102,000 miles, and these are giving up the ghost!

[FIRE UP]

Gang,
Well, the other day we'd pulled into our sons back yard to park for the Christmas week and were all done setting up the coach. The wife commented that before left home, she'd noticed some fluid on the floor as I pulled the coach out of its cave, getting ready to leave for the trip. My son, who helped us back into position on his new concrete slab, was not in favor of my coach dripping anything on it. And this coach NORMALLY never leaks a drop, at any time. So he popped under the coach to check out any potential leaking components. All it was was a loose hose clamp.

But, he noticed some rust around the shaft of the water pump tensioner pully. Hey also said the water pump v-belt was excessively loose. Hmmmm. He stated I need a new tensioner.

Folks, the coach is an '04 Itasca Horizon 36GD with the CAT C-7 330HP. It's a really, really long story but, we've owned it now for 10 years and over 100,000 miles. I've pulled the radiator on it TWICE now for maintenance and replacement of parts, belts and the like. I replaced the serpentine tensioner bearings 60,000 mile ago, as well as the serpentine idler bearings.

But, for the life of me, I could not get those bearings out of the water pump v-belt tensioner, TWICE. I pulled that radiator at 40K miles and did some maintenance and those bearings I mentioned. But not the water pump tensioner. It felt fine. Another 40K down the road, I pulled that radiator again for cleaning and other maintenance. The bearings I installed seemed fine but, again, I could not get them out of the water pump tensioner. They still seemed ok at that time.

Here we are at 101,000 miles and, it appears that they're on their failing side. So, I got home and went to work on that. Now, some of you may have experience with that water pump tensioner on either the C-7 or the 3126 and if you have, you know what kind of serious terror you're in for when attempting to do any water pump belt tension adjustment.

Folks, I've been a wrencher for 55+ years. I did everything humanly possible, to ATTEMPT to get that water pump tensioner out and off that C-7 without pulling the radiator. It wasn't gonna happen. So, I did what I had to do and that was to yank that radiator for a third time. That took me the better part of 3.5 hours or so. But, it did allow for me to get to that tensioner was much more ease. And even then, there is very little angle and room for a wrench to fit onto that slot bolt. The pivot bolt I got out way before the I'd even considered removing the radiator.

But, the bolt that covers the slot of adjustment, is all but impossible to get any wrench or a socket on, especially when the radiator is in place. One thing that's a main problem is, the serpentine belt runs right in front of that bolt head. So, you have to relieve tension on the serpentine belt to get it out of the way.

I turned to youtube to see if I could get any pointers on this project. Well, some of you know the "Adept Ape" series of youtube videos of him working on and discussing CAT engines. He has one on the R & R of a CAT C-7 water pump. So, I watched it with great enthusiasm. When it came time for him to remove that water pump tensioner, he simply put a socket on a ratchet and placed it on that slot bolt.

His tensioner, like all 3126 and C-7 tensioners, looks identical to mine. So, fitting a socket on that adjustment bolt, should be easy, well, in relative terms that is. But, not only is the serpentine belt in the way, but, what I encountered is, the dimeter of the pulley itself is just slightly too large and the edge of it, will not allow for a socket to fit directly on the bolt. It's a 1/2" or, 13mm and I tried every version of those two sized sockets I have and not a single one will go onto the bolt, due to the edge of the pulley not allowing for a straight on approach.

And, due to the close proximity of the inner edge of the pulley to the bolt head, not even a box end wrench will fit on it either. Talk about frustration. I finally had to use a stubby 13 mm wrench and even it, was limited in throw, based on all other obstacles in the area. What an absolute HORRIBLE design by CAT.

Ok, after all that being said, I finally got that tensioner off and, for some odd reason, I was able to press those two bearings out of it with relative ease this time. Folks, if you've never messed with any of those rotating components back on the back of your C-78 or 3126, those components each have TWO bearings, side x side in them. The water pump tensioner has two, NTN 6202Z bearings. They are 35mm O.D. x 15mm I.D. x 11mm thick. There is a simple snap ring that retains them on the shaft.

