Note: AW 30/40 series electronically-controlled transmissions are used on Volvo 960 and 90-series six-cylinder cars.
Maintenance: See the Automatic Transmission section for generic data also applicable to AW 30/40 transmissions.
[Inquiry] How do I check the transmission fluid level on my 960?
[Responses] Look way down just behind the throttle body intake assembly, low on the drivers side near the firewall and below the brake fluid container. You'll see a square yellow dipstick which doesn't have a handle on it. It which accepts a 3/8 inch drive extension: stick the socket extension on it, reach down and depress the hold-down clip, and pull it out. It is sometimes easier to reach from the side of the car, reaching down low. I just reach down and pull it out myself. You'll need a long funnel to put fluid in. Be sure that the car has been driven 15 minutes or so, stop, move to and stop in each gear about 5 seconds, and back to park. Check fluid level. Don't overfill by even a small amount.
I extended the dipstick with an old clothes hanger . I cut off both ends at the bottom and looped one end into a hole in the dipstick and made another loop at the top end of the hanger so I could pull it up. It really makes life easy if you check your trans fluid frequently.
[Tips from Mike Hale] I was riding in my Dad's 95 960 when I noticed that the shifting was a little rough. My Dad had mentioned that he also notice a pause at about 80mph when letting up off the accelerator-- It felt like the car coasted for a second or two before the gears kicked in.like putting the clutch in and letting it out on a car with a manual transmission. He had taken it to the dealer before about the problem while it was under warranty and suggested they change the transmission fluid. Volvo says that transmission fluid is permanent.it doesn't need to be changed the dealer said. Well, anybody with a shred of common sense knows that no fluid is permanent.it breaks down and gets dirty over time. So I told my Dad we'd change the fluid this weekend.what a difference it made. Not only is the coasting problem above fixed, it also shifts so smooth, you can barely feel it. As we drained the tranny, we were both amazed and disgusted at Volvo for saying it wouldn't ever have to be changed and at how dark the fluid was. For about 17 bucks we got the job done.[Al] Just a quick note on the results of my AW-30 transmission flush. 97 960 66,827 miles. Unbelievable how much the quality of the transmission shifts have improved. It made a huge difference to the plus side.
Because the transmission cooler is a little different than other RWD Volvos, I've outlined changing the fluid below. Note: IPDs new transmission flush hose DOES NOT work on 960s as they advertise (all RWD Volvos to 1998).the fittings on the 95- 960/90 are different. I called them after I received it and was told that they hadn't actually tried it on a 960/90 series.it didn't sound like it would work.
Start by pulling the dipstick. On 960s, there isn't a dipstick handle. It's easiest to reach under the car from the driver's side and follow the dipstick tube up OR if you have a long ½" extension bar, you can push it into the top of the dipstick and pull it out. Without a ½" bar, push up the dipstick until it's all the way out (and either grab it or let it drop to the floor). Unwind and bend one end of the hanger so it will hook in one or more of the holes on the dipstick. Insert the tube from the funnel into the dipstick tube.you'll probably have to push it in from underneath the car. Pull it up on ramps (if you have them)-the transmission pan is angled in the rear where the drain plug is so this drains more fluid (14mm drain plug). When finished draining, pour what you drained into a premarked bottle and pour that amount of fresh ATF into the tranny (approx. 2qts). Push the car down the ramps onto level ground.
