The Weekend Fun Build

If I tightened them and I very well may have, you won't break them loose without installing them in the rig and using a long cheater pipe on a big wrench and jumping up and down on the end of it.
Thanks for the heads up!

That's pretty close to my plan. I'm using a big bench vise to remove the bushings. When they're out, I can clamp the joint end in the vise and work on the jam nuts.

If the larger wrench I just picked up won't do the job, I've already been looking at what I can use for a cheater.

I'll keep in my that I may need to go bigger than that, though.
 
Thanks for the heads up!

That's pretty close to my plan. I'm using a big bench vise to remove the bushings. When they're out, I can clamp the joint end in the vise and work on the jam nuts.

If the larger wrench I just picked up won't do the job, I've already been looking at what I can use for a cheater.

I'll keep in my that I may need to go bigger than that, though.
Dunno if this will work for you not knowing the nut size, but when i adjust mine, I use a crow's foot with a 1/2" drive and a VERY large breaker bar.
 
Some recent highway driving has me thinking about tire size and gear ratios. With the OD off on a steady up grade I was comfortably running 3000 RPMs at 70 MPH. I figure it might be nice if I could get close to that with the OD on.

If I account for tire wear, 3000 RPM @ 70 MPH in 3rd is right on the money with Grimm Jeeper's calculations. Here are some numbers from Grimm Jeeper on some variations:

Transmission GearAxle RatioTire SizeMPHRPMNotes
3rd3.73Used 31s703012Current setup
4th (OD)3.73Used 31s702078Current setup
4th (OD)4.88Used 31s702719Better
4th (OD)5.13Used 31s702858Acceptable?
4th (OD)5.13Used 31s803266Still acceptable?
4th (OD)4.88New 32s702608Could fit 32s ...
4th (OD)5.13New 32s702741but go with 5.13
4th (OD)5.13New 33s702662

The plan is still to stick with 31s, but I would like to regear. I know 4.88 gears are what people would recommend for the 4.0 I6 with the 42RLE and 31s. But I'm still thinking about whether 5.13 gears would be too deep for that setup.

I'm happy at 3000 RPM @ 70 MPH and I know the 4.0 I6 makes its maximum torque at 3200 RPM, which leaves some headroom. If I ever went with bigger tires, I would absolutely want 5.13 gears. But this table suggests I could still be happy with 5.13 gears and 31s, since on the highway at least, that's not quite as deep as switching off the OD.
 
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I have a new project. Thanks to @06TJ35's spotting a local CL listing, I picked up a set of Savvy control arms for a reasonable price. @mrblaine may recognize them since they reportedly came off a rig that was in his shop for a mid arm upgrade.

View attachment 121875

I know these are more than I need at this point, but I figure I can use them to make some minor adjustments now and be prepared for future upgrades later. They need a little love, though.

I have three issues to deal with. I have to break the jam nuts loose. I want to break down and re-lube the joints. And the joints have some superficial rust that I need to correct.

Breaking the jam nuts loose is easier said than done. I managed to free a couple of nuts on the front uppers, but the other nuts are more stubborn. I'm soaking them in penetrating oil and lightly hammering the nuts to try to free them. I also upgraded to some bigger wrenches for the next attempt.

Breaking down the joints seems straight forward, but my snap ring pliers are crap. So I ordered some better quality tools.

The rig the control arms came from lived a stone's throw from the Pacific coast and the salt air did a job on the zinc coating on the control arms. Judging from the rust, zinc chromate doesn't do well in marine environments.

A quick test with a wire brush tells me that cleaning off the surface corrosion will be easy. I'll just wire wheel it back down to bare metal. Then I can prime and paint the external surfaces to protect them. I may use a cold galvanizing treatment on the threads and nuts, though.

All that will take a while, but I'm in no hurry.

When the new control arms are ready, I'll start with the rear set and match the stock control arm lengths, then adjust to correct rear pinion angle while keeping the axle in position.

