Box Panther Converging 4 Link: What I did.

[massacre]

Double post

[Alice87]

The bushings through the upper ear of the axle is not the same as on a Mustang? hm, I'd have expected all 8.8 rears to use the same bushings up there.

You would think so right? However the mustangs have I believe an OD of 1.79” whereas our panthers (‘79-‘97) have an OD of 2.08":

that’s correct. Not the same. I ran into that issue when I was trying to install some spherical upper axle bushings marketed for mustangs.

Dang, those aren't cheap either. The panthers being larger would be a good thing if aftermarkets made a set, as it would allow for more articulation in comparison to the smaller mustang ones. If anyone knows of a place that makes a set of appropriate size bearings let me know… I’ll put my money on them. They would definitely transmit more gear noise into the cabin, but the lack of deflection while having full articulation is worth it to me.

Glad to see y'all got a kick out of this.

-Kyle

[gadget73]

There is a way to fix that. Just need to make a reducer bushing to press into the Panther axle ear that will reduce it down to Fox size bushings. its a little over 1/4" difference, so better than 1/8" wall thickness.

kind of makes me wonder what the ID is of the steel sleeve on the bushing in the axle. I suppose it would be entirely too convenient if the part currently pressed int the axle is exactly the item required, just have to cook out the rubber and push a Fox bushing into the old shell. Not a chance its that easy.

still amazes me they didn't cast that center section with bushing holes the same diameter for all applications that use this style of suspension.

[massacre]

There is a way to fix that. Just need to make a reducer bushing to press into the Panther axle ear that will reduce it down to Fox size bushings. its a little over 1/4" difference, so better than 1/8" wall thickness.

kind of makes me wonder what the ID is of the steel sleeve on the bushing in the axle. I suppose it would be entirely too convenient if the part currently pressed int the axle is exactly the item required, just have to cook out the rubber and push a Fox bushing into the old shell. Not a chance its that easy.

still amazes me they didn't cast that center section with bushing holes the same diameter for all applications that use this style of suspension.

Completely agree. I mistakenly recommended the Mustang spherical bushings on here and was completely gobsmacked that they weren't the same.

[Arquemann]

Anything to mention about rubber / poly bushes or such, regarding the arms? I remember you wanting to buy and mentioning about trying to find suitable arms with bushings?
Heims and solid mounts aren't my cup of tea, but considering stock replacement rear bushes and arms are all NLA, knowing all the measurements would help sourcing cross-referenced rubber bushings.
You didn't find any stock replacement / aftermarket control arms that'd match a box?

[kishy]

This is a brilliant thread, thank you for posting it, and continuing your quest to make these cars better.

Something I picked up in here about the way the handling improves has me wondering: does the use of heims in place of bushings do anything to fix the lateral axle hop that these cars will do over a sudden jarring bump (e.g. railway track with rails that poke up pretty high)? I've found that fresh new moderately stiff shocks will make it go away, but if there's another way to make it go away as well, I'm definitely interested in trying it. I'm not sure how much of it is the tires literally hopping vs the axle twisting in its bushings.

[Alice87]

Anything to mention about rubber / poly bushes or such, regarding the arms? I remember you wanting to buy and mentioning about trying to find suitable arms with bushings?
Heims and solid mounts aren't my cup of tea, but considering stock replacement rear bushes and arms are all NLA, knowing all the measurements would help sourcing cross-referenced rubber bushings.
You didn't find any stock replacement / aftermarket control arms that'd match a box?

Unfortunately as of yet I've found no bushings that will press into factory arms. Only Option for factory arms are:

NOS FB 414 rubber bushings
Energy Suspension 4.3151G kit (works on 79-97)

Closest I could find for aftermarket control arms were for a g-body... they are too short though. Contacted a few other places, both are not making them anymore.

Another option would be to run tubular control arms but with 3/4in -16 threaded rubber cylindrical bushing ends like these (Howe 38120R & 38120L):
https://www.summitracing.com/parts/hre-38120r
https://www.summitracing.com/parts/hre-38120l

They have the appropriate width (2.40") to fit the box panther mounts and will thread right on to the tubes I mentioned earlier. Also I noticed Jegs sells their own threaded tubes cheaper btw.

[Alice87]

This is a brilliant thread, thank you for posting it, and continuing your quest to make these cars better.

Something I picked up in here about the way the handling improves has me wondering: does the use of heims in place of bushings do anything to fix the lateral axle hop that these cars will do over a sudden jarring bump (e.g. railway track with rails that poke up pretty high)? I've found that fresh new moderately stiff shocks will make it go away, but if there's another way to make it go away as well, I'm definitely interested in trying it. I'm not sure how much of it is the tires literally hopping vs the axle twisting in its bushings.

It helps, but IMO stiffer springs/proper valved shocks are what will really help out there. Even with the Bilsteins, I think I could use some rebound adjustment for sure... Wish they sold Koni sports for the panthers. Best thing would be custom valved shocks with remote reservoirs... but those get expensive.

