TCM swap

[abcdetech]

I agree, your statements above vtl are correct.

I added 1 oz Lubegard. Drove for 2-3 days - didn't feel an effect.
Added another oz of Lubergard. After driving for two days noticed that shifting is a bit smoozer.

However, now I can reproduce the problem 100% by : hold brake pedal, shift from D to R, wait for 1-2 sec - bang, something underneath of the car shifted, with some metal clunk. Brake, R to D, bang.

My original problem was on stop signs, set of lights. Probably when bake pedal was involved, so gears had to change. Now it seems is reproducible with switching from D to R or wise versa.

Switching from Auto to Manual, 1-2-3, 3-2-1 - no problem. On highways no issues.
This issue only occurs in town mode, after driving for 1 hr or so.

[vtl]

R<>D delayed engagement is a common problem with these transmissions, it's a low line pressure partially attributed to a wear in valve body, partially to lower viscosity ATF. Mechanical part of the transmission may also have problems.

So, is it shifting acceptable during normal driving? Delayed drive engagement will be hard to fix, it will require a transmission surgery, plus eliminating all the slack in CV joints, differential, collar spline, driveshaft. I did most of that and still have occasional thump changing direction on a heated transmission.

[vtl]

Also consider installing an external oil cooler (like Hayden ATF cooler) and Magnefine filter. A lot of hot ATF problems will be scaled down.

[abcdetech]

Thanks vtl for all your comments, I feel you are reading my mind.

"So, is it shifting acceptable during normal driving?"

- I would say yes acceptable. The problem at stop signs, set of lights, feels like someone hits you from behind. A bit scary. In these moments my wife says I want a new car, and honestly, can't argue because those bangs are not pleasant.

Will install Magnefine filter. "I think" if the problem comes up after 1 hr of driving it's probably due to temp and pressure change. Right?

What would you suggest? Here is my thinking - the car is in great shape, fits our family needs. However I wouldn't consider another Volvo due to a high number of transmission issues reported on internet.
Going to a local dealership/mechanic - I feel I exceeded a number of re-tries. I spent $200-400 each of 4-5 visits on "fixing" things like flush, recalibration, try and "give me a call if you still see the issue". Can't afford another visit. Amount spent is close to transmission replacement.
Transmission replacement? - $2100-$3500 plus 11-15 hours of labor - it's too much. And may be I would pull a trigger but my major concern is - we don't know a root cause of the issue, what if this "something" will be breaking a new transmission.

Don't want to say good bye to this car but driving it sometimes makes me scary. Do you think these bangs in transmission are Okay and I can drive until it dies?

[vtl]

With RND bang you can drive a lot of miles. I had that for well over 100k miles.

Still don't understand your traffic light concerns. Is it banging when down shifting to the 1st gear? Does not happen when gear switched manually?

Shifting imperfections produce wear product, it should clog some filter, and it better be a replaceable external filter.

The transmission design is fine itself, one of the best in fact. It's just a "lifetime transmission fluid" that kills it. Aisin itself recommends replacing ATF every 20k miles. Most of the hw problems have been solved long before 2006.

[abcdetech]

Thank you for explaining these things. It makes sense.

My problem is mostly when downshifting to the 1st gear on traffic lights, it bangs; also in traffic jam when you do stop and go - hard shift and kick; and D<>R; Sorry hard to explain, some days the car runs just fine, but sometimes it goes into state with symptoms I just described.

I guess my next steps will be to change ATF and install Magnefy filter. I thing it’s a DIY project.

[Georgeandkira]

When the unit in my '02 was acting like yours the original owner decided to sell it.
He had it flushed so I bought a 70K car with crystal clear red fluid.
A year into ownership I was billed $60 for a TCM download (pn 30677036) at a dealership. I saw improvement. Please note this TCM download was 10 years ago. Much may have changed and the dealership may have lied. For example: I may have been billed for merely checking that the "stop neutral feature" had been removed.
Also, the cowgirl behind the counter cheerfully telling me the "double bump" remaining meant I needed a new transmission didn't set well.

This , by the way, shines a light on the inadequacies of describing your, or anyone else's woes, as "bumped from behind" etc.

Then I added LubeGard (red bottle-not the HFM you mentioned) at the suggested dosage of 1oz./system quart.
The LG label stressed its lubrication properties.
I saw more improvement and decided to live with the occasional hiccough. Driving with a light foot is all it took.

I would've installed an external transmission cooler as my next step. At that time I wasn't aware of the slight differences between Volvo fluid and the various replacements I used. Those included Valvoline MaxLife Dex/Merc LV, Wolf's Head Super Universal Synthetic Transmission Fluid, Toyota T-IV and AW T-IV.

From what I've read the deep end of the pool to jump into was to replace the likely scored valve body not the TCM.
Many posts mentioned Volvo's stupid assertion that transmission fluid is "lifetime" resulted is scratched cylinders in valve bodies. That's why I went with the red bottle. I found one thread where a guy replaced the aluminum linings of the valve body's cylinders. God only knows where he got the parts to do that.

I eschewed the friction modification route.

There were posts suggesting that failed (as in cold soldered) connections in the ABS controller could contribute to communication problems throughout the ECM-TCM-ABS. I've never read a scenario which lead to your (our) specific condition being so caused.

I think the bottom line for this post is to restore and update your original electronics, dilute the FM as much as you can and go the plain lube route as I did.

I hope some of my inane prattle helps. Best of luck

[vtl]

From what I've read the deep end of the pool to jump into was to replace the likely scored valve body not the TCM.
Many posts mentioned Volvo's stupid assertion that transmission fluid is "lifetime" resulted is scratched cylinders in valve bodies. That's why I went with the red bottle. I found one thread where a guy replaced the aluminum linings of the valve body's cylinders. God only knows where he got the parts to do that.

Sonnax zip kit it is. Or a few hundreds bucks more and get a valve body rebuilt by Sonnax, coming with a life time warranty. I've paid about $700 for one in past.

Unfortunately I can't guarantee the VB will resolve the issue, so can't recommend it. It is likely a VB, but it is still $700 for Sonnax or $500 for GM and about 5 hours replacing it.

[vtl]

My problem is mostly when downshifting to the 1st gear on traffic lights, it bangs; also in traffic jam when you do stop and go - hard shift and kick;

I guess my next steps will be to change ATF and install Magnefy filter. I thing it’s a DIY project.

Sounds like harsh 1-2 and 2-1. Read about "Linear Lock-up Solenoid ( SLU)" here: https://www.sonnax.com/tech_resources/1 ... nformation

Get ATF cooler installed along the way. Idemitsu Type-TLS is the closest ATF match to Volvo 1161540, not quite there, but I think it was the best aftermarket ATF when I've tried half a dozen of them.

[abcdetech]

Thanks everyone and vtl! I agree with everything said above. That makes sense.

However, one thing bothers me...... Car runs just fine after start. After analysis I can state that the problem comes up 100% after running the car for 20-30 minutes. What has changed? - temperature of ATF, pressure, probably viscosity.
I "think"/hope IF the car runs just perfect in the first 20-30 minutes then there is a good chance no physical damage to the components.
The next logical step would be to flush transmission and install ATF cooler.

I've ordered two boxes of Mobil ATF 3309. Will use 8 qt, first time. If needed will do another flush or use it on my Saab.

Not a big fan of installing (DIY) aftermarket ATF cooler on this Volvo. Does anyone have recommended mechanic for this in BOS area?

I "think" cooling down ATF and getting right ATF viscosity (since this transmission type heavily depends on ATF type) "should" help. I read one guy fixed the issue by flushing transmission twice.

thanks