BALANCE SHAFTS & TIMING BREAKDOWN & HOW TO DO

A Special Thanks top James Hamilton for the contribution of these photos & this information. It is guys like this that make things easier for everyone who ones Saabs. Kudos! Saabsite admin!!!

The breakdown shown below is of a Saab 9000 1996. The balance gear setup is basically the same on the Saab 9000, Saab 95, Saab 93 and the Saab 900. There may be small differences but not major ones. These photos are designed to help those who are doing balance chain jobs.

A Special Thanks top James Hamilton for the contribution of these photos & this information. It is guys like this that make things easier for everyone who ones Saabs. Kudos! Saabsite admin!!!

So - What I did:

I was concerned about my car due to the chain noise, so I bought a 27 mm socket and took the chain tensioner out to check the wear. It was 14mm, way overdue. As I had no parts to do the job, and because I lost the tensioner cap screw when taking it out (doh!) I first bought a new tensioner, hoping it would take up the slack and quiet down the chain. I figured I had at least a month to get organized. Less than a week later, I was driving locally and the engine started to make louder chain noise and stumble badly. I took a risk and drove home, about 5 miles. As long as I kept the rpms up it seemed ok.

On taking the valve cover off I saw that the upper timing chain guide had broken apart, and the pieces had fallen down into the moving chains and sprockets. This had immediately started chewing up the other chain guides so now the motor and oil pan were full of plastic shards and shavings, with a few metal filings as well.

Parts I ordered included the timing chain, sprockets, and guides, a full balance chain kit, new serpentine belt and pulleys, water pump o-rings, and because of all the metal and plastic shavings in the oil, a set of oil pump gears and seals. Do yourself a favor and order a full set of water pump o-rings, one of every size including those for the adapter tube that presses into the engine block. They're inexpensive, and if you don't get it right the first time, you'll have to take the pump off again and reset it with all new rings anyway (which I wound up doing because the first o-ring I used wasn't exactly the right size).

Click here for Saab 900 94-98 timing and balance component prices!
Click here for Saab 93 98-2003 timing and balance component prices!
Part numbers (NG900 1996 B234 engine)
1 150462420 900 94-98 4 Cyl Balance Shaft Kit
1 9146598 900 94-98 4 Cyl O-Ring Small Feed line to water pump
1 4901625 900 94-96 4 Cyl Tensioner Pulley Smooth Center
1 9132929 900 94-98 Oil Drain Plug
1 9145376 900 94-98 4 Cyl Guide Rail Tensioner side
1 8822041 900 94-98 4 Cyl Valve Cover Gasket
1 9138009 900 94-98 4 Cyl Oring to Oil Pump Pickup Tube
1 9321936 900 94-98 4 Cyl Oil Pump Gears
1 9145392 9000 94-98 2.3L Mid Shaft OES
1 9130600 9000 94-98 O-Ring Oil pump
1 9173576 900 94-98 4 Cyl Front Crank Seal Oil pump side
1 4356127 900 94-98 4 Cyl Idler Pulley Upper Grooved Top Left
1 4359063 900 94-94 4 Cyl Serpentine Belt
1 5172184 900 94-98 4 Cyl Tensioner Pulley ONLY
1 9146614 900 94-98 4 Cyl Water Pump O-Ring Water Pump Tube to pump housing
1 9131145 900 94-98 4 Cyl Timing Chain Endless
1 9115197 900 94-98 4 Cyl Crank Gear
2 9115205 900 91-98 4 Cyl Camshaft Gear 2 needed
1 8859324 900 94-98 4 Cyl Guide Rail Upper
1 9145350 900 94-98 4 Cyl Guide Rail Right
1 7585086 900 94-98 4 Cyl Chain Tensioner for Timing AFT
1 7508690 900 94-98 4 Cyl Tensioner Seal 7508690
1 37394 Loctite Gasket Maker 518 (50 Ml Tube)