Once you have it out, and the snap ring off, if you're lucky, the pulley will come off the shaft with little resistance. If you're not lucky, like me, you'll have to work to get that pulley off the shaft. Then, again, if you're lucky, you can press those two bearings out with not too much effort. As stated earlier, those bearings would not budge, no matter how much pressure I applied in my 6" vice. What's needed is a couple of sockets of the appropriate size, to put on each side, to facilitate the pressing out of them. This time, for some odd reason, they were able to be pressed out like they were just installed the day before. Who knows.

Now, some of you might say, "why in the world didn't you just get a whole new tensioner"? Well, I'm a cheap bast... is the main reason. A brand new water pump tensioner from one of the Freightliner service centers near me, was gonna charge me $340 for it. Another, in San Diego, was gonna chare me $270 for it.

If that isn't the most ridicules set of prices for such a simple mechanism I've ever heard. I searched all over the net and came up with prices as low as $39 and as high as $170. But, I'd already had experience with replacing just the bearings in other components and, at that time, 60,000 miles ago, those bearings would cost me right at $10 each from Grainger. Each of those low prices I speak of, were as much as 10 days out, once payment is processed.

So, I just buzzed on down to my local Napa and of the 6 bearings I needed, they had two in stock and the others, will be in tomorrow morning. I paid a bit high for them because, I got 6 bearings, and a new serpentine belt and a new V-belt for about $150 or so. Incidentally, the bearings in the serpentine belt tensioner and idler are slightly larger. They are Napa part # 6203 and are: 40mm x 17mm (bore) x 12mm in thickness.

And, if any of you decide to take on this project, there are two different kinds of sealed bearings. One is sealed with either pure rubber seals or Vitron seals. And the other one is called "double shielded" bearings. Those have tin seals that basically keep out the big stuff. Small particles can get in an be invasive and destroy that bearing and you'll never know it 'till it's too late.

Anyway folks, I'm quite sure you're incredibly bored to tears reading this by now. All I can say is, those rotating components, tensioners and idlers on your older CAT engines, won't last forever. They're simple to service but a pain to get off, especially if the radiator and CAC is still in place.
Scott

[CountryB]

I'm glad you were able to get the job done on your own. At least you have the skills, tools, and a place to work. Nicley done!

On the issue of the adjuster bolt - could you replace that bolt with a different style (like an external torx head, or allen head, or such) that would provide better access to get a wrench or socket on it? Is there anything you can do now to make the job easier the next time?

[desertdd]

A couple of years ago while in Arizona the bearings went bad on my water pump tensioner. I took it a Freightliner dealer the the Mexican mechanic removed the crossmember and it seemed to be a easy job for him. This is on 2007 Discovery with a Freightliner chassis.

[FIRE UP]

Originally Posted by CountryB

I'm glad you were able to get the job done on your own. At least you have the skills, tools, and a place to work. Nicley done!

On the issue of the adjuster bolt - could you replace that bolt with a different style (like an external torx head, or allen head, or such) that would provide better access to get a wrench or socket on it? Is there anything you can do now to make the job easier the next time?

Hey CountryB,
OUTSTANDING IDEA!!!!!!!!!!!! You deserve a beer on the house! I never thought of that. I've got to go pick up the rest of the bearings I ordered this morning and I'll dig into the bolt bins at a hardware store to see if and what I can come up with. Although, based on all other considerations and hinderances in the messing with that tensioner, I'm really, really, really, really hoping I NEVER have to mess with it again.
Scott

Originally Posted by desertdd

A couple of years ago while in Arizona the bearings went bad on my water pump tensioner. I took it a Freightliner dealer the the Mexican mechanic removed the crossmember and it seemed to be a easy job for him. This is on 2007 Discovery with a Freightliner chassis.

desertdd,
Well, not quite sure what your cross member looks like but, the one that's in the way for my operation is GIANT and, it's main duty is to hold up the front end of that C-7. So, even though I too thought of removing it, it would be a major operation just to remove it and, I'd have to come up with some scientific way to suspend or support that engine. Pretty much hate to think about that C-7 deciding to tip or at least fall some while I'm under there goofing around with a water pump tensioner.
Scott


