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Not quite sure what is being said up above... Shocks have a bigger bearing on ride quality than pretty much any other part of the suspension. Springs would be a somewhat-close 2nd.

My suggestion would be a set of Bilstein or KYB shocks... Or if they're within budget, Fox 2.0 shocks would be my top recommendation (get the remote reservoirs if you like going fast on dirt). I have those on my BII and they beat pretty much everything else hands down for ride & handling.
The front shocks will need to be approx 19-20" long (fully extended length), and the rears need to be approx 28-29" to fit a 4" lift (you may need to consult the shock's specification chart to find the lengths, many application sheets typically only give stock-height fitments).

Remove the stacked rear blocks (keep just the OEM block with the bump-stop extension on it), and throw a set of Skyjacker #FR34 leaf springs on it. That should help fix up the rear. Or you could go with #FR36 springs and ditch the block entirely, though the ride might be a bit harsher (higher-arched spring)

For the front, you might consider Skyjacker coil springs pt# 136 since you have a Supercab truck (the bigger cab's heavier weight makes it sit at about 4.5" lift with those coils).

Lastly, I see your steering linkage isn't quite inline with your axle... dropping that down a bit (Skyjacker pt# FA600 drop pitman arm) should help the handling a good bit (reduced bumpsteer), as well as extending the life of your tires.

Nice score for sure. Looks like you got the good Dana35 front axle (which it should also have the BW1354 transfer case). Lots of gear ratio & locker options are available for it if you choose to go down that road. :cool:
It's possible you might even have the M5OD trans as well (I think I saw a stick in one of the pics in your other thread)... best trans Ford ever put in these trucks, and '90 was the only year 4x4 I've ever seen it behind a 2.9L.
I did notice some bump steer on the 12 hour drive home from Seattle.
It is a 5 speed, so unless there was another manual trans option in 1990 that's it.

Thanks for all the part numbers, seems in line with much of the reading I've done so far so it sounds like I'm on the right track.
 

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Looks like a Rough Country lift...stacked blocks and all. I would start by checking the drop bracket for the passenger side front axle beam. The bracket will be on the driver's side - is it two pieces, one of which being a flat plate that drops the bracket down?

If so I would really consider replacing it with an actual drop bracket as opposed to the plate - the plates are notorious for knocking a hole in the front diff when the suspension compresses. I am not sure what part # to use here but someone else may chime in - RC lifts have a few features that were not very well thought out.

You also have the option of simply removing the lift and going back to stock height... or even going so far as to install a better quality lift from another company.

Skyjacker is probably the easiest and best quality lift as far as the "common" brands go unless you want to spend a little more and move up to Duff, Camburg, Solo, etc... although having owned and destroyed a Skyjacker lift and two sets of rear leaf springs now, their quality is definitely not what it should be for the price.

Most of the common brands of TTB lift kits are designed to fit larger tires and that's about all - you gain very little performance offroad from them.
 

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two sets of rear leaf springs now, their quality is definitely not what it should be for the price.
Did they just wear out and sag quickly or what? I just installed a set of FR34 leaves on my truck and this worries me a tad. :dunno:
 

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Not quite sure what is being said up above... Shocks have a bigger bearing on ride quality than pretty much any other part of the suspension. Springs would be a somewhat-close 2nd.
I bow to your experience. I'm still learning. However I still think a swaybar will have an effect on ride handling. The swaybar connects the two axles and the springs/shocks. So if you hit a bump it's not just the one side spring/shock that is hit but the other side too. In the pic it looks like he may have a large bar, perhaps a 1", and that would definitely stiffen up the ride, re; bumps/potholes/cornering. It's also very easy to disconnect and check.
 

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if they're within budget, Fox 2.0 shocks would be my top recommendation (get the remote reservoirs if you like going fast on dirt). I have those on my BII and they beat pretty much everything else hands down for ride & handling.
The front shocks will need to be approx 19-20" long (fully extended length), and the rears need to be approx 28-29" to fit a 4" lift (you may need to consult the shock's specification chart to find the lengths, many application sheets typically only give stock-height fitments).
I'm noticing that Fox doesn't sell the remote reservoir shocks for this truck specifically. Will proper length ones just bolt up or will I have to build a bracket or something?

