NAG1 Transmission Fluid Change

stp57

Member
I gave up on the pan drain plug. I was really nervous about shearing it off, so I drained the trans like I would on the old American cars: I loosened the pan bolts & let it drain part of the way & then removed the front 4 bolts & tilted the pan to drain the rest. A little messy but it got the job done.
Steve
 

abittenbinder

Doktor A (864-623-9110)
I gave up on the pan drain plug. I was really nervous about shearing it off, so I drained the trans like I would on the old American cars: I loosened the pan bolts & let it drain part of the way & then removed the front 4 bolts & tilted the pan to drain the rest. A little messy but it got the job done.
Steve
Your metric allen bit was in more danger of shearing. These plugs can be very difficult to remove. The drain plugs have a very large shoulder and the matching seal washer shares that huge surface area- lots of friction when torqued (or over torqued). You were wise to drop the pan instead. Doktor A
 

contractor

New member
Thanks HKPierce for cutting up that tranny filter and great pics.:thumbup: I'm not surprised by what you found. I shall be doing mine very shortly because I have 26K on it. Let's see if mine has the same about of debris.
 

05highroof

New member
I changed the fluid in my 05 today.I bought the truck used with 138k miles and have added 10k more.I saw no signs that the trans pan or converter plug had ever been removed so this could be its first fluid change.The fluid was dark brown.I gave it the same service seek did and also removed the valve body per doctor A's Tech alert https://sprinter-source.com/forums/showthread.php?t=2476 FYI removing the valve body seemed to let loose another 1/2 quart +/- of ATF . I also changed the multi pin plug. I was concerned with what I would find when I removed the valve body but I found very little particulate matter on the speed sensors and what I could see of the circuit board looked clean. Also I must say removing the valve body was easy just follow Doc A's post and you'll have no problem.
I pried open the filter and it did have some metal bits trapped in as you can see in the picture.
The best part of the the deal is that my RSN on a scale from 1 to 10 has gone from a 10 to about a .5 It's almost non existent.BTW I used the Redline ATF.
 

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05highroof

New member
Originally Posted by stp57 View Post
I
gave up on the pan drain plug. I was really nervous about shearing it off, so I drained the trans like I would on the old American cars: I loosened the pan bolts & let it drain part of the way & then removed the front 4 bolts & tilted the pan to drain the rest. A little messy but it got the job done.
Steve
I started to remove my drain plug with a allen wrench (5mm?) and had the same issue.I was starting to bend the wrench. Enter 3/8 impact gun with allen bit,drain plug came right out.[/QUOTE]
 

Bajabum

Vi veri veniversum vivus
Reading all of these post gave me the enthusiasm to do this job myself. I replaced the transmission Adapter Plug Housing and dropped the valve body for cleaning and inspection. Put everything back and filled up the transmission for a test drive and the transmission does not shift out of first gear. I have reverse and first but that's it.
What did I screw up?
 

kkanuck

LUV my T1N
Have you checked the fluid level?


How many quarts went in?
 

rlent

New member
It's probably overfull for one thing (not that this would necessarily cause the symptoms you are describing ........ but a full overhaul fill is only 7.7 liters)

Did you drain the torque converter and lines as well ?

Did you make sure you did this:
 

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Bajabum

Vi veri veniversum vivus
Yes I did. After re-reading Doktor A's postings I realise now that I did not disconnect the neg battery cable before disconnecting the wiring harness plug. I don't think this would cause my problem but I don't know. To answer your question about draining the torque converter I did do that also. Since it looks like I will be draining the transmission again and doing this all over agian to see if I can find something wrong I will probably lose the little extra fluid I might have in it now.
 

sikwan

06 T1N Can
Hope you find what went wrong Bajabum. I didn't go through replacing the o-ring (probably the next fluid change), so my work was just a fluid job.
 

