Question identifying the Belt Tensioner Assembly

yayo_ayala

Registered User
Hi, I am trying to buy the Belt Tensioner Assembly but I cannot figure out the part numbers. Autozone couldn't tell me the exact part and I will appreciate the help.

I had a Squeaky and after reviewing the belt tensioner, I found two of the three tensioners had their indicator in the replacement area.

tensioner1.JPG
tensioner2.JPG

The guys in Autozone told me they had the parts on stock ... rookie mistake, I took it and found out they don't have it. I see in the tensioners the following parts number:

E9SE-6B209-HA
E9SE-6B209-JA
E9SE-6B209-kA

But I cannot find those part numbers in RockAuto or any other Auto Part company. I will appreciate someone helping me identifying the part numbers... thanks in advance.

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Hi, I am trying to buy the Belt Tensioner Assembly but I cannot figure out the part numbers. Autozone couldn't tell me the exact part and I will appreciate the help.

I had a Squeaky and after reviewing the belt tensioner, I found two of the three tensioners had their indicator in the replacement area.

View attachment 70880
View attachment 70879

The guys in Autozone told me they had the parts on stock ... rookie mistake, I took it and found out they don't have it. I see in the tensioners the following parts number:

E9SE-6B209-HA
E9SE-6B209-JA
E9SE-6B209-kA

But I cannot find those part numbers in RockAuto or any other Auto Part company. I will appreciate someone helping me identifying the part numbers... thanks in advance.

View attachment 70882
View attachment 70881
View attachment 70883

You sure you don’t just need belts? Usually only the pulley needs service.
 
I searched here & the factory manual, and after going thru several threads and studying photos of engines, I learned they apparently differ by location and tension & came up with the following info:

E9SE-6B209-JA 3.8L S/C Accessory (16 Lb-Ft)
E9SE-6B209-HA 3.8L S/C Supercharger (10 Lb-Ft)
E9SE-6B209-KA 3.8L S/C Jackshaft Drive (10 Lb-Ft)

As for the indicator, as the manual notes, it usually indicates belt stretch, which means times for new belts, not new tensioners.

Tensioners are expensive...be sure your belts and idlers are fresh/new first. Also be sure your's haven't been mistakenly installed in the wrong location - I found a lower rated one where the higher rated one should have been - it was jumpy/notchy and showed excess friction wear. I moved the higher rated tensioner to that location and the noise went away. I've also had squeaky idlers that needed replacement.

I suggest using or making a mechanic's stethoscope to help isolated the noise. Ive used long screwdriver/jug to listen to idlers, alternator, supercharger, water pump, power steering pump, camshaft sensor stalk and tensioners/idlers. If you need more listening capability, cut the bottom off a gallon plastic jug and fit the handle of that long then screw driver into the neck. Lay the tip onto those items and put the jug near your ear. Be careful!

As for new replacement tensioners, I haven't been able to find them, at least by part number. I think most SC owners either find serviceable used ones, or, buy new springs and DIY rebuild. Am told that isn't much fun, tho. I think SCP or Magnum Powers has new tensioner springs.
 
Good evening


If a tensioner is necessary use the Gates part number listed in Rock Auto 1990 ford thunderbird supercoupe with pre-fix number F4. Use this web site to decode the if the stamped ford part number for a thunderbird:

https://www.fordification.com/tech/partnumbers_overview.htm


The alternator mounting bracket tensioner will be the longer arm.

The supercharger and jackshaft will be the shorter arm (identified as air condition).



You will have to chose if you want the plastic or upgrade to the metal pulley with the corresponding diameter size.



Check youtube videos from Gates on inspecting/troubleshooting serpentine belts and pulley.
 
Belt

You sure you don’t just need belts? Usually only the pulley needs service.
Hi Ricardo, I just bought the car few months ago and the previous owner bought the belts. I checked the belts and they look brand new. The indicators on two of three was in the replacement section.

Thanks for the feedback
 
Thanks

I searched here & the factory manual, and after going thru several threads and studying photos of engines, I learned they apparently differ by location and tension & came up with the following info:
.......
Also be sure your's haven't been mistakenly installed in the wrong location
........
As for new replacement tensioners, I haven't been able to find them, at least by part number. I think most SC owners either find serviceable used ones, or, buy new springs and DIY rebuild. Am told that isn't much fun, tho. I think SCP or Magnum Powers has new tensioner springs.

thanks KTM,

This is valuable information. I bought the car and I got the impression that the previous owner was trying to fix it and gave up; and put the parts together but missed connecting many things (For example the AC, and the speedometer). I will not be surprise that he mixed the tensioners.

Let me check this point and move to your additional recommendations.
 
