Hi,

I have a 1990 240DL Auto with the downshift button on the shift lever.
When I drive up to 55 the car does not seem to shift into OD/4th, seems to be reeving high at 50+, cant imagine going 70, but if I hit the switch on the shift handle the car ABSOLUTELY DOES downshift every time and the orange up-arrow light illuminates on the dash.

I am confused and baffled, because it's my understanding that the car would not downshift if I was not in OD/4th. The downshift cable seems fine, and I believe the solenoid and relay are behaving properly, so whats going on?

Anybody have any ideas?

Yours truly,
Confused and lost...

 

You're correct...the button only toggles between 3rd and od. What you're describing sounds as if you're in 3rd and the button drops it into 2nd. While that isn't impossible, a couple of things have to be wrong for that to be the case. I'm guessing you have no tach or you would have mentioned the rpm's at speed. When taking off from a stop, have you counted the gear shifts?

 

Yes, I've counted many times and it seems to only get to third; noticeably,
that is why I am sooo confused... maybe the shift into 4th is so smooth,
that is un-noticeable, but I doubt it.
BUT, I AM POSITIVE if I hit that switch at 40+ IT DOWNSHIFTS! arghhhh!
I feel I am loosing my mind.
P.S.
If I had to estimate, I would guess at 60 MPH I am running at 3300+ RPM.
???!!!??
Thanks
What would those "wrong" things be?

 

Go for a drive. Stop, pull shifter into 1, OD off (arrow on dash) then drive off but hold each gear with the shifter and shift with shifter, don't let the auto shift. When you are in top, simply engage OD. You should see rpm drop if you have a tacho and you should feel it shift if you lift off the throttle at the same time you select OD.
It's impossible for the OD hydraulic circuit to influence a kickdown into 2 and you'd know if you were in 2 at 60 mph, you'd be near redline.
The change into fourth/OD on these transmissions can be VERY smooth, even on my modified auto with very firm shifts I often have a hard time detecting it, it's only noticeable by watching the tacho or on a lift off upshift. The change into OD can be really soft and OD can also slip and flare if the hydraulic lines under the valve body are not seated properly, that could make it feel as if you have not had a change into OD. It's also reasonably common for these lines to not be reinstalled properly after transmission service work.

 

I believe that OD does not come into play until you are at least going 45 MPH. Anything below that it stays in 4th. What does your tach do when you go past 45mph. It should drop down by a few hundred rpm's. I would also remove and re-plug the OD relay and see if that makes a difference. I believe the OD solonoid is triggered by the speedometer through the ECM. The OD is just the torque converter locking up .

 

I don't have a tach
OD may be engaging.
I do believe the engine is at or around 3500 RMP at 60 which is too high.
Wonder what else could cause this. (fluid level? I checked it properly and topped it off. Time for a fluid change <from the rad cooler line-I guess>, I think I'm going to add some Seafoam Transtune and drive a bit first)
Thanks for the help!

 

So do we assume that the tach is broke. See if you can get someone who has a sears or some other tach and hook it up and take it for a drive. I don't know what gears you have but my 89 740 is doing 2100 rpm at 55 mph. See if you can hook a tach up and see what you get. It sounds like you are not getting into 4th gear.

 

 

First, it's a 90 240DL just so we are clear , no tach, no one to borrow one from.
I drove it more today 20+ miles and believe it is shifting to OD (very smoothly).
I am positive it's downshifting/locking out OD when I press the switch as the engine revs higher and I feel the deceleration...
That said, the ISSUE is at 65MPH my RPM is over 3500.
I can tell because I have had 240s in the past GLs with a tach and I can estimate pretty well.
Any ideas?
Thanks to Everyone!

 

Hey swift , what set of gears you got in that thing. Is this the V8 conversion car. Looks like a set of low 300's

 

The OD solenoid purely and simply commands a manual downshift out of OD. Think of it as an electric shift lever but only for OD. Selecting OD off via the button stops line pressure to the OD servo, which is why a faulty OD solenoid causes loss of OD.
Normal shifting into and out of OD is handled by the valve body on non electronically controlled AW boxes. So every gearshift is dependant on throttle valve position and governor rpm/road speed. You can adjust when OD comes in by adjusting the throttle valve position via kickdown cable. My OD comes in at 60 km/h (35mph).
The OD is fourth gear, don't confuse it with the lockup torque convertor, which will only drop a couple hundred pm when it locks up.

 

So, any body have any input as to what might be causing the high RPM at speeds over 60.
(when going 65, if I take my foot off the pedal and coast, then put it back on, the engine has to get back up near 3300 RPM to accelerate.)
I am running some seafoam trans tune in it now and plan a fluid swap after some more driving, just looking for more input from the experts...

 

Changed, pumped all new trans fluid into the mucky system,same problem, soooo
Checked with a reputable pro in Atlanta today, he went for a ride with me.
4TH/OD is kicking in, it's just DEAD in the trans. So it kicks in allowing me to downshift; but it's useless, has no power (dead clutch in 4th?), and cant move the car until the downshift cable re-activates 3rd or I do it with the button on the shift lever. A70 1/4broken

Thanks to all,
P.S.
anyone have an A70 for sale near Atlanta, or want to rebuild one?

 

Make sure your kick-down cable is adjusted correctly, on its pulley and is moving freely in its sheath.
Ed

 

Thanks, Have checked it out and kick-down is perfect.

My questions now are...

If the OD Solenoid is malfunctioning, does that cause no/intermittent 4th gear?

In other words, if the cable/wires to the solenoid are shot (they don't look good at all) could I end up in this situation where 4th seems to kick in but wont offer any acceleration and still allows the car to downshift occasionally (speeds under 50) to third when I push the button.

Sorry this is so confusing , but it has a VETERAN Volvo specialist, a transmission expert and me stumped/confused.

Thanks.

 

maybe the engine is just sounding noisier than it should when its revved?

if the OD button causes a noticable upshift, then for sure you're getting it into OD, there's only 1-2-3-OD on these, they aren't 5-speeds (or 4+OD), they are 3+OD.

maybe your speedometer is reading low? can you borrow a GPS to verify the speed?

 

Yes, I considered ALL of that, GPS shows speed is acurate, the car is actually pretty quiet.
At this point I am wondering if the o-rings in the solenoid may have failed, going to remove it tomorrow and see. The solenoid is working, I got under the car and can here it click. The relay behind the vent is perfect too. I sure hope it's screwed up o-rings or a clog of some sort...
Thanks

 

if you do a steady 50mph (or 60 or whatever) on level ground in 'D' without the OD uparrow on then press the OD button so the light comes on, the RPMs should go up noticably. press it again, they go back down. if that happens, your overdrive is working perfectly. if your engine is doing X rpm in OD/4th, and you disable OD, it should be doing X*1.45 rpm in 3rd, so if its doing 2000rpm in OD, it will be like 2900 in 3rd.

on the AW70/71 transmissions, 3rd is 1:1 and 4th/OD is 0.69:1 ... 0.69:1 is equivalent to 1:1.45 hence my multiplier above.

 

ok, I was driving the daughter's 87 240GL sedan today... OD was 2000 rpm at just about 60MPH and 3rd was 3000rpm at just about 60mph. of course, +/- 200 rpm for the torque converter depending on if you're coasting or pulling.

 

A bad fan clutch can make the engine sound like it's going 5000 rpm at 40mph. Pulling gobs of air can have a fan making lots of noise.
Ed