P.S. Folks,
Again, this water pump tensioner on either the 3126 or the C-7, is a phenomenally, criminally flawed design from CAT. At least in the application of a rear radiator motorhome aspect. In the front of a dump truck or over the road truck etc. it still would be a bit of a pain but, not near as much as it's application in a diesel motorhome. It's one of those things that your arm, wrist, fingers, elbow etc, all need to be double jointed so you can bend in multiple directions at one time to get to it and work the bolts loose and out, should the need arise.

In the pics below, you can see, IF YOU LOOK REAL HARD, the position of that water pump v-belt tensioner. I'm not an engine designer. I don't know what could have been done differently to make this operation at least somewhat easier to deal with if and when the time arises. Again, on the front of a dump truck, it's more than likely considerably easier to deal with. Motorhome, NOT SO. In one of the pics, you can see it clearly and, it's a total optical illusion in that, it appears that the bolt head for the slot, is totally away from the edge of the pulley. Not so.
Scott

[bpu699]

Are you on the original water pump? Is it holding up?

[FIRE UP]

bpu699,
Nope, not the original. That one went bad at about 80K or so. I'd developed a coolant leak and was having a tough time locating it. I'd searched high and low and followed the evidence, as in the trail of coolant from the bottom drips to the highest point it could be emanating from. I was fairly confident it was something to do with the water pump connections or something very near it. But, as usual, it is virtually impossible to see in and around that area in our coach.

Sooooo, I yanked the radiator so I could get a closer looksee. I'd removed the serpentine tensioner and noticed that the back side of it was polished. I'd also noticed the front side of the water pump pulley was polished. Hmmmmm. It was kind-a pure luck that I found the problem. Below is the cause of the leak. Notice the front outer face of the water pump pulley? The video shows why it's like that.

https://www.youtube.com/watch?v=tEsnpyHow2k

Once I found out it was the water pump, I went on the hunt for one. As usual, CAT wants your first born, your house, and the dog in exchange for a new one. I found a brand new old stock one in Georgia for $90 + $15 for shipping. I couldn't hit the BUY NOW button quick enough on fleabay.

One of the claims to fame that guys have been stating forever when it comes to diesel longevity is, the fact that these engines will last FOREVER. Well, not so. While the internals of a diesel MAY last a long time, it's the outside attachments that can give up the ghost waaaaay ahead of the wearing out engine.
Scott

[bpu699]

Originally Posted by FIRE UP

bpu699,
Nope, not the original. That one went bad at about 80K or so. I'd developed a coolant leak and was having a tough time locating it. I'd searched high and low and followed the evidence, as in the trail of coolant from the bottom drips to the highest point it could be emanating from. I was fairly confident it was something to do with the water pump connections or something very near it. But, as usual, it is virtually impossible to see in and around that area in our coach.

Sooooo, I yanked the radiator so I could get a closer looksee. I'd removed the serpentine tensioner and noticed that the back side of it was polished. I'd also noticed the front side of the water pump pulley was polished. Hmmmmm. It was kind-a pure luck that I found the problem. Below is the cause of the leak. Notice the front outer face of the water pump pulley? The video shows why it's like that.

Once I found out it was the water pump, I went on the hunt for one. As usual, CAT wants your first born, your house, and the dog in exchange for a new one. I found a brand new old stock one in Georgia for $90 + $15 for shipping. I couldn't hit the BUY NOW button quick enough on fleabay.

One of the claims to fame that guys have been stating forever when it comes to diesel longevity is, the fact that these engines will last FOREVER. Well, not so. While the internals of a diesel MAY last a long time, it's the outside attachments that can give up the ghost waaaaay ahead of the wearing out engine.
Scott

Thats some serious "looseness."

[Douglee25]

Definitely not an easy job. I've done that belt twice and each time it required two people... one from the top and one from the bottom. I took the top and my legs were literally in the air while in the closet. Dumb design.

