Adventures of Snoball, the V8 ZJ

Well done.  Oscar approved.

I took Snoball back to Discount Tire to have the same tire patched for a third time. First time found a nail, second time didn't tell me what they found but it still leaked. This time they told me they found the problem - the rim bead-seal surface is pitted. They put some sealant on it and said it's holding but no guarantees on how long.

I kind of want to put a set of these on it:

But since I don't have $1000 to throw at it I've put up an ad on FB looking for factory gold snowflakes in good shape. I can probably get a set for $100 or less.  

Ah, the joys of vintage motoring...

Stopped by one of the local junk yards OTW home yesterday to look for a wheel. Only found one ZJ in the yard and it was the earlier style Limited, so no wheel matches. Lots of later model WJs and WKs

I did however ask them about police car push bars. "Sure" he said, "there's some out there. I tripped over one on that dirt road to the right last week. How about...uh...50 bucks?"

Best I've seen on CL locally is about $100 plus a 2 hour drive. 

So after I get the tire thing handled I'm going back and get a push bar. Also I forgot to check the earlier ZJ for skid plates. Need to do that too.

I finally received the OEM fan clutch I ordered over a week ago and installed it last night. Snoball is now 70% less box-truck-like!  Seriously, the noise factor at 55+ is significantly reduced, and the improvement in mid throttle acceleration is amazing. Butt dyno feels like 15HP or more. In the past when pushed into a trans downshift you suddenly got roaring lion noise but no acceleration. Now you get startling acceleration and a little noise. I like it.

As for cooling....too early to tell but it was fine on my 6 mile drive to work in 70*F weather. We're finally supposed to get fall temps tomorrow so a real head-to-head may be impossible until next summer.

I saved the one I took off, just in case. The OEM, $130 clutch was visually IDENTICAL to the $50 Four Seasons clutch, but it had a different part number on the back. So maybe I could have saved the money and bought another cheap one, maybe the one I had was just defective. maybe....

So I did a little Interstate testing yesterday after work since it was 92 Freaking Degrees when I left.  The truck performs amazingly well. Cruising at 75mph is now quiet enough to hear the tires singing a little whether you're running in OD or out. In fact, there's a little exhaust drone with the OD on, so I thing running without OD is actually a little quieter.

But...it also runs warmer than it did. I was expecting that, but it's warmer than I was hoping. With the AC cranking and ambient temps at 92F, I was running a steady 215F on the interstate. Once off the interstate in stop and go traffic it was running 217-219.  Once parked inmy driveway, in D witht he brake set and idling (to replicate traffic) it would slowly climb at about the same rate it always has. At 229F I checked and the fan was at least partially locked up, at least more so than it was with a cool engine. 

Now, I hear about these trucks running anywhere from 195 to 220 on a regular basis, and the middle of the factory gauge is 210.  The factory gauge's overheat marker starts at 247.5, which seems absurdly high to me. From this I take that the designed operating temp is about 210, so I'm not sure running at 215 or even 220, is a major concern. But it just seems awful high to me with all new cooling parts, a 195 T-stat, and a bunch of vent holes in the hood. I do have a slight leak at the water pump to block seal, but it's very small. Like I have to 8oz of coolant every couple weeks. 

So is my minor leak making this thing run warm? Is it just the nature of the beast? Is there some other issue? I mean, it can't be good for a transmission to run that hot all the time, can it? What do you guys think? 

I'm going to take it down the interstate a little further today if I can.

Started another thread on fan clutch issues HERE which I'm linking for posterity.

Summary: The truck now overheats slowly when running out of OD on the interstate. The new fan clutch doesn't lock up even when the truck hits 225+*, so I'm considering adjusting the actuator spring on the fan clutch to lower the engagement temp.

I also thing I have some other issue with the cooling system still, even though it's all been replaced.

More semi-action pics. Spent yesterday afternoon predriving the 100 mile route for the upcoming Sasquatch 2018 gravel grinder/MTB ride that my buddy Ray is putting on. Jeep ran great. Ray said it rides better on the gravel roads than his '18 Ram 1500, and I didn't even air down the tires.

Late Edit for the history buffs: Sections of what we drove is part of the original Seven Islands Stagecoach Road - one of the oldest known roads in America. It was originally a pre-colonial Native American trading route and was used as a stage route from Savannah to the edge of "Indian Territory," which was the Ocmulgee River here in central GA. As the country expanded it continued to Mobile Alabama. Right of way for it was negotiated from the Creek Indians and the treaty signed by George Washington.  Here's a YouTube video about the history.

