2013~2016: Belt Tensioner - Shouldn't this be a warranty item?

[CX-5um]

I went through a few of these wrenches on Amazon/Lowes/Home Depot and they had mostly positive reviews, same with HF with the last 1 star review from 2019. I wouldn't read too much into it honestly, there's going to be bad reviews about everything online. Anyways, my plan was to use a flare nut crow foot to see if it'll even fit in the tight space. I'm thinking it will fit so I don't need to buy any more tools but we'll see.

The biggest issue I have with the offset/box wrenches is that it's going to round/strip the bolt head and if that happens, it'll be a huge PITA to remove/extract the bolt and I won't run into that issue with a socket or a flare nut crow foot. Difference is that the box wrenches are 12 point vs a flare nut/6 point wrench having less of a gap

View attachment 227610

22-30lbs spec.

I unloosened then replaced the top nut from the engine bay and mine was easy to break loose. In fact I broke it loose and removed it by hand from the engine bay. Have a looksie:


Where's the Nut?!?!?!

Oh there you are

This top nut has been removed/attempted on a few times but still has tons of grip on a 12-point wrench. I also do have a flare nut wrench as well- good idea on it. That said you can literally just order spare ones cheap I'm assuming. Here's a spare but I wonder if this Bag of 20 Mazda Flange Nuts fits.

Here is the Replacement bottom bolt. I don't think you're gonna strip this enough though.

 

[Jmaz]

When I changed mine about 3 years ago (?) I used the long wrenches from Harbor Freight and did the job from the top,not the wheel well.I posted a detailed explanation at the time.Two things to remember:
1) you do NOT want to round off the corners of the nut or bolt.It's such a tight fit that the motor mount may have to be removed to remove the stripped fastener and that would entail pulling the underside plastic shroud to get access to support the engine .
2) The bolt will contact the frame rail and can't be pulled straight out to be removed.However there is a slot in the side of the the tensioner casting that allows the tensioner to be removed.Basically the bolt is not captive like it would be thru just a hole in the casting.

 

[Digbicks1234]

22-30lbs spec.

I unloosened then replaced the top nut from the engine bay and mine was easy to break loose. In fact I broke it loose and removed it by hand from the engine bay. Have a looksie:


Where's the Nut?!?!?!
View attachment 227618

Oh there you are
View attachment 227619

This top nut has been removed/attempted on a few times but still has tons of grip on a 12-point wrench. I also do have a flare nut wrench as well- good idea on it. That said you can literally just order spare ones cheap I'm assuming. Here's a spare but I wonder if this Bag of 20 Mazda Flange Nuts fits.

Here is the Replacement bottom bolt. I don't think you're gonna strip this enough though.

That's some beautiful curves you got there on that nut . Are those nuts from that seller OEM? I'm just wondering what's the corrosion resistance since they look uncoated.

 

[Digbicks1234]

When I changed mine about 3 years ago (?) I used the long wrenches from Harbor Freight and did the job from the top,not the wheel well.I posted a detailed explanation at the time.Two things to remember:
1) you do NOT want to round off the corners of the nut or bolt.It's such a tight fit that the motor mount may have to be removed to remove the stripped fastener and that would entail pulling the underside plastic shroud to get access to support the engine .
2) The bolt will contact the frame rail and can't be pulled straight out to be removed.However there is a slot in the side of the the tensioner casting that allows the tensioner to be removed.Basically the bolt is not captive like it would be thru just a hole in the casting.

I have a way to remove the stripped/rounded nut/bolt but I would need to test it out once I pick up my parts. Honestly, it would seem like a lot of fun getting it out of there though

 

[CX-5um]

That's some beautiful curves you got there on that nut . Are those nuts from that seller OEM? I'm just wondering what's the corrosion resistance since they look uncoated.

