Community Forums

jbringneck · 05-02-2014, 06:36 PM

First cry for help here on the forum! I have a 2004 Tropi-Cal with the 3126E Cat Engine and 56,000 miles. I have read that the non-greaseable fan bearing is prone to die around this mileage figure and I would like to replace it pre-emptively. I've been looking and scratching my head as to how to get the fan hub bolts out so that I can get at the stub shaft and bearing. Does anyone have any hints at to how to best go about it? Thanks for your help! John

Skip426 · 05-02-2014, 06:53 PM

Many posts on the cost of the hub replacement, not many try this themselves, may require , removal of rad & CAC to access.

You could search the Cat engine forums for the stories of the replacements.

P.S. you don't have to wait till you need help to post .

twn454 · 05-02-2014, 07:49 PM

Just did mine, they are greaseable, zerk fitting is at the 12 o'clock position.I had to replace my radiator so I did the bearing at that time, you'll have to pull the rad & intercooler to get to it.

jbringneck · 05-03-2014, 07:09 AM

Thanks guys! My fan bearing is NOT greaseable, apparently built during the transition from 3126E to C-7, CAT build specs verify this as do my eyes. Was trying to avoid having to remove radiator and intercooler, what a pain in the rear! I have read where owners of other coaches have cut access panels in the fan shroud and perhaps coach floor and was wondering if any other Tropi-Cal owners had gone this route and what worked for them?

mbrandt1402 · 05-04-2014, 04:40 PM

You are about 12k miles ahead of our '04 C7 TropiCal. I had the local Cat dealer service the rig last fall for a valve adjustment (annual services done by prev owner at RV super centers and no indication of a valve adjustment) and to get an expert opinion on the fan bearing. Mine is also not greaseable, and the tech said there was nothing to warrant a pre-emptive replacement.

I've read a lot of the same threads that you most likely have. I got a sense that many failures were on greaseable bearings that were never serviced.

In any event, I hope to have a fan clutch kit assembled some time this summer (Freightliner won't fill my order for a fan spacer due to high cost for single piece order to their supplier). I'll make a judgement on the bearing if/when I ever install the clutch. I want the peace of mind that comes from removing and cleaning the heat exchanger stack, so no short cuts (at least as I plan it right now).

jbringneck · 05-05-2014, 08:46 AM

Thank you very much mbrandt1402, you have given me some piece of mind! Please keep me informed of your fan clutch upgrade as I have been looking for one. Also, I have not yet had the valves adjusted (I am the original owner) but plan to do so this summer. Were the valves out of spec, and did you notice performance/economy improvements? Thanks!

mbrandt1402 · 05-05-2014, 10:33 PM

The tech that did all of the work told me that he strongly suspected the lash had never been set. When he does valve lash, he almost always finds a strong trend - all the valves are a little tight or a little loose, or maybe exhausts are one way and intakes are another. He doesn't do many "first time" valve lash adjustments, but often finds them all over the place - some loose, some tight. Mine was that way, so it appears my intuition was correct. The lash adjustment that is supposed to be done some time after the first 10k or 12k had never been done.

I also had the engine computer software updated. I was still on the version installed at the Cat factory in '04. We made a ~ 200 mile round trip before and after the service with just a few differences, all of which should have decreased mpg a bit. On the first trip we didn't tow anything, on the second we had our Miata with us. We also climbed a little further into the hills - about 400 ft higher elevation than the first campground, and with a couple of up/down cycles to "earn" that 400 ft. First trip was 7.8 mpg, second trip 8.3.

