My experience installing motor mounts in a C-5

This was an interesting project. First of all my car is not a daily driver so I was in no hurry to complete the job quickly.

First of all I read every post on this forum and some others on motor mount installation. I even looked at the shop manual
to see what GM said I should do.

My plan was to just jack up the engine and loosen the cradle and work form there. That was the plan, but here is what I had to do.

First do all the usual stuff, jack up, jack stands etc.

I put a jack under the lower control arm and removed the lower shock bolts. (somewhere in this process I removed the front sway bar, I forget where I did this in the removal order but an easy job, I don't think it's necessary but I had oil cooler lines running under the bar and I saw some potential problems) Then removed the upper control arm mounting bolts. Then lowered my supporting jack and
let everything settle to the point there was no tension from the springs. The first thing I noticed at this point was that the tie rods were holding up everything in place, and was carrying to much weight. The jack went back under and I popped the tie rod end joint, then let everything settle to the ground.

Several thing then materialized. First I had to remove and hence rip my brake duct cooling hoses. And noticed my lower ball joint boots were ripped.
The cooling hoses would be repaired during re-assembly. The boots were address immediately. I had some heavy duty urethane boots but I did not like the way they fit. The control arm put pressure on the boot forcing it down on the base but it was not quite wide enough to slip over the base so I could zip
tie it. So I popped the ball joint again and installed a rubber boot and zip tied it to the base.

At his point I had to wait for my new motor mounts to arrive, ( I had ordered the Hinson urethane mounts, my car used mostly as a HPDE vehicle and rarely driven on the street so I though urethane would be ok plus they were cheaper than GM mounts).

I kept working to remove the old mounts. I put a bottle jack under the engine I needed to stack 3 blocks made from one foot lengths of 2X4. I did not want to
remove the intake manifold as some posts had suggested so to check the Clarence between the intake and the body I slid a thin magazine in between them
and jacked till I felt slight pressure ( a lo tech feeler gauge). Then I loosen the 4 bolts connecting the sub frame to the frame. I went down to the point where there
were no threads showing on the bolts. I reached in an realized there was no way the mounts were coming out with the clearance I had.
The next step which was easy at this point was to remove the leaf spring. Four bolts and it was gone. This was a win win because with the spring out
it gave me a way to reach in and remove the mount with out removing or loosening the headers. But still the mounts would not come out.

The sub frame had to be lowered. I have an auxiliary oil cooler so I had to disconnect the lines from the cooler because I had no play in the lines for any movement.
I put two one foot lengths of 2X4 on a floor jack and placed it in the center of the sub frame. Then removed the 4 bolts holding the sub frame on.
With this extra room I could reach in and remove the passenger side mounts. ( I dropped the sub frame as far as it would go)
The drivers side still was giving me trouble. I could get the top stud out but could not lift it high enough to get the bottom stud out of the sub frame. The only thing to do at this point was to remove the bracket bolted to the engine that contacts the top of the motor mount. There were three bolts, two easy to get to, and one a little harder. With the bracket remove the mount came right out.

The new mounts. Well the studs on my new mounts are were slightly longer than the stock mounts, not by much maybe 1/8 to 1/4 inch total, but the passenger side (without removing he bracket) is so tight it was a bit of a problem, so a little pressure on the sub frame with a pry bar and it got low enough to slip the mount in.
The drivers side was easy because the bracket was out (not really out, I left the upper center bolt in place with the bolt back out almost all the way).
I could move the bracket around as I installed the mount. Then just bolt up the bracket and it was finished. Jacked up the sub frame replaced the 4 bolts then lowered the engine, put the motor bolts in place and tightened them up. I would like to emphasise that without removing the spring I don't know how I would have gotten the
mounts in and out since the headers were left in place.

I haven't gotten it all back together yet the re-fabrication of my cooling ducts took some time. I will finish up tomorrow probably take an hour or so.


I did not keep track of time but I think I may have a total of 8 hours invested. Now this is working in a small garage with the car on jack stands plus I am 67 and every time I put a tool down it takes me 2 or 3 minutes to find it.

 

There's a solution for this problem - and I wrote it down but I can't find where I put it. (63 years old and holding)

 

heehee i'm 57 and have the same problem