Thanks Sam

Good evening
If a tensioner is necessary use the Gates part number listed in Rock Auto 1990 ford thunderbird supercoupe with pre-fix number F4. Use this web site to decode the if the stamped ford part number for a thunderbird:
https://www.fordification.com/tech/partnumbers_overview.htm
The alternator mounting bracket tensioner will be the longer arm.
The supercharger and jackshaft will be the shorter arm (identified as air condition).
You will have to chose if you want the plastic or upgrade to the metal pulley with the corresponding diameter size.
Check youtube videos from Gates on inspecting/troubleshooting serpentine belts and pulley.

Thanks Sam, let me check the parts were installed in the right place and using the correct belts. If the parts look to be in the correct place, I will proceed to buy the correct tensioners using you info.
 
Thanks, I will also check the part numbers for the belts.

Part numbers should also reference length, which is what you really want to know:

Stock belt lengths - examples only, actual length may vary slightly by manuf.:
  • Supercharger - 39.17"
  • Jackshaft - 42.52"
  • Alt/Water Pump/PS/Crank - 89.96"
Since your belts were new not that long ago, you should be able to see the brand & part numbers still.

Keep in mind some owners change belt length when different sized pulleys are used.

List download for Goodyear belts P/N vs. Metric P/N, via SCCOA: http://www.sccoa.com/forums/attachment.php?attachmentid=26467&d=1178603907
 
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and if the belts are different, how to check the pulley.

  • Supercharger - 39.17"
  • Jackshaft - 42.52"
  • Alt/Water Pump/PS/Crank - 89.96"
Since your belts were new not that long ago, you should be able to see the brand & part numbers still.
Keep in mind some owners change belt length when different sized pulleys are used.

I checked the belts and I think they are in parameters (0.1 - 0.2 inches bigger).

PART NUMBER | METRIC Part NO. | NO RIBS | EFFECTIVE LENGTH | OUTSIDE LENGTH
4080392.............8PK0995.....................8....................39.25.........................40
4070425.............7PK1080.....................7.....................42.5..........................43.25
4080897.............8PK2280.....................8.....................89.75........................90.5

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Before removing the tensioners, I replaced two pulleys ( I have the originals). I am not sure how to identify if they tensioners are in the right place? and if I am using the right combination of pulley and belt.

tensio.jpg
 
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..not sure how to identify if they tensioners are in the right place?

I think according to the image marked up in red, they are correct.

if I am using the right combination of pulley and belt.

I think you are ok, again, according to that image.

Getting back to the tensioners, did you confirm they all still have their locating ears on the back?

And just to confirm, your image showing the indicators, has the tensioners off the car...you do know those indicators are supposed to be read when the tensioners and belts are installed, right?

I would buy a new belt for at least one of the tensioners that is well into the 'worn' indicator range, then install it (the lower radiator hose captures the longest belt of course), and install it and see what the indicator says. Return the belt of the indicator still says worn, then try to source new tensioner(s), or springs.
 
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Hi KTM about your questions

Getting back to the tensioners, did you confirm they all still have their locating ears on the back?

-- Yes, the tensioners have their ears.
image1 (5).jpeg image0 (6).jpeg


And just to confirm, your image showing the indicators, has the tensioners off the car...you do know those indicators are supposed to be read when the tensioners and belts are installed, right?

-- I put them back in the car and took some pictures.
image3 (3).jpeg image2 (3).jpeg

I would buy a new belt for at least one of the tensioners that is well into the 'worn' indicator range, then install it (the lower radiator hose captures the longest belt of course), and install it and see what the indicator says. Return the belt of the indicator still says worn, then try to source new tensioner(s), or springs.

I already bought the tensioners from Rock Auto. Unfortunately they will arrive next week. I followed Sam Jones recommendation, and found in Rockauto the two tensioners, they are describe as "Alternator Mounting"; the difference between these two - it is the size of the pulley. These are part number E9SE-6B209-HA (pulley 70mm)and E9SE-6B209-KA (pulley 76.2mm) (For more details review previous post from Jul 8th)

The tensioner for the supercharge is part number E9SE-6B209-JA and in Rockauto you will find it as a tensioner for the air condition.

Next week, I will share my results. Thanks.
 
In both of those images, I see no reason to replace either the tensioners or the belts.

Compared to your first images, you have a long ways to go... I'm all for shiny new parts, but it doesn't appear you need to spend the money now.

Don't throw the old tensioners away - I'll take them if you don't want them ;)
 
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In both of those images, I see no reason to replace either the tensioners or the belts.

Compared to your first images, you have a long ways to go... I'm all for shiny new parts, but it doesn't appear you need to spend the money now.

