gator79

I am installing a VB&P dual mount rear spring on my 71, will the rear diff crossmember come down far enough without removing the halfshafts to un bolt it from the differental?

doorgunner

If I had a clue.....I'd drive over and help! I'll see if I can google some instructions.

doorgunner

Vehicle Lifting. 1. Lift car on hoist or place on jack stands. Car must be at least 18" off ground. Caution: Jack car up only on level surfaces. • 2. If using jack stands in rear, place stands at corner of frame, just behind door. Use stands only. Do not use concrete or wooden blocks. Push on car to make sure it's secure.
Rear End Parts Removal. 1. To begin, remove our existing spare tire and tire carrier. Not necessary to remove half-shafts, strut rods, drive shaft or front differential mount.
Rear Spring Removal - Do Both Sides. 1. Placing a block of wood between jack and spring, slowly raise end of spring to remove tension from the spring end bolt. Remove the nut from the bolt. Then slowly lower jack. Use extreme caution. Repeat operation on opposite side of car.
2. Remove the 4 bolts holding the spring onto the differential carrier. Liberal use of penetrating oil will ease this job considerably. It is not recommended that heat be used to loosen bolts.
3. Remove the spring.
Installing Aluminum Dual Mount Bracket. 1. Referring to the enclosed drawing, position the kit's aluminum mounting bracket (Item 2) onto the differential carrier.
2. Mount with your two (2) original center bolts and the "L" brackets (Items 6 & 7).
Installing New Spring. 1. Spring easily mounts onto the dual brackets, using mounting blocks and plates (Items 3 & 4). Note that the blocks and plates come preassembled and must be taken apart in order to mount spring. First, bolt spring mounting block to mounting bracket, making sure polyurethane pad is on block with thick poly on upper block. Make sure grease fitting on block faces wheel for easy lubrication. To bolt block on, insert a 1/2" X 4-1/4"-long shoulder bolt (Item 5) through one of the 4 center holes* on the mounting bracket. Secure bolt with flat washer and nylock nut (Items 9 & 8). Repeat on other side of bracket. *The hole selection, or adjustment point, determines the dual mount's spring rate. See Spring Rate Guide at end of instructions.
2. Attach the new dual mount spring (Item 1) to both mounting blocks using the eight (8) 5/16' hex bolts, lock washers, and the clamp plates (Items 10, 11 & 4). Make sure the polyurethane pads are on the plates firmly. Torque bolts to 10-12 ft/lbs.
3. Attach the spring ends to the knuckle using the adjustable spring bolts kit (Item 12), which includes: 8"-long spring bolts, cushions, flat washers and nylock nuts. Spring bolts will run down through the knuckle. Run the nylock nuts up onto the bolt threads, leaving a minimum of 1-1/2' of thread showing on bolt ends, If needed, jack spring ends up, so enough thread is available for attaching nut. Caution: Using a block of wood, place jack underneath spring near ends only. Never place jack directly onto fiberglass. Repeat on other side. 4. Replace rear tire carrier. Take car off jack stands and lower to ground.

It doesn't say to lower crossmember.....would it make things easier if you did?

gator79

yes in their instructions they do not say to remove the half shafts but in their video they have them removed. either they are keeping it from coming down or that crossmember is really stuck. I had a 4 foot pry bar on the crossmember and it barley moves. I had this car down to the bare frame in 06 and the only two parts that stayed on the frame were the lower gas tank crossmember (had to cut two bolts off yesterday to replace the tank) and the rear diff crossmember that I am fighting now. Go figure I might have to go get my porta power with the expanding jaws.

doorgunner

Be careful that you don't bend it.......

I had to use a 2' long pickle fork with a 6 foot long extension to break the crossmember aloose on my '68.....

I weigh 170lbs time 6' = 1020 lbs of force to pop it aloose!

the rubber and rust had bonded together.......

be very carefl that it doesn't fall to the floor OR fall on you....

It took me two hours of trying/soaking the rubber bushings before it finally came out with a loud BANG.

68/70Vette

Do you have to remove the diff crossmember? The crossmember is originally installed with a bolt at each end. Unloosen the bolt at each end by about 3/8 inch. As the above post alludes to, you don't want to completely remove these bolts since when you get the crossmember loose, you don't want it to fall.

I used a large crow bar, and broke the crossmember loose with the large "Bang" also. Replacing the rubber bushings? The subject of another post. Hint: the repro bushings don't fit too well.

gator79

Wow that thing was stuck. I used my 4 ton porta power expanding jaws and it would still not come loose. ended up with the jaws holding pressure and a 4 foot prybar to break it loose. I promise if the two bolts that attach it had backed out there is no chance it would have ever fell off. Project completed and new VBP dual mount spring installed

doorgunner

As Emeril Lagasse says.......B A M !


Now we need some pics of the..........B A M completed!