Unscrew the top cooler line at the radiator by using a 1" wrench as a counter hold so you don't break the connection. Pull the cooler line out of the 1" brass screw and push it gently aside. With the hose clamp already over the 1" vinyl hose, push the hose over the 1" brass screw and tighten the hose clamp (real tight 'til it begins to form to the sides of the brass nut). Put the end of the hose in the bottle/bucket. Have helper start the engine and let it idle (do not push the accelerator). Fluid will begin to fill the hose and bottle. If the hose is inserted into an antifreeze bottle with a tight fit, push the hose in slightly at the mouth to allow the bottle to vent (otherwise it may expand and explode). Allow 2qts to drain (Tell the helper to shut off the engine just shy of 2 qts as some in the hose will continue to drain when the engine stops). Add two qts of fresh fluid (+or- depending on how much you drained. Repeat until you've drained 8 qts and you see clean fluid. Tip: as you do this, drain each 2 qt run into gallon jugs so you can keep an accurate tally of how much you've taken out relative to the number of empty bottles of fresh ATF you put in. Carefully remove the hose and drain any fluid in it into the jug.note how much and add that amount in fresh fluid. Replace the cooler line and dipstick. Run the engine and shift through the gears. Take it for a short spin to heat up the fluid for measurement. While running the engine in Park, pull the dipstick, clean it off, reinsert it, and pull it again to measure.note the position on the HOT markings. If its low, add a little (keep in mind that if the HOT marking says you're ½ qt low, it won't take ½ to fill it because the ATF from the bottle will expand when heated. If it's overfilled, open the drain plug slightly to get some out. That ought to do it.enjoy your revamped transmission!
Fluid Specifications. Use Dexron fluid in your AW-30/40 transmission. In the Lubrizol knowledge Base site at www.lubrizol.com, they note that two European commercial vehicle automatic transmission makers have posted specs for mineral oil versus synthetic automatic transmission fluid lifetimes. Voith allows 60k km drain intervals on mineral oil and Group III (hydrocracked semisynthetics) ATFs and 120k km intervals on full synthetics, both in Dexron III specs. ZF allows 30k km for mineral oil, 60k km for part synthetic, and 120k km for full synthetic, again in Dexron. This is an indication of the value of synthetics in normal use. Mobil 1 ATF is a full synthetic.
Fluid Level. [Editor] Some anecdotal evidence exists that fluid level in the AW 30/40 is very important: even a small excess may cause strange transmission noises. So don't overfill your transmission
Flush By Draining the Torque Converter?
[Frank] Some Euro indy mechanics have suggested that a better flush is achieved by first draining the torque converter. Not true: this creates a large air gap and forces the tranny to run dry while it refills. The Volvo OEM flush procedure is through the cooler lines as noted above.
Changing the Filter. [Editor] To replace the filter screen, remove the pan. The gasket used is a silicone paste. To remove the pan once the bolts are off, use a rubber mallet and gently hit the pan from all sides a few times until it falls down. Use care since there will be about one quart of fluid left in the pan. Clean up the tranny pan and scrape off all the old gasket material. Remove the magnets in the pan and wipe the metal shards off, then take some clean ATF fluid and wipe the insides of the pan. Use Volvo gasket material, RTV, or rubber gasket material when replacing the pan. Torque spec on the pan bolts is 65 IN-lbs; on the filter bolts is 7 ft-lbs. Merely draining the pan, instead of flushing, will require about 6.25 quarts of fluid.
Troubleshooting the AW 30/40 Series:
Symptoms. [Inquiry] My transmission will not shift out of park when I step on the brake. [Response: Bob] Shift lock solenoid not releasing. Possible causes, brake light switch, micro switch in shifter assembly. Micro switch most common. Access shifter by removing console; on passenger side near indicator is a small black switch with a metal lever. Switch about 1 in. long @1/2 in wide, mounted with a small round metal clip. There are two black wires. You have to unbolt the shifter and lift up slightly to access switch, but don't have to disconnect anything under car. Be careful removing switch retainer as its easy to break the small plastic post the switch mounts to. To test, short the two wires together with key on and brake pedal pressed. If it now comes out of park, replace or bypass the switch.
[Editor] This is a known frequent-failure item, in part because of the ridiculous design of the switch mounts on two small plastic pins with push fasteners to hold it on. The switch itself does not last long. If you replace yours, install the new one in such a way that a replacement can be easily installed.
