Broken Serpentine Belt…

While parked at the entrance kiosk of a campground I’ve never been to before, the Check Engine Temp idiot light on the dash flashed on, and checking the actual temp gauge I saw it was within 2-3 needle’s width of HOT! My gauge is labeled C for cold, 1/4, 1/2, 3/4 and then at the far right there’s a red line with H for hot next to it. There is a curved word ‘Normal’ printed above the 1/2 mark on the gauge. No indication of where normal might end except at the very far right, where the gauge needle runs out of room and the red line with the H is located.

Learned that the RV park was a membership park and I’m not a member. They didn’t mind that I drove into the park to try to turn around so I could leave. By now the needle was just below the H. Stopped and first tried to rev while in Neutral but that didn’t drop the temp from the fan like I expected, so there was nothing else to do but shut down the engine. About 30 minutes later restarted, found that the temp was already down to 1/4, so limped over to a nearby dry campground just 1/4 mile away. It’s a BLM campground on the Colorado River with maybe 25 spaces, named Crossroads Campground. Cost is $5 per night or $2.50 if you have a senior pass…which I do. The temp ended up at the 3/4 mark but no higher. That was encouraging because it meant that the ambient temp and the size of the cooling system would allow me to perhaps drive to a shop later.

After getting all set up at the campground, opened up the engine compartment and find there’s no serpentine belt. Doh! I vaguely remembered hearing a clank and clatter earlier in the day, but didn’t pay it much attention at the time. Messing around inside the compartment, found that the fan, fan idler, alternator, and tensioner all turned easily. But the A/C compressor was seized up.

The engine has 84,000 on it now, so it’s not surprising that something happened to break the belt. Just my luck it had to be a difficult to work on component. Not something I wanted to do, so I searched online and found Vinnie’s Auto Shop in Parker (about 6 miles away) had good reviews, and they work on RVs. Drove over there in my car and talked to the mechanic, and since he exudes confidence and competence I made an appointment 7 days later for the following Monday.

I took the weeks delay as an opportunity to see what, if anything, I could do myself to fix it. After 3 nights at the dry camp though, I could see that my batteries weren’t going to carry me the full week without it becoming uncomfortable for me so drove the car back over to the nearby Emerald Cove park where the over temp light had come on, explained my situation of having to wait until Monday to get into the shop, and asked the office staff if they ever did a Hardship thing? And they do! All I had to do was to come back the next morning and listen to the membership presentation…about an hour long. They always have a 2 nights free thing going on but they extended it to 4 nights for me. The presentation wasn’t too bad, only took 45 minutes. No hard sell really. Very nice of them. I enjoyed my stay and recommend a visit if you’re in the area. I decided I wasn’t interest in buying a membership though.

So now that I was in a decent park with water and power (but terrible Wifi), I could relax and think about doing the work myself. But, after spending way too much time digging into the guts of the engine trying to ‘prepare’ it for the mechanic, I decided that it was just not my sort of problem. I don’t know much about A/C compressors or how to deal with installing a new one because of the freon, so all I did was loosen the alternator so it could be easily removed if necessary, and spray clean the engine compartment after soaping it up with Simple Green – Purple. Since the parking space is all gravel, I didn’t feel much like crawling around under there trying to work on things.

And here’s a picture of what I’m dealing with, except this engine doesn’t have all the interfering parts like the fan and radiator that mine does. The compressor is on the lower left. Above the tensioner. And above the compressor is the Alternator. Then slightly to the right is the idler pulley, and then the fan hub (without the fan installed in this picture). You can see this engine has the zerk fitting extension installed.  That small black hose snaking up from the top and behind the fan hub. That extension makes it easier to grease the hub bearing.

Cat 3126

What I did do with all my free time was try to find the correct part numbers for the repair. I found recommendations online for the part numbers for the serpentine belt, the water pump belt, the tensioner, and the compressor. Except for the compressor, it was generally recommended that these parts be replaced as part of a maintenance routine at around 90K miles.

