Installing true 6 inch Alcan leaf packs, has anyone had to shim the rear???

Im currently running the 3inch fabtech block with stock springs. Im going to be installing a set of true 6 inch Alcan leaf springs this weekend and have everything ready to do the swap except shims. Im reading on line all sorts of mixed reviews on weather to install a shim pack, but of course alot of these opinions were on different makes and models of trucks and different setups.

My gut feeling is that i will need to install shims to correct the pinion angle, because the 3inch fabtech block is angled to correct pinion angle for the lift kit. But like i said iv read that alot of people (including people with Tacomas) just do the swap without the shims and have no problems... Have any of you had to install shims to correct pinion angle after installing new lifted springs or have you just left the angle alone with no problems????

 

Yes get shims. Unless you want to replace the last u joint at the diff every year or so

 

Any idea what degree of shim??? I thought i remember reading on Northwestoffroad.com that any lift from 4-6 inch's use 6-8 degree of shim. Or if someone can educate me on how to properly figure out what degree of angle the 3inch blocks are i can take that angle and use that to get my correct shim.

 

Good info here

http://www.4crawler.com/4x4/ForSale/Shims.shtml

I ordered my shims from this guy and they're quality

 

I have their 6" lift springs and didn't install shims. I have had mine in since Dec 2010. No problems at all.

 

It may matter that you are a second gen vs. a 1st gen.

 

My bad didn't even see this was for 1st gen. Well good luck anyways.

 

So pretty much after reading the article about finding the pinion angle on a double carden type driveshaft, I need to find the angle of the drive shaft and the angle of the pinion flange and whatever the difference is is the correct degree of shim i need? Alot of technical jargon in there.

What is your current set up and angle of shim you used? That to will help give me an idea as well

 

My rear lift was 2"-2.25" and I have 3° shims. If those packs give you a full 6" then you're probably looking at an 8°-10° shims, but I don't have experience with lifts that size so don't quote me haha...
The guys on seem to have more info on big lifts/shims, maybe check there if noone else chimes in

 

Or every month haha....

Really ??.... I want to see your pinion to shaft drive angle......the sly smile tells me different....

 

Ok so hears what im figuring and please correct me if im mistaken hear...

Beings this is my only vehicle and my daily driver i need to do the spring swap and still be able to drive my truck until the shims come in, plus i need to have the springs installed so i can measure for how much shim angle i need to correct it.

Soooo i can either figure out how much angle the fabtech blocks have and match that angle with a new set of shims (not sure how or where to find that info) and install everything all at once. Or i can install the springs, take my measurement and order the shims and in the mean time drive my truck until my shims come in.

My question is, if i cant match or find out what the fabtech block angles are would it be a bad idea to drive my truck with the pinion angle out of wack, say for about two weeks at the most until my shims come in?

 

Unfortunately the only way to find out for sure is to do the swap and feel how it rides. I drove my 01 with a 2.25" lift for a few months before shimming, but it's possible the 6" lift could rapidly decrease the life of your u-joints. Or it may be fine...all trucks are a little different in that regard

 

Well I remember what mine looked like after a 4.5" lift in rear without shims & how it rode, crazy vibration, I'd say you might get away with it for a short time if you baby it that kind of angle will eventually eat Ujoints or worse your pinion seal/ or pinion itself