Hack N' Tap Installed......Shim Questions

[builder]

6* shims with t/C drop lol all makes a difference!

 

[Achmed]

So is it safe to say say that nobody knows what degree shims I need to get the pinion back to 1.0*-1.5* under the shaft angle?

 

[kunaji]

What is so hard about taking the rear driveshaft off and measuring the angles? It's the only way to know for sure what shims you need and we can't measure that for you on the internet.

 

[Achmed]

Go back and read. I gave you every single variable.

 

[Ivan]

So is it safe to say say that nobody knows what degree shims I need to get the pinion back to 1.0*-1.5* under the shaft angle?

Go back and read. I gave you every single variable.

Cripes...how about YOU go back an read. People have offered up all sorts of suggestions, links, diagrams and other avenues to answer your question. Kunaji is right, we can't measure angles for you on the internet. You build a bad ass rig, yet you can't comprendhend basic driveline calculations. Also, quit being such a dick when people try to help.....this isn't the first time.

 

[ECKSJAY]

Nothing like taking a simple task and over-analyzing the living crap out of it.

 

[builder]

I tried to be nice about it... bottom line is ACCORDING to your figures, your pinion is already 2.5* BELOW the D/S! and you keep saying it's angle is above the D/S. did you take the diff reading off the machined part on the back of the dif? the 2 little machined circles on either side of the cover? i am assuming you got the d/s reading correct.if your using a protractor on the dif, on the machined part of it, and your reading is 75,then your pinion is 15*. when you read off the back of the diff cover anything less than 90 is you actual degree number.if the protractor is sitting flat, say like on your valve cover, then you get actual degree reading. if it says 6*, it's 6*.ONE more time. if your original readings you posted were taken right your pinion is ALREADY 2.5* BELOW THE d/s.

 

[builder]

and if they are correct a 3.5-4*shim instead of a 3* should get you where you want to be!

 

[PacificEd]

I installed my Hack N'Tap tonight and it went without a hitch. Ok, here's the question. I get a small bit of vibration only under load at 60-65mph. At coast, it disappears. I am currently running 3* rear shims. My driveshaft angle is 17.5* and my pinion is pointing 2* higher (15*) than the shaft tube. Obviously, I need to re-shim to a lesser degree to bring pinion angle down. When taking out shims, I seem to think for every degree of shim I remove, it will actually change the difference in the pinion/shaft relationship by 2* because you are decreasing each item by 1* and summing the 2 differences at the point of angle junction.

If my calculations are correct, if I drop down to a 1* shim, I will actually be running my pinion at 1.5* under the shaft angle which is about perfect. Does this sound right? If not, what shims do you think I need?

What are your thoughts?

Thanks,
Chris

I will say I haven't done a SYE yet, but by reading the angles and the drawing, I think you are very close in you calculations to having it correct. Having the axle pinion slightly lower would make the angles perfect when torque is applied (the axle pinion will rotate upwards just a bit, so the 1.5* below center line would sound about right.

Did this go on the burgundy XJ? I figured it already had a SYE installed.

 

[Achmed]

Did this go on the burgundy XJ?

Yes.