As you need to drain the coolant anyway, I also ordered a thermostat and lower radiator hose. If your car is more than 7 years old you might consider replacing all the coolant hoses since you'll have it all apart anyway.
Click here for Saab 900 94-98 Cooling system prices & Here for Saab 900 94-98 coolant hose prices!
Click here for Saab 93 98-2003 Cooling system prices & Here for Saab 93 98-2003 coolant hose prices!
1 4876215 900 94-98 4 Cyl Radiator Hose Lower
1 8822025 900 94-98 4 Cyl Thermostat Kit 89 degree

Tools you'll need:
3/8 inch ratchet
3/8 inch extensions
Misc adapters 1/2" <-> 3/8" <-> 1/4", swivel adapters
1/2" drive breaker bar for sockets
Torque wrench 1/2" drive, 1/2" extension bar
Metric socket set (6-sided) 9-21mm
Metric combination wrench set, 9mm-19mm
Torx socket set (solid one-piece type) t25-t50
Torx female socket, E16 (for cylinder head bolts)
Set of Torx L-wrenches, from very small to T-40
Set of allen wrenches / sockets
2-ton hydraulic jack
Jack stands (2)
27mm metric socket (1/2" drive)

So, how do you do it? In order:

- Jack up the car and set it on jack stands, put the jack stands on the tallest setting.
- Remove the air resonator and the top of the engine, stuff a rag in the throttle body to keep anything from falling in.

- unbolt and remove the air cleaner box from the passenger side fender.
- Remove the passenger side front wheel, the wheel arch liner and the plastic splash guard liners from under the front bumper.

- The crankshaft bolt will be under high torque, you will have to break it loose. Remove the spark plug wire plate from the valve cover, disconnect the spark plug wires from the spark plugs. Fit a 27mm socket to the 1/2" breaker bar, set it on the crankshaft bolt. Place blocks of wood as necessary to brace the bar, angled down from the crankshaft pulley towards the front of the car. Climb in the car, turn the key to the "start" position for about 1/2 second. This should break the crankshaft bolt loose. You may have to try this a couple of times to get it right.

- remove the oil drain bolt, drain all the oil out into a pan.
- remove the lower radiator hose, drain out all the coolant into a pan.
- insert a 1/2" ratchet extension (about 10 inches long) into the belt tensioner at the rear of the engine, from the top on the passenger side. There is a square opening just the right size for 1/2" socket drive. Pull against the tension toward the front of the car, slip the serpentine belt off one of the pulleys.

- unbolt the passenger side motor mount from the body (underneath). This is also the air conditioning compressor bracket. Unbolt the compressor (watch out it's heavy) - set it resting on the shelf below the radiator. Now you can get some movement of the engine, you can place a jack under the oil pan and jack it up a couple of inches. This will give you better clearance to get at the pulleys on the timing cover.

- remove the power steering pump. First loosen the pivot bolts from the side of the engine. To get at the bottom bolt you have to go in through the pulley from the is You won't be able to pull them out all the way but you need to loosen them. Then, remove the bracket bolts. Now, you can pull out the pivot bolts and separate the pump from the bracket.

- remove the water pump. Look at it, there are two metal tubes that go from the water pump across the front of the engine block to the transmission end of the engine. Loosen the bolt at the transmission end holding the tubes, then loosen the small bolt on the back of the water pump that fixes the tubes to the water pump. Loosen the hose clamps on the small u-shaped coolant hose, then pull the metal tubes away from the pump. Loosen the clamps to the lower radiator hose and remove it. Loosen the bolts holding the water pump to the engine block.

- on the back of the engine, remove the belt tensioner (a single bolt holds this on, same direction as the tensioner pulley bolt).