Also, you recommended the FA600 pitman arm, but that part says it's for 6-8" lifts, the FA400 says it's for 4-6" lifts. Is there a reason for the FA600?
 
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Did they just wear out and sag quickly or what? I just installed a set of FR34 leaves on my truck and this worries me a tad. :dunno:
I would not worry about it a whole lot. The first set lasted about 7 years/maybe 5000 miles? But the driver's side one sagged 1" within a year and over 2" when it came off the truck. I wheeled it a lot though. Leaf springs get bent, it's just the life of a wheeling rig, but I do not feel they're anywhere near as durable as factory or other brands of springs - however they flex real nice.

Skyjacker tech support back in the day was awful too - I called their tech line when I first noticed that one spring was bent and the guy said to swap sides and see if the sag goes away and if it doesn't then I'm just out of luck because I wheeled it.

I put a new set of 6" springs on in 2017. The driver's side still sags about an inch. I don't know why, after measuring I am convinced that the frame is tweaked somehow in the rear. I almost want to put a 1" block on that side but I'm sure that would cause other weird issues.
 

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Leaf springs have been around since, well since we needed suspension, horse and buggy/wagon days.
One of the benefits of multiple leafs is that they slide against each other, they are usually attached in the center then loosely clamped or pinned at the ends so they can slide in and out as needed.
This helped dampen a leaf springs deflection and return, like a shock absorber, the rubbing friction slowed it down in both directions
And why leaf springs were popular choice for automobile industry when it first started.
Draw back for leaf springs in automotive applications is that they need to be stiff because they hold the axles in position.

If a leaf spring sags jack up that side of vehicle so leaf is holding axle weight(tire off the ground), and bang on leaf with a mallet, see if it is stuck, i.e. it slid in but can't slide back out, spray penetrating oil between leafs as you see fit.
Could be leaf is beyond repair but free to try.

I don't think any shock made can overcome an over sprung axle, which is why I think springs come in 1st and shocks 2nd :) when ride quality is poor

Under sprung yes, shocks will definitely help, if it "drives like a boat", then time to get some good shocks
 

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although having owned and destroyed a Skyjacker lift and two sets of rear leaf springs now, their quality is definitely not what it should be for the price.

Most of the common brands of TTB lift kits are designed to fit larger tires and that's about all - you gain very little performance offroad from them.
I agree most of the kits for our trucks are very dated nowadays (and is why I pieced everything together separately for my BII, many components which were not even made for RBVs). The last major revision to Skyjacker's kits I recall was in the mid-'90s, aside from them going from tube-style extended radius arms to boxed-plate ones about 8 (?) years ago. James Duff's Stage-III kit could be considered somewhat more current, but they still have some of the same issues common to most other kits (incomplete/improper steering corrections for example).

The Skyjacker FR34s on my Ranger are over 20 years old now. I've had no issues at all with them (and it's been wheeled a lot too).
Another buddy of mine sports FR36s... He did have one of the the bottom leaves break, BUT he also continued to run them with the overload leafs splayed apart and it broke right where the edge of the OL leaf was grinding into the leaf above it. He replaced them with the same about 10 years ago (now keeping the OL leafs in check) and no more issues.
I also bent an FR34 under my BII, except that I've also bent more than half-dozen other brand & type OE-fitment springs under that thing too, until I finally went to Chevy 63-inchers.

So basically, if they're installed properly and not overloaded to the extreme with big 35"+ tires torquing on them, I think they will work out fine for the OP here.
Short of going to Chevy 63s, I still think they are among the best options available (I have not used Deaver leaf springs though, I know many do regard them highly also).

I was gonna guess that the OP's lift is Pro-Comp since the parts appear to be silver-gray (hasn't been made since the early '90s). IIRC Rough Country has always been black, and I think RC also has a couple "speed holes" on the face of the bracket for the driverside beam.
×2 on the axle bracket. A few guys here, rather than replace it, have simply cut off the offending part of the plate & bracket, then welded the two pieces together to reinforce it. If budget isn't real tight though, I'd say just swap it for something decent.