Actually the Tensioner top nut is the same part number as DEEZ Nuts:

Stabilizer Bar Nut, Power Booster Nut, Top Assembly Nut, Bracket Nut, Drive Shaft Nut, Spare Carrier Nut, Mount Bracket Nut, Shifter Assembly Nut, Upper Hinge Nut, Fuse Nut, Water Pump Nut, Alternator Nut, Front Mount Bracket Nut, Starter Nut, Retainer Nut, Shifter Nut, Support Bracket Nut, Automatic Transmission Shift Lever Nut, Instrument Panel Nut, Power Brake Booster Nut, Stopper Nut, Wiper Arm Nut, Air Inlet Pipe Nut, Clamp Nut, Drive Shaft Retainer Nut, Manual Transmission Shift Lever Nut, Nut Flange

Part number 9994-00-801

 

[Digbicks1234]

So I actually reached out to a Mazda parts department and inquired about the TSB and this was the response I received:

Either way, I purchased the GATES 39390 tensioner on Rock Auto since it has a lifetime warranty.

 

[minnesotaart]

I bought the long special Tensioner Wrench at Harbor Freight. $15.19+tax after my 20% off coupon. I'm going to try again on Sunday.

 

[Digbicks1234]

I bought the long special Tensioner Wrench at Harbor Freight. $15.19+tax after my 20% off coupon. I'm going to try again on Sunday.

Keep us posted. I'm planning to do mine this week as well. Hopefully the wrench works out for you.

 

[Digbicks1234]

Alright guys, I have all the parts ready:

1. GATES 39390: Belt Tensioner
2. PY01-15-909A: Serpentine Belt
3. PY01-15-908: Water Pump Belt
4. 9994-00-801: Tensioner Flange Nut
5. 9YA0-2A-818: Tensioner Bolt

 

[CX-5um]

Hey you actually bought a new lower bolt?

Ensure to get good lighting.

Water Pump Belt - I used a wrench and pushed it into and eventually over the water pump pulley while turning crank. No way I wanted to use my bare fingers. Or you can use the zip tie method found via a YouTube search. Removal of old one: I did not want to waste time and energy so I slowly cut it. Took a few seconds.

Serpentine belt - I like using painters tape....just enough to keep new one in place then remove tape later. Once in place I release tension on tensioner and slide the top portion of the new belt under the tensioner pulley and loop over the top of the alternator pulley. Release tension and test fitment by turning crank.

Turning Crank - I used my an extension bar but sure wish I had a socket extension to help clear the engine bay.

Old Tensioner: please retain for later dissection

Good Luck

 

[CX-5um]

I bought the long special Tensioner Wrench at Harbor Freight. $15.19+tax after my 20% off coupon. I'm going to try again on Sunday.

Looking forward to report!

 

[Digbicks1234]

Hey you actually bought a new lower bolt?

Ensure to get good lighting.

Water Pump Belt - I used a wrench and pushed it into and eventually over the water pump pulley while turning crank. No way I wanted to use my bare fingers. Or you can use the zip tie method found via a YouTube search. Removal of old one: I did not want to waste time and energy so I slowly cut it. Took a few seconds.

Serpentine belt - I like using painters tape....just enough to keep new one in place then remove tape later. Once in place I release tension on tensioner and slide the top portion of the new belt under the tensioner pulley and loop over the top of the alternator pulley. Release tension and test fitment by turning crank.

Turning Crank - I used my an extension bar but sure wish I had a socket extension to help clear the engine bay.

Old Tensioner: please retain for later dissection

Good Luck

Yeah, I bought a new bolt/washer since I didn't want to be empty handed in case something goes wrong. Might as well replace it since it's only <$10 for a peace of mind. Thanks for the tips, I'll keep them in mind when I'm working on it and I'll be sure to take lots of pics of the condition of everything overall.