- If you have jacked up the engine, now lower it a couple of inches. Down below, loosen the upper and lower alternator pivot bolts. You don't have to remove the alternator, just loosen the bolts. These can be tough, putting some penetrating oil on them an hour (or day) before might be helpful. The bolt heads are recessed, quite far in. They are large-size Allen (not Torx) bolts. A good way to tackle these is to use a tool steel Allen L-wrench, and put your 1/2" socket extension over the end of the wrench for extra leverage - wear eye protection. Once you get them free, put some anti-sieze compound on them so you don't have to go through that again. Take out the top pivot bolt, and pry the alternator away from the engine. If this is difficult (mine was), put some penetrating oil on the pivot points of the lower pivot bolt. You can also try removing the lower pivot bolt and prying out the alternator entirely. If you do this, be sure to disconnect the alternator wires from the back first to avoid yanking them out if the alternator falls - watch out, it's extremely heavy.

- remove the belt tensioner bracket (it is also the bracket for the top alternator pivot bolt.) The bolts for this have their heads facing the firewall.


Ok, now you are down to the actual timing cover. To give yourself enough room to work in, you'll need to unbolt the drivers' side motor mount from the body of the car, this is attached underneath the battery. Make sure the motor is supported on a jack and/or blocks, and drop all 4 bolts out. Take a short block of wood, and lever it between the fender where the air box used to be and the cylinder head (see picture.) If the motor is sitting on a wheeled jack, pull the jack handle towards the driver's side of the car and try and roll it an inch or two in that direction.

This will get you an extra two inches or so between the timing cover and the passenger side body steel, a huge help and enough to complete the job. Now you can remove the remaining pulleys, the valve cover and the timing cover. Make sure to get ALL the bolts out of the valve and timing covers before you start pulling them off. The valve cover should more or less slide right off, no prying necessary - remove the dipstick tube, and all the bolts around the spark plug well before pulling on it.

Very useful - once you get the valve cover OFF but while the timing cover is ON, put the crankshaft pulley back on, finger tighten the crank pulley bolt, and turn over the crankshaft with a ratchet until the timing marks on the cam sprockets come around to the top. Only turn the crank clockwise, in the direction of engine rotation. Watch on the timing cover, for the last few degrees turn the crank slowly and line up the crank pulley mark with the mark on the timing cover. This will set the engine at TDC, which is what you want. There is no mark inside the timing cover for the crank so you need to set this before the cover comes off. Loosen the bolt (watch the timing mark!) and pull off the pulley.

For the timing cover, two bolts drop from the top, two come up through the oil pan holes at the bottom and one or two come in from the sides. Start with a rubber mallet, bang all over the cover flats and sides. Be very careful if you have to jam a wedge into the crack to separate the timing cover from the engine. The mating surface is a precision fit, if you put a scar in it it may never seal again. If you have to pry do it in small steps, evenly all around about 1/8 inch at a time. The cylinder head gasket compresses the cover from the top so it will probably take some patience and effort to get it off.

If you have removed both motor mounts and levered the engine for clearance, once the cover is loose you will be able to lift it away from the engine, clear the crankshaft and lift the cover out. If you can't get it clear, try moving the engine further towards the battery by dragging the support the engine block is resting on.

In my case, due to the metal and plastic shavings I also wanted to get the oil pan off. To do this, I lowered the H-sub frame under the engine bay for clearance and jacked up the engine by fitting the crankshaft pulley and placing a block of wood under it. To lower the sub frame, loosen and remove the 3 bolts on the passenger side. These bolts are extremely strong and it takes a lot of torque to remove them. In addition they will be sealed with loctite so you won't feel them break loose, rather they will more gradually give way. I was concerned I might round the bolt heads but the mushy feeling was the loctite letting go - these bolts are super strong and hard, there is little chance of rounding them so long as you use the correct size socket for the bolt. Loosen and remove the front and rear bolts on the driver's side. Remove all the bolts from the oil pan and let it drop. Take your time with the oil pan bolts, some of mine were seized. Apply some penetrating oil, clean the bolt heads well, torch if necessary and apply more penetrating oil. I would have done well to order a half-dozen oil pan bolts before starting the job.

