Core support bushing replacement

[Littlebeefy]

Hi guys and gals,

I'm trying to replace my core support bushings, but I'm finding it to be more complicated than I thought. I originally bought the rubber replacements from JBG but they don't fit. The mounts on my frame have an oval opening instead hexagonal so those won't fit. I got a set of the Energy Suspension bushings, and they fit the mount, but the whole in the middle of the bushing is way bigger than the bolt and there is no metal sleeve supplied or available for the inside of the bushing. Am I supposed to install it like that or do I need to find a sleeve? Alternatively, the Prothane mounts are mentioned in the documentation section. They seem like they are identical to the Energy Suspension version but I can't tell from the picture. Is it the same situation with the Prothane mounts as well? If so, what have people done in the past when using these? Do you source a sleeve or just let the bolt float?

Thanks,

Chad

[Gary Lewis]

Chad - I'm surprised that the hole is that much bigger. Looking at the documentation I don't see any bushing used. Can you show us some pics?

[Littlebeefy]

Chad - I'm surprised that the hole is that much bigger. Looking at the documentation I don't see any bushing used. Can you show us some pics?

Hi, Gary. Great to hear from you again. Here is a picture of the one JBG sells with the hexagon that doesn't fit my mount (shown side by side):

Here is the Energy Suspension Poly bushing. The bushing fits perfectly inside the mount, but you can see that the hole for the mounting bolt is much wider than the bolt is (sorry, I didn't take exact measurements yet):

This is part number 4.4109 and includes all of the bushings for a Bronco (it's what they sell on JBG). They sell a hardware kit for this set (DHW011), but even though that set has sleeves for the rest of the body bushings, it does not have sleeves for the core support bushings. I ordered a set of the Prothane bushings, like you mentioned on your documentation page on the subject, but I fear they will have the same dimensions because they seem to be virtually identical and manufactured by the same company.

Should I source a sleeve based on measurements or should I assume that it was meant to be installed without a sleeve?

 

[salans7]

Hi, Gary. Great to hear from you again. Here is a picture of the one JBG sells with the hexagon that doesn't fit my mount (shown side by side):

Here is the Energy Suspension Poly bushing. The bushing fits perfectly inside the mount, but you can see that the hole for the mounting bolt is much wider than the bolt is (sorry, I didn't take exact measurements yet):

This is part number 4.4109 and includes all of the bushings for a Bronco (it's what they sell on JBG). They sell a hardware kit for this set (DHW011), but even though that set has sleeves for the rest of the body bushings, it does not have sleeves for the core support bushings. I ordered a set of the Prothane bushings, like you mentioned on your documentation page on the subject, but I fear they will have the same dimensions because they seem to be virtually identical and manufactured by the same company.

Should I source a sleeve based on measurements or should I assume that it was meant to be installed without a sleeve?

Wow, I have never seen a core support mount in that shape. Everything I've torn apart has the hexagon shape.

[Littlebeefy]

Wow, I have never seen a core support mount in that shape. Everything I've torn apart has the hexagon shape.

Shaun,

I don't know how common they are but I have to assume they aren't that rare. The reason why I jump to this conclusion is that the poly mounts for the 1980-96 Bronco fit inside the narrower oval opening; if they were intended only for the hexagon hole, they would be wider, since the flats on the hexagon are wider than the flats on the oval.

I prefer the poly mounts to the rubber ones, so I'm not concerned about the size or shape of the hole in the mount since the poly ones fit. What I am concerned about is how much wider the hole through the poly bushing is than the bolt used to mount the core support. Anybody using the poly bushings on the core would have seen that putting the bolt through the bushing is like tossing a sausage down a hallway. I don't see a sleeve in the illustration either, but given these are aftermarket, that OEM picture isn't as reliable.

 

[Gary Lewis]

Wow, I have never seen a core support mount in that shape. Everything I've torn apart has the hexagon shape.

I'm with Shaun. I've never seen a hole shaped like that on the radiator support brackets.

But to answer your question, I think you need a bushing. Or bushings since you don't want the bushing to go all the way through as the force from the bolt is supposed to clamp the two halves together.

Maybe call Energy Suspensions?

[mat in tn]

I'm with Shaun. I've never seen a hole shaped like that on the radiator support brackets.

But to answer your question, I think you need a bushing. Or bushings since you don't want the bushing to go all the way through as the force from the bolt is supposed to clamp the two halves together.

Maybe call Energy Suspensions?

Ok . Ill bite ! How are the core supports held to the frame?

I ask think wondering if they may have been replaced. And if so were they possibly from a different vehicle. I too have only seen hex holes on these. Even the repair plates that jbg sells to weld on are hex only.

[Rembrant]

Ok . Ill bite ! How are the core supports held to the frame?

I ask think wondering if they may have been replaced. And if so were they possibly from a different vehicle. I too have only seen hex holes on these. Even the repair plates that jbg sells to weld on are hex only.

Looks like somebody else found those brackets on a Bullnose Bronco before, and factory installed too (riveted on). So weird.

https://www.fullsizebronco.com/threads/radiator-core-support-and-body-bushings.183411/

 

[mat in tn]

Looks like somebody else found those brackets on a Bullnose Bronco before, and factory installed too (riveted on). So weird.

https://www.fullsizebronco.com/threads/radiator-core-support-and-body-bushings.183411/

Now that is kinda what i was thinking. I recently finished a custom bronco 2. One of the things that i found doing it was that the rear body bushings were oval where they went through the frame. Not exactly the same oval shape but enough that it gave me the idea of them being from someghing else. A factory anomaly maybe??? Haha

[Gary Lewis]

Now that is kinda what i was thinking. I recently finished a custom bronco 2. One of the things that i found doing it was that the rear body bushings were oval where they went through the frame. Not exactly the same oval shape but enough that it gave me the idea of them being from someghing else. A factory anomaly maybe??? Haha

This is strange. First, below is the illustration from the MPC on how it goes together - with an annotation or two from me.

But note that the bracket is 5A041. So I looked that part up and that's where the strangeness started. Note that the Bronco (U150) is listed three different way - 80; 86/on; and 81/85. Weird! But they all took the same part - E0TZ 5A041-A, which is the same as the F-Series trucks. But it was replaced by F2TZ. But they couldn't have been built with that part as it didn't come out until 1992.

So I'm completely at a loss as to why some of the brackets have an oval slot.