Is my transmission dead?

[Brett San Diego]

Brett, I can’t be certain the engine is running ok, just that what lead up to the issue it sure seemed transmission related. For some time I’ve been getting what I can only describe as a slipping or shudder when shifting (downshifting on acceleration on the highway, or going up hills) and occasional “thunk” when coming to a stop. The shudder is the sensation of the wheels briefly spinning as if they are trying to get traction. The last time I drove it a couple of days ago, I had just topped off the oil and coolant. About a mile into the trip, with the cruise control set, while going up a large hill, the car started shuddering very similar to how it has in the past when downshifting. This time the Check Engine light went on. Normally once the gear has shifted, or I switch to manual, the shudder goes away. This time, however, it kept shuddering as if it was still going up a hill, and kept shuddering for a few miles as I crawled to the driveway where I left it until I could try to get a better handle on the problem. As I was already in Drive, once I was in the driveway, I put it into Park. I have not tried to move the shifter since, but throughout I have not yet had a problem shifting it into Drive or Reverse. I’m hopeful that gives a better description. Thanks.

The clunk when coming to a stop is a classic valve body issue (harsh 2-1 downshift). It all sounds like a new valve body will fix it to me. I worry about the slipping some, but that could also be the valve body not holding the proper hydraulic pressure when in gear. As long as the slipping hasn't been severe and prolonged so as to completely wear out the friction plates, a valve body swap will probably fix it. The friction plates are the wild card here, and you can't really evaluate them without transmission teardown. If you do the valve body swap yourself with the new AC Delco valve body, you're looking at around $600. If you pay someone to do it with a new Volvo part, probably $2000 or a little more. Full rebuild, I don't know, maybe the $4-5,000 that you mentioned. Another option is swap in a complete used transmission.
Brett

[pbierre]

What color is the tranny fluid wiped on a paper towel? 117,000 miles is not usually a problem for this Aisin Geartronic tranny, unless there is a history of pulling a trailer load (which these XCs were not designed to do well). When you drained the tranny fluid initially, did it smell burned? Did any metal shavings come out?

I agree that you need an OBD-II scanner or DICE-VIDA to maintain your '05. As far as coolant leaking into the tranny fluid, was the fluid sudsy? This happens when there is an internal leak in the radiator, which has a separate core to cool tranny fluid. You have to catch this and fix it before it destroys the tranny...water mixed in the tranny fluid kills the viscosity.

[tieweb]

With any of these types of issues, you have to eliminate the obvious first.

I don't understand what you mean by "long screwdriver" to check the fluid level.

While the hot level is more accurate, in my experience, you can do a cold level check.

Idling, on dead level ground, run it through the gears, put it back in park, pull and wipe the dipstick, re-insert. pull and read. No screwdriver required.

Report back with that result and let's go from there.

The fact that you have a problem when going uphill suggests that the level is off...

Thanks for the replies. Was finally able to go the car and check some things. For starters, I’d venture to guess the fluid level is off. I turned it on, ran the gears through the stops, wiped the dipstick (the long screwdriver is to more easily release the metal tab holding it in) and put it back to check the level. With engine running the level didn’t look like it was registering. I added a couple ounces of ATF, and it was at the half way mark on Cold. Bottom line, I don’t trust where I have the level and figure I should have it checked by someone.

I also connected a code reader. It listed nothing under Logged Fault Codes or Historic Faults. However under Pending Faults it listed PO305 “Cylinder 5 Misfired Detected.” Is it possible I was experiencing 2 separate issues, where the shuddering I attributed to the transmission failing to engage on a downshift was the result of a misfire?

I may be in over my head as far as addressing this, but figure there may be insight to pass along to our independent mechanic.

Thank you again.

-Brian

[Brett San Diego]

Thanks for the replies. Was finally able to go the car and check some things. For starters, I’d venture to guess the fluid level is off. I turned it on, ran the gears through the stops, wiped the dipstick (the long screwdriver is to more easily release the metal tab holding it in) and put it back to check the level. With engine running the level didn’t look like it was registering. I added a couple ounces of ATF, and it was at the half way mark on Cold. Bottom line, I don’t trust where I have the level and figure I should have it checked by someone.

I also connected a code reader. It listed nothing under Logged Fault Codes or Historic Faults. However under Pending Faults it listed PO305 “Cylinder 5 Misfired Detected.” Is it possible I was experiencing 2 separate issues, where the shuddering I attributed to the transmission failing to engage on a downshift was the result of a misfire?

I may be in over my head as far as addressing this, but figure there may be insight to pass along to our independent mechanic.

Thank you again.

-Brian

Yeah, honestly, if you can't tell the difference between a slipping transmission and an engine misfire, then I don't think we can help you. If your input to the forum is bad, then the output of diagnoses from us is going to be equally useless. Garbage in/garbage out.

Brett

[Xfingers]

Clear that P0305 code and see if it comes back. If it does, that's the first place you should start. I had a misfire on cylinder 3 (P0303) and that had a huge effect on drivability - I didn't even want to move the car out of the driveway. My problem was a faulty ignition coil: https://www.fcpeuro.com/products/vol...-xc90-30713416

If you're handy, you can remove the plastic cover on the top of the engine (remove the plastic pipe going to the turbo first) to access the ignition coils. Swap the ignition coil to Cylinder 5 - on the driver's side end - with the coil on cylinder 4. If you then get a cylinder 4 misfire (P0304), you've got a bad ignition coil.

If this turns out to be your issue, it's a helluva lot better than a worn Valvebody.

[Astro14]

Personally, I would just order a coil from Amazon.

$45. If you're Prime, it arrives in 2 days.

Troubleshoot with that coil. If it doesn't solve your problem, then keep it as a spare. You'll need it one day...

https://www.amazon.com/Bosch-00117-0...omotive&sr=1-4

[tieweb]

Personally, I would just order a coil from Amazon.

$45. If you're Prime, it arrives in 2 days.

Troubleshoot with that coil. If it doesn't solve your problem, then keep it as a spare. You'll need it one day...

https://www.amazon.com/Bosch-00117-0...omotive&sr=1-4

Thank you Astro & Xfingers. Changing the ignition coil, as well as getting the atf level corrected, has it running very nice. I appreciate all the input.

[Brett San Diego]

Well, there's a reason I asked if the engine was running fine. Because no one has ever described a transmission issue as a "shudder." Hope that is all it is. I don't tend to believe the transmission is all that sensitive to fluid level (at least not to +/- 100 ml variances). If you want to diagnose a coil in the future, you can swap a suspect coil with another cylinder's good coil, clear fault codes, and see if the fault returns but on the other cylinder that you swapped the coil to. If the misfire code follows the coil, the coil is the issue.
Brett

[Rabid Koala]

If you are getting the harsh downshift, consider putting a transmission oil cooler in. I did this on mine, and it has worked miracles. It may be kicking the can down the road but I sure am pleased. I do a yearly "Gibbons flush" which also helps. I'm at 173,000 miles on a 2006 model.

Cars with electronics are hard to diagnose, I used to have a Caddy that I was convinced had a bad transmission on a couple of occasions. One time it was bad plug wires, the other was a clogged fuel filter. I was thinking I should order a coil pack or two to keep as an emergency spare, I did that with a Toyota that I used to have.