put my new 9" in but....problems

[12sec67]

put my new currie 9 inch in using brand new 1" lowering blocks and new u bolts. well, cruising around was fine durring the break in period but when i got on it i had some problems.

i decided to give it a go, rolled from a stop sign- nailed it hit second gear and bam! the lowering blocks shattered, the nine inch twisted up, my driveshaft u joints split and the driveshaft dented my mufflers along with denting my driveshaft

the only thing that stopped the rear end from twisting more was the rear caliper bolts that hit the leaf spring. i got under the car today and noticed dents in the floor board.


i'm so pissed

thanks for listining
rich

 

[Ronstang]

That is the craziest thing I have ever heard. Are you sure you tightened the u-bolts enough? Were those blocks the cheap cast type that are hollow or were they milled from solid aluminum?

 

[2nd Mustang]

That is the craziest thing I have ever heard. Are you sure you tightened the u-bolts enough?

.......or maybe you tightend the U-joints TOO TIGHT? It doesn't take much torque to tighted up the universal joints. If I remember right, it was something like only 14 foot pounds of torque. Others have said that when they torqued the universals too tight, it crushed the cups causing the bearings to fail inside, thus the universal breaking.

Sorry to hear of your problem.

 

[Hack]

I don't understand. You broke a Currie 9 inch rear with your 306 on street tires? Or the failure of the lowering blocks just allowed the rear to rotate and hit your car? Is the rear end still ok, or did it break?

I'm sorry to hear that your car broke. Just trying to understand.

 

[12sec67]

I don't understand. You broke a Currie 9 inch rear with your 306 on street tires? Or the failure of the lowering blocks just allowed the rear to rotate and hit your car? Is the rear end still ok, or did it break?

I'm sorry to hear that your car broke. Just trying to understand.

the 9" is fine-

i tighten the u bolts that hold the rear end in place to 95 lbs of torque( what it calls for) using the lowering blocks.

i never use them again (lowering blocks)

 

[Max Power]

Keep in mind that if you install new u-bolts and they aren't perfectly vertical, they will loosen up after the install. I always drive about a mile, pull it back in the shop and re-tighten. It's amazing how much more tightening I have to do sometimes.

 

[Mosse]

Loose U-bolts, without lowering blocks caused my 8" to blow up... Loose bolts let my rear to bounce and vibration cracked pinion gears inner support... I lost rear´s case, driveshaft, rear U-joint, both silencers, and Radiator. I also have HOLE and some dents in the floor... Consider yourself lucky..

I think proper lowering blocks are safe to use.

 

[ForceFed70]

Lowering blocks shouldn't be a problem so long as you don't use weak cast meterial. A 1" thick chunk of solid steel would be the best.

And yes, the ubolts need to be re-torqued. I'm guessing this is what happened..the bolts loosened putting the stress on 1 side of the lowering block...some wheel hop from getting on the pedal, and all hell breaks loose. Maybe look at some 4x4 websites.. lotsa lift block info (same as lowering block).

Also... when you put lift/lowering blocks in, you increase the amount of axle wrap..so you'll want to keep an eye on this.

 

[10secgoal]

Loose U-bolts, without lowering blocks caused my 8" to blow up... Loose bolts let my rear to bounce and vibration cracked pinion gears inner support... I lost rear´s case, driveshaft, rear U-joint, both silencers, and Radiator. I also have HOLE and some dents in the floor... Consider yourself lucky..

I think proper lowering blocks are safe to use.

HA let's not go into this. Ok I'm going to anyways. I twist a driveshaft into almost 3 pieces(2 completely) on the dyno at about 115 mph. Let's just say my next mod was to be a safetly loop because I just bought et streets.

The bloodly thing takes out both flowmasters,both pipes,tailshaft,bellhousing shatters into 6 pieces, that allows my tranny to shift pushing the stalls studs into the motor plate dstroying it, ripping out two arp studs in my stall,snapping the stator of my pump in my stall and last but not least destroyed the front planetary carrier. So there I'm madder than you.

How did it take out your radiator ?

 

[HistoricMustang]

Did you install the "wedge" blocks to keep the pinion angle correct after putting in the lowering blocks? You can get them from Speedway.

HistoricMustang
ww.historicmustang.com

 

[69PaleHorse]

How did it take out your radiator ?

He was driving in reverse, GISS style!

 

[Mosse]

Yep, a good one.

While my rear exploded, it pushed toploader and engine a little forward, but it was enough for fan to hit radiatopr.