[baddbob]

After installing a narrowed nine inch assembly in my Son's 70 Nova we discovered the pinion yoke we installed is for a smaller joint 1310 than the transmission yoke. We need to have a custom driveshaft built for the car and I'm thinking it would be better to have the larger 1330 joint on both ends. This will of course require changing out the pinion yoke to the larger 1330 size. I have a truck style 1330 pinion yoke I can install but it is the longer version which to me doesn't matter since the driveshaft needs to be made anyways. But it brings the question is there some durability problems running the longer yoke? Any problems running the longer yoke? Or should I just purchase a shorter 1330 yoke? Thanks in advance for any advice, Bob

[xntrik]

Originally Posted by baddbob

After installing a narrowed nine inch assembly in my Son's 70 Nova we discovered the pinion yoke we installed is for a smaller joint 1310 than the transmission yoke. We need to have a custom driveshaft built for the car and I'm thinking it would be better to have the larger 1330 joint on both ends. This will of course require changing out the pinion yoke to the larger 1330 size. I have a truck style 1330 pinion yoke I can install but it is the longer version which to me doesn't matter since the driveshaft needs to be made anyways. But it brings the question is there some durability problems running the longer yoke? Any problems running the longer yoke? Or should I just purchase a shorter 1330 yoke? Thanks in advance for any advice, Bob

It will be fine.
Theoretically you need to install a new crush sleeve when changing yokes. For performance a solid spacer is preferred. From Currie.

Be sure you don't install the u-joints backwards. Many people do.

[baddbob]

backwards? grease fittings towards the front? I've also heard don't install the joint so the grease fitting area is under compression-but never understood.... Care to explain? Thanks, Bob

[IanRiordan]

The 'grease fitting' thing is an area of some conjecture. I lke to see it compressed, in this way the grease nipple on the front uni is 'pushed around by the trans yoke - not dragged around.
At the rear uni the nipple should be pushed by the tailshaft - not the diff yoke. Conflicting views welcome. BTW, as a long time boat owner I always uses marine ( water displacing) wheel bearing grease on uni's and all susp/steering gear.

[baddbob]

That makes sense to me, I would thing the joint would be stronger having the nipple area under compression rather than stretch. Any more opinions? Bob

[xntrik]

Originally Posted by baddbob

That makes sense to me, I would thing the joint would be stronger having the nipple area under compression rather than stretch. Any more opinions? Bob

Some say conjecture..... fact is, most breakage occurs on those mis-installed.

He is correct regarding the compression.
And of course installed so that the zerk can be reached more readily.

Racers use only u-joints without grease fittings since those do not have holes drilled through the X, nor for fittings. Solid is stronger.

[fast68]

i had this same problem with a smaller pinion yoke on a 77 f150 4x4 when i swapped a carrier from a junkyard truck into it, i jut swapepd the yokes real quick,

im not sure why ford liked to use different size u joints on the same applications/axle,


wierd,

i wasnt about to have to get a custom u joint, and therefore downgrade to a smalelr u joint on the truck

i just tightened up the nut until it was snug and then a hair more tighter, and it has been fine

[baddbob]

Yeah, I don't think there will be any problems changing the yoke since we just rebuilt this centersection, if anything we can probably get a little more crush after it sees some use. It was definately no fun getting the new crush sleeve to collapse for a proper bearing preload. My main concern was if the longer yoke would be a problem since I'll be having a custom driveshaft built and don't want to spring for this twice. It'll be nice having the longer yoke actually because they seem to be more common from what I see. The center has a rebuilt traction lock carrier with 3.25 gears for street use with his 327 t-10 4speed combo but we'll be building another center for track/play time with probably 4.10 or 4.30ish gears and a solid spool. I'll be setting up U-joints correctly from now on-thanks for the explanations and advice.

Another thing that might be a benifit running the longer yoke is it might actually provide more leverage for housing rotation to plant the tires, we've got the pinion tipped down 4 degrees from the transmission angle and have the front of the leaf springs clamped fairly solid-hoping she'll push the rearend down under load without the use of slapper bars. Think it'll work? Bob

[xntrik]

Originally Posted by baddbob

Yeah, I don't think there will be any problems changing the yoke since we just rebuilt this centersection, if anything we can probably get a little more crush after it sees some use. It was definately no fun getting the new crush sleeve to collapse for a proper bearing preload. My main concern was if the longer yoke would be a problem since I'll be having a custom driveshaft built and don't want to spring for this twice. It'll be nice having the longer yoke actually because they seem to be more common from what I see. The center has a rebuilt traction lock carrier with 3.25 gears for street use with his 327 t-10 4speed combo but we'll be building another center for track/play time with probably 4.10 or 4.30ish gears and a solid spool. I'll be setting up U-joints correctly from now on-thanks for the explanations and advice.

