# Replacing Body Bushings



## peahrens (Jun 7, 2010)

Hi everyone. Assuming an upcoming restart goes ok (cam replacement), one goal for this year or next might be getting the body bushings replaced. I skipped this in '92 with the original frame on rebuild, but it's likely the most needed upgrade remaining on the car. The suspension, for instance, is otherwise renewed front & rear. It creaks like metal is hitting metal. I had parts to do it way back, but when trying one of the bolts, it seemed to just turn and I assumed a body nut was broken and turning, so I gave up (may not even have the parts anymore).

Anyway, what are the considerations in getting this done? I doubt I'd attempt it myself. Is a body shop the right place to ask? Can they get to these to do the job...any more required than perhaps removing the seats and carpet to access any bad receiver bolts? Can they jack up the loosed area to get the old part out and the new one in? What's a reasonable charge for this job? Please let me know what you think.


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## BearGFR (Aug 25, 2008)

peahrens said:


> Hi everyone. Assuming an upcoming restart goes ok (cam replacement), one goal for this year or next might be getting the body bushings replaced. I skipped this in '92 with the original frame on rebuild, but it's likely the most needed upgrade remaining on the car. The suspension, for instance, is otherwise renewed front & rear. It creaks like metal is hitting metal. I had parts to do it way back, but when trying one of the bolts, it seemed to just turn and I assumed a body nut was broken and turning, so I gave up (may not even have the parts anymore).
> 
> Anyway, what are the considerations in getting this done? I doubt I'd attempt it myself. Is a body shop the right place to ask? Can they get to these to do the job...any more required than perhaps removing the seats and carpet to access any bad receiver bolts? Can they jack up the loosed area to get the old part out and the new one in? What's a reasonable charge for this job? Please let me know what you think.


It's not as bad as you might think. If you're just replacing bushings all you have to do is remove the old bolts and pick up the body just enough to take the weight off the biscuits so you can get them out. You shouldn't have to worry about having to disconnect anything else, like you would if you were going to completely remove the body. If you've got one that you can't get out because it's stripped or has come loose and just spins, then you might wind up having to cut through from the top side to repair it. Replace all the ones you can first, but leave the bolts loose (just barely started) so you can get some slack to move the body around a little if you need to. Depending on your plans for the car and how you're going to drive it, you might consider using either solid aluminum or polyurethane bushings to firm everything up. The solids of course are going to transmit much more noise, and some have the opinion that they're too rigid for street use. I have no first-hand experience on that.

Bear


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## Eric Animal (Oct 28, 2007)

:agree.....If you aren't up to it, then I would go to your local body shop/resto shop. Like Bear said, it isn't all that bad.


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## 70gtorag (Nov 17, 2010)

I was also wondering the same thing, and I am going to do it myself, but since the front fenders are attached to the front of the body, won't this make it impossible to lift the body? or create a hinge effect and have the door gap close against the fender, thus chipping paint, etc. I think the fenders might need to come off, but I may also be pulling the engine for a new rear main seal, since my body on resto was completed in 1989. I have also missed some things that are going to get done this time around, body bushings being one of them, they have already been ordered from Ames, and are on their way. With the engine out already, it is time for a refresh also. When I get to that point I will have to post on the forum to find out what is the best cam, lifter, spring combo to wake up the stock 400. That is for another time.

I ordered the rubber bushings, since they will make a great improvement over the 40 year old dead bushings in there now. I went back and forth with the decision to go poly, but decided that the body mounts will be greatly improved with just replacing the worn originals, and that it did not require the stiffer poly. I am still debating the poly suspension bushings though. I did do the rear with polyurethanes from Energy Suspension in about 1995, and they squeek backing over larger curbs and shopping mall speed bumps, so a little leery about using them again for the front. I don't know if the poly graphite are any better with 15 more years of technology. The claim to be quiet because they are graphite impregnated.

BearGFR.- Checked out your website of pictures today, Great Work-Great Pictures!


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## BearGFR (Aug 25, 2008)

70gtorag said:


> *1)*I was also wondering the same thing, and I am going to do it myself, but since the front fenders are attached to the front of the body, won't this make it impossible to lift the body? or create a hinge effect and have the door gap close against the fender, thus chipping paint
> 
> *2)*When I get to that point I will have to post on the forum to find out what is the best cam, lifter, spring combo to wake up the stock 400. That is for another time.
> 
> ...


1) It might, if you had to lift it that far - but really it only takes 1/4" or so to get enough room to slide the old bushings out. The body's going to move around more on a bumpy road than you'll need for it to just to change the bushings. Everything from the firewall forward is mounted to something that has some give to it. The only two frame mounting points for all the front sheet metal are top and bottom of the body cowl at one end (so it can't "hinge" at that point) and the radiator core support at the other, and the core support is mounted on flex bushings as well so when you lift the body just a smidge, all that's going to happen is the core support might tilt forward a fraction of a degree. Just go slow, lift it only as far as you have to, and you'll be fine. Loosen all the bolts on both sides. Take all the bolts on one side out at the same time, use a couple of bottle jacks - one underneath the cowl area and the other near the rear - lift up that side just enough to slide all the bushings out and install then new ones (leave the bolts loose). Set it back down then lather, rinse, repeat on the other side, then tighten all the bolts. The whole job ought to take you less than an hour unless you have to deal with a bolt you can't remove.

2) "Best" is relative and all depends on what you want the car to do (how you're going to use it) and your budget. I built my 400 into a 461 stroker and am happy with it. Here's the dyno sheet. Spend your time now thinking about honest answers to those questions: how are you going to use it, and what's your budget?

3) If you're still using all the factory control arms on the rear, that's the main source of your squeaks. With the triangulated control arms and the way they mount, the bushings *have* to deform and flex some as the axle moves through its range of motion, especially in turns. They're going to squeak - even the graphite ones, and the poly just makes it worse because they're stiffer. The real answer is to use fully adjustable upper control arms that have fully articulated/spherical joints at the frame mounting points. That lets everything twist and turn the way it has to as the axle moves without putting anything into a bind. Ditto for the joints on the lowers, at least in "body roll" situations. Take a minute to think about how those lower arms have to move in order to allow the rear axle to rotate such that one wheel is "higher" than the other relative to the body like happens in a sharp turn, and you'll see what I mean. As the rear axle "rotates" relative to the front to rear axis of the car, the control arm bolts on the axle housing "rotate" too and get forced to move so that they're no longer parallel with the bolts on the front ends of the control arms. The only ways that movement can happen is for, 1) for the bushings in both ends of the control arm to deform (and squeak), 2) the control arms themselves have to twist, or 3) "other stuff" starts bending and breaking. Control arms having end joints that can "swivel" allow this motion to happen smoothy with no binding while still postively locking the end of the control arm in the same location, up-and-down, side-to-side, and front-to-rear - which is what they're supposed to do.

Thanks for the kind words on the project. They help keep me motivated. :cheers

Bear


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## grabber (Sep 23, 2009)

The front clip will have to come off, the parking brake disconnected along with the steering column and any exhaust clamps connected to the body. Also gas, brake, and clutch and transmission linkage must be disconnected. I dont know about air conditioning but if its a solid connection that will have to be disconnected as well. Otherwise you risk bending stuff out of shape. Also think about replacing the rag joint in the steering while doing it, its just part cost at that point.


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