And here’s a video of what can happen to your engine components if the the ‘tensioner’ has worn out. Gates says it has the same life as your serpentine belt, and I’d say believe them because that bad tensioner is what ruined my AC compressor. Making a $200 maintenance job of changing the belts and tensioner into an $800 job replacing the tensioner, compressor, water pump belt, serpentine belt, etc. Not to mention getting the dash AC working again.

Gates: Understanding Belt & Tensioner Failure Modes… 

Above is the link, and here’s the video the link goes to:

I ended up ordering one compressor at the O’Reilly’s store as they will hold it for 7 days if you order but don’t pick it up, and another one at Parker Auto Parts at $100 less, just in case it would be a universal fit…I’ve no problem with saving $100. Both stores used the info I’d gathered to decide which compressor was the right one. Both stores ordered the serpentine and water pump belts based on the P/Ns I’d found online and generally I went with the lower cost parts at Parker Auto. So now I had things all ordered since they were non-stocked but with overnight delivery, the next day went and picked up everything.

What I do to get ready for engine work in this model Winnebago Journey is to remove the mattress and either stow it somewhere out of the way (like in the living room), or just lean it up against the slide out closet in my N-S bedroom. It fits fine as long as the slide is extended but it does block the closets and the chest of drawers. I usually chose to lean it up against the closet assembly because I like sleeping on it at night and it’s handy there.

After removing the mattress I open the bed hatch and remove the two bolts holding the two gas struts and lay them down next to the bed frame so they’re out of the way. Then I remove 4 screws that hold the bedboard to the bed frame after marking the screws so I can align it when replacing, and then fold the hinged top piece over. I also make discrete marks on the headboard fabric on either side so it’s easy to align the bedboard when it’s time to put it back in place. Then muscle the board up and out of the way against the back of the mattress. The board affords some protection to the mattress so it doesn’t get damaged or greasy.

That all gives better access to the engine compartment but first the metal cover needs to be removed and I remove 3 bolts so it can. A quick glance in there and you can see there’s no belt!

So with the hatch cover off, I drape some plastic over the alternator and then spray Simple Green – Purple (their ‘safe for radiators and engines’) solution all around inside, go outside and spray the outside of the radiator as well. Let it sit for 30 minutes and then hose it off. I snake the hose in through the bedroom window but it could come up through the engine hatch too. The cleaning just makes it easier to work on AND is a maintenance item for those with engines that have the ‘slobber tube’.

Since I had the time, I tried to remove the alternator just to get it out of the mechanics way for when he removed the A/C compressor. And it turned out he didn’t need for it to be removed as he did all the compressor work from below. While trying to remove the alternator I found that the alternator bracket has a 6mm Allen flathead bolt. It was rusty so sprayed the area with P-B Blaster and let it sit over night. It was very difficult to turn so had to go buy a 3/8″ drive 6mm Allen because a simple Allen wrench wouldn’t get it out. I work from behind so have to insert the tool by feel. Why they used 6mm when everything else is SAE is a mystery.

Good view of the alternator bracket with the 6mm Allen flathead bolt. Shown there on the lower right.

The upper 1/2″ bolt also needed P-B Blaster. The top bolt on the alternator is a 3/4″ head NC. The lower swivel bolt is 1/2″ head and ~6″ long so you need a tool on both ends. The serpentine belt is tightened by adjusting the Tensioner so the alternator is fixed and you’d only adjust it with the swivel to align the bolt hole on the bracket. I marked it’s position with a marking pen before removing so knew where to adjust it to later on.

Once I got the bracket loose, there’s the alternator’s lower hinge bolt you can see in the picture above. It’s 6″ long or so and difficult to reach both ends at once. It spins if you can only loosen one end. I had everything loose and just left the alternator installed since I didn’t want to bother taking it all the way out. But now I know how to get the alternator out when I need to and it’s pre-loosened for the mechanic. I thought that with it out there’d be more room to reach the compressor.

Now is when luck played a part. My appointment was for 9 AM and the weather in the Parker area was for cool nights in the low 50’s. And not warming up to the 70’s until after 10 AM. It gets hot in Parker so I was a bit worried that I’d need to tow the rig rather than drive it up to the shop because of the overheating. So the morning of the appointment I was ready by 7 AM to drive in the cool of the morning the 6 miles over to the shop instead of having a tow truck take me there. A member at that park offered to drive my toad over and meet me there.

