Bronco sagging in the rear???

[mgb0302]

Need some help from those of you with a 3.5 inch suspension lift and 2 inch BL 35" tires.

I have recently started to notice that my rig appears to be sagging in the rear. I never paid too much attention as I started adding extra items (i.e. cage, tire carrier) so I am unsure if the sag is a result of the weight or if it is due to old springs (about 15 yr old suspension lift).

Here are some measurements. Please let me know if you have similar measurements.

From the ground to bottom of rear quarter: 23.5 inch
From ground to belt line above rear marker light: 31.5

Also, the space between flares and the front of the rear tire seems pretty small. my fenders are cut 6 inches back from the door jam (measured straight back along the rocker panel line). Judging from some pics I see of other rigs, I may need to cut a bit more. Thoughts.

 

[Mitche11]

I feel like mine is also sagging but don’t know what the easy fix is. Mine seems a little nose high now, and I need to add a tire carrier and probably a little heavier rear bumper. The PO put the suspension and body lift in before my frame off resto, so I don’t know what the initial lift was... I’ll get you some measurements and see how they compare. FYI, an important detail relating to the ground to bottom of quarter and “belt line” dimension is the wheel/tire size.
23.75”

I don’t know where, exactly you’re measuring at the “belt line”... a pic would help.
To the body line below the rear quarter light, mine is as 34” off the ground.
I have 35” tires.

Sent from my iPad using Tapatalk

 

[mgb0302]

Mitchell- good catch! Added tire size.

 

[knack]

I had to add another leaf to the rear springs (went from 10 to 11) to level out my Bronco. Not the same lift or specs as yours, but assuming you have a leaf spring rear suspension adding another leaf may be the answer.

At the same time you're doing that, it's not a big job to move the axle back a bit to center the wheels in the fender openings. Remember to check driveshaft lengths after you do that.

 

[mgb0302]

Knack- thanks. I will soon be doing a full width swap and intend to push the axle back an inch or so.

Who did you buy your add a leaf from. I asked wild horses and they said their add a leaf was only for stock suspensions.

 

[knack]

Mine came from Duff’s. So did the main leaf pack. 2-1/2” lift though. I’m not sure what’s available for yours.

 

[DirtDonk]

A better bet for consistency is to measure between the bottom of the frame rail and the top of the axle tubes. As long as the axles themselves have not been modified, this gives a good starting point for comparing other Broncos.

Stock measurements are generally accepted as being (approximately) 7" at the front and 6" at the rear. Anything over that is your lift, or what's left of a lift.
Anything less than that is sagged below stock height.
Measurements are generally within a 1/2" or so. Even stock was not 100% consistent, so we give ourselves that much leeway.

Tire sizes are not consistent when new. Add tread wear and there is no way to compare.
Body heights are relatively consistent, given a body lift or not, but if the body bushings are compressed, there is another inconsistency.
So the frame-to-axle measurement is the best we've found to use.

But the bottom line is a sag is a sag. If you are sitting low at one end or the other and don't like it, there are several fixes.
New leaf springs, new single leaf, re-arch, spacer block, etc.
Each one has it's advantages and disadvantages.

But let's see where you're sitting and go from there. It certainly could be at least partly to do with the extra weight, partly due to age, and partly due to the finickiness of individual springs.

Heck, if you like the height overall in the rear, and everything else is good, a simple fix is to drop the front with a new pair of coils! Not expensive or hard to install, and might do the trick.
Assuming you don't mind dropping the front an inch or so. But it also might depend on just how much your rear is down.

Good luck.

Paul

 

[mgb0302]

Dirtdonk- Paul. Holy cow!!! If you are correct about the measurement between the frame and axle is supposed to be ~7 inches, I am waaay sagging! I just measured 6.5 and that is with a 3.5 inch lift.

 

[DirtDonk]

Yikes! Are you sure it's got a lift?;D
If that's the rear though, you're still a half-inch above stock-ish (the rear is only 6" for stock) but yeah, that would sure look sagged from any angle.
Or was that the front? If the front, and the rear is lower still, then it's definitely time for some updating to your suspension.

