Perk, Beer? Can I help?
85 c4 suspension
Thread Starter
2nd Gear
Joined: Aug 2016
Posts: 2
Likes: 0
85 c4 suspension
Hey yall I recently purchased polyurethane bushing replacement sets for rear and front suspension on my 85 z51I'm considering doing the work myself I'm not a mechanic but I am mechanically inclined do yall think the project would be too much to handle by myself or is there any advice y'all can give me on doing myself
Heel & Toe
Joined: Jun 2016
Posts: 24
Likes: 0
From: Virginia
I did my own on the sway bars and linkages. Was pretty easy, had to press out some of them with a bench vise. It felt like a new car when I was done. I'm not a mechanic but have always tinkered with my cars.
Racer
Joined: Jul 2016
Posts: 308
Likes: 79
From: Orange CALIFORNIA
Over the summer, I changed out most of the bushings on my new to me 1989 C4. If you can put your car on jack stands and get a ball joint service kit (very large C-clamp with various tubular attachments) you can do all the work yourself. There are 24 mm, 22 mm, 19 mm, 18 mm, 15 mm, and maybe some other common sizes. Get sockets and open end wrenches for those sizes. Also for reassembly, get blue lock-tite and 20 to 180 pound torque wrench. Add beer, degreaser, and lots of sweat and you can do it!
Last edited by hawk454; Aug 29, 2016 at 05:18 PM.
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
Melting Slicks
Joined: Mar 2016
Posts: 2,778
Likes: 580
From: Langley BC
I certainly think it is something you can do yourself...
But, you will probably need/ want a few things to accomplish it:
- decent work space such as a garage or workshop you can do the work in.
-A hydralic press is pretty handy for bushing removal.
-you will proabbly want to consider doing the ball joints, U-joints and wheel bearings while its all apart.
-You need a decent torque wrench that can go to 200lbs to torque the wheel bearings.
I recently rebuilt my suspension, nothing is overly hard but it does take a bit of time and effort to accomplish. If you have any problems along the way feel free to ask and I'll try to help.
But, you will probably need/ want a few things to accomplish it:
- decent work space such as a garage or workshop you can do the work in.
-A hydralic press is pretty handy for bushing removal.
-you will proabbly want to consider doing the ball joints, U-joints and wheel bearings while its all apart.
-You need a decent torque wrench that can go to 200lbs to torque the wheel bearings.
I recently rebuilt my suspension, nothing is overly hard but it does take a bit of time and effort to accomplish. If you have any problems along the way feel free to ask and I'll try to help.
Last edited by DMITTZ; Aug 30, 2016 at 01:40 AM.
Team Owner
Joined: Feb 2006
Posts: 23,218
Likes: 117
From: San Antonio Texas
There is plenty of good advise right here on this forum. I should know, as a Ford guy that had to learn damn near EVERYTHING about how a C4 works!
A tip on urethane bushings! Do NOT use petroleum based grease on them. ONLY use synthetic grease for urethane bushings because petroleum based grease attacks the polymers in urethane and turns it into crumbling cornbread in less than two years. (Then you'll have to do it all over again and wonder why so many people swear by poly when you had such a terrible experience with it.) I speak from two time experience here; I didn't know that the first time!
A tip on urethane bushings! Do NOT use petroleum based grease on them. ONLY use synthetic grease for urethane bushings because petroleum based grease attacks the polymers in urethane and turns it into crumbling cornbread in less than two years. (Then you'll have to do it all over again and wonder why so many people swear by poly when you had such a terrible experience with it.) I speak from two time experience here; I didn't know that the first time!
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Instructor
Joined: Sep 2014
Posts: 237
Likes: 11
From: Houston Texas
I wouldn't put them in the rear, they cause binding in the suspension and will make it worse. The rear knuckles rotate on two plane and the poly bushings don't allow the proper articulation. You are better off keeping them rubber or go with spherical bearing rods like the banski set.
Thread Starter
2nd Gear
Joined: Aug 2016
Posts: 2
Likes: 0
thanks to all you guys a lot of useful information I see from a lot of experience Sounds like and I will use all advice this weekend me and co-worker are putting up on jack stands and going to find out first hand myself however I do have a last minute questionis there any difference in the bushing sets for a z51 vers regular 85 Corvette set up ? and where can I find rubber bushings I ordered whole kit front and rear polyurethane thinking they had discontinued rubberI don't wanna tear my car up
Team Owner
Joined: Feb 2006
Posts: 23,218
Likes: 117
From: San Antonio Texas
The people that complain about poly bushings the most, are the ones that have installed them dry or wrong. Use the correct synthetic grease on them and they will press easily into position usually by hand. When you install the control arms front or rear just hand tighten all the nuts & bolts first. Then put a jack under each shock mount and jack up that wheel until the car just BARELY comes off the jack stand (just so you can rattle it but not be way up off it). That will center the suspension pretty close to where the normal ride height should be, and THEN torque those nuts and bolts and let the pressure off the jack and rest that corner back on the stand. If you do that all around and don't over tighten and crush any of the ure bushings, they will all be centered to the normal ride height and shouldn't bind. You should do that same thing if you do rubber bushings so as to not pre-load any twist into the rubber bushings either.
Instructor
Joined: Sep 2014
Posts: 237
Likes: 11
From: Houston Texas
The people that complain about poly bushings the most, are the ones that have installed them dry or wrong. Use the correct synthetic grease on them and they will press easily into position usually by hand. When you install the control arms front or rear just hand tighten all the nuts & bolts first. Then put a jack under each shock mount and jack up that wheel until the car just BARELY comes off the jack stand (just so you can rattle it but not be way up off it). That will center the suspension pretty close to where the normal ride height should be, and THEN torque those nuts and bolts and let the pressure off the jack and rest that corner back on the stand. If you do that all around and don't over tighten and crush any of the ure bushings, they will all be centered to the normal ride height and shouldn't bind. You should do that same thing if you do rubber bushings so as to not pre-load any twist into the rubber bushings either.
Melting Slicks
Joined: Mar 2016
Posts: 2,778
Likes: 580
From: Langley BC
That's not true, I took every precaution to install them right and they still caused binding. Its a matter of the geometry of the dog bones and camber rod. It's the first time I replaced poly bushings with spherical bearings and the ride got smoother. I will tell you how you can tell it binds, unbolt the shocks and springs and move the knuckle through its travel with each type of bushing, the polys won't even allow the suspension to fully droop. And if you ask all the autocross/track guys that work with suspension they will tell you the same.
I have to agree, I installed the full Banski kit and it is amazing. However rod ends are more pricey, Get them if your budget allows.
However, on certain things such as sway bar anchors poly should not bind, I have greasable poly sway bar anchors which I grease once a month and never have any noise from them.
Global west sells greasable del-aluminum bushings for C4 control arms which are a good alternative to poly...