96 960 acts up when I've been driving in hot weather and stop and go traffic. I'm thinking of adding a tranny cooler. Any advice on what type and where to buy? Any help or other suggestions would be appreciated.

Ahughes
1996 960 140k.

I live in the south as well and have this same exact problem on my 1998 V90. Although my outdoor temperature gauge appears to read more correct temperatures about 85 to 95 degrees and I am guaranteed to have issues.

I do have a Nissens radiator which I bought from Groton and installed back in 2006. Did not start having issues until 2 years ago, have did the flush thing multiple times, initially it seemed better for like a month afterwards, then back to the same thing. Also I tried a synthetic blend last time but still when the temps get hot and I am in stop and go traffic the problem returns.

All this winter it has shifted fine now here comes summer and I am dreading it unless I get this fixed.

The possibility the radiator is it sounds plausible as nothing else seemed to add up.
--
~William~ 1985 240 DL - 365,000 & 1998 V90 - 190,000

The car is already equipped with a transmission cooler. What do you mean by acting up. Has tranny been flushed recently?
--
David Hunter

It shifts out of 2nd into 3rd gear too soon when the car has been driven in heavy traffic on hot Alabama days. It has to be temperature related, as it only does it on 90+ degree days and in stop and go traffic. The abient temp gauge is also always reading 115+ when it starts acting up.

Ahughes

You should not, in my opinion, add another tranmission fluid cooler. There may be another cause to the problem that you're not addressing that a cooler would not solve, unless of course the actual outside temp is 115. These tranmissions are normally very durable and require little maintenance AS a first less costly step, I would certainly change the transmission fluid and make sure there is a full supply added Synthetic is best.
--
John Shatzer, '97 V90 @ 105K

I would be more concerned what the engine temp guage says rather than the ambiant. The tranny circulates its fluid to the rad for cooling. If the engine heats up so will the tranny as they are both cooled by the rad. Is your engine temp staying normal?

I still recommend a flush as the first step and yes as John says go to synthetic ATF such as Mobil 1. The cause of the problem may be heat related but not heat caused. For example old worn out fluid could change viscosity or break down when heated up, therefore the cause is the old fluid, not the heat. On the other hand I have heard of shifting problems that only happen when cold, the cause is not the cold and the solution is not to heat the tranny.

A tranny is more likely to overheat during rapid acceleration, agressive driving or climbing mountains with a lot of shifting, certainly not in stop and go traffic.
What is the color of the fluid, nice and red or a dirty dark brown?

I consider periodic flushing a preventive maintenance item which should be done in any event and it will often make problems disappear. It is cheap and easy to do. See FAQ section for details, the procedure is the same for your 960. If you are not confident doing yourself any good shop will do it. Do not just get the tranny pan drained and fluid topped up as that only changes about half of the total fluid in the system. Do a flush which removes all the old stuff.
--
David Hunter

Look for a good "stacked plate" design. Most folks run the atf thru the stock radiator cooler than thru the aftermarket cooler then back to the tranny. Some skip the stock radiator cooler altogether and just run it thru the aftermarket cooler. Your choice.

DEWFPO
--
1998 S90 068,300 and 1995 964 152,300

I had this same problem when I changed radiators, to a non volvo unit. The tranny would mishift late in the afternoon in slow traffic. I went back and put in a Volvo radiator, 99% improvement. Next move will be tranny flush/synthetic refill. I've been told you can add a tranny cooler from a 940 turbo or 760, but I'm sure if it will work.