Old Man Emu: Questions, Answers & Pictures

Lol , no harm no foul

 

It feels really good. Firm but not hard. I get my alignment tomorrow so I'll take off the kids gloves and test it then.

Edit:
On the LR UCA's, you don't have to grease the ball joint right?
Does anyone know what the drive shaft angles are supposed to be relative to each other?

 

I just ordered my OME kit and LR UCA's!!

Can someone post a picture or two of what the center pin collar is for? I'm not getting it. I've gathered that it's to shim the axle to a new angle, but if you have to take the bolt out of the leaf pack to remove the collar and replace with shim, what's the point?

Will the CV boot ribs rub against one another? I'm wondering if I'll need to do the CV boot mod so they don't rupture over time.

 

The centre pin collar extends the head of the pin so you can add or remove the slide in style axle shims

 

the collar allows you to "slide" a shim in so you don't have to take everything apart like you stated above. Using shims of this nature.
http://www.jegs.com/p/Specialty-Products/SPC-Truck-Axle-Shims/1982009/10002/-1

 

Thanks. That makes more sense.

There must be a hole in the axle for the bolt head/collar to fit into, so-as not to interfere.

 

Ok, only the slide in style. Got it.

 

It'll make more sense when you take your apart but this first pic shows shims installed on a leaf pack with the center pin in the middle:


This pic shows a spring perch. The center pin goes into the hole in the middle to "center" the spring on the axle:

 

^^^^^

Those aren't slide in shims and don't require the collars

 

Ok that's what I thought. Thanks guys.

 

Yeah, I get it. Thanks for the clarification though.

I'll probably install the collars, install the lift, measure drive line angles, and machine some custom shims at work and slide them in (or buy them if whole degree increment shims will work, since they come in degree increments).

I've been lurking for awhile, and see a lot of people just try shims, carrier drop, etc. without measuring angles first, which is trial and error. That works if you have the time, but I'd rather only have to do it once and be done, so I'm going to measure and get it right the first time.

 

^^Good point. I'll do that.

 

Before

After

Thought I'd throw this out there, put 2,000 miles on the kit since install, working out nicely. Thanks to this thread for all the guidance.

 

What's with the shims? I'm about to order the OME complete kit with dakars...am I going to have use a shim? Sorry to sound like I have no clue but i don't. Thought I had it all figured out and then I read about shims and drive line angles...

What does this achieve and is it necessary for ordinary driving/light off road?

 

Shims are a corrective measure used to fix driveline vibrations that you may or may not get after lifting , adding the centre pin collars allows you to add shims later without needing to remove the centre pin

 

edit:

question answered

 

These guys have it right. You get drive line vibration when the transmission output shaft and the differential input shaft aren't parallel (or within some specified tolerance). Note that they can, and will, have an offset, but can still be parallel. It gets a little more complex with the 3rd u-joint on the double cab but that's basically it. It's all due to the nature of the u-joint. A constant angular velocity on one side doesn't give you a constant velocity on the other side of the joint, but if you have two u-joints like most drive shafts (which should theoretically have equal and opposite angles), the velocity phase difference between the two joints cancels out, so you get constant rotation speed at the differential. If the angles don't match, the phase doesn't completely cancel out, giving you a vibration.

This can be exaggerated by the fact that all physical things have multiple resonant frequencies, including a drive shaft. So you may only notice vibrations at certain speeds; when the rotational speed of the shaft matches it's resonant frequency(s).

Not that you care about any of the background...I just think it's cool. I'm geeky like that. Maybe I should do a write-up about this. I could even measure the resonant frequencies of the drive shafts / carrier bearing to correlate with the speeds that people experience the vibration. It will take a bit of time, but is there any interest?

I just bought the full OME kit too. The bottom line is that you shouldn't second guess doing the lift because of the potential vibrations. You may or may not have them, but there's a lot of people here that have had it, and fixed it.

 

Opinions please, with the help of a friend I started and completed my install of the full OME kit and TC UCA's. Should I immediately get it aligned or maybe drive for a day or two and let things settle. Maybe drive 15-20 miles in the next day or so.

 

Both time I lifted it I drove around for a couple days without getting it aligned, not intentionally but I just couldn't get in the shop. Worked out fine both times. I'm not sure how much settling is really going to happen over a couple days.

 

I did a quick drive way alignment with the help of this thread, drove around for a week or so and then paid for the laser deal. Surprisingly, my home alignment wasn't too far off from where I wanted it.