If I can get that to work, I can do the same with the front control arms and move the front axle forward by about 1/2" to get more clearance between the track bar and tie rod.

Then I can take the Jeep to a local shop for a full alignment to verify thrust and caster angles. That should correct issues from the recent lift and set me up for a future rear drive shaft upgrade.

Meanwhile, the Jeep is running well, so I can have fun driving it.
I posted a couple of threads when I rebuilt my Currie control arms. Might be of some value to you. The one thing that made a BIG difference for me is getting the proper joint rebuild tools. Makes the job WAY easier. I was lucky and able to borrow a set.

https://wranglertjforum.com/threads/my-04-rubicon-build.4191/page-20#post-336954
 
Better tools, better results. I managed to break down all the joints in the control arms and break loose all the jam nuts. Big wrenches and some gentle use of a propane torch did the job.

IMG_20191105_145424.jpg


The next step is to figure out how to deal with the surface corrosion on the joints and hardware. Some of the hardware is cheap and easy enough to replace, so I'll do that. I have to decide what to do with the joints themselves, though.

I also need to clean up the internals of the bushings and examine them for wear or other problems. I've already seen a couple of bushings that should be replaced.
 
I posted a couple of threads when I rebuilt my Currie control arms. Might be of some value to you. The one thing that made a BIG difference for me is getting the proper joint rebuild tools. Makes the job WAY easier. I was lucky and able to borrow a set.

https://wranglertjforum.com/threads/my-04-rubicon-build.4191/page-20#post-336954
That is awesome, and perfect timing! Thank you! I need to spend some time reading your build thread more closely.

I was thinking I might have to ask for advice about refinishing the joints, but seeing how you got the chromate redone makes me think that's the way to go. With the Navy and Marines in town, we have a good selection of metal finishing shops. I'll have to call around and see if I can get a deal like you got.
 
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Thanks to the inspiration from @Mike_H, I found a local shop that could redo the chromate finish on the JJ housings. They just came back today, and they look fantastic!

IMG_20191218_112008.jpg


I used some naval jelly and a wire wheel to take the surface rust off the outer portions of the ball centers. And all the other JJ parts are cleaned and ready to go. I did end up ordering a couple of rebuild kits for bushings that were obviously worn.

I pressed a couple of joints back together today, and things are going to start to come together quickly. I'm going to try to get the rear control arms in place by the end of the year.
 
Those arb sliders are my favorite. Jeep looks great. Can't wait to find a deal on a set and it never seems to happen! Nice clean trail jeep.
 
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Those arb sliders are my favorite. Jeep looks great. Can't wait to find a deal on a set and it never seems to happen! Nice clean trail jeep.
Thanks!

I only watched the price for a little while, but I didn't see any discounts on the ARB sliders either. Even at full retail, I think they're a good balance between price and function, which is why I picked them. If I didn't need the side steps, I might have gone with the Warn sliders instead.
 
Jeep has come a long way. So much for a way to get into the mountains to ride your bike. Now you're heading into the mountains to drive your Jeep!
True! But the Jeep and the mountain bike are still good companions.

There's a local trail that I thought might make a good Jeep route. I had been down it once on a road bike, which falls into the category of poor life choices, and noticed that it linked up with another road that might make a good loop. I didn't know what the conditions were on that other road, so I scouted the route with the mountain bike.

It was a beautiful day out on the bike, and now I have a good route in my back pocket for the next time we do an easy/fun run with first-time Jeepers.
 
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The rear Savvy control arms went in over the holidays. I'm still waiting on a part to rebuild the front set.

IMG_20191223_105421.jpg


For excessive precision, I wrapped each arm with a 1/12 rotation scale. That was pointless for the upper control arms, which get set to whatever length they need to be, but useful for the lower control arms so I could adjust both sides the same amount.

