firebirdStud

Ok, just found out the last u-joint I installed is already flatspotted - less then 100 miles. Precision ujoints are a f-ing joke.

I am thinking I will go Spicer now, because I am sick of replacing these damn things.

So, greaseless or greasable? Plain rubber seals or metal backed seals?

Metal backed seals:
http://www.northerndrivetrain.com/pr...PI-5-174X.html

greaseable:
http://www.northerndrivetrain.com/pr...PI-5-178X.html

nongreasable:
http://www.northerndrivetrain.com/pr...PI-5-447X.html

wierd government one?:
http://www.northerndrivetrain.com/pr...PI-5-471X.html

spicer Life series:
http://www.northerndrivetrain.com/pr...PI-5-799X.html

plain not greasable (one that came with the Tick Perf spicer yoke for the viper tranny:
http://www.northerndrivetrain.com/pr...-SPL30-1X.html

I dont know which ones are the better ones... I hate changing these things out.

What are all of you running with your dana 60?? Mine is a true 1350 series ujoint up front and out back.

THANKS!!

Cody

Injuneer

What do you mean by "flatspotted"?

firebirdStud

With the d/s out, I grab ahold of the caps, and rotate it back and forth. Right in the middle, I can feel a spot where it rotates just a little bit easier, and you can feel the change in pressure needed to rotate the joint. Does that make sense?

Injuneer

Let's see..... you have a serious driveline vibration. You have the tranny shimmed so high, the rubber bumper is up against the chassis. The driveshaft is eating up u-joints. I don't think the problem is poor quality u-joints. You need to have the driveline examined and set up by a professional.

firebirdStud

lol thanks for your vote of confidence Injuneer..
I admit I dont know everything about this setup process, but I am learning. If I had the cash I would take it somewhere, because I am tired of dealing with the headache.
I bought a digital angle finder today at sears, and it says the same thing my math was telling me with the gravity angle finder from sphon. I thought it was worth a shot just to make sure.
What I cant figure out is if the pinion angle should be set against the driveshaft or the trans output shaft. Fbody-ers on here and other boards are saying the driveshaft, but that assumed the trans output shaft is exactly parallel with the frame rails... of which mine is not.
Other sources of info (4x4 boards, chassis makers, hot-rodders and u-joint manufacturers [spicer]) say that the angles from

AL SS590 M6

I agree with Inguneer as to how you have it now.
Go back to square one.
Put the car up in the air with the suspension loaded and the rockers level.
Put the trans back down to it's factory location.
Measure the trans output shaft angle.
Adjust the rear end input shaft to exactly the same.
Then adjust it about 2-3° down from there.
Do not confuse driveshaft angle with pinion angle.

firebirdStud

I am sorry for not posting up, but I have been in China for over 3 weeks. I did line up the pinion with the trans, and went down -.5 degrees from that. Best I have gotten it.
It runs like glass now. I used to be limited to 80mph because of the vibrations, but they are gone now.

The only problem is that my pinion makes an upside down v with the driveshaft. Everyone says it should make a wide v with the nose of the diffy pointed down, but mine points up. I left the tranny shimmed up, because without that it would be even worse.

Chevycrew

Most of my experience is in the offroad world, but it all works the same..

The way i set mine is, if the output of the tranny is 2 degrees down, I turn the pinion 2 degrees up (with a linked rear suspension) If leaf sprung with no traction bars, I go 2 degrees less than the trans. So it would be 2 down at the trans, and 0 at the rear.

If the trans is lower than the rear this should also apply.

Injuneer

I think the pinion shaft on the Strange 60 is slightly higher than the GM 10- or 12-bolt. The pinion shaft being closer to the axle centerline is one of the main contributors to the 60's higher mechanical efficiency. Compare to the 9-inch, which has the pinion shaft set 3/4" lower than the 10-/12-bolt rears.

I watched Steve Spohn set up my adjustable torque arm. He simply compared the driveshaft angle to the pinion angle. He was satisfied with -1.8-deg, for an 800HP/800ft-lb setup. I've never had a problem with vibrations. I suspect that you can get away with a less negative angle with the spherical rod ends. They are not going to deflect like a poly bushing would. I also suspect that the very short DS required with the Gear Vendor hanging on the end of the TH400 also reduces the required negative angle.

firebirdStud

yup, exactly how I did mine. And this is the way that a driveline specialty shop said I had to do it. And lo and behold: it worked!

firebirdStud

I dont doubt that is how yours is set up. For whatever reason, that didn't work for my car to set the pinion angle against the driveshaft. I wonder why? Production cars should all be pretty close to the same when put together, right? Well, I suppose you even have a different tranny too, so that really throws a wrench in the mix. haha

Injuneer

Before I had the TH400/GV, I had the stock T56. I used the same approach to setting the torque arm. The main reason it was reset was because Steve built me a new arm, with the DS loop moved back quite a ways (welded to the side of the arm) because of the extension on the TH400/GV, and the very tight clearance between the end of the GV and the front spherical joint.

http://www.injuneer.com/images/photo...n/DCP04301.jpg

As much as I hate to say it, sometimes the theory overcomplicates things. I remember studying the u-joint in college, and learning that the input and output links had to be parallel for the pair of joints to provide truly linear rotational velocity and no "bind". But the practical approach, as much as I didn't want to accept it, worked just fine.

firebirdStud

Agreed!
Holy smokes, did you have a driveshaft let loose? The dents to the left of the driveshaft look like it hurt a little.

Injuneer

No..... I used to have a 3" Y-pipe with a 2x3" into 4" merge for the Mufflex 4" catback. The merge was right in the tunnel, above the torque arm cross-member, and it took a bit of gentle persuasion with a BFH to fit the merge into the tunnel, next to a 3.8" diameter carbon fiber DS. Courtesy of Mufflex.... I would have been a bit neater with the dimples.... .

http://www.injuneer.com/images/photo...t/TADS4in.jpeg

firebirdStud

haha I see. That would expain the dents in the floorpan.

That is rediculously tight... did it rattle at all? Mine had more room then that and would still hit on WOT... until I "persuaded" some areas to give the pipe more room.