I need to replace my 36 + years subframe bushings and upper and lower A frame bushings. Can this be done really by yourself or do you need a shop to do them? I took my 68 bird to a body shop and they quoted me $2500.00 for this. OUCH! Should I attempt this myself? The subframe bushing and upper control arm seem do able?. Can anyone offer me some advise, tips, etc on how to do or not do this. I would really appreciate it. Thanks!

sammypoodle,

Can't say for sure about doing the control arm bushings. It does require disassembling almost all the suspension and pressing in new bushings. You might as well rebuild it while you're at it. I hope that price included all the parts as well. Some people quote high when they don't want the job.

As for the body mounts, see your previous post:
"68 Firebird noise - Please help"
I gave detailed instructions how to do this. If you follow them, it should be a one day job with basic tools. Of course if you don't heed my warning about using the penetrating oil many times and well in advance, and you just use brute force you'll screw yourself pretty bad.

If you're near Detroit I may know someone who may be willing to do the front end rebuild. No promises (and it's not me).

I studied the frame bushing replacement issue for a long time. Some of the guys on this forum have done it and provided me with excellent pictures and techniques. So, I ordered the bushings and started soaking the old hardware with PB Blaster. As soon as I started turning first bolt, I chickened out. I was afraid of snapping off the cage nuts inside the firewall and seat areas.

Two months ago, when I took my '68 in for a quarter panel replacement I asked the resto shop if they would also do the six subframe bushings. Now I'm glad I had them do it because rust under the bushing required some frame welding that I would not have had the capability to do.

They did the new quarter, some wheelhouse welding and the bushings including rustproofing for slightly less than the price your being quoted. (I provided the parts)

And the ride and handling improvement is stunning.

Jim

I recommend pulling the control arms and taking them to a shop to have the old bushings pressed out and the new ones pressed in.

I actually found a shop that did the work for FREE with the stipulation that I bring the car back for the alignment.

What are the symptoms of worn out subframes bushings?

if they've never been changed, chances are they're worn out. symptoms can include crooked ride height, and body squeeking while going down the road. also general uneasy feelings esp. when cornering... like the body and frame are not attached securely. can also cause fenders/doors/bumper to not line up well, and steering alignment problems... and maybe other stuff...

mine had uneven ride height and were squeeking, and my front bumper was low. i hit a major bump and the bumper suddenly lined up. two bushings had frame rot.

I replaced mine with solid aluminum mounts. The difference is unbelievable, and that's with the rest of my suspension worn out. I gained about 1/2" in ride height.

Yes, I do have those directions printed out. I am soaking the bushings now with the oil. Used 2 cans so far. This way if I do attempt to do it or if I choose for the body shop to do it, they should be easier to get off. I think I may try it myself. A little short on funds right now....

Glad you're following the advice. Last thing you want is to break the gage nut welds.

Jimc2002 is right though. I was lucky enough to have a very rust-free car. You need to check your subframe to see what's left of it. Usually your holes will become oversized with corrosion. If so, Classic Industries I believe sell sections that weld in place. You'll need a competent shop if you want your frame to sit right. If it's still in good shape, but showing signs of rust, clean it and hit it with POR-15.

Does anyone have what the torque specifications are for the subframe mounts?

I believe they are 75-90 ft-lbs for the middle and rear mounts. I remember the radiator support is less, but those numbers are at home.

As long as your subframe bolts are not badly rusted, replacing the bushings is not hard. I have a set of new (repo) core support bushings if you want them.
The control arm bushings are another issue. The bushings themselves can be removed with a hammer and chisel and replaced with a home mabe press. I use a large C clamp/pipe set up held in a vise. The upper control arm can be removed easily, but you will need a ball joint fork to separate the spindle. The lower control arm is tricky. I've done it with a floor jack and a large bar throught the coil spring for safety..at least the perseption of safety. Let me add that I did this once and will never do it that way again..it's just to scary for me. I have an extra set of lower control arms that my friends and I have used as cores...one set gets new bushings/ball joints and a shop just swaps them out. My friends give their old arms. I still have them as well, but would rather sell them...cheap as I nor my friends have firebirds anymnore.

Sammy what tools do you have? That will make a big diffrence. A air chisle and a spring compressor are a must. I did mine my self including welding patches for the body mount bushings. I didn't have any cage nuts break on this car but had them break on my brother GTO. There is alway a way to fix it. I would also buy the hardware kit with the body bushing if you haven't already. If you don't have a air compressor that can be used with air tools you might want to pass on doing it yourselft. On the other hand you could buy a all the tools you need and have cash left over for that 2500 price you were quoted.