And it worked out all right, the engine temp never got above the middle of normal. When I moved over to the RV park from the campground 4 days earlier the temp had stayed normal then so I felt I could make it 6 miles. That the engine stayed well below ‘HOT’ was a relief because over the years I’ve learned that a cooling system that’s stressed too much because of overheating can blow a hose not long after. When this happened I’d only driven 100 yards after seeing the idiot light on the dash and it had cooled down quickly by shutting it off but didn’t want to press my luck when I extended that to 6 miles so the cool weather was lucky.

Ready for the mechanic…

Soon found that the work I did in the engine compartment was mostly wasted as the mechanic did everything from below. He only came into the RV once to look down into the engine compartment to find a bolt. I held a flashlight up there for him maybe 5 minutes.

And next is a picture of the old tensioner. After it was out, I could get a better feel when I spun it and I could feel that there is a bad bearing. So it was bouncing around and may be what caused the bearings in the A/C compressor to bust apart and jamb the idler pulley. OR, there was a bad bearing in the compressor that harmed the tensioner. Because it leaked out all the Freon back in May of ’18 I hadn’t turned it on since then so the idler pulley bearings likely failed due to the tensioner jerking the belt. This is a known issue with the tensioner in general. Not much to do about it other then changing out the tensioner every 70-90,000 miles I guess.

Replacing the tensioner is something I should have done the first few months I owned this rig in any case. Hope it didn’t damage anything else. During my survey of the engine, everything else I could reach would spin easily. Everything seems very smooth. The alternator, the fan hub, the idler all seem OK for now. But fan hubs are a known maintenance item so that might go next. Or the alternator since it was close to the bad compressor and the belt vibration from the bearing as it went bad could have strained another bearing somewhere along it’s path.

This Gates tensioner (shown on the right above) is a hard working piece of gear and I don’t regret paying $124 for it in this small town. I later found that Amazon and eBay have them for around $65. If I’d known it was bad, I would have ordered it from Amazon before the shop date. So it and the other items cost me but I saved time and effort and don’t regret it at all. If you have more than around 70K miles on your Cat, best order one now so you have it on hand.

And here’s some shots of the engine…

Nice shot of all the empty pulleys. I marked where the alternator aligns correctly. The bracket is fixed as the tensioner does the belt tightening.

Here’s a look at the wrong compressor I’d bought.

Wrong compressor on the right ready to check for fit.

First thing I did was grab my electric connector kit and cut the old special connector off the old compressor. The new one comes with a male butt splice and I used a female butt splice crimped to the cut wire so the two sections can just be jambed together.

The mechanic thought the substitute compressor would work, but when he got it in the space it just wasn’t going to fit. Lucky I had ordered another one from O’Reilly’s and even though both part stores worked from the same info, O’Reilly’s got it right. Theirs was an exact replacement, not a substitute. See the manifold on the back of the old one above on the left? It’s removable. The sub didn’t have that. That’s pretty much necessary on the Cat 3126e with Freightliner chassis with rear radiator in order to make the installation in the limited space that is available. The mechanic rerouted the hoses as he installed the new compressor and they look much better now.

I thought the mechanic knew how to do A/C properly but he just broke the pipe connections at the compressor and let the freon escape to the atmosphere. It’s easy to evacuate and save it from the front of the RV, he just didn’t bother. Damn. If I’d known he was going to do that, I would have insisted because it’s federal law AFAIK. So he screwed up and I screwed up.

After the replacement compressor, new tensioner, and new water pump belt were installed, we then tried to install the serpentine. And it was 3/4″ too short. A return trip to the parts store and they had the non-heavy duty replacement. So bought that, just to keep from adding a day to the repair. I’ll buy the HD belt later. I did help the mechanic install the belt. It can be done by one person alternating from underneath and up above but having help makes it a 5 minute job.

Here is the information if you need to do this job:

Location: Parker, Arizona

Date of serpentine belt failure: March 18, 2019

’02 Winnebago Journey DL, Diesel 36′ Engine: Cat 330HP, Model 3126e Rear Radiator

Mileage near 85,000 miles.