 

[minnesotaart]

OK, so I was mostly successful today. I went through the wheel well again. Once I realized how much force was needed and how slow the tensioner would move (courtesy of those videos) I was easily able to relieve the tension and remove the serpentine belt. I used my long-handled 17mm ratcheting wrench from below for this. The new Harbor Freight wrench serpentine belt would NOT fit in the cramped space. Since I was going to replace the water pump belt too, I took that off. However rather than use the "towel" method to pull it off, I cut it off like CX-5um suggested. Easy, right? Big mistake; more on that later. Next I was able to use a short-handled 12mm box wrench to take off the top nut from the top but I left the tensioner still hanging on the threaded stub. Then I used my long-handled 12mm ratcheting wrench from the bottom to loosen the bottom bolt. Due to clearance issues I could only back it off a turn or two, but I got it loose which would be really hard to do from the top. I loosened the bolt some more from the top with the short-handled 12mm wrench using the open end side. After a point I was able to loosen it the rest of the way by hand. Very tight quarters though. You can't pull the bolt out because there's no clearance, you just loosen it until it's no longer threaded. Then from the top I rotated the tensioner toward the front of the vehicle to free the bolt from the slot in the engine casting (there's a picture below of the slot for the bolt) and THEN pulled the top part off the threaded stub. A little bit of maneuvering and it came out from the top. It really wasn't oily, just dirty. A lot of the dirt came off just in the removal process. I've uploaded pictures of the whole unit front and back right after it came out. Then I cleaned it up and took pictures of the 2 sets of numbers that everyone wants to see. The new one went in easy-peasy using all the same tools and positions as the removal. No way to tell how torqued the nut and bolt got, I just made them tight.

After the new tensioner was in, I started on the water pump belt. I tried everything under the sun to get the new one on. I tried the towel method, the zip-tie method, screwdriver method; everything! To no avail. I came inside and reviewed all of the how-to videos in great detail until I made an "ah-ha!" discovery: none of the videos and none of those on here who replaced the water pump belt did so on a 2.5L CX-5! CX-5um has a 2013 so that's a 2.0L. The video from the Asian gentleman was also on a 2.0L CX-5. Videos that were on a 2.5L were either in a Mazda3 or a Mazda6. Guess what? The clearances are tighter and the access is slightly different on the 2.5L. I verified this by looking at those videos and comparing it to my actual view. My big huge mistake was cutting the belt off. If I had taken the time to use the towel method I could have easily reinstalled it since it was already stretched to fit. I ended up installing the new serpentine belt and closing things up. Tomorrow I'll bring it to my mechanic (only a mile from my house) and he can do his magic and get the water pump belt on for me! I'm sure Digbicks1234 will probably get his water pump belt on just fine and prove me wrong, but I'm just an old retired guy playing mechanic, what can I say? LOL

Lessons learned:
1-Maybe wait until you're sure there's a problem before you replace a part that is working fine. I should have just replaced the serpentine belt and called it a day. The tensioner was fine and not leaking although it probably would have at some point. The old serpentine belt was fine by the way, no cracks or anything. I'm keeping it for a spare.
2-If you are removing a part that might still be good, do so in a manner than it can be reinstalled if need be! Refer also to lesson learned #1!

Old tensioner front.

Old tensioner back.

Bottom numbers on back side.

Left side of top numbers from front (a little tough to read).

Right side of top numbers from front (also a little tough to read).

So the top numbers read as:
F-569897.07-0100
SLOVAKIA 16.04.13
1/10161

This is the slot that the bottom bolt slides into. The opening faces the front of the vehicle.

I hope this helps someone. I need a beer!

 

[MyFirstMazda]

Good job, thanks for that report. Your tensioner might have been leaking a little for the belt dust to stick to it like that, so it was worth your efforts.

Did you try with a zip tie like in this video?

 

[minnesotaart]

Good job, thanks for that report. Your tensioner might have been leaking a little for the belt dust to stick to it like that, so it was worth your efforts.

Did you try with a zip tie like in this video?

Yup! Lack of access made it impossible to guide the belt as needed for the zip tie method. And the shape of the water pump pully along with the tight clearance would not allow use of the tool shown. The water pump pulley is in a really sucky place on the 2.5L, the 2.0L seems to have better access.

