Spacer blocks

[1967coupe]

I just recently had my new rear put in and my mechanic is concerened with the spacer blocks that go between the leafs and the housing. Currently these blocks are about 2" (I didn't take measurements). What size if any spacer blocks did a '67 coupe come with? I'd like it to be back to stock for now and use different eye leafs to change ride height in the future.

 

[one2gamble]

there wouldnt be any in there from the factory as far as I know.

 

[rbohm]

no factory spacer blocks, but that is not a bad way to lower the rear of a mustang as long as you dont go too low. personally i think 2" is about the limit with spacer blocks.

 

[1967coupe]

My mechanic is concerened that the blocks make the rear sit at a funny angle and was the cause of my driveline failure. So if I have him take these blocks out it will sit higher?

 

[latamud]

Yes, it will sit 2" higher

 

[WORTH]

My mechanic is concerened that the blocks make the rear sit at a funny angle and was the cause of my driveline failure. So if I have him take these blocks out it will sit higher?

What failed? Ujoints? The only thing the spacer will do is change the angle of the front and rear joint, other than that there is no difference.

 

[1967coupe]

Yes it was the u joints that failed. I really don't want my rear to sit up any higher as I think it sits too high as is compared to the front.

 

[MrBobMarley]

You do have a t5 in the car. Was the angle right on it? I've heard incorrect driveline angles cause that failure too.

 

[rbohm]

if the u-joints failed because of the driveline angles, then they would have failed anyway. 2" lowering blocks change the driveline angles very little overall. likely the u-joints just wore out from time.

 

[blue66tang]

Yeah i have had 2"blocks in mine for 4 years now and not a single problem. The blocks are to lower the car not to raise it. So it raises the rear in the car, but the car sits lower. Opposite of most trucks.

 

[67coupe351w]

Wouldnt lowering using the diffrent eye'd springs still chage your pinion angle?

The object is to get the tranny output shaft and pinion to point right at each other. The U-joints allow the suspension to move but you want them, for optimal power transfer and longest life, to be straight on each other the bulk of the time(ride height).

If you had an empty engine block bolted to an empty transmission bolted into your car you would want to beable to run a string right down the crank centerline, through the center of the transmission and right through the centerline of the pinion in the rear end at ride height for optimal power transfer.

Angles produce higher stresses because as everything spins up it trys to all line up in a straight line putting latteral stresses on things such as your transmission housing, rear end, and u-joints.

 

[WORTH]

if the u-joints failed because of the driveline angles, then they would have failed anyway. 2" lowering blocks change the driveline angles very little overall. likely the u-joints just wore out from time.

That is half true, the worse thing you can do to a ujoint is to have it a straight on shot. If the joint doesn't flex enough to move the grease around, it will not lube itself properly. The cure for this is plenty of grease, grease it often and you will have less failure, and don't be afraid to take a speed bump a bit faster than normal to flex it

 

[12sec67]

i never had any problems with the lowering blocks till i started shattering them.... finally went to an off road dealer and cast steel 2" blocks.

 

[blue66tang]

How the heck did you shatter them. Let me guess.... slicks?

 

[12sec67]

How the heck did you shatter them. Let me guess.... slicks?

nope... it was on the street. 1st time i jumped on it with the 9"

i was cruising 1st gear... got on it and hit second and bammmmmmm....the rear end yoke spun up and the driveshaft went into the floor pan and put a nice little notch in my flowmasters.


and yes i did torque them down... and yes second gear hits very nice in my AOD