In other news, I swapped in ANOTHER fan clutch (see the other thread linked above.) Summary, the new one unlocks and locks like it should, but it seems to lock up at a lower temp which means it may stay locked all summer. It's an improvement for sure, and I may be able to adjust it.

Deeper info, for the masochist among you interested in the minutia of old Jeep fan clutches...

Here are some pics of the fan clutches in question:

In order of appearance:  Severe Duty Four Seasons | OEM type Mopar   |  Severe Duty GPD

Generic info: According to Hayden (maker of Four Seasons above), a "Severe Duty" clutch should spin at 20-30% of water pump RPM when unlocked (cold) and spin at 80-90% when locked (hot.)  Standard Duty (OEM type) should spin at 20-30% cold and 60-70% when hot.  The transition happens when the spring on the front reaches approximately 170*F, which translates to a water temp of 200-210*F.  Now, the air temp after flowing through the radiator is ultimately what determines the temp of the spring, so I'm not sure how they think they can translate a spring temp to a water temp without knowing a LOT of application parameters. So I take all that with a grain of salt.

In my case, the Four Seasons SD stayed locked all the time, and the OEM one never locked at all. Notice they are IDENTICAL except for a part number cast on the back. They even list the same patent number on the front. Just for kicks I looked up that patent number. It covers a new and improved system of internal valving that minimizes the internal fluid drainback at rest, therefore minimizing locked operation on cold startup. So I have 2 fans with the same proprietary internal valving that affects lockup, and neither are locking up correctly. Sounds to me like their patented idea doesn't work so well in application.

The GPD clutch is obviously a different design, and it's the ONLY aftermarket one I could find that didn't look like identical to the other two.  It's listed as Severe Duty.  It does start locked up in the morning after sitting, and it takes a couple minutes and a few revs to unlock it (no fancy patented valves, I guess.) Once spun up, it unlocks and the Jeep runs quiet and is nice and snappy off the line. When the engine temp hits around 197 it locks up well and the truck roars like crazy, but it cools down and eventually unlocks. So basically, it works like it should. Now, since the truck runs a 195* thermostat and the gauge centers on 210*, I would like it to lock up a little higher. Say 215* or so. I think at the lower number it will likely stay locked all summer.

But, now that cool weather is here it's running great and staying unlocked. When it warms back up I'll see how it does. I think I could raise it a few degrees by shortening the spring a little but I'm not going to Berk with it for now.

And I'm sending the OEM one back and getting my $138 back.

I was thinking further about this. The ZJ runs higher ambient temps under the hood than any other vehicle I've ever driven. In the summer the grill is so hot you can't keep your hand on it. I've even had friends comment on it standing next to the truck. I think because of this, the spring on the clutch may be at a higher ambient temp for a given water temp than in other vehicles, and cause it to lock earlier than expected. This may be the problem with Hayden's design which is universally acknowledged NOT to unlock on a V8 ZJ. It was designed based on parameters for an average vehicle and they don't apply.  And honestly, what company is going to spend actual R&D dollars fine tuning a $40 part for a 20 year old non-collectible, cheap-ass Jeep?

Well, that problem and their crappy patented valve thingy to minimize less than 2 minutes of startup lock to "maximize efficiency."

This may be why the GPD seems to be locking up a little too low as well.

Facebook informed me we bought Snoball one year ago today. Its come a long way.

Doesnt look a lot different on the outside, but boy is it underneath!

In reply to ultraclyde :

Happy Anniversary !

Today I finally took the time to install the front track bar I've had laying around. I also replaced the front sway bar end links. Now I can finally say everything that moves in the front suspension has been replaced.

I also had to replace the sway bar to frame bushings. I put new Moog factory bushings in about 6 months ago and their already beat up enough that the bar was flopping around. I put the urethane one back in, we'll see how long they last.

Another step towards becoming a Real Car. I got 2 key fob remotes for Snoball today. Brand new and programmed for $90 from a local locksmith.

The biggest surprise is that it still adjusts the driver's seat position to match the key fob that unlocked it! I've never actually had a car that DID that. It also adjusts the side mirrors to match, but the position sensors are flaky so it usually points them all the way down. So I'll have to disassemble and clean the sensors at some point.

Keep it up man. Every time I see this thread it makes me want another one of these.

I started another thread on this, but since its turned into an issue I'm recapping here in the build thread.

Friday morning about 1AM I was on the Interstate running about 75mph when a vibration developed. It feels like you ran off the edge of the road and are running on the rumble strip. Feels like it's in the front. At first it came and went but in a couple miles it was constant and getting worse. It seemed to be causing drag on the engine and I was working pretty good to do 60mph when I pulled off the next exit. I checked for loose parts. Finding none I figured out if I kept it under 45 it was ok so I eased home the last 20 miles on B roads.

