Transmission adaptation
 

So I did my final (third) transmission fluid drain and refill, and added 12 ounces of LubeGard Platinum just for good measure. This time I reset the fluid change counter and reset the TCM, and put the transmission in adaptation mode.

And the I drove around as "instructed" by the VIDA screen, at various engine speeds, etc. It went pretty well, though my 1-2 upshift did seem a little firmer than I'd expect. I was getting the proper messages and lights indicating that each stage of the training process had completed. The thing that surprised me was that when I got to the "downshift training", I got pretty consistently poor 3-2 downshifts, with a really noticeable clunk. I went through probably 20-30 prescribed gradual stops, using very little brake, then progressively more as I tried to find a "sweet spot". Never did... finished the (long) TCM training drive process with clunky 3-2 downshifts. Worse than the occasional clunk I was getting that initiated all this effort.

Did some more diagnosis when I got home, including trying to listen to the shift and linear solenoids as they were being commanded by my VIDA computer - shift solenoid 4 was nearly inaudible, and I never did hear anything out of the #2 and #3 linear solenoids. Finally, I just gave up and packed away the laptop and DICE interface.

Just for giggles, I took the car out for a spin and lo and behold, it shifted with absolute perfection - the upshifts were smooth but "firm enough", and the downshifts smooth and subtle. The transmission should still have been plenty warm (as much of the testing I was doing was with the engine running, and it was GOOD and hot). Drove around for a few extra miles and it shifted fine.

My questions - is it normal to experience less than perfect shifting during the training drive, and have everything fall into place afterward? And does the audible results I got from my shift / linear solenoids sound right?

I can tell you that I've done many adaptations of these transmissions after changing the linear solenoids. In some cases, they shift smooth during the adaptation and in some cases not. I recently had an S60 that did just what you described, a bit rough during the relearn mode, but smooth after.

What I can tell you is that we've created a 20 mile loop that we drive that is a combination of stop and go for the first half and then freeway during the next 1/4 and then the last 1/4 is stop and go. In the end, they seem to respond well after the adaptation.

There are some that suggest that you drill holes in the cover so that you can access the solenoids for fine tuning. I use Rostra brand which claim that they are a matched set. In any case, I've never did any manual adjustment of the solenoids after they were installed. If the rough shifting has stopped, I'm done.

Update - the car shifts perfectly until it's really warmed up (something that takes a while even in Arizona August heat), and then I get a pretty consistent clunk downshifting from 3rd to 2nd gear. Doesn't feel like a sledgehammer, but is certainly firmer than it needs to be.

I keep reading about the B4 servo cover being redesigned over and over and over trying to fix problems between 2nd and 3rd gear. This cover is what fixed my 2001 V70 T5, though supposedly Volvo "fixed" this problem by 2004/5. I'm wondering if it's possible that the B4 servo covers that are being sold now are a later design that has additional improvements incorporated into the design (above and beyond the factory servo cover in my 2005 V50). I get the impression that even a little improvement in the 3rd gear mechanism will have my tranny shifting perfectly at all temperatures. Here's the B4 servo cover IPD is selling: https://www.ipdusa.com/products/5538...ate-aw55-50-51

OTOH, I suppose I could just swap out all the shift and linear solenoids and call it a day, but I always enjoy my repairs to be more like a rifle shot than a hand grenade toss... ;-)

In all of the Volvos that we have sold, I have NEVER found it necessary to change a servo cover. Maybe the prior owner did, but we never found it necessary.

We have changed dozens of shift solenoids over the years, model years 2001 through 2008. I have a 2010 right now that has the 6-speed automatic and it probably will need the solenoids changed. The 6-speed has more solenoids so we'll do our first one.

The shift solenoids will fix the clunking. The servo cover only was for shift flare, like going from 2 to neutral and then to 3.

Thanks for your sage advice, Tony... I appreciate it. I'd read about the downshift improving with the servo cover, but if you haven't seen it used to fix a 3-2 clunk, I'd be wasting my time (and $30) buying one.

Do you ever try to swap out individual shift solenoids, or do you always do them as a "kit", and do you include the linear solenoids if you're in there anyway?

We do not replace a single solenoid if we detect a shifting problem. We go through the process of replacing all three linear solenoids. We buy them as a matched set from Rostra. I've never had a circumstance where it didn't cure the shifting issues.

You can find these kits pretty inexpensively now days. When we do a service, we buy the gasket so that we can immediately assemble the vehicle and put it back on the road. The standard process is to drain the transmission, remove and install new solenoids, install the pan w/gasket, add 4 qts of Mobil 3309 and test.

With out Snap-On software, I've discovered that we can put the transmission in adaptation mode immediately and drive the car. Technically you can't do this until the fluid is up to temperature but we can put it in adaptation mode early. When the fluid reaches temperature, it will then enter adaptation mode. We drive a 20 mile or so test loop and by the time that we are back you'd think that we installed a new transmission.

I have not found a reason to flush the transmission. A drain and fill is sufficient.

Thanks, Tony. I have a Rostra linear solenoid kit on the way, as well as a new valve body gasket and another case of Mobil 3309 fluid.

Last time I did the adaptation I let the car idle until the tranny fluid hit 65°C - that doesn't take too long in Arizona in August. ;-)

I assume that you mean a valve body cover gasket. There is no reason to remove the valve body itself. Here's the gasket that I'm referring to.

https://www.rockauto.com/en/moreinfo...433144&jsn=330

Yes, that's what I have coming (or a Transtec gasket that crosses to the same part number at least). I've done shift solenoids before, and am happy that it doesn't require pulling the valve body!