View Cart / Back to 900 Faqs!/ Visit Tom Townsends site

AUTO TRANSMISSION SERVICE 900 up to 94

• First, drive the car and get it to normal temperature. Then jack it up, preferably as high as you can get it. Remove the skid plate if equipped, two bolts and two nuts, 12 mm on the bolts and 13 mm on the nuts. Make sure before you remove the plate that there is clearance between the plate and the bottom of the transmission. If the plate has been bent into the transmission, bend it back out so they don't touch.
• Remove the flat screwdriver plug in the front pan and drain the fluid. It has a seal which should be replaced. Letting the front end of the car down will allow more fluid to drain. Then remove the 10 mm bolts holding the front pan.
• Remove the pan and clean the magnet and the pan. Use Brake clean and a rag and shop air if it is available. Be real clean with it. Scrape off any old gasket/sealant on the pan and the transmission.
• Then remove the right large aluminum pick up tube to access the right screw holding the filter in place. The tube is held in place by a metal tab you just pull back and extract the tube. It has an o ring so don't lose it. Then remove the two flat screws holding the filter in. Clean the filter by running brake clean through the hole that goes around the tube. Blowing it out with air helps a lot. Do not use carb clean on or in the transmission. Brake clean is as strong as you want to use, be careful with it, use it sparingly and allow any residue to dry. Put the cleaned filter back and reinstall the pick up tube you removed. Double check all the tubes you can get to to make sure they are all tight.
• Make sure the pan hasn't been bent up into the filter. If so, straighten it out or replace it. Check that the pans have not been over torqued and that their sealing surfaces are smooth and level. A little work with a hammer can straighten minorly deformed pans out. Ones that this won't get a level surface on should be replaced or leaks will result. If the filter has been bent, replace it. Clean all the sealing surfaces well, cleaning any oil off with a rag and brake clean. Use a new pan gasket and use LocTite 518 anaerobic sealer (Not the thread lock stuff) on both sides of it. Do not use silicon sealers, they can flake off inside the transmission and block critical passages.
• The 518 only dries between sealed parts and can be easily removes on future repairs. Just before you put the pan back on, wipe off any dripping fluid on the transmission sealing surfaces. The secret to getting these pans to seal is dryness, torquing the bolts, and using the LocTite 518. The pans can be hard to seal otherwise. If you don't have a torque wrench or torque meter that reads really low (like 5 ft lbs) just try to get the bolts as even as possible by feel and don't over tighten them. The torque spec is 18 INCH pounds (Not much). Hand tight is enough.
• Since the transmission holds 8.5 quarts of fluid, removing the front pan only gets out about 3.5 quarts. Most of the remainder is held in the torque converter and there is no way to get it out. What I do is service the transmission as above, refill, take it for a test drive and then change the fluid through the drain plug again and refill. Then change it again this way at the next oil change.
• Not doing this renders the whole procedure not worth the effort as the majority of the fluid will be old. Do not use additives. Put three quarts in on refill, start the car, move the selector through the gears, pausing about 30 sec. at each position to flush any air out. Then recheck the level and adjust as necessary. Test drive until the car is warm and recheck level with the car idling in park. Overfilling is as bad as under filling.
• To check the final drive, there is a 3/8 square plug at the right axle, remove it by inserting a racket in it and turning it out. Then remove the drain at the back of the transmission, either a 12 mm Allen or a 3/8 square drive, depending on the year. This plug can be tight as hell. Giving it a good smack with a hammer usually makes it easier to remove. Drain the fluid and refill with 75W90 for cars up to 92. 92-93 and 94 convertibles used 10w30 engine oil in the final drive. It is fine to switch from oil to the gear lube in the final drive, but if the final drive initially contained gear lube, do not switch it to engine oil. You can tell gear lube by its strong sulfur smell. Fill until the level is even with the bottom of the hole on the right side plug (fill it till it runs out the hole). Fill through the side hole by putting a length of rubber tubing on the end of one of the gear oil bottles and squeezing. It usually takes around two of the bottles of gear lube/oil. Buy three to be sure to have enough. You can take back one if you don't open it, or save it for next time. Run a little fresh through before putting the drain back to wash out the case a little bit.

 KICK DOWN CABLE ADJUSTMENT

• The kick down or downshift cable normally has a stop crimped to the cable just where it emerges from the sheath at the throttle. Normally, the cable is adjusted so that this crimp is 2 mm from the cable end. Perfect adjustment requires a pressure gauge. You can get an acceptable adjustment by feel. If the car is upshifting late or downshifting too soon with throttle application, loosen the cable tension by shortening the distance from the crimp to the sheath by means of the lock nuts holding the cable to the throttle bracket. If the car upshifts early, and doesn't have a passing gear, tighten the cable, effectively lengthening the distance from the crimp to the sheath again by means of the lock nuts on the cable.
• Click here for Kick down cable pricing!

BAND ADJUSTMENTS

• Though not part of a specified service interval, sometimes adjusting the bands will improve an autos shifting and prolong its life. This is not usually done with transmission routine service. The factory manual gives no interval for adjusting the bands. Adjustment of the front band requires pan removal and a special spacer tool. It is not advised to be done without the tool. If you want to try, the tool is actually just a 1/4 inch thick spacer to be placed between the piston and the arm's bolt end and then retorquing the nut against the spacer. The torque spec for the square headed bolt is 10 inch/lbs, for the lock nut, 10 ft/lbs. The rear band can be adjusted by loosening the lock nut on the adjuster and torquing the adjustment bolt to 10 ft lbs and then loosening the adjuster 3/4 turns, holding the adjuster and tightening the lock nut. because of the use of the special tool, it is advised you see a Saab shop to have the band adjustment done. Since the pan must be removed to carry it out, you might well let the shop do the servicing at that time.
• Profz on SaabCentral posted his method which says:

  Only the earliest trans used the spacer as called for in the instructions from "thesaabsite". If you have a Turbo car and the trans serial number is 001-1700 or lower, or if your non-turbo trans has serial number 002-2800 or lower, then use a 1/4-inch (6.4 mm) spacer. Tighten the adjuster stud to 11 inch-pounds (one foot-pound is close enough), then back it off one turn. While preventing stud from turning, tighten its locknut.

  Many of these older trans were upgraded by Borg-Warner, and will have a number beginning with the letters RS. For these, and for ALL OTHER trans with serial numbers greater than quoted above, the adjustment procedure is this:

  Use a spacer of 8.9 mm thickness. Tighten adjuster stud to 11 inch-pounds (for all practical purposes, one foot-pound) and DO NOT back it off. Tighten its locknut.

  Some practical advice from my own experience:

  (1) Make your spacer from a cut-down bolt (or other stock) from 1/2-inch to 3/4-inch in diameter. Hacksaw and file it to the correct thickness. Try to get it as precise as possible, but a 10% error is acceptable.

  (2) Measuring one foot-pound takes either a micro-torque wrench or a torque screwdriver: Both are hard to find and expensive. (I nailed a torque screwdriver on eBay a year ago for $20, but this was a fluke. And...I had already done my band adjustment by feel, as described below.)

  Here's an approximation if you don't have the torque-measuring tool: For the early trans, finger-tighten the adjuster stud then give it a 1/2-turn with a wrench. For the later trans, again finger-tighten the stud but give it 1 and 1/2 turns with the wrench.

  Now change the fluid and filter, and cruise on for at least another 100k miles...

PARTS LIST

Drain seal 4118527 $2

Filter 7544125 Click here for filter pricing!