Rolling from a stop

[CUAviator]

Hemi engine with automatic trans:

When going from park/reverse to drive, or when taking foot off brake at stop light, my truck no longer rolls forward as quickly/aggressively/powerfully as it used to. This has been going on about 2-3 weeks. I checked to make sure the parking brake wasn’t on.

Any ideas?

(Side note, the bottom part of my differential looks “wet”).

 

[SYKRAMMAN]

Is your idle lower than usual? 650/675

 

[CUAviator]

Is your idle lower than usual? 650/675

No, it’s right around 900. Maybe a little less.

 

[BWL]

If the truck was brand new it seems they like to lurch a bit coming to a stop and roll off the brake a bit aggressively for the first few thousand km's and then mellow out. My 17 has eased up a bit already at 1500 km. My sisters and neighbors 17 sports are both over 15000 km now and they feel more normal now, but used to do the same as mine.

 

[CUAviator]

Sorry. It’s an 03

 

[BWL]

If it's older it may be worth doing a Trans fluid and filter change with a band adjustment.

 

[SYKRAMMAN]

900 is a little on the high idle side, it should be around 650/675. At least that’s what alldata says it should be set at in the pcm.

 

[CUAviator]

900 is a little on the high idle side, it should be around 650/675. At least that’s what alldata says it should be set at in the pcm.

Sorry. That 900 was in park. In drive at idle it’s right at 675.

Update: that 675 was at my first stoplight. Once I was half way to work until I parked it was right around 500

***would 10/30 oil have anything to do with this? I put that a little bit ago because it was starting to get warm and it seems like the only thing I do is sit in traffic in 90 degree heat).

 

[xtremewlr]

No, oil won;t have anything to do with that. 500 is fine when the truck is totally warmed up or hot and you have it in D. I've seen that on my truck. If you are worried about the oil in the hot with traffic, start using a full synthetic if you aren't already. I use Shell Rotella T6 5w40 and will sit in traffic in the summer without worries. I also go out to the desert a lot and have seen 115 deg out there with no concerns.

For the transmission, try adding some Seafoam Trans Tune to it. I use that in mine and my truck has over 200k. No issues, shifts great. I would also do that before changing trans fluids and filter. Never had a band adjustment done on my 04 and haven't really heard of the 545 really needing one but I'm not an expert on the subject.

 

[BWL]

If it has the 45or545rfe then there are no bands to adjust. They're electronically controlled clutch packs. Not 100% sure if that's the Transmission in your truck though. Not sure what issues you could have that wouldn't throw a code. A valve block problem usually does. Does it go through all the gears fine once driving? It still could be a clutch pack slipping.

 

[SYKRAMMAN]

BWL Is correct, no bands in the 45/545rfe’s just clutch packs. And no the oil wouldn’t have anything to do with that. They are actually the same exact transmission, only difference is the 545 has a different tcm that gives it 5 gears, I switched my tcm with a 545 tcm and now have the fifth gear. Does it shudder when you let off the brake? The idle is ok at 500 but should be 650/675 in park, drive, neutral, etc. that may be why it feels like it’s not moving as much when you let off brake. Jmho.

 

[CUAviator]

Nope. No shutter. Actually, it’s driving about the smoothest it’s been in a while. It just has a really hesitant roll when taking my foot off the brake lately.. (and if the steering wheel is turned at all, it will not roll).