Hoggy

Hey guys this is my 1st automatic trans so maybe its me but, I think this thing shifts too hard at slow speeds. I'll be in stop and go traffic and you get rolling about 10 mph and then have to let off and coast and it clunks into the next gear. I've tried it with the O/D button off and w/it in tow mode and it still does it. Always at slow speeds. It only has 6k on the dial but has done this since new. Anybody else or anybody with any ideas.
I've always had manual trans, and I drive big trucks for a living so I'm no rookie to big torque and diesels, but I am to autos. the wifes cars don't do this at any speed so I'm thinking this is unique to my truck.
I just had to buy an auto this time so she could drive it too didn't I ?
I dropped 33k on it and now it pisses me off. I wish I'd have bought the stick, but this is my truck for the next 10 yrs and I need it to not do this.

HELP

wreedCTD

mine does that too at low speeds. these trans shift very firm which is good. i wouldnt worry about it. this auto trans is the best i have had besides my Allison. it is not sloppy in shifting at all.

someone else may chime in here to correct me though.

my truck has only clunked maybe 10 times in 14k.

Fog Runner

I have the same problem and have had it since new on an 06 that now has
10K on it. It is the same issue, if I let off around the city steets before the shift, when it does shift it clunks. I have asked about this before and have never gotten a solution. I have had many trucks with autos, and it the stock form this is the only one to do this. This is my only complaint with this truck. From what I have read, the 48RE seems to be a decent trans though as long as you don't try to feed a bunch of power through it, it is just hard to feel good about your trans making a clunk when shifting. Is there something that can help this, valve body etc.????

PCM

My servicing dealer who is a diesel owner, too, says the hard shift is what you want. Especially under a load. If you don't feel the hard shift, it is probably slipping. The big block Cummins/Allison 6 speed I had in a diesel pusher motorhome did the same thing - very stiff jerking like shifts. If you are doing a lot of lower speed city stop and go traffic, cancel the overdrive to avoid excessive shifting.

wreedCTD

every 4l60e gm tranny i have had clunks on the 2-3 shift. and does the same thing when you let off the throttle right before a shift, it clunks into next gear.

inarush76

The clunk comes from a couple of things. Say you take off at 30-40% throttle, the ECM is looking to shift cased on tables in the programming based on throttle position, speed, etc. Also the torque being produced allows for pulling through the shift with the driveline loaded. When you accelerate and suddenly lift throttle, you unload the geartrain, throttle position drops, lowering throttle pressure, so the trans shifts while under low torque, unloaded gear train. Sorry for the short answer. Dodge uses throttle pressure and governor pressure balanced against each other to up and down shift. Many manufacturers just use computer commanded shift solenoids to accomplish shifts. HTH
James/JTT

Hoggy

Ok thx guys...obviously there is no damage being done and this is just normal in stop and go traffic w/ a truck that was not designed for that. With the power on the truck shifts and pulls great through the whole range.
I'm still glad I bought it. Thats the only complaint, I had.