-Kyle

[Alice87]

There is a way to fix that. Just need to make a reducer bushing to press into the Panther axle ear that will reduce it down to Fox size bushings. its a little over 1/4" difference, so better than 1/8" wall thickness.

kind of makes me wonder what the ID is of the steel sleeve on the bushing in the axle. I suppose it would be entirely too convenient if the part currently pressed int the axle is exactly the item required, just have to cook out the rubber and push a Fox bushing into the old shell. Not a chance its that easy.

still amazes me they didn't cast that center section with bushing holes the same diameter for all applications that use this style of suspension.

I might look into doing this, its a good idea for sure. Just so were on the same page: I'm thinking a sleeve would have to be machined, then the sleeve would have to be pressed onto the aftermarket bearing housing (BMR-BK075 for example). Once the sleeve & housing are put together, press the whole assembly into the axle housing. At least that's what makes sense in my head.

When I burn out some old rubber bushings to install ES urethane, I'll measure the OE sleeve thickness. Like you, I doubt it will be that easy to use the OE sleeve... but you never know.

-Kyle

[gadget73]

Yep, machine a reducer bushing, press it into the Panther axle, now the hole matches the available bushings. Possibly have to do a flanged bushing so it doesn't end up getting pushed out when the new smaller bushing pushes in but thats not a big issue. Just have to watch that the flange doesn't push the bushing put a little and cause it to be off-center. Worst case, no flange and use some Loctite to secure it.

Some quick looking around at available materials makes me think a bit of 2" schedule 160 pipe would get it done. Its smaller on the ID and larger on the OD but not by obscene amounts.

[Alice87]

Ok, thanks for confirming. Makes sense, and it should work.

First, I’ll order some cheap mustang bushings so I can confirm the 1.79” OD measurement (should match the bearings housing OD regardless if it is a rubber press in I assume). From what I wrote down 1.79” OD is the correct measurement based off my research.

From there I will order some bearings, probably BMR but I'll research what brand is the better of them all. Once I get all the parts here at the shop, I'll experiment around... Hoping I can make it work, basically like how you outlined.

that’s correct. Not the same. I ran into that issue when I was trying to install some spherical upper axle bushings marketed for mustangs.

I'm curious, do you still have that set you mentioned? If so, can you put a dial indicator on them and post the measurement please?

-Kyle

[gadget73]

yeah it should be a fairly simple lathe job to knock out a couple of reducer bushings. Even with a press fit I might use some red loctite just to be sure.

[87gtVIC]

I'm curious, do you still have that set you mentioned? If so, can you put a dial indicator on them and post the measurement please?

-Kyle

it’s been years since I had eyes on them. I gave them to my pops as he has an1985 mustang gt. He hasn’t installed them and I honestly have no idea where they are.

one thing worth mentioning is that they are held in place like a nut and bolt iirc. Don’t know how that alters anyone’s thinking surrounding pressing in reducing bushings etc but wanted to mention it.

[massacre]

The spherical bushings i installed in my Fox were a design like this- they are threaded and have a large nut on one side. The link is for S197 bushing (which i am also running on my Mustang) which is a different bushing but same mounting design

https://www.steeda.com/steeda-mustan...-555-4104.html

[Arquemann]

For the sake of easier information seeking, I'll copy this here.

Exact measurements of both poly aftermarket bushings & original rubbers based off my ‘87 wagon are as follows:

Original Ford rubber with factory sleeve are:
2.37" width, OD 2.08” small end & 2.11” big end (corrected)

Polyurethane inserts (no sleeve) are:
2.44” width, OD 1.98” small end & 2.01” big end (kit 4.3151G works with box panthers).

G-Body’s don't work. They have correct width but wrong OD (1.87” small end 1.91” big end).

Also now that I got the factory arms out; their exact lengths are:
Lower: 20.5” bolt center to center
Upper: 12” bolt center to center

I did quite a bit of digging, cross-referencing and stuff, and it seems like the fact that the bushings have a step-down with different diameter ends is a "large" issue in finding suitable replacements from something else.
For example:

Nissan 55045-V7000 (supercedes V0102) - it's almost a correct fit, width 60mm (2.36"), inner sleeve ID close enough at 14mm and the outer diameter is 54.5mm, slightly larger than both factory sizes. But the width of the outer sleeve is only 45mmm which might be too short or very close to it. This bushing happens to be an actual control arm bushing, but it is for a Y30 Cedric, so availability isn't the best.

FEBI Bilstein 36460 is much easier available, VW part. Front control arm bushing so use fits. On it the outer diameter is 53mm, so it would need a sleeve to fit in a box arm. Other dimensions are alright aswell, except the outer sleeve width, again. No measurement is given, but by eye it looks rather short.

There's also FEBI Bilstein 36459, which shares the same OD and ID, but is 84mm wide, which is definitely too wide for the bushing pockets in a box. But the outer sleeve would definitely be long enough and the bushing looks like it could be shortened relatively easily.

I do not like the fact that there's seemingly no replacement rear control arm bushings available. Seems like the only way to retain the comfort of rubber bushes is to make your own control arms with the threaded rod ends with bushing like what Alice87 linked above. OR find aftermarket (adjustable) control arms that fit the measurements, overall length, bushing width and bolt size. And with both those options, you're ditching the possibility of installing a factory sway bar.

I like my land yachts comfy and sporty cars sporty, I don't mix those. I might be biased.