So excited I got rid of that rig and got a side radiator now!

[FIRE UP]

Well boys and girls,
I ordered and received, 6 new bearings. Two each for the serpentine belt tensioner and idler, and two for the water pump tensioner. As I stated in another thread, just in case anyone's not aware, there are TWO bearings, sitting side by side, in each of those components. The two for the serpentine belt tensioner and idler, are the same, NAPA 6203 *sealed* bearings.

The two for the water pump tensioner are NAPA 6202 sealed bearings.

The dimensions for the 6203 are 40mm O.D. x 17mm bore x 12mm thick.

The dimensions for the 6202 are 35mm O.D. x 15mm x 11mm.

If one chooses to spend a great deal of money, you CAN simply purchase new components without messing with changing a mere $90 worth of bearings. That's your choice. But, if you do take on the task of changing the bearings, make DARN SURE that, you don't get METAL SHIELDED bearings!! There are some auto parts stores that will attempt to tell you that they're the same as a rubber sealed bearing, WRONG!!!!!!!!!!!!!!!!!!!!!!! Yes, they are the same size and will fit. But, they are NOT SEALED in the mannor to keep out all contaminates in that ultra hostile environment. So, just make sure your 6202 and 6203 bearings are rubber sealed.
Scott

[ftodaro]

I have replaced my water pump and tensioner for the serpentine belt but not the tensioner for the water pump. Did yours make any noise at start up? When i first start my coach i can hear excess noise in the rotating assembly and i cant really pin point it. When its warn it all sounds normal. Just wondering if this is a sign.

[FIRE UP]

Originally Posted by ftodaro

I have replaced my water pump and tensioner for the serpentine belt but not the tensioner for the water pump. Did yours make any noise at start up? When i first start my coach i can hear excess noise in the rotating assembly and i cant really pin point it. When its warn it all sounds normal. Just wondering if this is a sign.

ftodaro,
Are you kidding? Noise from a Clatterpillar? All kidding aside, no Sir, I didn't notice any *unusual* noise or noises. I highly suspect that if any of those rotating components were bad enough to make a noise that's audible above the standard clanging and banging of a CAT, whatever would be making the noise, wouldn't be making it for long. At least that's my assumption.

I have to really thank my son for all this. As most of us rear radiator drivers know, that total front engine area is for the most part, fairly concealed. And, just like the old cliche, *Out-a-sight,,,,,Out-a-mind*. Meaning, I'd done a bunch of work back there 20,000 miles ago but, It's just been out of my mind since. If he didn't check on what was my dripping, which turned out to be a loose hose clamp, he wouldn't have noticed my loose water pump v-belt and also the rust emanating from the bearing in the tensioner.

Well, that led me to a lot of work but, at least I (we) caught it before something serious happened, especially out in the middle of nowhere.
Scott

[RayChez1]

If you are not young and mechanically inclined, you have no business trying to work on one of those engines. I change the oil and filters, grease all fittings, but to actually work on the rest of the coach, I take it to Freightliner and they have done a good job for me so far. Freightliner in North Las Vegas has done most of the work on my coach. Just had the four air bags replaced with new ones and I also had the dash air conditioner recharged and they replaced the condensor and fan under the coach. Expensive, but well worth it to me since I am 79 years old and the joints in my body are starting to hurt working on these coaches.

[FIRE UP]

Originally Posted by RayChez1;6048664[B

]If you are not young and mechanically inclined, you have no business trying to work on one of those engines.[/B] I change the oil and filters, grease all fittings, but to actually work on the rest of the coach, I take it to Freightliner and they have done a good job for me so far. Freightliner in North Las Vegas has done most of the work on my coach. Just had the four air bags replaced with new ones and I also had the dash air conditioner recharged and they replaced the condensor and fan under the coach. Expensive, but well worth it to me since I am 79 years old and the joints in my body are starting to hurt working on these coaches.