 

[Digbicks1234]

OK, so I was mostly successful today. I went through the wheel well again. Once I realized how much force was needed and how slow the tensioner would move (courtesy of those videos) I was easily able to relieve the tension and remove the serpentine belt. I used my long-handled 17mm ratcheting wrench from below for this. The new Harbor Freight wrench serpentine belt would NOT fit in the cramped space. Since I was going to replace the water pump belt too, I took that off. However rather than use the "towel" method to pull it off, I cut it off like CX-5um suggested. Easy, right? Big mistake; more on that later. Next I was able to use a short-handled 12mm box wrench to take off the top nut from the top but I left the tensioner still hanging on the threaded stub. Then I used my long-handled 12mm ratcheting wrench from the bottom to loosen the bottom bolt. Due to clearance issues I could only back it off a turn or two, but I got it loose which would be really hard to do from the top. I loosened the bolt some more from the top with the short-handled 12mm wrench using the open end side. After a point I was able to loosen it the rest of the way by hand. Very tight quarters though. You can't pull the bolt out because there's no clearance, you just loosen it until it's no longer threaded. Then from the top I rotated the tensioner toward the front of the vehicle to free the bolt from the slot in the engine casting (there's a picture below of the slot for the bolt) and THEN pulled the top part off the threaded stub. A little bit of maneuvering and it came out from the top. It really wasn't oily, just dirty. A lot of the dirt came off just in the removal process. I've uploaded pictures of the whole unit front and back right after it came out. Then I cleaned it up and took pictures of the 2 sets of numbers that everyone wants to see. The new one went in easy-peasy using all the same tools and positions as the removal. No way to tell how torqued the nut and bolt got, I just made them tight.

After the new tensioner was in, I started on the water pump belt. I tried everything under the sun to get the new one on. I tried the towel method, the zip-tie method, screwdriver method; everything! To no avail. I came inside and reviewed all of the how-to videos in great detail until I made an "ah-ha!" discovery: none of the videos and none of those on here who replaced the water pump belt did so on a 2.5L CX-5! CX-5um has a 2013 so that's a 2.0L. The video from the Asian gentleman was also on a 2.0L CX-5. Videos that were on a 2.5L were either in a Mazda3 or a Mazda6. Guess what? The clearances are tighter and the access is slightly different on the 2.5L. I verified this by looking at those videos and comparing it to my actual view. My big huge mistake was cutting the belt off. If I had taken the time to use the towel method I could have easily reinstalled it since it was already stretched to fit. I ended up installing the new serpentine belt and closing things up. Tomorrow I'll bring it to my mechanic (only a mile from my house) and he can do his magic and get the water pump belt on for me! I'm sure Digbicks1234 will probably get his water pump belt on just fine and prove me wrong, but I'm just an old retired guy playing mechanic, what can I say? LOL

Lessons learned:
1-Maybe wait until you're sure there's a problem before you replace a part that is working fine. I should have just replaced the serpentine belt and called it a day. The tensioner was fine and not leaking although it probably would have at some point. The old serpentine belt was fine by the way, no cracks or anything. I'm keeping it for a spare.
2-If you are removing a part that might still be good, do so in a manner than it can be reinstalled if need be! Refer also to lesson learned #1!

Old tensioner front.
View attachment 227730

Old tensioner back.
View attachment 227731

Bottom numbers on back side.
View attachment 227732

Left side of top numbers from front (a little tough to read).
View attachment 227733

Right side of top numbers from front (also a little tough to read).
View attachment 227734

So the top numbers read as:
F-569897.07-0100
SLOVAKIA 16.04.13
1/10161

This is the slot that the bottom bolt slides into. The opening faces the front of the vehicle.
View attachment 227735

I hope this helps someone. I need a beer!

Great job!!! I haven't had a chance to start the belt tensioner process yet but I'm glad I haven't yet because you just provided some very new crucial information and insight. I don't know if you have access to the service manual but I attached the files in case it helps you. I snipped off the important pages so I didn't have to go through everything.

