I must admit, this transmission deal Volvo has is quite disturbing. I have taken quite a journey through them since I purchased my 2001 V70 T4 in June 2009. Within a month of purchase I noticed the 1-2 thump or 2-1 hesitation. Of which a promissing full fluid flush only "fixed" for about 2 weeks.

So I decided to do more research. The consensus? The valve body is to blame. Advice? Get it fixed ASAP and don't ever, EVER!, force the tranny if it doesn't want to pull or is thumping. Meaning, if you are taking off, just take your foot off the accelerator, let it thump into gear, then accelerate. Even if you fix it, I recommend this habit as it will help ensure a longer relationship between you and your tranny.

What is a valve body? Basically it controls the flow of fluid through your tranny. This fluid then engages and disengages clutches to rotate the wheels. The fluid direction and pressure is controlled by solenoids.

I purchased a new valve body, while not exactly sure what I was getting into. But with the hope that I would be able to fix the problem for only $1,500 as opposed to a new transmission priced at $4,500, I didn't think twice.

I found the following article online since I needed to know where it was located and how to get to it. I got much more info than that. Did you know that 3 of these solenoids are adjustable? And one of them happens to correct a 1-2 thump or 2-1 delay. The second one corrects a P-N clunk or N-D delay. The third adjusts the overall system pressure which you will need a gauge to set correctly using the ports on the end of the tranny case. I am still working on that. READ THE ARTICLE CAREFULLY. Some info is technical that I am still trying to understand. Don't worry about dissassembly or removal of the valve body or testing with the air pressure. Just concentrate on modifying the cover so you can try to see if adjusting fixes your issue. If not, then you will most likely need to buy a new valve body.

http://www.sonnax.com/tech-articles/PRE-ATRA08-RCW.pdf

NOTES:

For removal of the pan I recommend removing the two front lower frame bolts (the really big ones). They are on tight and will require a 3 foot breaker bar with 1/2 inch extension and 1/2 impact socket. Also remove the front motor mount bolt and nuts and whatever else is needed to get access to it. Don't touch any of the wheel suspension bolts, it isn't worth it. Just pull down on the frame to widen your access zone.

To modify the cover, I used "T nuts" from OSH and bolted them to the pan using 4-40 hex bolts. I then placed a rubber o-ring around the T-nut to seal around the hole. Then I plugged the inside of the T-nut with a hex bolt and an o-ring as well. This bolt is what you remove to make the adjustment between test drives. I will send some pictures later. You will have to "smash" the pan flat in one place to make a nice seal and so the hole lines up with the adjustment on the solenoid.

I am still test driving mine. But it is getting better with every adjustment. I recommend keeping a log of how many clicks you turned each solenoid as well as what you noticed during the following test drive (i.e. 2-1 thump got worse, 1-2 delay is awesome!, etc.).

 

What? No love? Is someone wilng to try this out on their car, without replacig the valve body. Just adjust it on a known problematic transmission and tell me what you notice.

Is there enough adjustment avilable? Or is a new valve body innevitable?

The cost is still much lower than replacing the entire transmission. Labor time is also quite a bit less. Besides, you will need the modified pan to adjust a new valve body anyways.

If the pan mdification has you worried, just mail it to me and I will modify it for you. Maybe charge $50 or something like that.

 

WOW, that s gonna be useful! is your car the auto/manual shift tranny? gonna need some pics to wrap my head around this!

 

I will post some pictures as soon as I can find some time to organize them. I know that just writing alone can be confusing. I also have purchased myself a oil pressure guage kit ($75 from Grainger) so I could accurately adjust one of the solenoids.

Stay tuned...

 

The '01 V70 is the newer chassis - right?
My wife's '02 S60 has a 1-2 thump / p-d delay when it is cold. After it warms up a little, it is better, but still detectable. We had the trans "flushed" ($250+ for 12q of 3309 trans fluid) about 2 months ago (89k miles) and the p-d delay got worse - not better.

I am wondering if this would be something to look into for her car.

My '00 V70R AWD uses a different tranny - it isn't having any problems to-date.

 

Chris - Thanks for your initiative! I'm looking forward to seeing photos of the work, too. I think I will modify the pan on my spare (broken) transmission so it's ready if I ever need it.

 

It seems that this adjustment would help with your issue. However, I did notice one thing today. After reading the article I posted in more detail, I decided to purchase a pressure guage that I could hookup to the transmission and monitor the pressure for various conditions. It was then I noticed that based on the behavior of the pressure at the "C-1" port that my car may not have had the recommended TCM (Transmission Control Module) software update. I am in the process of making an appointment with my dealership to have this checked out.

The only thing I am confused on is properly adjust the SLU solenoid, which is basically the main system pressure. I plan to contact the authors of the article to see if I can get some more info on this adjustment.

Stay tuned...