Here's the key part: the main bolt on the driver's side is the critical piece. Loosen it slowly a couple of turns and pull down on the H-frame on the passenger side to see how much slack you're getting.

WARNING - IF YOU LOOSEN THIS BOLT TOO FAR THE WHOLE ENGINE WILL DROP OUT OF THE CAR, quite possibly ON YOUR FACE AND KILL YOU.

So - make sure you position yourself out of the way, with your body out from under the car. Just reach in far enough to pull on the ratchet handle. Go very, very slowly (1/2 turn or 1 turn at a time) and only loosen as much as you absolutely need, to get the oil pan out. Get as much slack by jacking up the engine as you can, and pull down on the sub frame on the passenger side after every turn on the bolt. My oil pan came out no problem, just be careful to not gouge the mating surface so you'll be able to get it back together later.

Once you have the oil pan off, raise up the H-frame and refasten one of the bolts on the passenger side to hold it in place.

You can see in the picture, the timing cover is covered with crud on the inside. The valve cover was about the same over the chains but cleaner down at the distributor end. This from an engine with 95,000 miles, using regular oil with changes every 5,000 miles or so. In the oil pan, there was a pile of plastic pieces, metal shavings and a teaspoon or so of sludge. The oil pickup screen was about 1/2 blocked. All in all not a lot of sludge but a very good thing to get it out. The oil pan here looks brand new. When I took it out it was completely coated with varnish. I tried several solvents, the only one that worked was carb cleaner which worked fabulously. I used about a dozen cans of the stuff with a fine wire brush, thankfully Wal-Mart sells it for about $1 a can. In the end the valve cover, timing cover and oil pan all came out squeaky clean.

Due to all the shavings in the oil I also wanted to open up the oil pump. The pump is integrated in the timing cover. In the photo of the timing cover, you can see at the bottom a circle about 5 inches in diameter. This is the oil pump. To remove the oil pump cover, you need to remove a big clip using a set of these:

This is a set of 16 inch snap-ring pliers, a good set is made by OTC and costs about $80. You may be able to get by with a 10-inch model but these work great. One squeezes rings in, one spreads rings out. You only need the one that squeezes in. As it turns out, the oil pump gears are super-hard steel. Unless someone dumped several handfuls of sand into your oil they are probably fine. What would wear out before the gears is the soft aluminum housing (molded into the timing cover) and the pump cover disc. So if you're concerned about a loose oil pump you should get a new timing cover and oil pump cover first. If your chains haven't failed and there are no metal shavings in your oil pan you should be fine with the oil pump that you have, it should last the life of the engine. Just plug up the oil channels in the timing cover with paper so you don't get any dirt in them, and remove it when you reinstall the cover.

Removing the chains - mark the chains and sprockets with alignment marks, so you can see how many links between sprockets and the relative angle the sockets should take.

First, remove the balance chain tensioner, as they have a ratchet mechanism that maintains the chain tension. Then, remove the balance shaft chain guides. After the guides are out, unbolt the idler sprocket and slip it off the bushing. This will give enough slack to remove the chain. When the chain is off, pull the balance shaft crank sprocket off the crankshaft.

For the timing chain, use same steps except there is no idler. Keep the chain tight on the exhaust side of the engine, slide the crank sprocket off then remove the chain. Without rocking the crankshaft, slide on the new crank sprocket and fit the new chain. Set it in the sprocket teeth to be as tight as the old chain, with the same number of chain links between sprockets.

When putting the timing cover back on, put the loctite 518 on the engine block, oil pan lip, and up on the bottom of the cylinder head gasket. Put the timing cover on slowly, working it on 1/8 inch at a time and keeping in parallel to the engine block face. When the timing cover is flush against the block, the loctite will start oozing out from the seal. Take some loctite and press it into the seal at the corners where the cylinder head meets the engine block, along the top cylinder head gasket, and along the seal at the oil pan. Insert and tighten all the bolts, taking care to use the correct torque wrench settings for each bolt.

