I just completed my swap and went for a test drive. After a mile or so of normal operation the transmission began bogging. It seemed to almost drop off into neutral. I would let off the gas a bit and things would return to normal. No CEL or flashing up arrow. It happened 3 times before I made it back home. I turned around immediately. I accelerated for the last stent of the drive and things seemed normal again. Driveshaft has yet to be reinstalled if for some reason that has a bearing on things. Upon inspection the fluid seemed a bit on the high side. I'm going to drain a little and check again.
I had a conversation with a volvo tech a while back and mentioned I would be changing out the transmission. He claimed it may be necessary to marry the new unit. Is this accurate?

 

Anyone in the know care to chime in? On what I think is the 2-3 shift (around 30 mph) the transmission shifts then feels as though it boggs and downshifts again immediately. You can feel the car using the gears to slow down. I'm not certain it will even allow me to drive up to 50 mph for the volvo drive cycle. It's very odd. The first 2 gears feel completely normal and the car accelerates great. I took the cover off and tested the solenoids before installing this transmission. They were within spec although sometimes I hear they can still be bad. Would not having software adaptation cause symptoms such as these? Still no flashing up arrow or check engine light. Any ideas?

 

Sounds like that replacement transmission might be bad. Did you try at home flushing of the fluid? Seems odd the CEL on is not on. First to second works fine but as soon as third engages it runs rough is a bad sign. Some internal issues with shifting to third is not easy to fix even by rebuilding the valve body.

 

There is a software update available,I dont know if you vehicle has the latest software.You can check with the dealer,they would be able to tell you. But as far as I know,there is no download software for a tranny swap.

I also just looked at the parts side of the trans.There is no software download box telling me that the new trans would need software.But there is a software upgrade for the trans if it has not been done all ready.

 

Heath, I finally got my 2000 XC70 started this weekend after almost two months of replacing various parts including a used transmission. On Sunday I took it out for a drive to make sure it shifted through all gears and to my surprise (relief) it worked very well. So well I might do the same transmission swap to my S70. No need to do any software upgrades (trans came from a 2000 XC70) or any special driving to re-learn shifts. Before I purchased the transmission I ran a VIN check to make sure the mileage was correct from the salvage yard.