I bow to your experience. I'm still learning. However I still think a swaybar will have an effect on ride handling. The swaybar connects the two axles and the springs/shocks. So if you hit a bump it's not just the one side spring/shock that is hit but the other side too. In the pic it looks like he may have a large bar, perhaps a 1", and that would definitely stiffen up the ride, re; bumps/potholes/cornering. It's also very easy to disconnect and check.
You're absolutely correct. A stiff swaybar will create a lot of side-side rocking & tossing when one side hits a bump or undulation (this is quite noticeable on SLA IFS trucks with their huge swaybars) I still think overall the shocks & springs come before it though (at least for ride smoothness, if not handling).




I'm noticing that Fox doesn't sell the remote reservoir shocks for this truck specifically. Will proper length ones just bolt up or will I have to build a bracket or something?
You just need to make sure the shocks are the right length and have the correct mounts (stem-upper + eye-lower for front, eye & eye for the rear). You may need to get or make a bracket to mount the reservoirs though, as there isn't enough room up front to have it beside the shock itself.

They also have a number of custom valving options available... If you don't specify, I think they give you 40/60 (though it might be stiffer for stem-type shocks, not sure). I have 30/90 (F) and 30/80 (R) on mine and I've thought of going maybe to 40/90 all around (mainly because, as I eluded to above, I typically carry a lot of weight in the rear of mine). Your Supercab truck should be a bit heavier on the front than my BII, so maybe 45/90 or something like that (rear might be good with 30/70 or 30/80 if you don't haul heavy loads often).

I'll concede I do need to play around with mine some more to get a better feel of the different valving options, but I think the above should still be well within the ballpark. Couldn't hurt to speak with a Fox tech (which is what I did initially) and maybe give them some idea what you want for ride quality.

Also, you recommended the FA600 pitman arm, but that part says it's for 6-8" lifts, the FA400 says it's for 4-6" lifts. Is there a reason for the FA600?
See here:
http://www.therangerstation.com/Magazine/winter2008/steering_tech.htm

Please don't ask me why they are like this, I haven't a damn clue, but virtually every kit made for these trucks since the very beginning comes up two or more inches short on the steering (and almost guaranteed that is why yours is the way it is). It's actually given these suspensions a bad rap for tire wear & handling because of being so common, when it's never been any fault of the suspension itself.




Ron, I do agree with you an extremely stiff spring would make for an awful ride, but they'd have to be pretty dang stiff to make it worse than a crappy set of shocks. I think Fox shocks with Skyjacker springs would work out very well for the OP here. A set of swaybar disconnects can be used also which would make barreling down a rutted road a lot smoother as well (and of course allowing for better articulation too).
 

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I would not worry about it a whole lot. The first set lasted about 7 years/maybe 5000 miles? But the driver's side one sagged 1" within a year and over 2" when it came off the truck. I wheeled it a lot though. Leaf springs get bent, it's just the life of a wheeling rig, but I do not feel they're anywhere near as durable as factory or other brands of springs - however they flex real nice.

Skyjacker tech support back in the day was awful too - I called their tech line when I first noticed that one spring was bent and the guy said to swap sides and see if the sag goes away and if it doesn't then I'm just out of luck because I wheeled it.

I put a new set of 6" springs on in 2017. The driver's side still sags about an inch. I don't know why, after measuring I am convinced that the frame is tweaked somehow in the rear. I almost want to put a 1" block on that side but I'm sure that would cause other weird issues.
Is your fuel tank still on your drivers side? Every Ranger I have seen has a drivers side lean. I did install a BII gas tank between the frame rails on my truck and removed the factory tank, perhaps that'll help even out the weight distribution. I also have an anti wrap bar that should keep the leaves from twisting as much.

I was running explorer leaves before, and the ride was terrible with an empty bed. The Skyjacker leaves have a much softer ride.
 

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