My research found a PWM fixed output choice for the Cat computer's fan control setting was added at some point, so I had that enabled along with a different exhaust brake setting. I also stumbled across a junkyard Borg Warner Visctronic fan clutch from a C7 powered Freightliner Century class. I need to find a fan spacer, then I'll be ready to install the kit. I'm hoping to get into the high 8s. The fan clutch has been worth a solid .5 mpg for the handful of people that have done it.

stink · 05-05-2014, 10:52 PM

I did my hub bearing and its not that difficult. If you have the bearing you must have a rear rad. I cut a 6 by 10 inch panel from the top of the shroud. This will give you access to the 6 fan bolts. After the fan is removed you will find four bolts holding the bearing housing to its bracket, just remove bolts and housing. Take housing and new bearing to an automotive machine shop and have them press in the new bearing. Reassemble parts. Mount the cut portion of your shroud with some hinges and latches using self locking nuts and bolts. This panel will give you access to clean your rad and cac.

jbringneck · 05-07-2014, 09:43 AM

Thanks stink! What was your access to the top of the shroud like? My shroud is tucked under the rear closet as the access door in the bedroom floor stops at about the front (rear?) of the engine block. If I knew for sure that cutting the shroud as you did would allow me to reach the fan, I would do it in a minute! Not sure I can contort that much??? Your thoughts?

mbrandt1402, thanks for your reply! I will look forward to hearing how it goes! When I talked to CAT Tech Support I asked about the software updates and was told there were two since mine was made. As I was about to ask "Should I have it updated", the Tech said "But if you're happy with the way it runs, if it ain't broke, don't fix it". I have read in some of the forums that it's a mixed bag as to benefits with updated software. Your thoughts?

mbrandt1402 · 05-07-2014, 11:25 PM

I understand the "if it ain't broke" viewpoint.

I have a contact at the Cat factory that looked at some of the updates issued after my version. IIRC, there have been a couple dozen since 2004, though not any in the past few years (standard practice). Some improved engine function, some tailored engine performance to the Allison trans better, etc.

There is a post in the Cat forum about a guy having a couple of sensors fail during a trip. He also got the most current software revision and got significantly better mileage afterwards. Some of the increase could have been because of poor sensor function before the outright failure, but the mpg he claimed he got was way beyond anything my rig has turned in. That prompted me to get the update. I suspect most of the mpg increase after servicing came from the software, not the valve lash. Too tight would have burned valves, too loose should have been audible (I think - it is pretty noisey back there).

stink · 05-08-2014, 12:05 AM

Quote:

Originally Posted by jbringneck

Thanks stink! What was your access to the top of the shroud like? My shroud is tucked under the rear closet as the access door in the bedroom floor stops at about the front (rear?) of the engine block. If I knew for sure that cutting the shroud as you did would allow me to reach the fan, I would do it in a minute! Not sure I can contort that much??? Your thoughts?

mbrandt1402, thanks for your reply! I will look forward to hearing how it goes! When I talked to CAT Tech Support I asked about the software updates and was told there were two since mine was made. As I was about to ask "Should I have it updated", the Tech said "But if you're happy with the way it runs, if it ain't broke, don't fix it". I have read in some of the forums that it's a mixed bag as to benefits with updated software. Your thoughts?

My barge has a rear closet and the floor in closet lifts up. This gives me good access to the fan and front of engine.

Dean757 · 06-19-2014, 09:30 PM

Got 9 miles from home on start of 2 month vacation trip . Overheat alarm . Stopped and serpentine belt was gone . Towed to Cat dealer and he said fan is loose with broken bolts , I suspect seized fan hub . More info later . Just got home . 53000 miles on c7 in 2005 tiffin

jbringneck · 06-20-2014, 07:40 AM

Thanks Dean757!

I am about to start a 2 month summer trip also and I hope mine starts out better than yours! I'll look forward to hearing more......

John

Dean757 · 06-20-2014, 12:13 PM

Quote:

Originally Posted by jbringneck

Thanks Dean757!

I am about to start a 2 month summer trip also and I hope mine starts out better than yours! I'll look forward to hearing more......

John

Hi john , I just came from the cat dealer and they removed the exhaust pipes/muffler. Air cleaner and other stuff to attempt replacement of the fan hub. If the broken bolts are too hard to get out , they will have to remove radiator. Technician said it is a sealed bearing hub. I am glad it failed 9 miles from home because it will not be done until Monday or Tuesday. I think that the new hub will be good until 30000 to 50000 miles so IF I had 30000 miles on this again , I would have it replaced so it would not fail during a trip.