Transmission shifts 'early

Law2500

2002 Freightliner 158"
Hi everyone I have been doing all the service work on my recently purchased 2002 T1N 2500 LB-HT (FedEx owned 481000 miles) and I was wondering if I should service the transmission. The trans looks as if it has been replaced, the fluid is rose red with a pink ish tint when you wipe the stick on a clean towel, the bolts that hold the trans to the engine show marks of removal and mounts show no cracks in them. I read a tread in the database that advice you not to remove and clean the valve body with you are not getting any trans codes and I am not getting any when I scan the trans nor am I getting any check engine light, but the issue I am have is,,,the trans shits from 1fst to 2nd too soon and its a firm shift, it does it ever time the van is driven.
Would a slightly smaller tire cause this issue, the van came with 4 brand new Yokahoma Geolander G015, 215/75R15 6 ply tires on it.


Thanks Amous
 

220629

Well-known member
Cost wise one of the more effective things I would do is drain the pan and TC, replace the filter, refill with MB approved/rated fluid (or
Valvoline MaxLife if money is short), and see if things improve. During the fluid change you can inspect the stuff which may be settled in the pan. If your symptoms go away you're good to go. If not, at least you know the transmission is serviced and filled with proper fluid. At this time do you know what fluid is in the tranny?

vic
 

Law2500

2002 Freightliner 158"
Cost wise one of the more effective things I would do is drain the pan and TC, replace the filter, refill with MB approved/rated fluid (or
Valvoline MaxLife if money is short), and see if things improve. During the fluid change you can inspect the stuff which may be settled in the pan. If your symptoms go away you're good to go. If not, at least you know the transmission is serviced and filled with proper fluid. At this time do you know what fluid is in the tranny?

vic
I have no ideal what fluid is in it. I did buy a filter and harness connector alone with Shell 134 fluid, but I was unsure if I should change it if I had no codes. I also thought about putting a pint of Lucas transmission condition fluid in it, not the stuff for a trans that is slipping but the conditioner.
I have always put a pint in automatic trans after serving them,
I don't have a lot of experience with MB but i have 5 Volvo's one with over 200k on the original trans, so I am trying to learn the do's and don't of these vehicles.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
A fluid change is a good place to start...
You could also try an “adaptation drive” and see if the controller chooses better shift parameters. The TCM is constantly adjusting to your driving style... your style may exacerbate the 1-2 shift settings that worked for the previous owner?

See the service manual for the adaptation driving procedure... it’s essentially a VERY gentle drive with four or five up- and down- shifts below 1800 rpm in each gear, then park and idle for ten minutes to allow the TCM to store the settings. You’ll need a long, flat, empty road... especially for the 4-5 and 5-4 shifts.


-dave
 

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