Serpentine belt P/N: Gates #K080716HD; Napa #25-08716HD; 72 & 1/8″; 8-groves $84
Water pump belt P/N: Gates #25-9341; MBH 9341 (Cat p/n so everyone has it $25)
(Purchased a Non-HD Serpentine: Gates #K080716 $52- just to speed up the work, also ordered the HD)

Tensioner: Gates #38511 – $125
Compressor: Murray MRY 58616 (direct replacement from O’Reilly’s – $335)

Tools and other: $25

Shop Labor plus: $276.50 for 3.5hours; Parts: $12.99; Misc: $7.17; Tax: $1.25=$297.91

Total: $844

Some of the problems I ran into:

1) The first compressor I got turned out to be wrong and I returned it for a refund. The parts store had based the one they ordered off the original p/n TAMA Mfg TM-1-16HD. The one they provided just didn’t fit although it was suppose to be a substitute. The 2nd one I got from O’Reilly’s and it was an exact fit and had a removable manifold like the original – which helped installation a great deal. The mechanic said there just wasn’t room for the first one I’d brought plus it has a fixed manifold making installation impossible. He couldn’t tell that until he tried to install it. The parts store looked at me suspiciously when I tried to return the A/C compressors because it had some scratches on it but relaxed and came up with a refund as soon as I said ‘the mechanic says it doesn’t fit’. Something I remembered from my days of wrenching. Parts stores make allowances on returns if you have your rig in a local shop. 

2) The serpentine belt number I ordered I had found in an iRV2 thread. Turned out to be wrong. It was 71 & 1/2″ long when the one I actually need is 72 & 1/8″. Two of the 3 parts stores I went to didn’t carry stock, but one of them had the non-HD (Heavy Duty) belt. So I bought that one to save a day, and ordered the HD and I’ll carry that one in a vacuum pack which is recommended for long term storage. Threading the belt can be difficult for one person, but not impossible and can be done from the bottom or top of the engine. With two people, it’s easy. It needs to be worked around the fan blades but it just needs to be turned horizontal to slip inside the fan shroud.

3) The water pump V-belt is also a maintenance item and changing it around 70-90,000 miles is recommended. The tensioner for it is manual and mechanics sometimes miss it. There is a trick for installing the new belt without adjusting the tension though, and that is to install the belt up to the water pump pulley and then twist it 180 degrees and push (or maybe pull) on the tensioner so the belt slips over the pulley grove wall. It untwists on it’s own as it slips into the pulley grove. That’s in case you’re in a hurry and don’t want to mess with resetting the tensioner. That tensioner is on the engine block very close to the water pump pulley.

4) The old Serpentine Tensioner was in poor condition from road salts and of course I could feel a ‘tick’ when I turned it. It’s condition may have been what caused the A/C bearings to break apart and jamb the compressor’s idler. It’s good advice to replace the tensioner at 70-90,000 miles just to be on the safe side. It’s not that difficult to reach from under the engine and there’s only one bolt holding it. It does require a tool to relieve tension when installing or removing the serpentine belt of course.

5) Checked other rotating parts, fan hub and belt idler, and everything was smooth. Fan wasn’t damaged when the belt broke which sometimes happens and the broken belt was found in the engine compartment. No numbers left on it though, all scuffed off.

6) Neither new compressor came with the connector that would mate to the chassis connector so have to cut that off of the old compressor, crimp on a female butt splice and attach it to the new compressors male butt splice.


So that’s the story. There are forum threads I’ve read about this job and the costs normally run between $1500 to $2500. I’ve even read of a shop that insisted that the radiator had to come out. Yikes.

For me it came to just under $900 and it could have been a whole lot less if I’d done the work myself, and realized what parts I needed before hand. Like the tensioner I could have ordered from eBay or Amazon at half what I paid. And I imagine with some looking I could have found a replacement compressor at a better price too.

But I’m retired, I don’t want to wrench much anymore but I will as long as it’s not too difficult. The weather cooperated and it was a comfortable week in Parker. After the repairs, I spent another couple days at the Blue Water RV Park at $35/night. Used the time to button up everything. There’s a casino there too. I didn’t go, but it’s there.