I have a Volvo 740 that has an odd trans issue. It has 202xxx miles so it could be dead but it does not seem to be the case. Oddly it only slips when I slow down to where the trans downshifts from 4th to 1st or 2nd. Then when I step on it it feels like it bogs out then the trans grabs and goes fine. It does it about 50% of the time. I am wondering if there is shifter adjustment on it since it seems like the gear just does not engage? I have never owned an automatic.

It will typically not slip at all going up a hill though which does not make sense to me.

Thanks

 

is the transmission fluid clean, and the levels good?

AW7x transmissions last a LOT of miles with a bit of maintenance, like a fluid flush and replace every 50 or 100k miles.

 

I flush and refill every 50K miles on our 89 740. We have 345K now and still shifts OK . If there is no history of a fluid change and you do it now it may help but my bet is it will kill the transmission. Take it to a transmission specialist and let them put the gauges on it to check the pressures.

 

if doing a fluid change kills the transmission, I contend the transmission was already dead, you just didn't know it yet.

 

Zandrew, are you sure you are even having a problem? I don't know how a transmission even shifts "from 4th into 1st", and then "bogging down"? You may be having another drivability issue, not necessarily a transmission one. Still, a good way to start is to change the trans. fluid if it wasn't changed in recent memory.

 

also check the adjustment on the transmission throttle cable.

see Transmission. Automatic AW70 and ZF for the procedure.

 

This is what someone else mentioned to me but I had no clue what they were talking about. The car sat for a considerable amount of time. I bought the car and drove it about 80 miles home on the interstate without issue. Up 2 considerable grades that are about 3 miles long so you would think if there was an issue it would show up here.

lev it is definitely not a drivability issue. I was driving down a hill that you can 55 on and turning off on another road where my speed has to decrease to 15mph to make it. Once I turn and hit the gas it just spins or sometimes it will bog.

The first thing i did was change the trans filter and gasket. I replaced the 1.5 quarts that came out with lucas additive and fresh trans fluid. It has not helped.

If I am going up a hill and mash the gas it will eiher go or it will bog and the engine cuts out. When I let off the gas it will then take off.

If need be I can get you guys a video. Thanks for the replies.

 

Also if I need a trans what all models will work for it? How hard is to swap?

Thanks

 

there should be about 4 quarts of ATF in there... just draining by the plug won't get out whats in the torque converter or the transmission cooler.... you need to flush the system not just drain. you disconnect the transmission cooler line from the radiator, connect it to some hose, then start the car in park, and for each dirty quart that comes out, add a fresh quart, til it comes clean. I usually end up using about 8 quarts total.

the full procedure is on that same FAQ site as I linked above.

Dexron III is the proper ATF, I don't use any additives, never have. I like Castrol "Multi-Import" ATF, which is designed for toyotas etc, as these AW7x transmissions ARE Toyota transmissions (AW is Aisen Warner, which is Toyota's tranny factory).

re: the tranmsission throttle cable, this comes off the drum/spool that the accelerator cable is connected to (and possilby your cruise control, if its a 7/9 and you have cruise... 240 cruise is elsewhere). the adjustement is at the end of the bowden cable that goes down to the tranny right near that same drum/spool.

look here,


thats a 940 turbo with cruise. the top cable is from the throttle/accelerator pedal. the diagonal cable that goes to the bellows thing is the cruise control. the lower horizontal cable that goes into the orange little cap on the end of the ferrule is the transmission pressure cable, this is what you adjust. that little bead on the cable should be like 1/8th inch from the orange cap when its at idle. when you step on the gas pedal (engine off) to full throttle, you should feel a distinct 'cam' notch just before the pedal goes all the way to the floor, thats the kickdown. when you let off on the gas pedal, the cable should smoothly fully retract without hanging. you adjust the ferrule near that orange cap for the correct amount of slack.

 

I have not had a chance to adjust it BUT I will tell you it has a ton of slack. Its raining so once its done I will work on it.

Thanks for the replies and help.

 

there should be just the tiniest bit of slack at idle AND that 1/8" (or maybe its 1/16"?) gap between the bead and the end of the ferrule. some people do like to run them a little looser, which leans towards lower RPM shifting

 

Having the transmission kickdown cable misadjusted like that can damage the transmission, I have been told. Fools the trans. into thinking there's never any load on it, so no reason to downshift. This excessively loads the higher gears. Hope yours revives itself after you get the kickdown cable adjusted.

 

a touch looser than spec is OK. totally loose, or disconnected is bad.