IMG_20191223_120953.jpg


It all came together pretty easily. I set the arms to the original stock length so they could slot in easily in place of the old Moog arms. Then I tweaked the two lowers and one upper to get the pinion angle where I wanted it. When I put the second upper control arm in, I set it to fit the space and biased the bolt to the same end of the hole in the control arm mount as the first upper control arm. I reconnected the sway bar while I was setting up the control arms to help keep the axle level.

I also wanted to make sure I didn't mess up the thrust angle for the rear axle. That's just me worrying about something because I haven't dealt with it before. So I figured out a way to measure thrust angle.

IMG_20191223_115631.jpg


I clamped the angle bar that I use for front-end alignment to the rear disc and shot a laser level straight down the axis parallel to the disc. Then I measured the distance from the laser line to the center body mount on both sides. If you measure the width between the two discs (as you do when you're doing a front-end alignment), and you get the body mount width from the FSM, a little geometry will get you the thrust angle of the rear axle.

What I learned was that as long as you keep both lower control arms the same length, the thrust angle is going to be well within spec (assuming the frame and axle are straight!). So I didn't really need to sweat it that much. But playing with lasers is fun anyway.

used some steel strap just like @k-huevo did to make brackets to attach the brake lines to the upper control arms. All I had to do was Dremel out the holes in the strap a little to fit the bolts. I'm not sure I can match Mr. Blaine's brute strength on the jam nuts, so I marked the jam nuts and control arms so I can tell if they loosen at all.

And that's where the fun started.

I still had a tiny bit of vibration left after the lift and the transfer case drop, and I figured that correctly aligning the rear pinion angle would help, but on the first test drive it was very clear that the vibes were much worse with the Savvy arms in. I played around with pinion angle a bit more, and even set the arms back to stock length, but nothing helped.

I thought some of the problem might be that the u-joints in the rear driveshaft had 130k miles on them, all at stock height. If they had wear from operating in the original range and I pushed them out of that range with the lift, they might be causing the vibrations. So I put in new Spicer u-joints. That helped a little, but not much.

That left me thinking that the vibes had been this bad all along, but that the Clevite bushings in the Moog control arms were doing a good job of isolating the vibrations. After all, rubber is good at that, and maybe the poly bushings in the JJs pass more of the vibration through. That's one more data point for the discussion on whether control arm bushings affect NVH.

So, I figured I'd put in the MML that I had bought but not installed, which was an adventure. I had to learn that unless you lift the tub, the transmission runs into it and prevents you from getting the motor mounts to line back up. Until I went at it with a spiral Dremel bit, I had no idea how I was going to notch the fan shroud without taking it out. And then I found that with both the MML and transfer case drop in, the top of the valve cover just rubbed the firewall, which transmitted lots of engine vibrations into the steering wheel and dash. Reducing the transfer case drop to 3/4" fixed that.

And, in the end, the vibes are gone and I've moved my transfer case skid up a bit. I might even be able to move it up more, but I'll just have to play around with it later. Also, the net u-joint operating angles and cancellation for the rear drive shaft are good, so I'm happy with how that all worked out.

Front control arms go in as soon as Currie gets back from their holiday break and sends me the part I need.
 
are you keeping the pinion parallel to the output shaft of the transmission?
Yep.

With the old Moog control arms and the t-case drop, the difference between t-case output and pinion angles was 3 degrees. After all the messing around, the difference is 0.4 degrees. The FSM spec is +/- 1 degree, and it takes some really tiny adjustments to get those last few tenths of a degree.

Edit: Also, the margin of error on the measurements is probably +/- 0.2 degrees just because the surfaces aren't perfectly machined.
 
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After installing the motor mount, I had an annoying rattle when driving over bumps. Which is pretty much all the time when you're off road. I figured it was something with the exhaust, or maybe a clearance issue at the bell housing, but some GoPro video from above the transfer case showed that wasn't the problem.

I was looking around for another spot to put the camera to try to figure it out when I spotted this.

IMG_20200117_152919~2.jpg


The motor mount bracket was contacting the frame perch on the passenger side. I got some video and confirmed that was the problem.