I'm on the same boat as you, just a home mechanic that's going through trial and error. Your age isn't an issue, don't sweat it haha.

For the water pump belt, I see that most people started off putting the top portion of the belt onto the water pump pulley first and then slowly rotated it onto the crankshaft pulley. If there's no room, I wonder how that can be done then....

Just one question though, do you think that I would be able to fit in a breaker bar/ratchet with an extension?

 

[Digbicks1234]

Yup! Lack of access made it impossible to guide the belt as needed for the zip tie method. And the shape of the water pump pully along with the tight clearance would not allow use of the tool shown. The water pump pulley is in a really sucky place on the 2.5L, the 2.0L seems to have better access.

In the attached file, "Belt Tensioner," on page 5 there should be the "Water Pump Drive Belt" walkthrough. If you're still interested in attempting the process, I think it should help or at least I hope so

 

[CX-5um]

You did a steller job. Consider returning the serpentine belt kit to Harbor Freight and just say it did not fit. Sorry you could not get the water pump belt on.

For 2.5l engines being tighter in space and clearance the alternative could be to push the belt from bottom portion of water pump pulley where there's more clearance and the engine bay is not in the way. I seen my mechanic do this on my 2.5l engine but with his bare hands. Dude is much stronger than me. I used a chrome wrench.

Anyways the idea is a portion of the belt can't get on. You are sliding the belt onto the smooth portion of the pulley but will be stopped because of a slight hump transitioning from smooth section to get it over to the pulley's belt ridges. The goal is to shove 1mm at a time over said hump. I used my chrome wrench and gave a stiff push on the side of the belt and not letting tension off...I turned crank 1 inch counter clockwise with right hand. That first 1mm is the hardest so be patient. It took me 3-4 attempts. Once the first 1mm catches then it gets a bit easier since a portion of belt cleared the dreaded hump. Another strong shove with wrench and another turn. The belt then eventually settles in place.

Or just have you mechanic install water pump belt and not have to worry about it for a long time.

Picture Credit: The Critic via https://www.bobistheoilguy.com/forums/threads/diy-mazda-2-5l-skyactiv-water-pump.314294/

 

[minnesotaart]

Digbicks1234 and CX-5um, I appreciate both of your comments.

Digbicks1234 - No, your breaker bar and ratchet aren't going to fit. My breaker bar with the socket was twice as large as the amount of room there was. Even the Harbor Freight serpentine belt tool with a 17mm socket was too thick to get in there. You're going to need a wrench, either long-handled or something you can rig an extension to (like in the one video from the Asian gentleman). The best wrench would be an offset box wrench, but I made my swivel-head ratcheting wrench work with some wiggling. As far as the belt goes, where those fingers are drawn in that illustration is not possible on the CX-5 2.5L with adult size hands and the vehicle on the ground - there's just no room to get to that 8 o'clock position on the pulley (thinking of it as a clock face) and that's the critical spot to get 'er going. My CX-5 is at the shop right now where there's a lift and a mechanic who can get his fingers in at a better angle because of the lift. Oh, and I tried it on the water pump pulley first and then to work it on the crank pulley - that didn't work either.

CX-5um - If the access to the water pump pulley was as open as shown in that picture I'm sure I could have done it. But the unfortunate fact is that it isn't as open as that and you would need to be a human contortionist to work it onto that pulley while also cranking the crankshaft pulley. Again, I'm sure it's doable on a lift, but it wasn't doable flat on my back! I'm going to bet that you saw your mechanic do it with his bare hands because it was on a lift!

P.S. - can't really return the tool to Harbor Freight since I had to totally destroy the packaging to get it out of there. It might come in handy for something someday and I've wasted more than $16 before in my life!

