Just fixed driveline vibration!!!For free!

CB is shimmed 3/8" with the OME CB shim kit , lift is 2 1/2" front and back

 

I haven't actually done the trig to calculate your final angles but seat of the pants, I'm guessing you won't need more than maybe 1/2" worth of CB shims. The final angle at the Tcase will be the largest operating angle and it is nowhere near being a problem. You read that 3 degrees is "ideal", but NO high clearance vehicles operate within that spec. Not even a stock Tacoma does. A more realistic maximum is around 7 degrees, and you won't be even lose to that. Fix the pinion and then measure your resulting angles in shaft one and two. Figure about 1/4" of CB shim for each 1.5 degrees of difference that you need to correct. Trust me, you aren't off so far that you have to worry about this. Just fix the angles and you'll be fine.

It's true. You will feel the vibes once they reach some level. Actually, by the time you feel them, it's pretty frigging bad. It's easy enough to monkey stuff around till you you can't feel it, but it's still there working on yoir bearings unless you take the measurements and set things right.

You will probably notice that many people talk about developing vibes
after some period of time. That's not true. The vibes were always there, because the angles were never right. Eventually the joints got enough slop, or perhaps a bearing got tired and now they can feel it. It's important to set these relationships right.

 

Ok, that makes sense . I saw that MRW says that summit has narrow angle shims? Need to check that. If so, then get the .5 degree shim and get that pinion right. If what you are feeling is indeed from the driveshafts, that is the problem. Do the pinion then check the 2 shaft angles. The pinion adjustment should move the 2 shafts closer to zero. As long as you retain a few tenths you are fine.

 

Thanks

 

Is one of the symptoms of the drive line vibration feeling a vibration in the gas and brake pedal? I have the TSB on the rear and 2" coilover on the front and have been feeling this sometimes. Feels like I'm driving mud tires instead of highway tires.

 

See if the vibe goes away when 4wd or in neutral. If it does then it could be the front diff bearing, if it goes away in 4wd..

 

I've been reading this thread ever since I lifted my truck 2.5" (OME +2"AAL) a few weeks ago and noticed I had a start-up vibe. I originally tried following the Spicer PDF by "adjusting the axle to be on the same angle as the first shaft" and using the rules they mention with little to no change. I did this with a combination of flipping the CB and shimming and different degree axle shims 1.5* and 3*. I've now returned CB to stock and removed all axle shims and starting from scratch.

My rear pinion is 3* up from TC output and shafts 1 and 2 are .8* to each other with a 1/8 " shim under CB ... still have a slight shudder when starting to drive from a stop. Would my next step be to put a 3* axle shim in fat side fwd, bringing pinion angle down, which is opposite from what most people do but its becoming obvious that every case is different, and shimming CB as necessary to maintain proper shaft angles?

What confuses me is, I don't believe the Rear diff pinion angle in relation to the TC output should change when lifted in the back by AAL or blocks if they are not tapered. . The angles at either end of the second shaft will change though but how would the Diff rotate? I wish I measured my angles before the lift.

 

I'm gunna have to find some random, non lifted, tacoma in a parking lot, and measure it's angles.

 

If you look back to my post about the 3 options, the spicer scheme is #3. Tacomas operate on #1.

You're right that lifting doesn't have to change the pinion angle. No fundamental reason why it should, but the parts have to be designed right.

3 degrees of mismatch is enough to cause pretty bad problems. I would double check before shimming, but you'll need to correct that before adjusting the CB

 

looks like we're in the same boat. that's reassuring. I'll be installing 3.5* shims this weekend to bring the pinion angle down. Then the CB needs to drop about 1/2".

Thanks for the help badgar!

 

I zeroed my digital inclinometer on the TC and then checked Diff pinion angle and got 3* . I will check again tomorrow and if i get the same numbers I will try the 3* axle shim fat fwd.

Is the fact that the 2" Toytec AAL not being symmetrical (centre pin is fwd of center) cause the Diff to rotate due to the longer section of leaf being aft and applying more lift pressure rotating Diff as it lifts???

