Transmission slipping when cold out

[justin32691]

I have a 2004 Dodge Ram 1500 4x4. 4.7 engine. I had this problem last year when the temperature outside dropped below about 35 degrees my transmission would slip it would rev high rpms but my truck would barely move. It went away as the temp got warmer but now the issue is back same problem it’s cold out and I’m having the slipping. Anyone have a clue what could cause this?

 

[Bloody_Knuckles]

Low or old fluid.

 

[Fast69Mopar]

I have seen this caused by a couple of things. Once the fluid gets cold the viscosity changes and the fluid becomes super thick. Cold, thick fluid doesn't travel very fast until the fluid warms up. The other thing that I have seen cause this is a failed cooler return filter in the trans. The cooler return filter can allow the fluid to drain out of the torque converter and it will feel like the transmission is slipping once you put the shifter in drive and try to accelerate. What is actually happening is the front pump is filling the torque converter up with fluid and it feels like its slipping.

How long has it been since you last service the transmission? Have you replaced both trans filters?

 

[justin32691]

I’ve had the truck for about 4 years I haven’t had a flush on the tranny at all. So can’t be sure the last time it was serviced before that.

 

[Fast69Mopar]

I’ve had the truck for about 4 years I haven’t had a flush on the tranny at all. So can’t be sure the last time it was serviced before that.

If I were you I would NOT flush the trans. I would only service the trans so I could replace the filters and get a look inside the pan to check for abnormal amounts of debris.

Check the part number on the cooler return filter. There were some factory installed cooler return filters that caused torque converter drainback. The last 2 digits on the bad filters is AA or AB if it still has Mopar filters installed.

 

[Burla]

I’ve had the truck for about 4 years I haven’t had a flush on the tranny at all. So can’t be sure the last time it was serviced before that.

So you need a fluid with a low pour point, I will give examples.

redline c+ pour point -76f

m1 pour point -58f

I'm not sure of your transmision, I have the rfe, what tranny fluid was recommended in 2004 ram? Let me know I can say which fluid will flow fastest when cold. I'm with other guy, never flush, drop pan or use a pan with a bolt and drain and refill. eventhough it is mixing old and new fluids, this is the best safest way to do it. Tranny's are sensitive, flush could kill it. Redline mixes fine with oem fluids. If you want to try another fluid, search pour points, the lower the better performance in the cold. Look for pao fluids such as redline.

 

[WMick]

I'm certainly no expert... but I did have what seemed like some slippage very soon after I bought a 2004 with about 200,000 km on it... I took some advice to not do the full tranny flush, because sometimes it can cause more problems than its worth..... I changed the oil and filters myself... and haven't have any slippage since..... 320,000 km on it now...