shift points on NAG

[SprintED]

Any one know if the NAG trannys shift points etc..can be manipulated by a DC Tech with the proper equipment?

I know that techs would do this once and a while on some of the Dodge trucks I used to own.

My 05 seems to shift prematurely from 2nd to 3rd under light acceleration...forcing it to really lug...you have to push the accelerator down a fair bit before it kicks back down into 2nd.

It seems to be getting worse (32000 miles on van) and of course RSN like crazy when it does this...almost rattles your teeth out if you dont change position of accelerator after it shifts.

Any thoughts on other possible causes or things to check out..I am kind of wondering about tranny fluid level???

Ed

 

[sikwan]

Definitely check the tranny fluid level? When was the last time you checked it?

Also, I'm not sure if this is correct and I forget where I read it so take this with a grain of salt...I've read that if the battery is disconnected for a certain amount of time, it can relearn the shift points. I'm might be spooing out misinformation, so be careful.

 

[SprintED]

Seek,

Dealer checked it about 4000 miles ago...I have requested a check everytime I bring it in. I know they have checked it at least once...I have the busted plastic cap on the tube to prove it. They never replaced it with a new one...just shoved the busted one back on. They always tell me the level is fine.

Since my dealer gives me such a feeling of confidence when it comes to service...i think I will have to go out an buy my own dipstick...plus a couple of replacement caps.

I like the battery disconnect concept...anyone else want to weigh in on this idea...how about the "Wonder from Down Under" who lives in an Altered State?

Thanks all!
Ed

 

[tab380]

Any one know if the NAG trannys shift points etc..can be manipulated by a DC Tech with the proper equipment?

I know that techs would do this once and a while on some of the Dodge trucks I used to own.

My 05 seems to shift prematurely from 2nd to 3rd under light acceleration...forcing it to really lug...you have to push the accelerator down a fair bit before it kicks back down into 2nd.

It seems to be getting worse (32000 miles on van) and of course RSN like crazy when it does this...almost rattles your teeth out if you don't change position of accelerator after it shifts.

Any thoughts on other possible causes or things to check out..I am kind of wondering about tranny fluid level???

Ed

My 2003 did the same thing and the only thing that helped was a trans. service (oil change) every other engine oil service. I think thats the RSN that every one is complaining about and changing Drive shafts to no avail. I always though that the trans. was shifting to early but the dealer just kept doing a trans service to fix it and it lasted about 10000 miles.

 

[tab380]

PS. My differential seal went bad just before I traded it possibly because of the RSN. Replaced seal and went bad again in 2000 miles. Dealer said the rear axle would have to be replaced because they cant repair a Sprinter Differential at $5000.00.
I traded it in for the 2007.

 

[Altered Sprinter]

Seek,

Dealer checked it about 4000 miles ago...I have requested a check everytime I bring it in. I know they have checked it at least once...I have the busted plastic cap on the tube to prove it. They never replaced it with a new one...just shoved the busted one back on. They always tell me the level is fine.

Since my dealer gives me such a feeling of confidence when it comes to service...i think I will have to go out an buy my own dipstick...plus a couple of replacement caps.

I like the battery disconnect concept...anyone else want to weigh in on this idea...how about the "Wonder from Down Under" who lives in an Altered State?

Thanks all!
Ed

It's a non issue down under! in the main, Mechanics top end we have, and we DO NOT HAVE TO HAVE WARRANTY OR SERVICE DONE AT THE DEALERS, It's our choice were we have it done, if warranty is involved the costs and parts are reimbursed from Benz.
Another exclusive for the States I guess
Richard

 

[talkinghorse43]

My 05 seems to shift prematurely from 2nd to 3rd under light acceleration...forcing it to really lug...you have to push the accelerator down a fair bit before it kicks back down into 2nd.

My '02 has done this since day 1 (no RSN for me at that point tho). I've always thought that was torque converter lockup in second, not a shift to 3rd. Makes sense to me in your case that it's also lockup because RSN is always associated with the application of the lockup clutch.

 

[AzteK]

Ed, dont take it to Varsity, as they prolly dont know where the tranny fluid tube is. They will look with their eye balls, and maybe kick a tire, change the oil then say all is good. Or try and find something broken that prolly isnt broken at all.

 

[SprintED]

Aztek,

No worries...my Sprinter will never go back to Varsity after they way I got treated when I bought the van from them and when they did some service to it early on.

Ed

 

[SprintED]

Talkinghorse,

Could very well be the lockup...I usually just get a little miffed everytime it does it and never really pay attention afterward to count shifts etc... because I am in a foul mood. That and it always seems to happen in city driving at "going around a corner" speed and not from a dead stop...so I usually have not paid attention as to what gear the tranny is in.

Will attempt to pay closer attention...not that it will help when giving explicit details of what it is doing to the service writer at the dealership!

 

[FredSheldon]

If I understand the documentation describing the operation of the torque convertor there are 3 modes that it can be in. Unlocked, Partial Lockup and Full Lockup. The torque convertor can begin to lockup in second gear, but it is designed to slip to smooth the transation. I believe that's what is causing the RSN under light acceleration at 20 mph in my vehicle. I don't worry about it and expect it to occur under certain conditions. The transmission learns your driving habits and if you are a easy driver it tends to shift early and lock up the torque converter early to increase your fuel mileage. I guess the lockup clutch in the convertor doesn't have friction material that can wear off and therefore can perform this operation for the life of the vehicle without the need of replacement. Of course, I could be way off base here and just didn't understand the documentation on the operation of the torque convertor and transmission

Fred

 

[abittenbinder]

Any one know if the NAG trannys shift points etc..can be manipulated by a DC Tech with the proper equipment?

My 05 seems to shift prematurely from 2nd to 3rd under light acceleration...forcing it to really lug...you have to push the accelerator down a fair bit before it kicks back down into 2nd.

It seems to be getting worse (32000 miles on van) and of course RSN like crazy when it does this...almost rattles your teeth out if you dont change position of accelerator after it shifts.

Any thoughts on other possible causes or things to check out..I am kind of wondering about tranny fluid level???

Ed

The shift points cannot be directly modified by a technician-however keep in mind the NAG1 transmission has 4 levels of adaptation-a short key cycle, 2 long and a "wear and tear" adaptation. The tech can perform a "reset of adaptations"(to factory pre-selected settings) using the DRBIII and about a 30 minute test run, fully prompted by the DRB. It won't be cheap- but it may be worth trying. Doktor A

 

[jdcaples]

keep in mind the NAG1 transmission has 4 levels of adaptation-a short key cycle, 2 long and a "wear and tear" adaptation. The tech can perform a "reset of adaptations"(to factory pre-selected settings) using the DRBIII and about a 30 minute test run, fully prompted by the DRB. It won't be cheap- but it may be worth trying. Doktor A

What is:

A short key cycle?
A "long" cycle?
A "wear and tear" adaptation?

Are they stages in the operation of the NAG1 during a drive, or are they stages of the lifespan of a NAG1, or something entirely different?

-Jon