Shift Lock Switch Replacement. [Tips from Tom Irwin] Lately, my AT has been failing to allow a shift out of PARK about 90% of the time. I have to press the Shiftlock override to get going. This car was serviced in 1996 under the recall campaign to replace a defective shiftlock microswitch inside the shifter console. The A-hah! went off in my head because I have been substantially underwhelmed about the abilities of the dealership where I purchased the car. I got out the books and went looking for trouble. To get at this thing, it is advisible to remove the following parts, roughly in this order [applies to both 960 and 940 as noted]:
Disabling the Entire Park-Shift-Lock System:
[Editor] Cursed 940 park-shift-lock microswitch! My 95 has been through two of these in twelve months. They are a small pain to replace, but bearable until the park-lock solenoid died. I have been parking in N and pulling the emergency brake handle to hold the car: it won't go into P. Worse, this solenoid costs over $100 and is buried inside the shifter assembly. Worst of all, it is a positive locking device, so if it fails, or if the microswitch fails, it locks the car either into or out of park. I prepared to remove the entire idiot-proof locking assembly and be done with this annoyance. Here's how to do it:
[Inquiry] We took the 960 up the mountains. The ambient temps were in the low 60's. We topped out at just above 2,000 feet. No trailer, just 220 pounds of 'persons' between the two of us and maybe 100 pounds of gear in the trunk. As we are climbing up the last of the twisty's, I missed a switchback and had to make a tight 3 point turn. The trans went rough into reverse and started to just not act right. With a mile to go, the mode selector and dash arrow goes berserk. The lights are all blinking REALLY fast! I just throttled back and eased into the campground. This morning, no lights. We got out OK. Got home and pulled the codes... 235 Fluid Temperature too High. (above 300 degrees) Now I am running Mobil One ATF, freshly serviced just last month. My load was light, compared to what the vehicle is rated for. And the lights went out when it got cooler, so I don't suspect a defective sensor. What could be failing inside the transmission to cause, or add to an overheat condition?
[Response: Abe Crombie] Hard pulls at lower revs in higher gears causes this. Driving uphill for a distance at lower revs in either of gear ranges 3 or 4 will build oil heat due to the stall speed of torque converter. Next time pull it down into a lower gear. The transmission has a two-stage overheat program. The first stage locks up a bit sooner in the upper two gears. The second stage (when arrow blinks) goes to full pressure, shifts up sooner, and locks torque converter in second gear as well as third and fourth. The lights do blink for a stage two overheat until the temperature of the oil falls below approximately 280F. It is very easy in E mode (even in S mode) to get an unlock in 4th without a downshift to 3rd or to get unlock in 3rd without a downshift to 2nd. No need to worry about a fluid change if you had synthetic in it. The normal routine would be to drain and replace fluid, drive car, and if transmission functions okay, then send it down the road.
960 AW30-40 Self-Destructs in Hot, Hilly Climates. [Cautions from Rafael Riverol] Leaving your 960 stock with OEM radiator, no cooler, and cheap transmission oil, together with dealer maintenance according to the schedule, has resulted in a new transmission in every single one 960 I know about in Puerto Rico at around 50k miles. Not only are we talking about thousands of dollars, but a much worse never ending tale of woes and headaches. Volvo technicians tell horror tales throughout U.S. To help prevent this, install a transmission cooler. The factory kit is a simple bolt on, but not cheap. I bought one for my 960 (1995) for $385. Of course, you should also use synthetic transmission fluid. Mobil is a good choice and readily available. If you are careful, you may want to install a Magnefine transmission oil filter ($20, from their website) and perhaps a transmission fluid temperature gauge. If you want to mount the gauge on the pillar you can get a pod from the MVP website for about $30. If you have a 960, I emphatically recommend you do all the above and watch your radiator and coolant like a hawk for any signs of contamination transmission oil particularly in you have the Volvo plastic radiator. But if you do the above, you should be OK as the transmission on the 960 is a Warner (Asia) unit closely related to the one in the Lexus. Be safe or you will be sorry.
960 With AW-30/40 Has Busy Shift: Electrical Glitches. [Inquiry:] I have a '92 960. The car has 95,000 miles. I have noticed that the car seems to shift frequently. The best way to describe it is that it is busy. It is more pronounced in traffic when there is a lot of stop and go. It seems as if it slipping in and out of gear. I have had it at the dealer twice and they agree it is busy, but can not give me a reason. Any ideas?
