I ordered some ES polyurethane body bushings today, for my chevelle. I'll be replacing them without taking the body completely off the frame. It will help some that the car is up on jackstands with no suspension or driveline parts under it, but I'm still worried.

There's very little rust under the car, I don't think the old bolts are corroded too bad... but any advice other than soaking them well with WD40 before attempting the removal? I'd rather not have to strip the interior out of the car to try and get to a broken off bolt, and I've heard horror stories about this job.

thanks,
Brian

WEll, first of all, I'd leave the WD40 on the shelf. Reach for the PB blaster. If you are going to do this job friday and today is tuesday, go blast it once in the morning and once in the evening everyday until you do it. The PB blaster devours rust and gunk. Also you only need about 1-2 inches of clearance to get the mounts out if you jack the body up. PB blaster hopefully will loosen the bolts up enough so that you do not snap the cage nut off and have to cut your floor pans so you can get a wrench on that nut.

Originally posted by YenkoChevelle69:
WEll, first of all, I'd leave the WD40 on the shelf. Reach for the PB blaster. If you are going to do this job friday and today is tuesday, go blast it once in the morning and once in the evening everyday until you do it. The PB blaster devours rust and gunk. Also you only need about 1-2 inches of clearance to get the mounts out if you jack the body up. PB blaster hopefully will loosen the bolts up enough so that you do not snap the cage nut off and have to cut your floor pans so you can get a wrench on that nut. What is PB blaster? :confused:

Applying heat is a must. If you don't have access to a torch then the next best thing is a bottle of hand held "mapp" gas with the trigger handle. Wal-Mart used to sell the small tank and ignitor as a set.
Heat the head of the bolt for a couple minutes then hit it with a impact wrench. If the bolt starts to come out slowly then run it back in, then out repeating this until it moves freely from the square nut.
I've used the mapp gas in the salvage yards when hunting parts; and it's been a life saver.

Dave

Unless ES has redesigned their poly body bushing kit, I would return them and buy a set of stock replacements from a resto supplier. Tried to make them work on my 70 and got nowhere (and I am a decent fabricator). Do a search or email me for more details.

I was blessed with a California car and the bolts came right out. I was amazed at how soft the factory body mounts were!! With the ES kit you will have to reuse the original hardware, i.e. sleeves. In the instructions they say to use the bushings # 4042 & 4045 in positions 3,5,7. I believe the correct ones to use are bushings # 4044 & 4041, as the holes are a little wider to accept the stock metal sleeves. I failed to notice the extra set of bushings containing the 4044,4041, and ended up using a dremel tool and a sanding wheel to make the bushings accept the sleeve. It ended up working, and now I have a few extra bushings for a later date! Be sure to apply the poly lube as it will help longevity and prevent squeaks. Hope this helps!

Does the ES kit come with new bolts? Jegs called me and said the ES body mount kit was backordered. From what I'm hearing, sounds like I may want to just cancel it, and order a set of stock bushings from OPG, which come with new hardware as well. I'd prefer the poly body mounts, but not if they don't fit right.

kidwell, I would think that heating the bolt would expand the metal and make it tighter in the nut?? Or do you let it cool off again before trying to turn it? I could see how heating and cooling it could help break it loose.

ES kit = no new bolts. I purchased the kit for my entire car and it came with bolts for the endlinks. Other than the vague instructions on which bushings to use where I pointed out, the installation was easy for me and only took about 2 hours. The hardest ones to change for me were the body bushings at the cowl. Now rusted hardware could also make the job a lot harder and more interesting. Good Luck!

Are they a 'standard' size bolt, so that I could go to the hardware store and get some grade 8 bolts to replace them?

I think it wouldn't be a problem finding GRade 8 hardware at the store, but there is a little difference in the bolts but I don't know why. The body bolts come to a point at the end of the threads. The only thing I can think of is that it would make it easier to find the hole with the bolts, but there might be a reason. Maybe wait a few and see if someone els knows. I think the ES kit has such minor problems with it, I would do it again. I took the stock bushings out and they were liked sponges!

Oh yeah, when you are lifting the body don't open any doors and watch the door gaps. I chipped my brand new paint like an idiot.

The stock bolts are pointed, but as mentioned, it is possible to use regular bolts (just a little harder to get lined up).

I bought a kit from Muscle Factory, and it came with non-pointed (regular) bolts, and I didn't have a big problem. I did have problems getting one bolt in, but just re-used an old bolt that was in good shape. I could have probably swithced the old one for the new one after I got all the rest torqued, but my old bolts weren't too bad.

I am thinking about getting some polys for mine. When going over small road irregularities, the car feels kind of shakey. I think the polys might firm things up (already have poly suspension bushings).

I don't know if the 68-72s are any different, but the 64-67 bushings are all the same except for the ones under the middle of the door. They have a smaller counter-sunk hole in the frame to receive the bushing "step". I ended up having to shave a little off of them to get them to fit down in the hole in frame. I just put a bolt through them and chuck'd them in a drill, then spun them and reduced the step diameter (like in a lathe). I am not sure if that was the same modification everyone else is talking about.

Originally posted by 69boo307:
Does the ES kit come with new bolts? Jegs called me and said the ES body mount kit was backordered. From what I'm hearing, sounds like I may want to just cancel it, and order a set of stock bushings from OPG, which come with new hardware as well. I'd prefer the poly body mounts, but not if they don't fit right.

kidwell, I would think that heating the bolt would expand the metal and make it tighter in the nut?? Or do you let it cool off again before trying to turn it? I could see how heating and cooling it could help break it loose. Try it both ways and let me know which is the best. Maybe I've been wasting a lot of mapp gas.

Dave.

I'm sure if it's been proven in practice to work, then it works...but I was just trying to figure out HOW it works smile.gif

Make sure you have enough stretch in your brake lines when you jack the car up. If you have installed stainless or a new barake line without a coil, then there may not be enough stretch. Also the emergency brake cable may have to be disconnected from the frame. (this I am not sure of, mine wasn't there when I installed my body mounts. Yes you can go to the hardware store and replace the bolts with a grade 8 bolt, however there are two different length bolts. The long bolts position 8 and 2 pass right through, while 7, 6 and 4 will hit sheet metal if the long bolts are installed. (I am not totally sure of the numbers, I don't have my book in front of me.) Proper torque is 20 ft. lbs.

I won't have to worry about the lines, everything, and I mean EVERYTHINg, is torn out from under the car already smile.gif . I'm replacing all the lines, but havn't done so yet.

This thread is very helpful, i feel better prepared to do this now.

Just to chime in on the proper torque.....

I have both a 68 and a 72 factory assembly manual, and both call out 30-45 lbs ft torque; residual torque after roll test (meaning, drive it for a little while :D ) should be minimum of 25 lbs ft.

The "Prothane" urethane bushings I purchased state to use the factory torque specs.

Crankshaft