Well Ray,
I almost have to agree with you. However, If you've been wrenching as long as I have, about 55+ years or so, on everything that moves on the planet, it's kind-a in my 69 year old blood, to keep on doing it 'till I can't any more. And I'm feeling it more and more each day, as time goes on. Most of what I do (which is ALMOST EVERYTHING) is not very "high tech". Nor does it need advanced education to accomplish. Most of it is common sense. The main problem, at least that I have is, very, VERY difficult to get to fasteners.

Winnebago/Itasca did and especially great job in HIDING or, at the very least, making it very difficult to see, a large percentage of the fasteners that have to do with the r & r of the radiator and CAC. And if you can't see a fastener, it's all a form of *Brail* type work. That type of wrenching IS NOT FUN!

Annnnnnywaaaaay, you are right about the "young" part for sure. Arthritis is now raring its head in and around both thumbs. Shoulders hurt, back aches, and the stamina is rapidly diminishing. But I've still got a little "fight" left in me to at least make an effort in continuing to be self-sufficient before I give up and reach for the wallet.
Scott

[Deep Grouper]

Originally Posted by FIRE UP

Gang,
Well, the other day we'd pulled into our sons back yard to park for the Christmas week and were all done setting up the coach. The wife commented that before left home, she'd noticed some fluid on the floor as I pulled the coach out of its cave, getting ready to leave for the trip. My son, who helped us back into position on his new concrete slab, was not in favor of my coach dripping anything on it. And this coach NORMALLY never leaks a drop, at any time. So he popped under the coach to check out any potential leaking components. All it was was a loose hose clamp.

But, he noticed some rust around the shaft of the water pump tensioner pully. Hey also said the water pump v-belt was excessively loose. Hmmmm. He stated I need a new tensioner.

Folks, the coach is an '04 Itasca Horizon 36GD with the CAT C-7 330HP. It's a really, really long story but, we've owned it now for 10 years and over 100,000 miles. I've pulled the radiator on it TWICE now for maintenance and replacement of parts, belts and the like. I replaced the serpentine tensioner bearings 60,000 mile ago, as well as the serpentine idler bearings.

But, for the life of me, I could not get those bearings out of the water pump v-belt tensioner, TWICE. I pulled that radiator at 40K miles and did some maintenance and those bearings I mentioned. But not the water pump tensioner. It felt fine. Another 40K down the road, I pulled that radiator again for cleaning and other maintenance. The bearings I installed seemed fine but, again, I could not get them out of the water pump tensioner. They still seemed ok at that time.

Here we are at 101,000 miles and, it appears that they're on their failing side. So, I got home and went to work on that. Now, some of you may have experience with that water pump tensioner on either the C-7 or the 3126 and if you have, you know what kind of serious terror you're in for when attempting to do any water pump belt tension adjustment.

Folks, I've been a wrencher for 55+ years. I did everything humanly possible, to ATTEMPT to get that water pump tensioner out and off that C-7 without pulling the radiator. It wasn't gonna happen. So, I did what I had to do and that was to yank that radiator for a third time. That took me the better part of 3.5 hours or so. But, it did allow for me to get to that tensioner was much more ease. And even then, there is very little angle and room for a wrench to fit onto that slot bolt. The pivot bolt I got out way before the I'd even considered removing the radiator.

But, the bolt that covers the slot of adjustment, is all but impossible to get any wrench or a socket on, especially when the radiator is in place. One thing that's a main problem is, the serpentine belt runs right in front of that bolt head. So, you have to relieve tension on the serpentine belt to get it out of the way.

I turned to youtube to see if I could get any pointers on this project. Well, some of you know the "Adept Ape" series of youtube videos of him working on and discussing CAT engines. He has one on the R & R of a CAT C-7 water pump. So, I watched it with great enthusiasm. When it came time for him to remove that water pump tensioner, he simply put a socket on a ratchet and placed it on that slot bolt.

