Dual pulley tensioner belt problems

My 97 f250HD has the upgraded dual pulley tensioner. When i bought it it had one from ford that the whole front half of the tensioner rotated so that both pulleys rotated. The replacement i got from the parts store only one of the pulleys rotate. the one from ford is 172 bucks while the one from the parts store is about 50 bucks. The belt that was on the truck is #5081223 which is about 122 3/4" long. The problem i am having now is that with the new tensioner the belt is too tight. Every time i replace i have to loosen the alternator bolts to get the belt around the pulley. The belt is also pulling the power steering pump pulley off of the pump shaft. Does anyone have a part number for a belt that is maybe a 1/2" or 1" longer? The belt i just ordered is Gates # K081243HD. It is 124 7/8" long. Hopefully this will work and give my tensioner a break. It's pretty much maxed out right now. Couldn't find a belt that was the same width and rib count in between the above two measurements. The tensioner i am using is Gates #38191. It's for a super duty but the number is supposed to replace the ford number. Any input or advice would be greatly appreciated. Thank you.

That 38191 tensioner and belt is for the 99-03 SD drive layout. The OBS tensioner is the 38119 and uses an even shorter belt.

That is correct but the number for the obs truck is only a single pulley tensioner. Ford put out a TSB before that upgraded the obs to a super duty style dual pulley tensioner. The problem that i am running into is that the dual pulley tensioner that i get from the parts store is slightly different than the dual pulley tensioner that i can get from ford. This is causing my belt to be too short. According to the parts store the super duty part replaced the TSB part put out originally by ford. The dual pulley tensioner doesn't have the problem of the obs single pulley tensioner rotating off axis as it wears. Just trying to find a belt that is the same width and rib count, but a little bit longer to account for the difference in tensioners.

First of all, the dealer is raping you for charging you $172. The Motorcraft belt dual tensioner (part # BT-50) is $77.79 from Rock Auto or $113.00 from O-reilly's if you have near you.

The correct belt you need is Motorcraft JK81227 which is 122 7/8" long. The application is a SD truck w/o the cold weather package.

Billy T.
[email protected]

Thanks for the part numbers. Going to save me a lot of money and headache.

The JK8-1227 Motorcraft belt is just under $43 also at RockAuto. You can find it with a Part Number search.

Got the belt and tensioner from rock auto the other day. Installed them and it was much easier than any of the other tensioners. Thanks for the part numbers and info on where to get the parts. Saved me a lot of time and headache.

And another PSA success story....:walkin:

Link to TSB:

http://www.thedieselstop.com/faq/9497faq/tsb/tsb/files/982314.pdf

Found out that aftermarket dual pulleys have only one pulley pivoting instead of both pulleys. This makes the JK8-1227 belt too short. Gates is one of the bad tensioners.

Use only Ford/Motorcraft SD/van dual tensioners. About $77 at http://Rockauto.com

Motorcraft: BT-50

Ford: F8UZ-6B209-CA
F8TZ-6B209-BA