[Response: Abe Crombie] The mileage on that car and the symptoms make it a candidate for a failing throttle position sensor. This can be monitored by their Volvo scan tool on a drive while it is overshifting. The transmission computer uses this signal read directly from TPS by Fuel computer which passes it on to trans computer. You could unplug the TPS (this will set code/turn on check eng light) and drive the car and see if it shifts less and holds gears better. There will be a default signal from ECM to TCM when the signal is missing.
[Inquiry: Similar Problem] '93 960 ran smooth and quiet before I brought it in for tranny service, and it still does. But since the servicing, the tranny searches around a bit at times. The tach indicator will jump forward and back, then forward again, and ther car lurches.
[Response: John O] Changing ATF will not make the trans act up unless someone put in the wrong fluid (like Ford Type F, not likely). What I've seen a couple of times with early 960s (especially '92s) was a corrosion (oxidation) problem affecting the large electrical harness connectors on the left, upper area of the transmission, seen from under the car and near the dipstick area. Remove the plugs from the bracket, unplug them and spray inside with electrical contact cleaner, let it dry then re-install with silicone dielectric grease smeared insided the wire connectors. I've seen this help a couple of our customers who previously experienced unusual trans problems and worth trying before condeming the trans itself.
[Tip from Tom Irwin] Those connectors can be hard to separate: use caution, they crack easily.
If both W and E are flashing and your UP arrow on the dashboard is on, the (in)famous PNP switch is the most likely cause of your symptoms. If you can read error codes, if the code is 313, it is the PNP switch. It is good to shift a couple of times from P to L and back to 'refresh' contact points in PNP. [Rafael Riverol] Usual failure mode is: the PNP switch fails on the highway, AT enters "limp home" mode (fourth gear in D and third L), ATF then overheats, orange arrow and E,S,W lights flash,and ATF smells burnt. OBDI reads missing or shorted PNP signal and overheated ATF. [Walt Poluszny] When it happens, use your left hand to turn the ignition key to the start (crank) position and hold it there. With your right hand, slowly move the shift lever forward and/or reward until the starter engages. If this works, your P/N sensor is out of adjustment or bad.
What Not to Do. [John Roberson] If your PNP switch is failing, try moving the shifter several times to reactivate the PNP and then restart the car. If it starts in first gear, not third, and shifts fine through all gears until stopping then you can drive the car. If it is still stuck in third do not drive as the tranny will heat up and cause real problems.
PNP Diagnosis. Put the trans in PARK. Turn the key to #2. Step on the brake and attempt to shift out of Park. Does it happen? If so, your PNP is working.
[Inquiry] Does anybody know where the starter inhibitor switch or neutral safety switch is located on the transmission for a 94 960 w/ automatic trans. Also tips on removing it would be much appreciated. I think it is sticking when cold. Starts OK on initial start up for the day, or when warm or hot, but when turned off when cold (anything less than 15 minutes) will not crank. Battery, alt., starter all check out. It seems the trans is not sending the signal to the ignition switch.
[Tips from B and Stan Sexton] The PNP or gear position sensor is located on the right side of the transmission case. It slips over the manual linkage shaft and bolts to the case. The wiring routs to the left side of the trans, where it is attached to a short metal rail toward the front of trans. The pigtails are long and the clips are released by squeezing with a needle nose plier from atop the trans pan lip.
Mine gave out at 48,000 miles. When it fails, you will have 3rd gear only and the check engine and tranny dash lights will go on. The switch R&R at a Volvo dealer runs between $300 and $400. I decided to buy the switch from Nils Sefelt Volvo in Houston on the Internet for $110.00 plus $8.00 shipping UPS instead, and do the labor myself.
[Tip from JohnG] DO NOT purchase an aftermarket (Scan Tech) switch. Spend the extra $10-$10 and get an OE one.... trust me.