Would the fact that some people have DBL cab long box trucks and some have DBL cab short box trucks not relate to some of the shaft angle differences amongst different vehicles??

Thanks for all the help Badger and everyone else contributing

 

I have a DCLB with Dakars and my pinion angle was only .65 up relative to the TC

 

That's a good question. If the spring were properly tapered, I'd say no. With a straight taper it could. That AAL has to exert alot of pressure on the springs to raise the truck that much. If it isn't tapered just right it could make the spring shape asymetrical. Any asymetry in the spring will rotate the pinion. It brings up a question though. Do the instructionns say to put the longer section to the rear? Is it possible yours is backwards? I've never been crazy about single leaf lifts. Too much work done by one leaf IMO. I think the multi leaf kits are much better. Interestingly, The All-pro pack is longer in the front section than stock. In fact, it moves the axle back about 3/4". Perhaps that is how they maintain the pinion angle.

The final shaft angles will be a bit different because the LB has a longer driveline. It should have no affect on the pinion angle though. The pinion could be 20 feet back and still perfect, but the final DL angles would be shallower

I'm happy to help. It's kind of a fun problem to work through

 

I have the 2" Toytec AAL and my truck is DCSB. My pinion is 3.5* too high

I'll check again tonight to see if they are in backwards or not. But when I was installing them I expicitly remember going to the ALL install guide to check which which way they go in. But now I'm wondering if it's possible that 2" Toytec AALs are the exception and perhaps are designed to be installed the other way around?

 

My Toytec AAL did the same thing. Made the diff./pinion angle up about 2.5*... I will soon be getting rid of it and getting the 3 leaf AAL instead.

 

Please try putting that shim in backwards. That was going to be my next step. The pinion DOES change when lifting the rear. To prove it just jack up the back of your truck another 1.5-2" then check the angle on the pinion. I did that and it increased as I lifted it more. Also have two big guys get in the bed and check. You will see the angle go down to almost zero which is where it is from the factory (I measured a stock prerunner at near zero - in that truck the CB had a 4 degree opposing angle from the Trans)). When I jacked up the rear 1.5" to equate a 3.5" lift I had 4.5 degrees opposite the TC which is at 5 degrees. I mentioned that in an earlier post. I'm dying to see the result you get if you rotate the axel shim and the CB angle is near zero.

 

I'm sitting at +3.5* pinion since I installed the 2" Toytec AALs. However, I have 200 pounds of sand bags in the rear (for winter). I also heard that these AALs take time to settle. So what would you recommend I do when measuring the pinion angle? Sand in? Sand out? Half sand in? I installed the AAL December 3rd.

On a related note: I also have some axle wrap. Would this possibly come from the fact that my pinion angle is too high or is it 100% 2" AAL issue? If it's an AAL issue I'll save myself the headache and kill 2 birds with one stone by getting a leaf pack that doesn't cause pinion angle issues or axle wrap

 

try measuring both ways. 200lbs probably wont make that much difference. 400 does. lets see if jsilver gets the shim on backwards or go buy a 3-3.5" leaf pack and drop the CB a little and I bet you wiil be good_ please do that I'm curious. I'm seeing a pattern here - 2' lift put us in nowhere land, cant get the DL dialed in (just waiting for someone to put a shim on backwards). I'd do it but with a wife and two kids its not a priority. Guys with over 3" seem to be ok with a small CB drop. It makes sense to me I just want to confirm a couple of things I mentioned.

 

My AAL is installed long part towards rear as per instructions.

The Toytec TSB AAL is symmectrical. Does anyone have this that knows there pinion angles??

I'll try to get the axle shims in tonight fat fwd and post results.

 

Installed 3* shims thick end Fwd which brought Diff pinion down to 0* (TC output at 0) Shimmed carrier down 1/4" to keep shaft 1 and 2 to .8* to each other and took it for a drive. Worst vibes so far. Not only at start up but seems to be constant driving around the block a few times. So now I have to remove them again tonight to avoid having issues on the highway tomorrow when I drive to work. Soooo frustrating....