C2 Rear Spring Install

[Mark H.]

Before I bring the car out this spring I will install a new rear leaf spring. Do I need to drop the under-car exhaust to get the old one out? Or, can I slide it out once all attaching bolts are removed? Thanks!

[Donald O.]

Re: C2 Rear Spring Install

No need to remove the rear exhaust pipe and mufflers, but you will need to remove the rear tires/wheels.

What's wrong with your old rear leafs? If the rear is riding a bit low, repalce all of the cushions first. You'd be surprised how much of a difference they can make. You'll be replacing them anyways when replacing the spring.

If it has been a long time since this was ever don, spray the spring mounting bolts with some Kroil for a day or two before using the wrench. I'd do this on the two outer bolts at the TA as well.

with the car still on the ground loosen the four spring attaching bolts. Then with the rear onf the car on jack stands, use a small floor jack just inside of the outer bolt and attach a strong C clamp just inside of the jack puck to prevent it from sliding away. Remove the outer bolt's cotter pin and nut and then SLOWLY lower the floor jack. Repeat for the other side. Then remove the four center mounting bolts and plate. The spring can now be slide out either side.

Installation is the reverse. Just remember to torque the four ceenter bolts LAST, with the weight of the car on the spring. Failure to observe this last step can cause premature failure of the rear cover.

All told, this is about a 1.5 hour job, or more if you go after the cosmetics of the spring.

DonO

[Michael H.]

Re: C2 Rear Spring Install

No need to remove the rear exhaust pipe and mufflers, but you will need to remove the rear tires/wheels.

What's wrong with your old rear leafs? If the rear is riding a bit low, repalce all of the cushions first. You'd be surprised how much of a difference they can make. You'll be replacing them anyways when replacing the spring.

If it has been a long time since this was ever don, spray the spring mounting bolts with some Kroil for a day or two before using the wrench. I'd do this on the two outer bolts at the TA as well.

with the car still on the ground loosen the four spring attaching bolts. Then with the rear onf the car on jack stands, use a small floor jack just inside of the outer bolt and attach a strong C clamp just inside of the jack puck to prevent it from sliding away. Remove the outer bolt's cotter pin and nut and then SLOWLY lower the floor jack. Repeat for the other side. Then remove the four center mounting bolts and plate. The spring can now be slide out either side.

Installation is the reverse. Just remember to torque the four ceenter bolts LAST, with the weight of the car on the spring. Failure to observe this last step can cause premature failure of the rear cover.

All told, this is about a 1.5 hour job, or more if you go after the cosmetics of the spring.

DonO

Don,

I have ask why do you " Torque the four center bolts last with the weight of the car on the spring " ? This was not done this way when they built the car new was it ? The frames were built upside down when the springs were installed, were the springs compressed in this position by a hydraulic press or clamp device during frame assembly ?

Mike

[Donald O.]

Re: C2 Rear Spring Install

Don,

I have ask why do you " Torque the four center bolts last with the weight of the car on the spring " ? This was not done this way when they built the car new was it ? The frames were built upside down when the springs were installed, were the springs compressed in this position by a hydraulic press or clamp device during frame assembly ?

Mike

I believe that is how it was done, upside down with the spring compressed to ride height, just before being aligned using the same "press".
IIRC John Hinckley has a picture of these operations, but I've been wrong before.
DonO

[John H.]

Re: C2 Rear Spring Install

Don,

I have ask why do you " Torque the four center bolts last with the weight of the car on the spring " ? This was not done this way when they built the car new was it ? The frames were built upside down when the springs were installed, were the springs compressed in this position by a hydraulic press or clamp device during frame assembly ?

Mike

Mike -

Yes, it was. The plant used an overhead-hung hydraulic compression fixture that took the rear suspension to Engineering-specified normal ride height (to de-camber the spring and normalize the bushings) before torquing the spring plate bolts and bushing bolts.

Torquing the spring plate bolts without having the suspension at ride height is a sure recipe for breaking the ears off the rear cover casting. That requirement didn't show up in the Chassis Service Manual until about 1971 or so.

[Mark H.]

Re: C2 Rear Spring Install

Guys, thanks for the great advice and replies. I last changed a rear spring on a mid-year....oh, in about 1976. Best regards.

[Edward J.]

Re: C2 Rear Spring Install

Mark, One added step to the rear spring removel is to un-hang the rear mufflers, sometimes the pipes under the rear axle are tucked up tight, It just gives you a little extra room to rotate the spring out.

[Mark H.]

Re: C2 Rear Spring Install

Don, thanks for the details on the process. Question: I had not heard about Kroil before. Is this a superior product to something such as liquid wrench? Thanks.

[Jack H.]

Re: C2 Rear Spring Install

Methinks this is in the wrong thread, but here goes...

Aero Kroil has been around for a LONG time. But, it's not sold through typical retail channels. For a private consumer purchase, you have to go to their web site and buy direct.

Those of us who've used it in comparison to other 'rust busting' forms of penetrating oil swear by it!

They typically have an annual sale (two for one) which was in progress the last I checked. That'll hold you for YEARS!

There's the original formula, Aero Kroil and the 'new/improved' formula, Sili Kroil. The difference is the new formula has a bit of silicone in the blend. I've not tried the new stuff, but I trust the mfgr...

[Donald O.]

Re: C2 Rear Spring Install

Don, thanks for the details on the process. Question: I had not heard about Kroil before. Is this a superior product to something such as liquid wrench? Thanks.

Mark,
Kroil, from Kano Labs is THE best stuff ever. I use their Sili-Kroil, its their regular Kroil with silicon. Their add say it will creep into any gap larger that one millionth on an inch. I bought a gallon about 20 years ago, I still about 3/4 of it as you only need to use it by the drops. In 50 years of wrenching I have tried them all and this is the only stuff I know that works. Damn I'm getting old

DonO