PNP Replacement. [Procedure by Walt Poluszny/John Gislason]
Removing PNP Switch:
Installing the New PNP Switch:
An autopsy of the switch reveals it is really a very simple electrical contact switch but subject to moisture and salt contamination .There are numerous springs keeping electrical contact certain. After opening it up, it appears that on one side of the switch, the grease is yellow and looks new, on the middle and right side of the switch it is as black as carbon and a strange texture making me think the knife-slide contacts are arcing and burning the grease. This black 'stuff' finds it's way between the contacts causing a fault. I figure it will fail without warning and need replacing every 4 years.. After replacing the switch, you can reset the tranny light by pulling out fuse # 14 (if I remember right: the drivetrain diagnostics fuse.) The check engine light takes a mechanic with a scan tool to reset. Go to an independent Volvo place and pay him to do it (another $32.00).
Alternative PNP Technique. [Ladson Geddings ] This is the second time I have replaced the PNP switch in my 960 and I decided to try something a little different to remove the switch. This time I removed the switch in about an hour and most of that time was spent thinking about it and setting up for the job. Jack up the front of the car and secure the front wheels on a set of ramps by setting the parking brake and chocking the back wheels.
Check that the backup lights will turn on when the selector is in "R" and the car will turn over the engine in "N." Keep rotating the switch by tapping it easily until all three conditions are met, i.e., the car will start in "P" and "N" and the backup lights will work in "R;" tighten down the small bolt and re-check the operation of the selector one last time.
PNP Preventive Maintenance? [Rafael Riverol] To avoid such headaches and AT replacements at a cost of several thousand dollars, perhaps maintenance should include PNP overhaul (cleaning the inside electrical parts and regreasing, and perhaps replacing the wire loom or patching it with electrical tape if frayed) when we flush ATF every two or three years. I found I did not have to touch exhaust pipe or ATF line to get to the PNP switch. So it can be overhauled with little trouble, particularly if the car is on a lift, and expense. This would be a good time to clean and repack with dielectric grease AT electrical connectors on the driver side of AT by ATF filler tube.
960/90 Shift Indicator Bulb Replacement. [Peter Penguin] -- Depending on the year, the AW 30 gear shift lever light can be easy or extremely hard to replace. the 1995 (and possibly 1994) have the light bulb mounted in a small square plastic holder (about 1/4 inch square) with two wires about 24 inches long. The bulb is not replaceable by itself (the entire set up is about 20 dollars). There is no discussion in the factory manual how to replace it (or even where the wires go). It is a real pain -This is what you have to do:
960 AW30-40 Converter Locks Up and Does Not Disengage Correctly. [Symptom] My 1992 960 shudders when the transmission locks up. Most times it works fine except for repeated locking and unlocking in slow traffic. Occasionally when trying to stop the converter is reluctant to unlock and the whole car shudders until it drops to 500 rpm when it finally unlocks. [Response: AreJohn] See DCS43-02-1194 Sticking Lock-Up Solenoid, AW 30-40 960 1992, which describes your problem to a tee. Fix is to replace the lock-up solenoid and is a common problem. The part lists for about $250.
960 AW30-40 Torque Converter Module Fried. [Tip from Jim Bowers] The TCM, which governs torque converter lockup, in the AW3-40 can fry through the wrong voltages leaking into the module. A common way for this to happen is for the ground connections to get bad. This allows kick-backs from actuating coils etc. to get by snubber/protective circuits. Do the things that ensure the grounds stay good! Always disconnect the battery, or otherwise ensure the circuits are un-powered, before plugging or unplugging connectors in the system.
On-Board Diagnostic Codes for AW-30-40 Series Automatic Transmissions. [Tips from Tom Irwin]
There is also a self-test mode 3 you can enter which is a two man job. One enters the code through the DLC and the other guy is under the car feeling for each solenoid and other device to activate in sequence. Then, you can run through all the gear positions and modes and the DLC will respond with a code that shows the input was good or not. Good for isolating bad components.
Transmission Removal. See the FAQ section for AW-70, which is similar to that for the AW-30.