Don't throw the old tensioners away - I'll take them if you don't want them ;)

I'm into shinny new parts
I hope he posts a picture of his shinny new parts
Try to get the cam sensor wire harness routing in the shot too please. :)
 
I searched here & the factory manual, and after going thru several threads and studying photos of engines, I learned they apparently differ by location and tension & came up with the following info:

E9SE-6B209-JA 3.8L S/C Accessory (16 Lb-Ft)
E9SE-6B209-HA 3.8L S/C Supercharger (10 Lb-Ft)
E9SE-6B209-KA 3.8L S/C Jackshaft Drive (10 Lb-Ft)

As for the indicator, as the manual notes, it usually indicates belt stretch, which means times for new belts, not new tensioners.

Tensioners are expensive...be sure your belts and idlers are fresh/new first. Also be sure your's haven't been mistakenly installed in the wrong location - I found a lower rated one where the higher rated one should have been - it was jumpy/notchy and showed excess friction wear. I moved the higher rated tensioner to that location and the noise went away. I've also had squeaky idlers that needed replacement.

I suggest using or making a mechanic's stethoscope to help isolated the noise. Ive used long screwdriver/jug to listen to idlers, alternator, supercharger, water pump, power steering pump, camshaft sensor stalk and tensioners/idlers. If you need more listening capability, cut the bottom off a gallon plastic jug and fit the handle of that long then screw driver into the neck. Lay the tip onto those items and put the jug near your ear. Be careful!

As for new replacement tensioners, I haven't been able to find them, at least by part number. I think most SC owners either find serviceable used ones, or, buy new springs and DIY rebuild. Am told that isn't much fun, tho. I think SCP or Magnum Powers has new tensioner springs.

I can't see any difference in the HA & KA versions. Both mine have been modded to include the HD springs sold by Magnum Powers and I actually have KA on the supercharger belt and HA on the jack shaft pulley belt. Is the difference the length of the arm ?

David
 
Is the difference the length of the arm ?

David

Spring tension. No visible difference I've found, other than P/Ns.

After I found those specs, I went out to my '90 and used a torque wrench to check how many ft. lbs. it took to make each swing. What I found mirrored the 10/10/16 spec & P/Ns, except that they weren't in the OE location. I found my Anny had the 16 lb tensioner on the jackshaft instead of a 10 lb. That meant a lighter 10 lb on the accy. train instead of 16 lbs.

I know the top end has been apart in the past, before I got the car, and i figure someone just threw them on without checking.

I like knowing the jackshaft bearing sees the correct/lower/OE tension load now, and it seems ok at present, but I have a fresh JS bearing and as soon as I get my hands on a spare bracket, I'll rebuild it/swap it in. I'm running a 7% sc pulley.
 
Spring tension. No visible difference I've found, other than P/Ns.

After I found those specs, I went out to my '90 and used a torque wrench to check how many ft. lbs. it took to make each swing. What I found mirrored the 10/10/16 spec & P/Ns, except that they weren't in the OE location. I found my Anny had the 16 lb tensioner on the jackshaft instead of a 10 lb. That meant a lighter 10 lb on the accy. train instead of 16 lbs.

I know the top end has been apart in the past, before I got the car, and i figure someone just threw them on without checking.

I like knowing the jackshaft bearing sees the correct/lower/OE tension load now, and it seems ok at present, but I have a fresh JS bearing and as soon as I get my hands on a spare bracket, I'll rebuild it/swap it in. I'm running a 7% sc pulley.

Thanks, mine needed extra tension to prevent belt slip from back when I was over driving my MP II supercharger about 25%. Still using same tensioners with 4.2 motor and 2.3 Whipple with a 10% crank pulley, 10% JS pulley and 3.50" blower pulley.
 

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Everything is on the table when it comes to preventing belt slip ;)

I was having trouble isolating a chirp on the front of the engine. Checked most everything and finally isolated it to the js tensioner with a DIY stethoscope. Noticed it would bounce in time with the chirp (it was the only tensioner bouncing). Took that tensioner off and found a shiny rub spot that seemed to indicate a very tiny/focused friction point, arm-on-bracket.

Went away after moving the tensioners. The js tensioner still bounces a bit and I wonder if it's normal for that location..that, or the js bearing is acting out?

I think the heavier spring was causing that tensioner to move less that normal, and rub in just one spot, rather than swing, allowing it to short-stroke rub/file instead of just move back/forth as designed.

All conjecture on my part, of course, but the good news is tensioner layout matches the factory manual, and the front of the engine is as quiet as i could wish for now, so all good.

Ken
 
Shinny Stuff

Thanks, mine needed extra tension to prevent belt slip from back when I was over driving my MP II supercharger about 25%. Still using same tensioners with 4.2 motor and 2.3 Whipple with a 10% crank pulley, 10% JS pulley and 3.50" blower pulley.

Nice David
 
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