Bajabum

Vi veri veniversum vivus
Thanks sikwan, I haven't had time to revisit the transmission yet, kind of waiting, hoping one of the more knowledgeable contributors on the fourm might have some idea of what would cause the problem I am experiencing. It may be the selector valve to the detent plate but I am not quite sure what the function of this is, if it would cause the problem of not shifting or if it is more likely something in the valve body itself. Then again it could be something with the electric socket, I guess any one of these could be the culprit.
 

rlent

New member
It may be the selector valve to the detent plate but I am not quite sure what the function of this is, if it would cause the problem of not shifting or if it is more likely something in the valve body itself.
Me guesses the shifter assembly is connected to detent plate, which is (ideally) connected to selector valve (which is connected to shin bone .... :eek:)

The shifter selects the gear ya be in by causing the detent plate to move the selector valve to an appropriate position. It might be possible that the detent plate could bang the selector valve into only R and 1st ....... dunno for sure without having the pan off and twinking the valve linkage and seeing where the positions/stops are ........ and how the mechanism functions. HTH.
 

rlent

New member
Well, scratch that ...... not quite correct - it looks like the selector valve only controls P, R, N, and D - the selection of a specific forward gear, or gear range, is controlled via the TCM (transmission control module) - hence the are no specific positions for the selector valve for 1st, 2nd, 3rd, 4th, or 5th. Specific gear ranges are selected via the shift assembly communicating to the TCM, and then in turn to the transmission itself.

First thing I'd do is the easiest - you mentioned you had failed to pull the ground at the battery when you disconnected the electrical connector at the tranny - I'd pull it (ground at bat) now, give it a few minutes and reconnect and then see if it clears out any electrical cobwebs.

BTW, does the display in the IC show "D" or "1" ?
 

Bajabum

Vi veri veniversum vivus
Thanks for your help rlent, to answer your last question first, the display read 'D'. I will try removing the ground today and see if that helps. When replacing the valve body I made sure the selector valve and detent plate were engaged. I pulled the valve out so as I pushed the valve body up into the transmission the two went together. It may be possible that they didn't go together quit right. Also I seemed to have some difficulty with the electrical connector going back in but I don't see how I could have the socket in the housing improperly, it is either in or not as far as I can see. I'll get back with the results of disconnecting the ground as soon as I can.
 

rlent

New member
Thanks for your help rlent, to answer your last question first, the display read 'D'. I will try removing the ground today and see if that helps. When replacing the valve body I made sure the selector valve and detent plate were engaged. I pulled the valve out so as I pushed the valve body up into the transmission the two went together. It may be possible that they didn't go together quit right.
My guess is that if you can repeatedly shift P-R-N-D and back you got it back in correctly.

Also I seemed to have some difficulty with the electrical connector going back in but I don't see how I could have the socket in the housing improperly, it is either in or not as far as I can see.
..... when I reinstalled mine, I also had some degree of difficulty getting the electrical connector lined up and fully in and seated .....

IIRC, the locking tab on the outer edge of the housing was in approximately the 6 or 7 o'clock position. It had to be twisted, to approximately the 12 o'clock position, to fully seat the connector (or maybe vice-versa) I'm not sure whether it's even possible to get the threads on the retaining bolt started before the connector is seated ........... :thinking:

I'll get back with the results of disconnecting the ground as soon as I can.
Yeah, keep us posted - hopefully the Docktor will show up and offer his :2cents:
 

Bajabum

Vi veri veniversum vivus
Disconnecting the ground did'nt help. I will disconnect the transmission Adapter Plug again and see if that does anything before I drain the pan and inspect the selector valve and detent plate.
 

sikwan

06 T1N Can
Disconnecting the ground did'nt help. I will disconnect the transmission Adapter Plug again and see if that does anything before I drain the pan and inspect the selector valve and detent plate.
I think you will lose some fluid if you play around with this adapter. :thinking:

Also after reading this from the manual...

The transmission control is divided into the electronic
and hydraulic transmission control functions.
While the electronic transmission control is responsible
for gear selection and for matching the pressures
to the torque to be transmitted, the transmission’s
power supply control occurs via hydraulic elements
in the electrohydraulic control module. The oil supply
to the hydraulic elements, such as the hydrodynamic
torque converter, the shift elements and the hydraulic
transmission control, is provided by way of an oil
pump connected with the torque converter.
...the adapter plug would be my first pick to check as there could be some misalignment of pins. Since you can shift it to "D," maybe it's not the detents but either an electrical or a hydraulic problem due to the drop of the valve body.
 

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