Default 240 Transmission Diagnosis... Help?
So... or 1978 242 has been a pretty weird little bucket of fun lately. Currently, its loosing power while driving. To explain it best, the engine seems to be running fine and strong, but at times at looses power to the wheels. It feels to me like when a clutch is terribly worn and its just burning up and not gripping the flywheel. BUT this 240 is an auto tranny. Last night i was driving it and even though the motor was at like 3-4k the car was just barely creeping along up this hill at like 35mph. Then at times it seems like it would jump back to life, like the tranny would "catch" and it would lurch forwards at full power, but then start all over again. I was able to down shift to 1st gear and kind of trick it into shifting around and hooking up, but then back to low power.

So Can someone point me in the right direction to positively diagnose the issue? My thoughts are that either the tranny is just toast, out of nowhere. Or Could the Torque convertor be acting up?

Second, if i go to pull the tranny out, what should i be looking at for an upgrade? This is currently what i would assume to be a 3 or 4 speed auto tranny. The wife would like to stay auto, but i have visions of a turbo mule 5 speed.....

 

I would start by checking the fluid level (during idle after shifting through each gear twice). On level ground.

 

Check your transmission fluid level. If it's a couple of quarts low, it will slip. If fluid level is ok, then smell the stick. If it smells burnt, the transmission is most likely toast. Your car's transmission, if original, is the 3 speed AW55. Finding another in decent shape is difficult, rebuilding is a crap shoot and quite expensive. An option would be to install an AW70 from a newer car. You would need other parts from the donor car; the transmission cross member, the front portion of the drive shaft, the shifter, the electric overdrive harness and relay. Not an afternoon project but certainly doable.

 

What can I use on the ATF? The volvo manual specifies Type F. Can i use dex merc?

 

Sure...use Dexron 3 or 4. I've been told not to use Dexron 5. Type F was discontinued for a few years but is still available some places. Also, when a tranny is in foul shape like yours and topping off w/ fluid does not help, invest in a filter and fluid change. It may not fix anything but is money well spent as occasionally will avert a swap for awhile.

 

So, i found the Type F at the local O'rielys. Added a full quart to bring it up to topped off. Definitely still seems weak. LIke, from a stop it takes a 1/4 mile to gut up to like 25mph. Definitely something is not right.

Wierd that it could have been that low on fluid, but act totally normal. Then all of a sudden it starts acting up.

Is it fairly easy to do a filter change?

 

Theres no way that this could be caused by a bad kick down cable is there?

 

Well, with a disconnected shift cable, it will just short shift into a taller gear way before you want it to. Also, a bad cable would be consistently bad.
Being a quart low, while to be avoided, is not the cause of the slipping. Most automatics can tolerate a quart short w/o slipping.
The hardest part of changing the filter is removing the dipstick from the pan. Remove the pan and the filter is right there. Messy but not too tough.

 

interesting, well, ive ordered a transmisison filter kit, so ill get to tearing it down tonight probably. Curious, whats the hang up on the dipstick removal?

 

So, now i see the dipstick issue.. Im totally scared of even trying to break that nut loose. It looks like with enough force that fitting would completely shear off the pan. Whats the catch here?

 

The fitting is often much tighter than it could possibly need to be. If you can't loosen it you can always remove the bracket higher up on the dipstick and remove the entire thing w/the dipstick.

 

OK, dipstick loose, pan off.. Now im SCARED... Parts of the metal filter screen are missing, look ripped away. So, like VH1 asks, where are they now?

 

..........Super awesome. Well, I found 2 of the bigger parts of the screens, so thats good. But I bet even a tiny bit of the screen fragments would be very bad news to the innerworkings of the auto trans. Not to mention, How long has it not been filtering? Crapcity.

 

Wow...that's some harsh Friday night news. The filter cratered as a result of diminished flow (clogged) most likely. It's possible the remnants are caught up in the valve body but you do not want to disassemble that. Simply replcing the filter won't fix your shifting as the destroyed filter obviously wasn't a restriction. About all you could do is pull the 15 or so bolts that hold the valve body in and carefully lower it without tearing the paper gasket or separating it. Gentle! After it's pulled you will see the accumulators that act as shock absorbers between shifts. They may be fouled by the screen.

 

If I do what you described above, am in any danger of parts, springs, or bits of tranny shooting out and never going back together again? ( i have this nightmare when i disassemble without know whats underneath)

As seen in the picture, the larger parts of the screen have been found, but this doesn't mean very small bits of wire didnt get in there. So, it it "worth" pulling the valve body, or is another can of worms? I see what your saying, replacing a filter that wasn't acting as a restriction isn't changing any variable that would play into my current issue.

Regarding a tranny swap. Im currently looking at a few on Craigslist- But I have no idea what year/ model i can pull from. I think i need an AW70.... ? But as mentioned, i would really almost want the whole donor car for other bits and pieces? Cross member ect?

for example:
http://seattle.craigslist.org/est/pts/2626302945.html

http://seattle.craigslist.org/est/pts/2668726366.html

Thanks!

 

What to do is entirely with what you're comfortable. Sure there's metal in the transmission. Something somewhere is restricting the fluid flow. That alone can make a transmission slip, clutch packs starved for fluid will die too. Finding another good AW35 is really tough; they were not terribly hardy to begin with. I mean, if it were my car, I'd feel as though I had nothing to lose by going further. So...to swap in an AW70 is mostly a swap w/ a little conversion mixed in. Having a donor car is always a plus imo. Too, finding an otherwise good running car that has sustained serious collision damage is generally as cheap as finding the transmission alone. I've purchased 2 240's and a 740T each for $200 that were hit hard. Not only did I have every little part for my project(s), the parts were right there which saved a TON of time.
If getting a donor car isn't possible because of space or significant others, the list isn't too long as to what you need other than the transmission.

 

Thanks for the input. Im comfortable with alot. I took my 88 mazda Rx7, and swapped out the auto tranny for a 5 speed- which consisted of quite a fit of fabrication, and uncharted territory-- So, im down to do it. I do have plenty of space for a donor car, also, not an issue.

- Now, stop me before i go to far- Whats next? Find a donor car with a straight 6 and a 5 speed? Redblock with turbo? In my mind, if im going this far, lets not play games with all 98 horsepower that sits under the hood currently. So i guess what im asking is, whats a complete package ( that fits ) with out spending more than 2 or 3k.... Just looking for ideas here.

 

The sky's the limit...forget a Volvo 6 cylinder. A few people love 'em but they are under powered and nearly non-existent. Being a 242 of a desirable year, you could swap in a turbo drive train from, say, a 93+940. Keep in mind, they're LH2.4 electronic fuel injection so you'd need to swap the rear end too with a tone ring for the speedo and the ecu. That would be the newest and strongest way to go. You'd still need to source the cross member from a later 240 though as they are different. You could check out my stickie at the top of the 240 subforum here to see what I'm going through to drop a turbo motor into an 80 GT...a bit more work as I'm doing a resto along the way.

 

Innnnteresting! OK, well... ill continue down this path, yank the valve cover and see what i see.

 

...trying to pull the valve cover in the tranny, started removing bolts, now im confused. What i though i was removing was the lowest part of the cover, just south of the black gasket. Then i cracked a certain bolt loose, and the entire assembly seems to want to be lowered now, This would be NOT breaking the gasket apart, but the bottom and top of whatever this assembly is. Ill wait to continue before I get some advice.

See the thin black gasket ( currently the top and bottom of this is moving up and down, ready to drop down out of the tranny)