Just about got my entire sub-frame back together. Disassembled entire front clip, sub-frame, pulled engine and trany. My car came from AZ, so I had very little rust - only broke 1 bolt (WD-40 and/or Liquid Wrench ). You can get a set of sub-frame body mounting plates from Classic ($50) if you need them. To replace the upper control arm bushings you'll need to remove the coil springs. I bought an internal spring compressor from O'Reillys ($35), still scary. In my opinion, there are only 2 ways to remove bushings/ball joints: 1. pay to have them pressed out or 2. buy the "Special Tools" as decribed in the Service Manual. BTW, I tried to install my new bushings and thus made a second trip back (bring the new stuff on the 1st trip). About $40-60 to press out all the old and press in all the new bushings/ball joints (upper and lower), thus the easiest and cheapest option. You'll also need a ball joint fork and possibly a tie-rod fork ($10 each @ O'Reillys). I bought the front suspension re-build kit (included the inner tie-rod ends) from Classic ($210, sway bar link end kit is poly). This did not include sway bar bushings ($20/pr @ Classic) or tie-rod adj. sleeves (@11.50/ea @ Classic). Used my old coils and bought Monroe Senstratic shocks from O'Reilly $20/ea. I had the sub-frame and all suspension parts sand blasted and painted w polyurethane gloss blk. I used POR-15 ($32.50/qt. - ouch!) on the body (after many hours w a drill w a wire wheel). You'll need a torque wrench ($70 for a Craftsman) and finally when everthing is back together a front end alignment for caster, camber, and toe-in, in this order. salmon38 gave me his torque specs. from the 67 Assembly and Service Manuals:
Upper ball joint to steering knuckle: 70-95 ft-lbs (assembly) and 82 (service)
Upper control arm to frame: 50 ft-lbs
Upper control arm bushings: 50 ft-lbs
Front shocks: 90 in-lbs upper and 20 in-lbs lower), however my service manual says 12 ft-lbs upper and 20 ft-lbs lower?

Kcpaul, I hate to say this but I have a car that I went to replace the shocks on, and found out it had Monroe Sensatrac (sp?) shocks that had less than 300 miles on! I thought they were shot! The car would wallow over gentle bumps on the highway, and when I encountered a big bump, it felt like the suspension was bottoming out. The shocks are designed to have soft valving in the middle of its travel, then switches to hard valving as it approaches the ends of its travel, if I remember correctly. This is certainly how they behaved. Unfortunately, by the time the shocks had switched to the hard valving, the car's downward plunge on bigger bumps was fast enough (since it was essentially unrestricted) that it usually bottomed out. Not a performance shock!
I would strongly recommend a normal linear action high-pressure gas shock. I have heard better things about the Edelbrock IAS shocks, although I haven't driven a vehicle with them. They are velocity-sensitive rather than position-sensitive, and sound like a better design. I considered changing the Monroe shocks out on my car, even though they were almost new. Economics won. Bought a better computer instead. Should have replaced the shocks!

Maybe the performance of the shock is related to other equipment on a car. I have Monroe Sensa Track on all four corners of my 'bird (came with 2 nearly new rears, added 2 new fronts to match), new 5 leaf rears with no added lift or stiffness over stock (loaded 'vert weighs them down), stock 11/16" front sway bar and springs, no rear sway bar. The car rides smooth and straight on the freeway with road feedback but no roughness, is taut enough for the same freeway ramp speeds as my Durango (which is not a sports car, but handles better than most SUVs), and handles railroad crossings and potholes with ease. They are not stiff hard cornering shocks, but are very pleasant on road trips and cruises. It all depends on your usage, equipment, and point of view. If I was building a hard cornering 'bird I'd have to replace a lot more than the shocks

The car that has the shocks is a 6000 wagon, and can't be mistaken for performance anything! The shocks are too sloppy for my driving style and preferences. My "summer" car has factory spec gas shocks and has a smooth, controlled ride, and despite a bit more lean than I would like, handles fairly well, too.
I'm not the type that has to feel every tar strip but the floating ride is too soft for me. Like you said, to each their own, and I know I didn't have Sensatracs on my '69 last time I drove it, so I can't comment on that combination! That's the value of having many people's input!
I was using my '69 for autoslaloms, kept the stock springs and upgraded to firmer gas shocks and Addco front and rear bars. The ride was still reasonable, but the extra stress from the big sway bars caused the body to flex on uneven corners, enough that I have a stress crack forming at the top of my left rear wheelwell. Oops! I did win my class that year though!

