Mike's 1978 FJ40 Build

[DSB345]

Mike, Your axle is already getting dirty

 

[78fj40mg]

Mike, Your axle is already getting dirty

Thanks Dave! You've noticed the mess, unfortunately, I drive on a gravel road which is about a mile long and it sucks on rainy or extremely dusty days, some UN-welcomed dirt/MUD stains are expected to my dismay. IH8MUD!!!!

 

[78fj40mg]

Also installed several electrical boots which I purchased from @Coolerman

Ignition coil boots installed

Alternator B+ terminal boot installed

Starter +lug boot installed

 

[orangefj45]

Are those shims aluminum?! If so, then do yourself a favor and replace them with steel counterparts. I have a few aluminum shins hanging on our "wall of shame". Tgey flatten out, crack in half, .... just not reliable.
If they're steel, then forget I said anything.
Haha
Georg @ Valley Hybrids

 

[80FZJ]

Today I installed the rear spring shims to correct the drive line angles. Used 3* degree Belltech shims and I'm happy to report the drive line angles are once again pretty close to perfect.

Here are a few pics of before and after pics, used the exact same reference point for taking the before and after pics.

Before

After, sorry for the dark exposure

Before

After

Belltech shims

How much is your truck lift to have that much of shim?

 

[DSB345]

Nice touch on the boots

 

[orangefj45]

How much is your truck lift to have that much of shim?

To find the proper shim you'll need to measure the angles of the Tcase output flange ( in this case it's the ebrake drum ) and the pinion flange. The two surfaces have to be parallel when using a standard drive shaft with a single u-joint at each end. Otherwise you end up with driveline vibrations.
Since the Tcase flange isn't movable, you'll need to use shins to adjust the pinion angle if necessary.
Georg @ Valley Hybrids & Cruiser Brothers

 

[78fj40mg]

Georg @orangefj45 , thanks for your input.

Below is the 6 step sequence and calcs. followed to arrive at 3° shims.

Background: Installed Old Man Emu suspension springs and shackles with 2.5 inch lift

Cause: Experiencing Drive line vibration with an audible sound, vibration was speed sensitive

Note: Did not have this condition with old leaf springs

Goal: Minimize drive line vibration and audible noise and prevent premature U joints wear, and match drive line angles

I removed the drive shaft and used a magnetic angle finder to determine the drive line angles, while vehicle was flat and level on concrete floor slab.

Step 1 measure pinion angle

Pinion flange angle reading 81°

Step 2 measure E-brake drum angle


E-brake angle reading 84°

Step 3 calculate drive line misalignment


Sketch for clarity

(∴) 3° shims required in order to correct the drive line angle misalignment

Step 4 installation of 3° shims

Step 5 recheck drive line angles post correction method installation

Results: Pinion flange angle 84°, E-brake angle is static and unchanged

Step 6 Road test

Pending


~As far as the shim material is concerned I'm confident that what was used is of adequate strength and its longevity will not be compromised by normal driving conditions, on and off road.

 

[orangefj45]

Mike I beg to differ. If the shims you installed are aluminum, then I'd highly recommend you replace them with steel units.
Put it this way ....... if the aluminum shims were reliable, do you really think we would go thru the hassle and expense as well as time investment to have billet steel shims machined?!
I don't have that kind of time or money.
You don't have to take my word for it. Ask any 4wd shop owner and they'll tell you the same thing.
Aluminum shins are cheap and easy. But they do not last.
Georg @ Valley Hybrids

 

[78fj40mg]

Georg, I fully understand your position as a shop owner, and again appreciate your input. However, I do not plan on rock crawling and any off roading that I currently engage in is either on gravel or bare dirt roads.

The only way these shims might break, crack or prematurely wear is by under torqueing them which will allow vertical and lateral movement during normal driving, and thus will accelerate wear and minimize longevity. As long as the U bolts are torqued in accordance with the FSM specifications, of 60 ft.lbs. I don't see a problem.

Conversely, if the U bolts are over torqued then undue stress is applied and premature failure may be possible. I have the same shims on the front springs, which experience greater load forces than the rear ones, which I've been running for many years without any issues.

 

[orangefj45]

I'm gonna have to disagree again. Not just on the material but the load put on the shims. The rear u-bolts, springs and shims experience much more stress because every time you accelerate or decelerate they're having to deal with those loads. The front does not.

I'll dig out some of the failed aluminum shims I have at the shop. None of them came out of rock crawlers or what you might consider a "hardcore wheeler". These were removed from vehicles that are very similar to yours and see similar usage.

