[SoCal805]

My $.02 about measuring angles is use a magnetic angle finder, mechanical or digital. While I have the Tremec APP, I find it difficult to hold the phone dead nuts steady and the edge surface of the phone is not flat with case on, so I get inconsistent readings. The magnetic type of angle finder is hands free, and the reading settles quickly. I find the $5 mechanical one the easiest to use then just do the math.

Car should be sitting on wheels so for us who do not have a drive on lift than cribbing of some fashion to get the car up high enough to take measurements is needed.

With lowered cars or aftermarket trans & X member combos the DL angle variables start to go off the rails so shims for X member and or trans along with angled shims for the rear end come into play.

Once DL angles are within spec and you still have a vibration, especially around 60-70mph, that often is drive shaft balance issue which sometimes can be fixed with a rebalance IF the shop can spin it at high enough RPM. Very few shops in the country do. A wider, 3 1/2" Aluminum high RPM balanced DS would resolve those kinds of vibes. I always use Dennys driveshafts.

 

[StevieBB54]

Thanks everyone for help and suggestions. I will go out and retake measurements and drop DL to get a reading from the machined face. Unfortunately for me now we had another major atmospheric river with 50-70 mph winds and our powers been out almost 30 hours now. Think ill get some good use out of the inverter on the Tacoma charging phones, laptops and cordless’s work lights.

 

[StevieBB54]

Well here's what I came up with today. I disconnected the drive line and took readings again, and used front machined surface of yoke, only this time I rotated the angle finder 90* and the numbers came out better. I have no idea how and why they would be so different.
The previous 8.5* reading is now 2.7*, if I flipped it to the magnetic side against yoke it reads 8.5, rotate 90*=2.7*. See attachments.
Tell me what you all think. These readings are with no shims, just 1” lowering block. Had a discussion today locally and it was suggested to shim trans a little higher to change crank reading from 2.9 to 2.7*.

 

[StevieBB54]

 

[ridesdirt]

Good deal, that sounds more like it. I was thinking if it was 8 degrees, you would see that it didn't look right with your eye!

 

[SoCal805]

I think trans shim would nail it. 1" rear block by itself is fine. 2" and you would likely need a 2 degree shim (I did) along with the trans shims.

I got my trans shims from Speedway. 4 pack of 1/8" shims. Just remove bolts on trans mount, jack trans up enough to slide shim(s) in, lower and reinstall bolts. You can do one at a time and remeasure...or put all 4 in and measure and remove 1 if needed.

G Force GMTM-SP GM Transmission Crossmember Mount Shims (speedwaymotors.com)

 

[RifRaf]

In your original post, the engine/trans was angled down 0.4° (going from front of engine to back of trans), and now you currently show the engine/trans is angled down 2.9°. Did you measure the angle from a different spot?... or use a different procedure for measuring your angle?

In post #14, you mentioned the the pinion yoke was pointed slightly towards the ground.... is that still true with the new 2.7° pinion angle you just listed?

Is the illustration shown below correct for your Camaro?

 

[StevieBB54]

Let try to explain what has happened. My first posts were done with a analog magnetic 4" angle finder, 1" spacer under trans, 1" lowering block in leaf perches. Toss post 14 as I dont know what was going on at that time it seemed like. I was interpreting one side of 0 as up and the other side of 0 as down. The angle finder would not fit between shroud and dampener pulley (new dampener and aluminum pulley), so I was using steel straight edges to try and get readings.
So I bought a digital angle finder. I went to take new measurements with new finder, but noticed the centering pin that went into the perch was too tall and I probably had the entire assembly cocked in all kinds of angles. I fit the block into perch correctly and proceeded to take measurement. The finder had arrows pointing up or down, thats how I came up with those readings.
Rif Raf, to answer your question that doesnt look like my setup in your pic.

 

[RifRaf]

Thanks for the update.
Is the revised illustration below correct?

 

[ridesdirt]

@RifRaf Where did you get that calculator? I like it.

 

[RifRaf]

@RifRaf Where did you get that calculator? I like it.

It is something I created in photoshop with several adjustable layers. I try to adjust the illustration so it is easier to match the op's description... so everyone is on the same page as to the correct orientation of the driveline angles. I manually change the information within photoshop (based on the op's comments) as needed.

Once I have an image within photoshop (that I think is a correct representation of the op's description), I copy the illustration with a "snipping tool" and paste the image into a post.

