howardc64
01-29-2014, 06:38 PM
I've had little random infrequent transmission shift issues (2001 121k miles). Have done all the typical repair items regarding this tranny (B4 servo, torque mount, flush, TCM software, adaptation, even rebuilt the linear solenoids and changed a couple of valves with the Transgo kit).
I found this thread and decided it was simple enough to give it a try
http://www.volvoxc.com/forums/showthread.php?25253-01-v70-xc-trans-questions&p=167803#post167803
While I didn't have any severe pronounced problems before, the newly installed transmission cooler seems to reduce majority of the shift issues when ATF is hot. Most noticeable is my RPM would show a little up swing bump when coming to a stop at times which coincides with a likely 2-1 downshift. This is pretty much gone now and I recall this how a good AW55-50 down shifts coming to a stop.
Anyhow, curious if we can gather more statistics on this remedy for transmission that shifts poorly when hot but perfectly fine when cold.
The installation itself was pretty easy. Had to pull off the bumper, radiator fan, intercooler/ETM pipe (just to make plenty of room and I knew how to do this step quickly, probably unnecessary) The Hayden transmission cooler installed easily and came with just enough hose. A couple of 3/8 brass garden hose fittings connected all the rubber hoses. I did have to cut a little slot under the bumper to route the aux cooler hoses into the engine bay. Total part cost is like $35 ($30 for cooler, $5 of connectors/extra clamps) The cooler installs in front of the existing radiator so it gets the best cooling opportunity from the incoming cooler air.
Many claim external coolers will drop the temperature by about 20-30F. I believe the built-in ATF cooler runs close to somewhere just under 90C when hot from my previous VIDA/DiCE observations. Post installation runs shows around 65C when hot. Both of these were taking with outside temperature of about 40F. Pretty significant drop. In fact, the VIDA/DiCE adaptation only occurs when ATF Is hotter than 65C. With this external cooler, definitely takes quite a bit longer to enter adaption mode.
As for the reason shifting problems occur only with hot ATF? I believe the conventional wisdom is hot ATF is thinner and easier to leak past wornout seals.
If anyone have poor shift when only hot, perhaps you can consider giving this a try if B4/flush/torque_mount/adaptation doesn't help. This is one more low cost step before going to the more expensive route of valvebody or total transmission rebuild.
Here are post install pics. The silver duct tape you see wraps around some plastic protection I wrapped around the hoses to protect it against the sharper edges of the hole where the hoses routes into the engine bay. I could find no other entry path. On retrospect, a short section of PCV pipe would have worked better. Need to be inserted before connecting up the hoses of course.
https://live.staticflickr.com/65535/50219939341_655bb250c0_z.jpg (https://flic.kr/p/2jvLjk8)DSCF7327-edited (https://flic.kr/p/2jvLjk8)
https://live.staticflickr.com/65535/50219939256_50036d129d_z.jpg (https://flic.kr/p/2jvLjiE)DSCF7328-edited (https://flic.kr/p/2jvLjiE)
I found this thread and decided it was simple enough to give it a try
http://www.volvoxc.com/forums/showthread.php?25253-01-v70-xc-trans-questions&p=167803#post167803
While I didn't have any severe pronounced problems before, the newly installed transmission cooler seems to reduce majority of the shift issues when ATF is hot. Most noticeable is my RPM would show a little up swing bump when coming to a stop at times which coincides with a likely 2-1 downshift. This is pretty much gone now and I recall this how a good AW55-50 down shifts coming to a stop.
Anyhow, curious if we can gather more statistics on this remedy for transmission that shifts poorly when hot but perfectly fine when cold.
The installation itself was pretty easy. Had to pull off the bumper, radiator fan, intercooler/ETM pipe (just to make plenty of room and I knew how to do this step quickly, probably unnecessary) The Hayden transmission cooler installed easily and came with just enough hose. A couple of 3/8 brass garden hose fittings connected all the rubber hoses. I did have to cut a little slot under the bumper to route the aux cooler hoses into the engine bay. Total part cost is like $35 ($30 for cooler, $5 of connectors/extra clamps) The cooler installs in front of the existing radiator so it gets the best cooling opportunity from the incoming cooler air.
Many claim external coolers will drop the temperature by about 20-30F. I believe the built-in ATF cooler runs close to somewhere just under 90C when hot from my previous VIDA/DiCE observations. Post installation runs shows around 65C when hot. Both of these were taking with outside temperature of about 40F. Pretty significant drop. In fact, the VIDA/DiCE adaptation only occurs when ATF Is hotter than 65C. With this external cooler, definitely takes quite a bit longer to enter adaption mode.
As for the reason shifting problems occur only with hot ATF? I believe the conventional wisdom is hot ATF is thinner and easier to leak past wornout seals.
If anyone have poor shift when only hot, perhaps you can consider giving this a try if B4/flush/torque_mount/adaptation doesn't help. This is one more low cost step before going to the more expensive route of valvebody or total transmission rebuild.
Here are post install pics. The silver duct tape you see wraps around some plastic protection I wrapped around the hoses to protect it against the sharper edges of the hole where the hoses routes into the engine bay. I could find no other entry path. On retrospect, a short section of PCV pipe would have worked better. Need to be inserted before connecting up the hoses of course.
https://live.staticflickr.com/65535/50219939341_655bb250c0_z.jpg (https://flic.kr/p/2jvLjk8)DSCF7327-edited (https://flic.kr/p/2jvLjk8)
https://live.staticflickr.com/65535/50219939256_50036d129d_z.jpg (https://flic.kr/p/2jvLjiE)DSCF7328-edited (https://flic.kr/p/2jvLjiE)