Shift points for 2008

After having a leaky pinion housing repaired, it seems like RPMs are much higher then they used to be before upshifting.

For example, on flat road with steady acceleration, the tranny doesn't upshift until something in the 2600-2800 rpm range; sometimes seems like it boarders on 3000 sometimes. This seems much higher than it used to be, but I don't have more than a feeling at this point

I would expect that somewhere there is a list of approximate rpm rates which trigger the tranny to upshift.

Can someone point me to a link where this might exist?

Hi Keith,
Is this when your Sprinter is cold, or at all times?
It's programmed into the ECU and TCU to delay shifting when cold to bring the
engine temps up more quickly for lowered emissions.
This occurs until the engine temps reach around 150 deg.F.
It could be that the ECU/TCU was reset (or has reset itself) due to colder weather.
This is the "adaptive" feature at it's best (or worst).
Having the trans shift up at > 2400 RPMs could actually be getting your better mileage.
How is your fuel mileage, compared before the rear end work?
On the 2010 I have (different emissions package, but same engine) shfiting up @ < 2400
rpms seems to lower my mileage a bit.
When the trans shifts up is not completely on any programmed "schedule".
If you have more load, or are accelerating faster, the Sprinter's engine/trans management
systems will delay the shift points.
Hope this helps,
Roger

Hikinginpdx said:

<snip>
the tranny doesn't upshift until something in the 2600-2800 rpm range; sometimes seems like it boarders on 3000 sometimes.

<snip>

I would expect that somewhere there is a list of approximate rpm rates which trigger the tranny to upshift.

Can someone point me to a link where this might exist?

Click to expand...

If I'm gentle on the throttle, my 2007 shifts at around 2200 rpms for at least the first three gears.

There's no document mapping shift points to throttle position, engine load, vertical incline or speed, but I believe that those three (perhaps more) impact the shift point at any given moment.

2008 Sprinters had a default axle ratio of 3.9x to 1. Did they give you the lower axle ratio gearing (4.18:1)?

This might help verify:


RPM comes from the analog tachometer.

Speed: RPM

55 mph: 2000
60 mph: 2200
65 mph: 2400


Or are your RPMs higher at those given speeds?


If so, a Dodge or MB dealership could use a scan tool to reset your transmission control module's adaptives and force it act like it did when it was first driven. I don't know if the other scan tools mentioned like Diagun can do it (the names of other scan tool products that seem to work with US/Canadian NCV3s escape me at the moment).



-Jon

But the real point is that there is nothing about just replacing a pinion seal that effect shifting or engine management.................so if there another problem it would most likely be pure coincidental or just your taking notice of a normal condition.

Got some answers today

Ran the Sprinter through the local Freightliner shop just to have the tranny fuild level checked. Running about a quart low and 2 leaks were found.

Shifting is back down into the 2200 / 2400 range which is what I was used to seeing.

We'll schedule the repair after the holiday, but for now, mystery solved.

Thanks for all the input