Another Forum Member with a Transmission issue

[DannyStringhamMarquis]

Greetings Forum-ers,

My 2005 XC70 has approximately 188,000 miles. It has had all regularly performed maintenance at the dealership through 150,000 miles. Most of those visits were paid by the original owner, a doctor.

I'm an audio-visual tech and musician, so I'm trying to do more and more of the maintenance myself, even independent shops are charging tons to work on this aging car.

My vehicle has been occasionally rough shifting for about a year. Many drives it runs smooth, but, then it will rough shift coming off the highway. I've determined that this seems to be related to downshifting, then suddenly needing to accelerate again without coming to a complete stop.

Another thing that has happened probably 4-6 times over the past year - for a few drives in a row, it will be rough shifting more and more often. I'll sometimes try to manually shift gears to help it, but that doesn't seem to make a difference. Then the Check Engine will come on, but no error codes are generated by the TCM, and no message in the digital display at the left.

I'll really try to go easy on the slowing down and accelerating, and the transmission sort of recovers and the check engine light goes away.

Sunday night, the Check Engine Light went off after a particularly bad weekend. On the rainy Saturday morning, as I accelerated up a hill to get on the highway, the car would not shift out of second gear. I put on my hazards and did not get on the highway. I pulled over, turned off the car, waited, prayed, and turned it back on. I drove through a nearby neighborhood at no more than 20mph for a few minutes, then tried again, and it shifted through all gears more or less normally.

I've read a lot of the other posts, and am pretty ready to change/flush the fluid with Mobil 3309. Here's the latest wrinkle. The car has been running smooth since Sunday night, but when I got off the highway on my evening commute Monday afternoon (approximately 7 miles/12 minutes on the highway, with a good amount of stop and go on the street level before that, and even during the highway driving due to rush hour - total drive time 25-30 minutes) the car did the rough downshift as I slowed to avoid potholes and a car with a flat tire, before then needing to accelerate through the green light with heavy traffic behind me.

I decided to immediately check my transmission fluid level when I parked the car. I had checked it cold a couple months previous mainly to check for color and smell. It was more brown than red a couple months ago, but not burnt, and, at the time, I was hearing some voices (my brother, one of the mechanics, and maybe even some forum members on here) suggesting that flushing could make it worse. So I waited

Last night, I checked it hot, and the color was still about the same, did not smell burnt. BUT, here's the kicker, the quantity was well over the 3 lines on the dipstick for HOT level.

I'm now thinking my symptoms are mostly related to an overfilled transmission system!
So, my new plan is to only drain and refill, not flush the system. But, I'm not sure how much to take out and put in to try and get the level right. Plus, I'm not sure if this is a great idea or not. My thought would be to drain and refill tranny fluid at each 7500 mile motor oil change, and continue to observe (hopefully ever-improving) transmission function.
I've searched around VIDA for "overfilled transmission" and didn't find anything to guide me on what quantities to remove and add to get back within spec.
Thanks for reading the story, hope to have your expert opinions to inform my next move.

Final Post Script -- I currently also have a slowly leaking rear differential. Inspection has told me it's coming from the right axle seal, which I intend to replace at some point, but am currently adding more diff fluid at (yet to be determined) intervals. I've cleaned the differential of leaked fluid and added until it came out the fill hole one time in December. I know that is overfilling it, but I figured, hey, it's leaking anyway, might as well top it off.
The only reason I mention this here is if a now probably low fluid level on the rear differential could be somehow contributing to this problem at the front end.

[hoonk]

I'm not sure how much to take out and put in to try and get the level right.

Plus, I'm not sure if this is a great idea or not.

A drain and fill takes 3.5 quarts and it's always a good idea to change fluid unless there is brown burnt mud in the transmission.

[pbierre]

It might not be overfilled by that much. But, the ATF fluid hasn't been changed since when??...50-100K miles ago? It's time to flush the tranny, and replace with Mobil 1 3309 ATF. Read up on the Gibbons method (where you use the pump in the tranny to pump out 2 qts. at a time, then refill with new ATF.) If that procedure seems to complicated....

you can do a series of 3 pan drain and fills (3.5 qts. each time) in succession, and get almost the same ATF purity. Of course, you want to run the engine, and step through all the gears (R, N, D) after each fill (car immobilized with handbrake and wheel blocks), so that you're not just draining out the new stuff in the pan.

ATF gets "tired" and loses viscosity, and this is the most likely cause for your downshift trouble. Periodic flush of the ATF is needed to restore correct viscosity. Volvo recommends flush every 52.5K miles if you are pulling a trailer. For normal driving, it's more like 80-100K. And, earlier if you are
experiencing unsmooth shifting.

[Xfingers]

The HOT level reading on the dipstick is accurate when your fluid is at 80C operating temp. Because the fluid expands with heat, if the temp of your fluid is only 65C it may appear that you need to add ATF. If the fluid temp is 95C when you take your dipstick reading, it may appear that your ATF is overfilled.

You attached a screenshot of the codes read by a VIDA/DiCE unit. That setup also has a screen to display the ATF temperature.

[Brett San Diego]

New ATF does not damage your transmission. If your transmission doesn't work properly on new ATF, then the transmission is not functioning properly. I don't see a justification for not getting as much fresh ATF in there as possible. It's not designed to run better on dirty fluid. The good news is that the likely problem is just the valve body, not the clutches, bands, or other internals of the transmission which would necessitate a full rebuild. The valve body can be DIY'd for under $600 as documented on multiple threads, now. It's possible that it may only be the three linear solenoids, which you can replace for less than that, and some have good results with just removing, cleaning, and reinstalling them for even less outlay of cash using a Trans-go kit. Your choice of what to try. But, there's no reason not to flush the ATF and get the fluid as clean as possible.

Brett

[DannyStringhamMarquis]

That setup also has a screen to display the ATF temperature.

I discovered that after posting.
I tested with a oil temp of 89 degrees Celsius yesterday and compared my stick to the picture in VIDA on checking Oil Level.
I'm at the MAX, but within spec.

My transmission is not overfilled. Gibbons method flush it is.
I'll order the case of 12 Quarts of Mobil 3309 on sale from Amazon for about 60 bucks plus the other needed items (gaskets and washers and all the ancillary items) in the next couple days. Hoping to take it nice and easy on the old girl until I can get this flush done.

[pbierre]

The tranny pan plug washer for the Geartronic 6-speed tranny is the one with 23.5 mm O.D. (volvo part number 977751)

(FCP Euro's confusing parts description led me to order the 26.5 mm washer, it dripped afterwards, and I had to do the pan drain all over again.)

[Xfingers]

Order that $60 case of ATF while it's on sale. One time I got it for $60, the next time I ordered the case it was like $85. I guess the price fluctuates...

[DannyStringhamMarquis]

The tranny pan plug washer is the one with 22 mm O.D. (FCP Euro's confusing parts description led me to order the 26 mm washer, it dripped afterwards, and I had to do the pan drain all over again.)

I checked my parts catalog in VIDA and got 977751, which seems to be corresponding to the match for my car at FCP Euro. Same part for transmission fluid gasket and motor oil gasket.
Please advise me if I'm still about to make the same mistake as you did

[DannyStringhamMarquis]

Order that $60 case of ATF while it's on sale. One time I got it for $60, the next time I ordered the case it was like $85. I guess the price fluctuates...

Ordered just now. Thanks for pushing me to the finish line with that