How was the rear lifted? Spring only, or block, or add-a-leaf? Or a combination?
What type of springs?

Anyway, now you have something to mess with for the coming warm weather. And something to look forward to in the new stance your Bronco will have.

Paul

 

[mgb0302]

Paul,

The measurement I gave was the rear. I am positive it has a lift; I installed it (unless I was dreaming - HaHa). It was the Duff Ultimate suspension. 10 pack leafs - no blocks.

So now my fear is if I install new springs, the Bronco won't fit in my garage with 7' doors!!! Guess I need to buy new springs and a new house!!! Ha

 

[aaronnandi]

Paul, love the info you gave up higher in the thread. I used it to measure my bronco's lift because it's sagging a little on the rear drivers side. I measured the following:

Passenger rear- 8"
Passenger front- 7"
Driver rear- 7"
Driver front- 6.5"

I could "guess" from those measurements that at one point, someone added something to get a 2.5" lift. But how do you really know? I want to get new leaf springs in the back and coils up front, and it sounds like a 2.5" lift would get it back to where it should be, but that's a lot of money to spend on a guess at how high I need to make it.

Is there anything else I can look at? My leaf springs look like stock springs (although I doubt they are, based on my measurements) and I don't see any added leafs and I don't see any blocks. I can't imagine measuring the coils when they're compressed and probably sagging is a good indicator of a lift. Anything else that will make it a more educated guess?

 

[DirtDonk]

Either upload some pics to your "garage" or send some to me at paulb@wildhorses4x4.com and I can load them right to this discussion.
Some shots of the front coils (especially at the top) and an overall of the rear leaf packs should do it for now.

It is hard to tell sometimes of course, because your measurements are close enough to stock to still be stock. If one corner dips, it also will usually raise the opposite corner. The radius arms act like torsion bars mounted along the frame rail and will transmit much input along the way.

But certain clues, such as progressively wound coils are a giveaway that they are aftermarket replacements. The originals were always linear (same gap between most coils) where some aftermarkets have three or four tightly wound coils near the top.
Leaf springs are relatively easy (though not guaranteed) to see if they are four, five, or six-leaf designs, and might have an add-a-leaf or spacer block or something that's not original.
Even a reversed shackle can be a giveaway that someone has at least had the rear springs off at one point.

Let you know more when we can see what you've got.

Paul

 

[rguest3]

You stated New Cage and Rear Tire Carrier. Do you have a Hard Top too, no Top or Soft Top?

I would assume the 15 year old rear leaf springs might be the culprit.

 

[hyghlndr]

I have used a small 1 inch lift block with the 1 inch back for the axle. Nice for fine tuning and if not new rear Duff leaf springs.

 

[DirtDonk]

I've got 1" blocks in both of mine. Now that the front of the '68 has settled down a bit with the big bumper and winch, I need to take them out.

Paul

 

[DirtDonk]

Try to re-send the pics. Can't open them for some reason.
They show to be in an .heic format, which I've never seen before.

And apparently, neither has my computer!%)

Paul

 

[904Bronco]

I've got 1" blocks in both of mine. Now that the front of the '68 has settled down a bit with the big bumper and winch, I need to take them out.

Paul

Sorry to hear your Fronts is a sagging.... ;D

 

[DirtDonk]

Sagging? Never!
They're just "settling in" naturally. As I like to say...

And while they may not, it's possible they could spring right back up, or part of the way up, if I removed the winch and bumper.
Lot of work to experiment, but it would be cool to know.

Paul

 

[DirtDonk]

Notice how I steered the conversation away from you old-folks joke? And right back into Bronco-tech?
With age comes experience. And sore knees...

Paul

 

[904Bronco]

Notice how I steered the conversation away from you old-folks joke? And right back into Bronco-tech?
With age comes experience. And sore knees...

Paul

Annnd Naps...