the performance of the shock is definitely interrelated. monroe specifies that their sensa-trac must be installed with springs of the correct height and rate specified for the car. if you do this, IMO you have a 50/50 chance they will ride okay, and noislessly. i've installed shocks and struts on hundreds of vehicles, and sensa tracs gave me the most customer complaints for noise, and/or poor ride quality. the national chain i worked for quit carrying them shortly after they started. they had ~40% comeback rate at our shop, and i also had to inspect a lot of vehicles which just had them installed at other shops.

i had them on the back of my 87 cutlass, and they were okay most of the time, kinda wiggly when stopping/stopped... but there was a long curve w/ railroad tracks i used to take at about 50mph, and they were just plain scary. i switched to cheap gas shocks and it was fine. if you want hard cornering, stiff shocks, get bilsteins. they are expensive, they take a couple hundred miles to break in, but they're the best. otherwise, a regular gas shock will do.

my $0.02+ on shocks

I usually run KYB's when I can get them for my car(s). They worked quite well on my '82 Cutlass with the 455, cut coils and big sway bars!

Update........I soaked the H$$L out of all the subframe bushings and let them soak and soak and soak. All of them came off very easily. This was the easiest replacement I have ever done. Everyones advise was so valueable!!! I really appreciate it!!!. I had very little rust on the subframe. Mostly all of the rust I had was from the washers and cores of the subrame bushings rusted out. Cleaned with a dremel tool and treated with POR 15. I had purchased the kit from Classic for the bushings and bolts. I recommend it. The kit worked great. Thanks again.......

Almost forgot....Gained almost 1/2 inch in height. Very cool.

FirebirdMike, how much more noise are you getting with the alum mounts? Not that it makes much difference (have a convert), just curious!

Before I answer that, I should tell you my setup. Since I only have one point of reference (my car)I have no idea what changing the suspension might do if comparing solid bushings to rubber.

My car is a convertible and presently has factory coil springs, factory rollbar, non-performance gas shocks, 75 series radial tires, and a worn out stock suspension. It's probably as mushy as mushy gets.

After installing the mounts, there was no difference in the ride quality or noise. I went over some uneven road stips just to if I would feel everyone of them and it was as smooth as ever.

And for noise, if anything it seemed quieter. Maybe from the lack of flex? I real benefit was a more connected feel to the steering and reduced body lean even though the rest of the suspension still needs replacing.

In the future, I plan to install 400lb/in springs, KYB G2 shocks, delrin control arm bushings, Hotchkis anti-roll bar, and 45 series tires. Would there have been a difference if I had that combination before I put in the solids, I don't know. But I want to use subframe connectors, so these mounts are a must.

If you do switch to solid bushings, give us your setup and your results. So far for me they've been the biggest bang for my buck change.

FirebirdMike, I also installed the solid alum mounts and when I was buying them the warning was to make sure you had enought clearance under the hood to allow for the half inch drop of the body over the frame. I wonder how you ended up with a half inch gain in ride height? BTW, mine's a coupe and I didn't notice any extra harshness in the ride but it has been nearly ten years since I drove it last.

Robert

For my car, the height change was pretty obvious, because the slightly oversized tires in combination with worn out mounts and 35 year old springs, the tire literally was line to line with the top of the fender.

There are companies which sell aluminum mounts that when installed are 1/2" lower.

So either:

1) My bushings were so bad, I didn't have much more than the thickness of the metal seperating body from frame.

2) The bushings you bought were the 1/2" lower than stock type hence the warning.

I bought the standard height mounts just because I was worried about hood clearance should I ever go to a taller intake.

If none of that adds up, all I can say is... it is what it is.

Sammypoodle listed a 1/2" gain, but didn't indicate if he used stock, poly, or aluminum.

I used the OEM rubber mounts. I wanted the smooth ride, so stuck with the rubber. I was missing 2 subframe bushings and the other were bearly intact. So that is most likely why I had a 1/2 inch gain in height........Just got back from my test drive after installing the bushings. All I can say is WOW! What a difference. Unbelievable!!! Thanks for everyones advise, It was priceless. I really appreciate it. Firebird Mike your the best!! Your directions were perfect!! Thanks much. Time for another ride........