Even though you haven't had an issue with the aluminum shims, that doesn't mean you won't.
To me, if there's any question about the durability of a part and something better is readily available ..... Well that's a very easy decision.

I'm not trying to sell you a set of the billet steel shims here. But I don't want people to think that the aluminum shims are perfectly reliable either. Just sharing first hand info I've gathered from 30 years of wrenching on cruisers.

Georg @ Valley Hybrids

 

[80FZJ]

Georg @orangefj45 , thanks for your input.

Below is the 6 step sequence and calcs. followed to arrive at 3° shims.

Background: Installed Old Man Emu suspension springs and shackles with 2.5 inch lift

Cause: Experiencing Drive line vibration with an audible sound, vibration was speed sensitive

Note: Did not have this condition with old leaf springs

Goal: Minimize drive line vibration and audible noise and prevent premature U joints wear, and match drive line angles

I removed the drive shaft and used a magnetic angle finder to determine the drive line angles, while vehicle was flat and level on concrete floor slab.

Step 1 measure pinion angle

Pinion flange angle reading 81°

Step 2 measure E-brake drum angle

E-brake angle reading 84°

Step 3 calculate drive line misalignment

Sketch for clarity

(∴) 3° shims required in order to correct the drive line angle misalignment

Step 4 installation of 3° shims

Step 5 recheck drive line angles post correction method installation

Results: Pinion flange angle 84°, E-brake angle is static and unchanged

Step 6 Road test

Pending


~As far as the shim material is concerned I'm confident that what was used is of adequate strength and its longevity will not be compromised by normal driving conditions, on and off road.

Mike, Great visual explanation. I'm considering OME 2.5" lift in the future. Now I know. Thx

 

[80FZJ]

Georg @orangefj45, What is the cost for aluminum shim? and cost of steel billet shim?

 

[oldschool4wheeling]

I have a 2.5 OME on my rig and I think I may have a vibrations issue. It seems to be at highway speeds. Strangely enough, I think I hear it, instead of feel it. I thought may be I had a high speed miss fire that I could hear through the exhaust. But I believe it could possibly be the vibration Im hearing????

When I get some time, Ill measure my angles to see how they align. If I need shims with out a doubt, I'll buy steel.

Aluminum has it place but I don't believe this there. I even wonder about effects of electrolysis since there are two dissimilar metals. Over time causing the aluminum to degrade, and then fail under load??

 

[Weber Sarge]

The aluminum shims do degrade over time - and fail . I had 2 crack in half over time and become loose despite painting them with aircraft etching primer/paint on my old Sami - steel is the only way to go and the cheap aluminum ones should be outlawed . Finding out your axle is loose and has moved off the spring pins in an intersection sucks - had to have the police move traffic so I could back up far enough to pull it in place with a ratchet strap and lay under the truck with 2 cops directing traffic while I tightened the u-bolts . Never again , I prefer to re-weld the perches at the necessary angle . Most don't have the ability/tools to do this - so the steel shims are fine .

Sarge

 

[orangefj45]

Here's a pic .......

Georg @ Valley Hybrids & Cruiser Brothers

 

[orangefj45]

Mike.
I'm not trying to hijack your thread. It's very evident that your methodical and do clean work. And I certainly appreciate that or I wouldn't chime in.

Georg @ Valley Hybrids

 

[orangefj45]

I have no idea how much the aluminum shims cost and I don't need to know; I would never install them.
As for the steel shims, we have them machined from billet blocks at a local machine shop. All the parts we manufacture or have manufactured here in the USA. I realize we could save money by going overseas .....
2 degree billet steel shims are $30/pair the 4 degree version is $34 and the 6 degree runs $36.
We have new spring center bolts here as well. I always replace them when installing shims or any time I take them out for whatever reason.
These bolts, just like u-bolts will stretch .....
Georg @ Valley Hybrids & Cruiser Brothers

 

[78fj40mg]

Mike.
I'm not trying to hijack your thread. It's very evident that your methodical and do clean work. And I certainly appreciate that or I wouldn't chime in.

Georg @ Valley Hybrids

Georg, I do not consider this a hijack on the contrary this is a healthy discussion. Again I appreciate your input.
The only thing that might change my mind is imperical data, so far I haven't found anything that suggests steel shims are superior to aluminum shims. All metals wear over time and under certain conditions and steel is certainly not an exception.

 

[orangefj45]

I know you're an engineer. I know how your mind works and why. I studied mechanical engineering.
But sometimes you have to step outside of that box ......

Hahaha!!!!

Georg @ Valley Hybrids & Cruiser Brothers