His tensioner, like all 3126 and C-7 tensioners, looks identical to mine. So, fitting a socket on that adjustment bolt, should be easy, well, in relative terms that is. But, not only is the serpentine belt in the way, but, what I encountered is, the dimeter of the pulley itself is just slightly too large and the edge of it, will not allow for a socket to fit directly on the bolt. It's a 1/2" or, 13mm and I tried every version of those two sized sockets I have and not a single one will go onto the bolt, due to the edge of the pulley not allowing for a straight on approach.

And, due to the close proximity of the inner edge of the pulley to the bolt head, not even a box end wrench will fit on it either. Talk about frustration. I finally had to use a stubby 13 mm wrench and even it, was limited in throw, based on all other obstacles in the area. What an absolute HORRIBLE design by CAT.

Ok, after all that being said, I finally got that tensioner off and, for some odd reason, I was able to press those two bearings out of it with relative ease this time. Folks, if you've never messed with any of those rotating components back on the back of your C-78 or 3126, those components each have TWO bearings, side x side in them. The water pump tensioner has two, NTN 6202Z bearings. They are 35mm O.D. x 15mm I.D. x 11mm thick. There is a simple snap ring that retains them on the shaft.

Once you have it out, and the snap ring off, if you're lucky, the pulley will come off the shaft with little resistance. If you're not lucky, like me, you'll have to work to get that pulley off the shaft. Then, again, if you're lucky, you can press those two bearings out with not too much effort. As stated earlier, those bearings would not budge, no matter how much pressure I applied in my 6" vice. What's needed is a couple of sockets of the appropriate size, to put on each side, to facilitate the pressing out of them. This time, for some odd reason, they were able to be pressed out like they were just installed the day before. Who knows.

Now, some of you might say, "why in the world didn't you just get a whole new tensioner"? Well, I'm a cheap bast... is the main reason. A brand new water pump tensioner from one of the Freightliner service centers near me, was gonna charge me $340 for it. Another, in San Diego, was gonna chare me $270 for it.

If that isn't the most ridicules set of prices for such a simple mechanism I've ever heard. I searched all over the net and came up with prices as low as $39 and as high as $170. But, I'd already had experience with replacing just the bearings in other components and, at that time, 60,000 miles ago, those bearings would cost me right at $10 each from Grainger. Each of those low prices I speak of, were as much as 10 days out, once payment is processed.

So, I just buzzed on down to my local Napa and of the 6 bearings I needed, they had two in stock and the others, will be in tomorrow morning. I paid a bit high for them because, I got 6 bearings, and a new serpentine belt and a new V-belt for about $150 or so. Incidentally, the bearings in the serpentine belt tensioner and idler are slightly larger. They are Napa part # 6203 and are: 40mm x 17mm (bore) x 12mm in thickness.

And, if any of you decide to take on this project, there are two different kinds of sealed bearings. One is sealed with either pure rubber seals or Vitron seals. And the other one is called "double shielded" bearings. Those have tin seals that basically keep out the big stuff. Small particles can get in an be invasive and destroy that bearing and you'll never know it 'till it's too late.

Anyway folks, I'm quite sure you're incredibly bored to tears reading this by now. All I can say is, those rotating components, tensioners and idlers on your older CAT engines, won't last forever. They're simple to service but a pain to get off, especially if the radiator and CAC is still in place.
Scott

Some that may take on this enormous task of removing the back end of the coach to service all the bearings (along with a pretty paint job like Scott completed) you want to be sure that the bearings have Viton seals, not Buna. A friend of mine thought he got a great deal on bearings until 30K miles later he was back into the engine again due to bearing failures. Buna is good for sustained 200f where Viton is double, 400f. Your local automotive store normally wont have Viton. So, you may need to contact a local bearing house that specializes in industrial grade bearings.BUT, be prepared to pay up for higher end bearings: 30-40% more.

I too had the entire back of my coach apart. Cleaned the radiator, Cac and completed all hoses and bearings. My son aided in removing the radiator but I was able to complete the remainder of work myself in two full days, and I mean full days.

I found the BEST tool to complete those "hidden" BRAIL bolts is the ratcheting box wrenches. Without them,,,,,,, add two more days of fun.

Nice write up Scott