 

[yrwei52]

OK, so I was mostly successful today. I went through the wheel well again. Once I realized how much force was needed and how slow the tensioner would move (courtesy of those videos) I was easily able to relieve the tension and remove the serpentine belt. I used my long-handled 17mm ratcheting wrench from below for this. The new Harbor Freight wrench serpentine belt would NOT fit in the cramped space. Since I was going to replace the water pump belt too, I took that off. However rather than use the "towel" method to pull it off, I cut it off like CX-5um suggested. Easy, right? Big mistake; more on that later. Next I was able to use a short-handled 12mm box wrench to take off the top nut from the top but I left the tensioner still hanging on the threaded stub. Then I used my long-handled 12mm ratcheting wrench from the bottom to loosen the bottom bolt. Due to clearance issues I could only back it off a turn or two, but I got it loose which would be really hard to do from the top. I loosened the bolt some more from the top with the short-handled 12mm wrench using the open end side. After a point I was able to loosen it the rest of the way by hand. Very tight quarters though. You can't pull the bolt out because there's no clearance, you just loosen it until it's no longer threaded. Then from the top I rotated the tensioner toward the front of the vehicle to free the bolt from the slot in the engine casting (there's a picture below of the slot for the bolt) and THEN pulled the top part off the threaded stub. A little bit of maneuvering and it came out from the top. It really wasn't oily, just dirty. A lot of the dirt came off just in the removal process. I've uploaded pictures of the whole unit front and back right after it came out. Then I cleaned it up and took pictures of the 2 sets of numbers that everyone wants to see. The new one went in easy-peasy using all the same tools and positions as the removal. No way to tell how torqued the nut and bolt got, I just made them tight.

After the new tensioner was in, I started on the water pump belt. I tried everything under the sun to get the new one on. I tried the towel method, the zip-tie method, screwdriver method; everything! To no avail. I came inside and reviewed all of the how-to videos in great detail until I made an "ah-ha!" discovery: none of the videos and none of those on here who replaced the water pump belt did so on a 2.5L CX-5! CX-5um has a 2013 so that's a 2.0L. The video from the Asian gentleman was also on a 2.0L CX-5. Videos that were on a 2.5L were either in a Mazda3 or a Mazda6. Guess what? The clearances are tighter and the access is slightly different on the 2.5L. I verified this by looking at those videos and comparing it to my actual view. My big huge mistake was cutting the belt off. If I had taken the time to use the towel method I could have easily reinstalled it since it was already stretched to fit. I ended up installing the new serpentine belt and closing things up. Tomorrow I'll bring it to my mechanic (only a mile from my house) and he can do his magic and get the water pump belt on for me! I'm sure Digbicks1234 will probably get his water pump belt on just fine and prove me wrong, but I'm just an old retired guy playing mechanic, what can I say? LOL

Lessons learned:
1-Maybe wait until you're sure there's a problem before you replace a part that is working fine. I should have just replaced the serpentine belt and called it a day. The tensioner was fine and not leaking although it probably would have at some point. The old serpentine belt was fine by the way, no cracks or anything. I'm keeping it for a spare.
2-If you are removing a part that might still be good, do so in a manner than it can be reinstalled if need be! Refer also to lesson learned #1!

Old tensioner front.
View attachment 227730

Old tensioner back.
View attachment 227731

Bottom numbers on back side.
View attachment 227732

Left side of top numbers from front (a little tough to read).
View attachment 227733

Right side of top numbers from front (also a little tough to read).
View attachment 227734

So the top numbers read as:
F-569897.07-0100
SLOVAKIA 16.04.13
1/10161

This is the slot that the bottom bolt slides into. The opening faces the front of the vehicle.
View attachment 227735

I hope this helps someone. I need a beer!

Thank you for all the detailed adventure of changing belts and belt tensioner on your 2014 CX-5 GT with 2.5L, and posting those serial numbers on tensioner. Would you please tell us how many miles on your CX-5 with the tensioner condition like that; and what kind of long offset box wrench or swivel-head ratcheting wrench you’re using (a picture or link would be great)?