Which axle shim would I need here?

Hi All!

With these driveline angles which shim should I use?

2001 2.7L taco........I have 5100's all the way around, 882 springs in front with diff drop,and new general springs and AAL in the back. Left the overload spring in with the AAL so I think about 3" lift in the back and 2.5" in front. Stock tires

Took some measurements using my phone inclinometer app. Im getting a tiny shudder on deceleration even in neutral around 15 to 30 mph. Carrier bearing drop helped eliminate shudder on acceleration. Seems to drive normally. The front feels pretty floaty after the lift.

 

Currently going through this nightmare myself. I'd really suggest getting something more accurate than your phone for an angle finder. You have to be really careful with measuring the OEM yokes (at the transmission and pinion as they are tapered)- it's best to measure the flange itself.

TLDR: I had the most success by aligning the rear drive shaft slope with the pinion. That's your 14 and 6 degrees. That math works out to be 8 degree shim, which is insane, and why I suggested a better angle finder.

 

Ok I'll get like a magnetized one and measure again. Did you fix your nightmare then?? What did you have and end up doing?

 

I have not completely eliminated my vibration. I am going to stick a go pro down there and get some video this weekend to try to pinpoint the source.

https://www.tacomaworld.com/threads/driveline-angles-sanity-check.764885/

 

Just a suggestion, before you add the pinion shim, try a CB spacer and see if that helps. You can use stainless steel fender washers. You can probably get you front and rear angle closer in ° to see if that helps. I can’t tell from you pic if that’s a spacer in there. If it is, maybe remove it and see how it feels.
Another option could be to flip the cb upside down.
I’m not and expert and have a 3rd Gen but I chased vibes too and wanted to share my experience. Good luck

 

Yes I have the CB drop in there and it helped on acceleration but did not completely eliminate it. Its not terrible but I just want it to be like before. Lol Where is the best place to measure on the rear drive shaft? The slip yoke where all the grease is or up from that?

 

Ok it kinda looked like it was there but was not 100%. Using your phone, I would just measure where it fits. I usually take a few measurements and see if they’re close to get a better idea.
Last suggestion, on the 2nd and 3rd gens, the cb can be slightly off center, left or right, take a string and it it from from front of the front shaft to the rear of the rear and see if it’s in a straight line.
Sorry I can’t really help much more than that. But getting a 2° shim might be a good starting point and try the slotted ones from headstrong off-road. Makes install really easy!

 

When a truck gets loaded down why does that not change axle geometry and cause vibrations?

 

Loading it down makes the angles straighter which would tend to reduce the chances of vibes.

 

New numbers with my digital angle finder!
Rear Diff pinion 4.7
Rear Driveline 11.9
Flange at Double Cardon 4.6
Driveline 4.7
Flange at transfer case 1.9

Would So Im thinking a 5 degree axle shim?? Anyone see something wrong with how im doing this?
Thank you!!

 

How are you calculating the flanges?

I used a speed square where you used a file so I could always keep the angle finder on the same plane.

 

Yeah those numbers are wrong. I wasent thinking. Im minusing from 100 instead of 90 Lol......Let me correct them.

 

I spoke to Josh at Tom Woods custom drive shafts and he said if my pinion angle is 4.7 and adjacent drive shaft slope is 12 and the flange to flange drive shaft length is 37" then I need a 3 degree shim with the fat part facing the back of the truck. DONE!! ???

 

Did you happen to take before and after measurements when you swapped out your leaf springs?

And just to confirm, you have 3 main leaves, 1 AAL leaf, 1 overload leaf? or is a 3 leaf AAL? 3 + overload would really increase the pack height and overall lift.

I think we're in the same post rear spring upgrade boat, in that we ended up with way more lift after the spring swap than desired.

But yeah, you have 7.2 degrees of difference between your DS and pnion flange. Which is a ton.

 

Interesting... That calculator for me says I should have gone from the three degree shim down to a 2 degree shim. I went the other way.. to a 4. Guess I'll be swapping that to a 2 degree this weekend as well as taking video...

 

Yeah its a 3 leaf AAL and I left in the overload spring. No I didnt measure but should have. I didnt think it mattered since the original leaf pack was totally shot. I knew it would be jacked up!

So if I have 7.2 degrees of difference then why only a 3 degree shim?

 

I'd bet you have more lift than you wanted with the 3 leaf AAL + overload.

I'm not sure why 7.2 = 3, but I trust tom woods more than my intuition.

 

Yeah the ass is in the air more than it should , I actually like the rake going the other way a bit like a baja truck! But only by maybe an inch. Nothing that looks like hell Lol.