Then I noticed that the through bolt on that motor mount was at the far end of the slot in the bracket.

IMG_20200117_153117.jpg


So I loosened up the through bolts on both sides and used the bottle jack between the spring perch and engine block to move the engine over.

IMG_20200117_164138.jpg


Tightened everything back up, and the rattle is gone!
 
I also wanted to make sure I didn't mess up the thrust angle for the rear axle. That's just me worrying about something because I haven't dealt with it before. So I figured out a way to measure thrust angle.

View attachment 133026

I clamped the angle bar that I use for front-end alignment to the rear disc and shot a laser level straight down the axis parallel to the disc. Then I measured the distance from the laser line to the center body mount on both sides. If you measure the width between the two discs (as you do when you're doing a front-end alignment), and you get the body mount width from the FSM, a little geometry will get you the thrust angle of the rear axle.

What I learned was that as long as you keep both lower control arms the same length, the thrust angle is going to be well within spec (assuming the frame and axle are straight!). So I didn't really need to sweat it that much. But playing with lasers is fun anyway.

I'm interested in checking this on my TJ.

What type of laser level did you use?
Can you eloborate on the mounting, can't quite tell from the PIC?
 
I'm interested in checking this on my TJ.

What type of laser level did you use?
Can you eloborate on the mounting, can't quite tell from the PIC?
If you're just curious, measuring thrust angle for the rear axle is pretty simple and kind of fun.

Based on my experience, though, there's really no reason to do it unless things are seriously jacked up. Like bent frame, bent axle, or majorly screwed up control arms. Otherwise, things are just going to line up.

To make the measurements, you need these tools:
Here's the process.
  1. Park the Jeep on a level surface, preferably in the garage where you can turn off the lights so the laser is easier to see.
  2. Remove both rear wheels.
  3. Support the Jeep with the rear axle at ride height. You can do this by putting jack stands under the rear axle (make sure to spread the load so you don't damage the axle tube!) or by some other method.
  4. Measure the distance between the outer faces of the brake discs. On my Dana 44, the disc faces are 1456 mm apart. That might vary for other Jeeps and will certainly vary for other types of axles.
  5. Measure the distance from the center of the hub to the center body mount. You can use the laser level to help mark the center points. This distance will vary depending on how much lift you have and how your control arms are set up.
  6. Clamp the L-bar to the face of the rear disc at about a 30 degree angle with the forward end up. (Not sure what you'd do if you have rear drums. :unsure:)
  7. Place the laser level on the tripod directly behind the front wheel and aim it so that the vertical line projects directly down the length of the L-bar along the face of the brake disc. This takes some fiddling. Move the laser left and right to line it up with the forward edge of the L-bar, and rotate the laser to line it up with the rear edge of the L-bar. Pay attention to reflections off the L-bar — they can help guide you but they can also be misleading.
  8. Measure the distance from the center of the middle body mount to the vertical laser line. Don't worry about being extremely precise here — being off by a few millimeters isn't going to matter. A reasonably good measurement is good enough.
  9. Repeat the same measurements on the other side of the Jeep.
According to the FSM, the nominal width between the center body mounts is 1224 mm. You don't have to measure that unless your frame is bent, and if that's the case you have bigger problems.

Do some math:

Left angle = atan( ( (axle width - body mount width) - distance from laser to left body mount ) / distance from left hub to body mount )

Right angle = atan( ( distance from laser to right body mount - (axle width - body mount width) ) / distance from right hub to body mount )

Thrust angle = left angle + right angle.

Hopefully I got that math right! I have it in Excel and I tried to transcribe it here but I may have screwed it up.

Note that a positive angle is to the right and a negative angle is to the left (per the FSM).

The spec from the FSM is +/- 0.25 degrees. That's a lot! If you're like me, you'll find that you end up with results in the range of +/- 0.01 degrees repeatably even if your measurements are slightly different each time.
 
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