Later that morning i put it up on 4 jack stands and ran it in drive. All 4 wheels were turning with no vibration and drive shafts ran smooth. No play in shafts or wheels at rest. One tire looked funny so I took it to the tire shop and had the fronts checked an balanced. Both were fine but one had slung a weight. After a rebalance I drove about 5 miles on the interstate and it felt great. Ran it up to 85, beautiful.

Thinking it was cured I loaded Jeep and trailer for a weekend mtb event and we headed out that night. We had been on the interstate when the vibration came back, worse this time. I pulled off and found a big parking lot where I did a couple big figure 8s to check the viscous coupler in the t-case was working right, but it was fine. I topped off the trans fluid too, it was a little low. No help. I was able to get home but the vibration was worse and now down to 30mph.

We through stuff in the car and went to the event without Snoball. I just got home and wont have time to check it out till after Thanksgiving. 

So I've got a bad vibration that come on when it's been run at high speed for a while. If you bump it into neutral the engine spools fine, so it's not an engine issue. If you stand on the brake and increase rpms in drive but sitting still, theres no vibration so that eliminates TC issue.

I think it's probably the ujoint or double cardon joint in the front axle. Might also be the front diff eating itself. Could be CV axle up front, but slow figure 8s were quiet plus they're less than a year old.

I'll pull the drive shaft and check the diff fluid for shiny bits when I can, and then go from there.

Edit: forgot to include that it vibrates under power, is almost smooth under coast, and also vibrates when geared down and compression braked.

Sounds like radial play in an inner tripod-style CV.

I think you may be right. I drove it a couple miles in town to the vets office and it seemed fine. Coming back I stopped on a vacant lot and put it in 4lo to see if that changed anything. I now have a "tikka-tikka-tikka...." noise on moderate acceleration. Classic CV sound. So it's either an axle or the CV on the driveshaft.

I tore down the front axle yesterday. The Ujoints seemed fine and the CV joint has zero play in it. I'm waiting on parts to put the axle back together but I'd be surprised if it was the problem. I'm replacing the ujoints and the centering yoke with OEM Spicer units but I'm going to pack some grease in the CV and call it good. I can't see how it's a problem with no play in it.

I also pulled the cover off the front diff. Lube looked fine and wasnt sparkly. No bits of metal, everything seemed tight and ran smoothly. Only thing I saw was some possible cracking in the planetary teeth but I'm not sure it wasnt just an optical illusion.  Here's a pic:

Once I get the parts in I'll reassemble and see where I go from there. I havent really seen anything that would make vibrate yet.

Mmmm...freshly rebuilt double cardan...

Got everything bolted back in. Going to drive it to work and a mtb ride tomorrow for testing. I dont think anything i found was causing the vibration, but only one way to find out.

I know from the Odyssey forums that vibration under acceleration but not when coasting usually points to a drive axle/CV joint issue.

In reply to dj06482 :

Yeah, that's my next stop but the axles and CVs are less than a year old, so it's less likely. I'm also not ruling out a tire problem that Discount Tire didnt find the first time.

Update time. I bolted the DS back in and took it for a drive on the interstate. The major vibration was gone. Unfortunately I gained a much more subtle vibration that starts around 60 and increases with speed, loaded or unloaded. I marked the joint parts and reassembled them the same way but it feels like the shaft is out of balance. The only difference is I put in a new centering ball unit.

I pulled the shaft back out and drove it without it. No vibration. So whatever is going on, it's in the shaft.

I rechecked the u-joints. Everything looks right and it rotates smoothly with no binds. I did find a rough spot in the CV joint so I replaced the CV too. 

This is what you do when you dont have a vise:

With the shaft reinstalled I still have the vibrations. 

I think my next step is to have the shaft balanced. I can't believe that the new centering ball link would cause that much of a problem, but maybe? 

What do you guys think?

Today Snoball moved on to a new adventure with Nick. Their first adventure is driving from Georgia back to Detroit. 

What's going to replace it?

In reply to docwyte :

Already bought a 2013 F150 4x4.  It will be plenty capable for any off road terrain I'm going on, plus it will tow a larger boat. And it's SO super lux. 

In reply to ultraclyde :

Nice!  I'd love to get a pickup next but they just don't fit in my garage.  My SUV fits and it's 192 inches long, a Toyota Tacoma or a Jeep Gladiator is more like 225 inches long.  That extra two feet kill it for me...