Dropping Sub-frame, complete poly-bushing install

[Ravenous]

The time has come for me to get new tires (Potenza 960 pole position All Seasons) and due to some previous work I will need an alignment to get the most life out of my tires. I also happen to be sitting on a full set of Energy Suspension Poly-bushings. In order to not have to have my car (1990 GSX) re-aligned in the next few months I want to install the full set before I get the new tires.

The biggest question is: Can I drop my subframe completely without removing the engine and transmission. Would the side transmission and engine mounts be strong enough to hold the drivetrain assembly by themselves? I want to replace the inner and outer tie rods anyway so I was going to pull the rack which would make dropping the subframe easier. I also read somewhere that I can just lower the subframe and drill holes in the bushings and pry them out without removing the subframe completely, has anybody done this?

Any other advice from others who have done this would be appreciated? I have read the suspension vfaq's in the Suspension section so have a pretty good idea of what to do.

 

[DSM Jeff]

You can pull the subframe with the engine in. I have my car up on stands at the moment with the rear subframe out and the front subframe lowered (I pulled the fuel and brake lines) I'd say clean your steering rack joint off and paint a line so when you reassemble you have a reference to line up with. Then pull your strut bolts, and calipers (hang them on the springs with wire). Remove the through bolt for the rear engine mount and your subframe mounts.
To get the bushings out, I just torch them. (but remove your rack first.) I leave the bushings on fire for a couple minutes. The sleeve will most likely fall out on its own or you can push it with a long screw driver. Let them burn some more then you can use a long screw driver or pry bar to actually peal the rubber away from the inner shell. (the rubber bushing is bonded to the shell in which its in. Heating/burning them releases it, do this outside of course!) Keep some water near by, and put out each burning bushing. Then let the subframe cool, clean up with a wire brush. Maybe paint the subframe. Put in your bushings.

 

[Ravenous]

Thanks so much for the info. I was going to just do the control arms and sway bars, but if I can get away with not dropping the subframe completely that is the way I'll go. That is a good mini-walkthrough, thanks again.

 

[DSM Jeff]

Thanks so much for the info. I was going to just do the control arms and sway bars, but if I can get away with not dropping the subframe completely that is the way I'll go. That is a good mini-walkthrough, thanks again.

Just make sure you have the car solid on jack stands, if its just the front, use wheel blocks. If anything I'd put stands on the front cross member and on the pinch welds. Also I forgot to mention you need to remove the 2 bars going front to back to drop the frame, but I'm sure you'd realize that.

Also side note, if you buy a 2nd subframe kit, the smaller bushings can be used in that front crossmember. Mine were totally shot.

 

[Ravenous]

Alright, I started doing this on Monday night and am in the process of putting it all back together. I've learned a few things that I think may help others.

Burning Bushings: I burned out every bushing that was pressed in and it was very easy. Some people let the bushing burn out and that is fine but it makes a lot of foul smoke and can take a long time (My rear motor mount burned for over 30 minutes). If you use a handheld propane or MAPP gas torch you can just heat up the middle insert and tap it out rather quickly. Hold the flame approx 2 inches from the metal insert and wait for the rubber around the insert to bloom(looks like it is flowing from the outside of the insert) after it has bloomed for about 10 seconds hit it with a hammer or in my case an air chisel and it will shoot out the other side. Then a screwdriver will pry the rest out and in my case all the bushings came out clean. On the motor mount bushings I used a large toothed hacksaw blade to cut a wedge out of the rubber from the inside to the metal insert and then switched to a medium toothed blade to cut through the insert, once I was all the way through the insert I used the air chisel to knock the metal ring towards the center of the bushing and once it broke free from the mount just knocked it out with a hammer.

Re-installing the Subframe: I completely removed the subframe from the car as I didn't like the idea of burning the bushings out while it was in the car. It was actually fairly simple to remove and one person can take it out. I am sure one person can put it back in to, however I had my girlfriend help me since I also installed the urethane rear motor mount insert at the same time and it takes some force to push the subframe and the insert into the mount bracket. I followed the article in the tech section and tied a rope to the rear motor mount and had my girlfriend pull it up while I lifted from the bottom. With the Prothane motor mount it is a trick since it is slightly over sized and had to be wedged in place. I would recommend either installing the mount in the bracket first and then align the subframe to bolt up to it or do what I did and use a jack to lift the subframe into place. After I got the subframe bolted up the center bolt in the motor mount slid in perfect... I'm just not that lucky usually.

Takes Two: I would definitely recommend having 1 other person on hand as it makes things a lot easier. Lining up the subframe and also re-installing the steering rack as I removed it and installed it 3 times before getting help because I couldn't install it and make sure the steering wheel stayed straight at the same time. Could these be done by one person, absolutely but why not use the helping hands if they are available.

Herbal Essences and Nitrile Gloves : I came in each evening looking like I had been bathing in oil. You can only wash with orange pumice soap so many times before you feel like you are rubbing through your skin. A washcloth and herbal essences (drama clean for me supposed to remove build-up and excess oil from hair so why not?) got off the oil and grime that the orange pumice stuff couldn't. I always try to use those blue nitrile gloves when I work on my car they keep your hands relatively clean and are way more durable than the white rubber ones. They were $4.44 at Wal-mart for 30 of them, I used to be able to get 100 for $6-$7 but can't find that size at Wal-mart anymore.

 

[DSM Jeff]

Glad ya got things done.

 

[Byrd]

I really appreciate the write-up!

How does she feel?! Any pics? How long should I expect this to take going your route?

 

[Ravenous]

I've got everything installed except the front sway bar. Of all things to get hung up on, this should of been the easiest. I managed to bung up the threads pretty good on the subframe so I will need to chase them to see if I can clean them up good enough to get the bolt through. I don't see why somebody couldn't do this in a weekend. I've done almost all of it with just a few hang ups after work this week about 3 hours a day. So 15 hours total I'm thinking. If you keep moving it all actually goes pretty quick (relatively speaking) I will let you know how they feel once I get this sway bar thing figured out. Hopefully tonight!

 

[Byrd]

When I did my front sway bar we had to shave down the bushings and use a longer bolt to be able to start the threads and pull the rest of the metal over the bushing. It sucks cause it's pretty tight quarters but if you have the subframe off I'd think it should be pretty easy.

 

[Ravenous]

I had the sub-frame off of course, but after fighting with my rack to make sure the steering wheel was straight on with the hubs I'm not going to take it off again :shakes fist:. I actually ended up making a tool with a piece of threaded rod with a perpendicular slit cut in the end and an adjustable foot off a bed frame that allowed me to press the bracket all the way down but I had already bunged up the threads by then. The tool rests against the opposite side of the sub-frame and the slit goes on one of the edges of the bushing bracket, the bed frame foot already had an hex adjust at the bottom so I just wrenched on it till it expanded and pushed the bracket down. I don't know why I didn't expand the hole or use a longer bolt, I guess I didn't want to sacrifice any little bit of performance or I'm just stubborn.

I also installed new inner and outer tie-rod ends along with the full bushing kit and motor mount kits. My motor mounts didn't have inserts at all, they were all full bushings with the front one being solid. I was able to press it through with my bench vise. Just thought it was interesting as I was expecting inserts. I really dig the motor mounts, yes they vibrate but I feel much more in tune with my car now.

 

[DSM Jeff]

I definatly use longer bolts when ever putting poly swaybar bushings in. They are always a nightmare.

 

[Ravenous]

I got those little bastards in I feel victorious. I got home from work today and my girlfriend left me a new creeper in the garage. She is the best! No more scraping my back across the ground.