A couple of tips:
- several of the bolts screw into very soft aluminum threads. Get a shop manual that has all the torque specifications and check them before torquing every bolt. A little too much force and you will strip out the threads in a flash - I did it twice, fortunately it hasn't prevented things from working OK.

- use a permanent marker to mark the position of the chain relative to the sprocket teeth (one mark on each sprocket, matching marks on the chain) before you take the old chain off. In particular, this will show you the correct number of links between sprockets and will help you align all the shafts correctly when refitting the chain. This will save you a lot of time later and ensure you properly hook it all back up.

- The timing chain goes on first, count out the number of links across the cam sprockets and make sure the chain is tight along the front of the chain, towards the exhaust side of the engine. When it's set, screw in the tensioner and turn over the engine by hand. As the timing marks come back around, check that everything still lines up.

- Buy and use the loctite 518 gasket maker. This stuff is cool - it looks and smells like candy, is super strong and 100% safe for oxygen sensors. Silicone can ruin your (expensive) sensors, despite what the labels say about being "sensor-safe", so just go ahead and use this. Plus, if you have any gasket leaks after the job is finished, you can loosen the bolts around the leak and smush some Loctite 518 into the hairline crack with your finger. Wait an hour or two, and the leak will be sealed.

- When removing the balance shaft idler sprocket, be careful. Use the correct size Torx socket or wrench, put a torch on the bolt before working it and get the best grip you possibly can. Due to the cramped working room, if you strip one of these sprocket bolts you will be stuck and unable to drill it out. I believe the shaft sprocket bolts are T50 and the idler is I think T45 but be sure and triple-check this.

- If you replace the valve cover gasket, glue it in place with a small amount of sensor-safe silicone gasket maker. Do not use "general trim adhesive," contact cement etc. As soon as hot oil hits them they will turn into slimy goo, and have no adhesive properties whatsoever leaving you with a mess to clean up instead of a stable valve cover gasket

While you're in tightening up the timing in your cylinders, you might also want to check you emissions lines. When I had my job all closed up and the motor running smoothly, the check engine light promptly came on. In the end I used 2 oxygen sensors, some vacuum line, a new plastic valve cover nipple and a check valve for the air injection system. The sensors were old, they tend to fail at about 100,000 miles so I don't mind having new ones - they're not cheap though. Even with those working I still had to replace all the emissions-related tubing and seal up broken or missing vacuum lines into the throttle body before I was good to go. The plastic y-nipple fitting was completely clogged with sludge, and the air injection lines in particular had totally disintegrated leaving multiple vacuum ports on the throttle body uncovered and the engine sucking in air.

By the way the universal 4-wire oxygen sensors work great, a few minutes with wire cutters and you're set. I ordered a universal sensor for the front but then found that I really needed it for the back. So, I unscrewed the wires, clipped the rear connector and hooked it up to that instead. Works like a charm, no problem.

1 558570504 900 96-98 4 Cyl Oxygen Sensor Universal 4 wire requires splicing
1 7515190 900 94-98 4 Cyl Bushing Valve Cover
1 9165903 900 94-98 valve cover y-nipple
1 4301669 900 94-98 Check Valve Upper
1 9189473 900 94-98 Emission Hose 4 Cyl

The original job took me about 3 days, now that I've done it once it would take maybe 2 days assuming I had all the parts needed. Take your time, especially with seized bolts and tightening into aluminum threads. With new chains, vacuum hoses, and sensors the car is running like a top, very smooth and quiet.

When I started it up, I ran for about 80 miles on cheap oil and a cheap filter, then flushed it with B-12 chemtool and drained out the oil, which made a big dent in the remaining varnish. I put in Mobil1 0w-40 synthetic and a Bosch premium filter which I found out is a 15-micron filter. With full synthetic oil and a 10 or 15 micron filter the engine will slowly clean itself out and remove all varnish, plus the oil is good for 5 or 6k between changes. So far so good!