Another thing that might be a benifit running the longer yoke is it might actually provide more leverage for housing rotation to plant the tires, we've got the pinion tipped down 4 degrees from the transmission angle and have the front of the leaf springs clamped fairly solid-hoping she'll push the rearend down under load without the use of slapper bars. Think it'll work? Bob

U-joint angle is proportional to wrap.
"Leverage" as you called it is provided by the pinion gear climbing the ring gear, not u-joint angle. Stiffening the leaves should require less angle since there is less wrap. 4* angle will cause you vibration problems when cruising, ideal is 0* overall.

Clamping to stiffen front leaves has been done for 50 years.

I prefer to reverse the 2>4 leaves then clamp. Mopar Super Stock springs.
There have been several threads about this the last 2 months.

[xntrik]

I guess I should also comment on the solid spacer vs. crush sleeve. Yoke torque determines the bearing preload. If it is insufficient, then the pinion can shift and damage the ring gear. Too tight makes the bearing preload too much. The crush sleeve is a torque-to-yield thing, to be used ONCE.

Solid spacers are to prevent the engine torque from making the pinion try to come out of the ring gear and squash the crush sleeve, making more and more slack, wear, noise, failure.

[baddbob]

Thanks, Good info! I guess the longer yoke won't provide any leverage then-oh well. The Mopar Super Stock example photo you provided looks identical to what we did with the Nova springs. The number 2 spring ends up really close to the front spring eye and the third and fourth are proportionately staggered below. We've got 5 leafs per side with four clamps forward of the axle, sitting on it's feet and jouncing the rear suspension it seems like it'll ride just fine-we'll see. So the driveline angles have nothing to do with axle housing rotation and it's all related to axle ratio I would assume-more ratio more leverage? I understand the need for zero angle difference under load guess we'll need to play with shims to see what it needs. Bob

[baddbob]

Also, didn't Mopar suggest the use of an adjustable pinion snubber to help the SS springs work right? I assume when the snubber limits rotation it sends more upward force through the spring?

[xntrik]

Originally Posted by baddbob

Also, didn't Mopar suggest the use of an adjustable pinion snubber to help the SS springs work right? I assume when the snubber limits rotation it sends more upward force through the spring?

Yes they did. They also adjusted the snubber to very close clearance at static height and the nose of the car up high. It was drag race only since it limited suspension compression. They also did not use shackles behind, but a slider.

The springs act like semi-flexible (short) ladder bars and will make the rear end rise on launch, so a pinion snubber is moot.

Urethane bushings in all the spring attachment points front and rear is highly recommended. Aluminum is very stiff for the street. Rubber is ridiculous, except for cushy ride.

You also need to dump the rubber cushions around the springs in the axle pads.

Also if you are launching very hard, stiff 50/50 shocks will reduce the initial hit on the tires and also reduce the tires unloading 10 feet out. I've found that air shocks (10 psi only) to be very stiff both directions, price is right.

[baddbob]

Cool, we have the urethane bushings and ditched the rubber spring pads. We did use the urethane pads supplied with the kit but they seem stiff enough that I think there won't be any problems. No sliders in the rear since this is going to be mostly a street car. We might try the airshock trick and will put seperate lines for each side if we do, I remember how bad the cars I had years ago handled only running one line and a T fitting. Or we might use truck shocks-a good friend of mine cured a lot of launch problems with his Camaro using them-worked better than his adjustable drag shocks.

[xntrik]

Originally Posted by baddbob

Cool, we have the urethane bushings and ditched the rubber spring pads. We did use the urethane pads supplied with the kit but they seem stiff enough that I think there won't be any problems. No sliders in the rear since this is going to be mostly a street car. We might try the airshock trick and will put seperate lines for each side if we do, I remember how bad the cars I had years ago handled only running one line and a T fitting. Or we might use truck shocks-a good friend of mine cured a lot of launch problems with his Camaro using them-worked better than his adjustable drag shocks.

Remember that the tight springs will act as an anti-roll bar. Not stiff and rigid like ladders, but some flex to allow roll.