New 3D-Printed 944 Timing Belt Tensioner Tool
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wjtbootstrap
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Fantastic! Saves me trying the old 90 degree twist method
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Mr McPhisto
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Will this work on a 1988 Turbo S? I know someone who has one but doesn’t have a 3D printer, so I can make this for him.Tom wrote: Fri Jul 01, 2022 7:21 pm Here is our popular 3D-printed timing belt tensioning tool for the 8-valve 944 engines. The first file listed below is the original and most popular. The alternates have more durable drive ports, but require either an M12 triple square socket to drive it, or a heat-set insert from McMaster Carr.
Please note You need at least one post on Carpokes to download files!
Carpokes 944 Timing Belt Tensioner.stl This is the version most people will want if you don't have an M12 Triple Square socket to use.
944 Belt Tool Triple Square by CP.stl See post #494 here. This version has a more durable drive port that uses an M12 triple square socket to drive the tool.
Carpokes 944 Tensioner with Heat Set Threads.stl This is the version I sell, with a heat-set metal threaded insert to drive the tool. This is the most durable version of the tool. For more info on this version, see post #143 here.
[Note: if you cannot download the .stl above, be sure you register and account and are logged in with at least 1 post on Carpokes. If, after that, you still have problems, feel free to email me at [email protected].... ]
The basic idea is that it relies on a torque wrench to measure how tight the belt is. The tool has two small pointers that correspond to the new and used belt factory tensioning specs. The appropriate pointer should line up with the guiderail on the water pump when the torque wrench reaches 7 ft. lbs. (84 inch pounds).
The one in the video is posted in ABS with 100% infill and 4mm wall thickness. PLA should also work fine, if not better (as would CF filaments, nylon, etc.). The original version of the model has holes for six sheet metal screws (No. 6 screws, 1.5 inches long) to give the tool the mechanical strength it needs to hold together. The tab that applies pressure to the belt is prone to snapping off without the screws, and the 3/8" square drive socket is prone to cracking apart or rounding out. The screws seem to solve all that, as long as you don’t go past 7 ft. lbs. with the wrench. The alternate version of the tool add durability to the drive port, so don't need those screws, but ALL versions of the tool still need the two screws to reinforce the tab that presses on the belt.
See it in action in the video below! All feedback encouraged!
[This post last edited on 11/17/25.]
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Tom
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Yes!Mr McPhisto wrote: Mon Aug 31, 2026 5:17 amWill this work on a 1988 Turbo S? I know someone who has one but doesn’t have a 3D printer, so I can make this for him.Tom wrote: Fri Jul 01, 2022 7:21 pm Here is our popular 3D-printed timing belt tensioning tool for the 8-valve 944 engines. The first file listed below is the original and most popular. The alternates have more durable drive ports, but require either an M12 triple square socket to drive it, or a heat-set insert from McMaster Carr.
Please note You need at least one post on Carpokes to download files!
Carpokes 944 Timing Belt Tensioner.stl This is the version most people will want if you don't have an M12 Triple Square socket to use.
944 Belt Tool Triple Square by CP.stl See post #494 here. This version has a more durable drive port that uses an M12 triple square socket to drive the tool.
Carpokes 944 Tensioner with Heat Set Threads.stl This is the version I sell, with a heat-set metal threaded insert to drive the tool. This is the most durable version of the tool. For more info on this version, see post #143 here.
[Note: if you cannot download the .stl above, be sure you register and account and are logged in with at least 1 post on Carpokes. If, after that, you still have problems, feel free to email me at [email protected].... ]
The basic idea is that it relies on a torque wrench to measure how tight the belt is. The tool has two small pointers that correspond to the new and used belt factory tensioning specs. The appropriate pointer should line up with the guiderail on the water pump when the torque wrench reaches 7 ft. lbs. (84 inch pounds).
The one in the video is posted in ABS with 100% infill and 4mm wall thickness. PLA should also work fine, if not better (as would CF filaments, nylon, etc.). The original version of the model has holes for six sheet metal screws (No. 6 screws, 1.5 inches long) to give the tool the mechanical strength it needs to hold together. The tab that applies pressure to the belt is prone to snapping off without the screws, and the 3/8" square drive socket is prone to cracking apart or rounding out. The screws seem to solve all that, as long as you don’t go past 7 ft. lbs. with the wrench. The alternate version of the tool add durability to the drive port, so don't need those screws, but ALL versions of the tool still need the two screws to reinforce the tab that presses on the belt.
See it in action in the video below! All feedback encouraged!
[This post last edited on 11/17/25.]