Tool for Compressing Drive Belt Tensioner

by Duncan Edwards

These are the instructions to create a replica of the Saab tool that compresses the multi-groove drive belt tensioner on later Saab 9000 engines. It should be usable on all balance shaft 2.0 and 2.3 litre engines fitted with the hydraulic adjuster.
The reason for creating this tool is that it is not always possible to use the suggested tool in one of the popular workshop manuals because it simply holds the tensioner in its compressed state and will not allow for replacement of the tensioner unit when it fails.
The creation of this tool requires only basic welding skills to complete. The welding could easily be done by a local engineering shop if required.

If you prefer not to make your own tool, a ready-made tool is available, based on the original Saab design.

Shown left is a picture of the Saab tool as a guide. Measurements of the body and bolt are the same at 100mm. (The small spring is not needed but could be added if desired.)

It is preferable to obtain two pieces of box steel, one which fits snugly inside the other. The sizes chosen for the prototype were 20 and 14mm as these sizes closely resemble the original. This type of steel can be easily picked up from a larger hardware store or a steel stockholder. I bought all the bits from a local B+Q warehouse.

1. Cut both these pieces of box to 100mm (4") lengths. Ensure you file the sharp edges down so both pieces slide between each other easily.
   
2. Take the two 20mm x 6mm bolts and weld them onto one end of each of the two 100mm pieces of steel. When welding pay particular attention to ensure there is plenty of weld on the head of the bolt. You can loosely screw the matching nuts onto the ends of the bolts.
   
3. Take the large nut and weld it onto the opposite end of the smaller box section from the previously welded bolt. You may have to grind the edges of the nut to ensure they do not protrude outside the box section.
   
4. Tack weld the washer onto the bolt end of the larger box section.
   
5. Place the box sections together and ensure the smaller one runs smoothly inside the larger one. Apply grease and feed the long bolt through and engage it with the nut, which should be inside.
   
6. You can test try the tool on the car, fit it carefully into the two notches on the adjuster. It is advisable to adjust the nuts on the two pin bolts to take up any slack and reduce the forces upon the welds.
   

Hopefully these instructions will allow successful creation of a suitable tool. Any amendments or changes to the instructions are welcomed to make the production process easier.


This is an image of the prototype. (Please excuse the poor welding, it does actually work!)

Any queries to dedwards@forressandlemanor.hants.sch.uk




An example of the tool in use on a 1992 2.3 engine.