 

[SoCal805]

when you raise the rear end with block to "lower" the car the pinon needs to then point down a little more that is was before being raised. This is done with angled shim. I suspect if a shim is needed for OP, a 2 degree would work. "Sometimes" though with just a 1" block you "get away" with not needing a angled shim. 2" block, yeah you need one. With the 1" block in rear maybe OP just needs to raise the trans but sometimes you can't get it high enough before it hits tunnel so a combo of trans shim and angled shim for rear is needed. I could only get 1/2" shim under trans and still have about 3/8" clearance of trans and tunnel with my TH350. YMMV

I got my trans and angled rear end shims from Speedway

 

[StevieBB54]

It is something I created in photoshop with several adjustable layers. I try to adjust the illustration so it is easier to match the op's description... so everyone is on the same page as to the correct orientation of the driveline angles. I manually change the information within photoshop (based on the op's comments) as needed.

Once I have an image within photoshop (that I think is a correct representation of the op's description), I copy the illustration with a "snipping tool" and paste the image into a post.
View attachment 303709

I think the pinion angle is the opposite, it appears pointing down. So would that be 2.7* up? The DS is definitely going downward from trans to pinion.

 

[StevieBB54]

when you raise the rear end with block to "lower" the car the pinon needs to then point down a little more that is was before being raised. This is done with angled shim. I suspect if a shim is needed for OP, a 2 degree would work. "Sometimes" though with just a 1" block you "get away" with not needing a angled shim. 2" block, yeah you need one. With the 1" block in rear maybe OP just needs to raise the trans but sometimes you can't get it high enough before it hits tunnel so a combo of trans shim and angled shim for rear is needed. I could only get 1/2" shim under trans and still have about 3/8" clearance of trans and tunnel with my TH350. YMMV

I got my trans and angled rear end shims from Speedway

This makes sense, when I bought the car it had a 2" block, I took it to a shop to have angle corrected and they installed a 2* shim. I didnt like the profile look of the car, the front was an inch or so higher than the rear, it looked like the car was accelerating when parked. So I tried a 1-1/2" block, then finally a 1" block when I put the coilovers in front. I just kept the 2* shim in there until now when I installed the TKX.

 

[RifRaf]

I think the pinion angle is the opposite, it appears pointing down. So would that be 2.7* up?

Yes... If the front of the pinion yoke is pointing down towards the ground, that would be considered an "upward" pinion angle (when all driveline angles are referenced/viewed from the front of the car to the back of the car).

The DS is definitely going downward from trans to pinion.

I was trying to use the drawing you had attached in post #24. In the drawing, it looked like your driveshaft was going upward from the trans to the pinion.

Let's try this again... how about the illustration below? Is this correct?

P.S... You mentioned that 1" lowering block are currently installed. You also mentioned that you lined up (and inserted) the locating pin on the leaf spring with the hole in the lowering block. Did you check/measure the hole in the lowering block to be sure the locator pin on the leaf spring was fully inserted and not bottoming out within the hole in the lowering block?
Some lowering block also have a "button/pin" on the top side of the block. If so, did you check the height of the lowering block button/pin and confirm it would fit into the locator hole on the bottom of the leaf spring perch without hitting the axle tube?

• When I measured the locator hole on the bottom/center of the leaf spring perch, I came up with 7/32".
  

 

[StevieBB54]

Since I removed the 2* shim the locating pin was too tall at .500 and hole in perch was about .320. I compressed the interference fit pin on block to .280. Now the blocks sit flush on perch and leaf.
In your last drawing its showing a pinion working angle of 4.7*. What needs to be done to correct that, if anything?

 

[RifRaf]

Thanks for the info about the lowering block fitment on the leaf spring and the axle perch. This helps verify the the differential is not "tweaked" due to poorly fitting lowering blocks.

In your last drawing its showing a pinion working angle of 4.7*. What needs to be done to correct that, if anything?

I would first need to know if the entire photoshop illustration (shown in post #35) is a correct representation of ALL of your driveline angles (trans, driveshaft, and pinion).

 

[StevieBB54]

Thanks Mike for all your help and the various
suggestions to try and remedy my situation. I may try this setup you sent using a 6* shim. I raised the rear of the trans as far as I could which is 1.085".
Hopefully this could work.

 

[Melmount]

U needed a 6 degree shim to be still down a degree? That pinion way too low an angle initially. Like perches welded wrong. Both down 1 degree is fine. Especially if u have a good driveshaft

 

[StevieBB54]

Im beginning to believe the perch angle is off. I really want that to be my last resort to have them relocated. I have a set of 6* shims, I was going to try out tomorrow. My DS is a new steel 3.5" . What do you mean by a good DS?