Nag1 TECH ALERT

[abittenbinder]

-Has your Sprinter clocked over 80K miles?
-Does your Sprinter see severe "stop and go" service and clocked 50K miles?

If you answered yes to either question-I recommend you perform this additional procedure during your routine ATF fluid/filter change.

-Are you experiencing transmission related malfunction codes and/or symptoms of transmission malfunction despite having proper fluid level?

-Is your dealer recommending a transmission replacement?

If you answer yes to either of the last 2 questions-don't wait. Perform this procedure immediately.

Here's the procedure that has benefited "severe service" delivery fleets and I'm hoping will help group owners avoid needless transmission replacement.

If you answered yes to any of the above questions- I recommend you drop your transmission valve body (or as DC calls it ,"the electro-hydraulic unit"). It's simple to do and I'm recommending dropping it specifically for inspection and cleaning of the 2 circuit board mounted speed sensors.

Here's the procedure-When you have the pan off and the fluid drained (and inspected) and the filter removed-don't throw out the old filter just yet. It's halves can be uncrimped with a channel-lock plier and you can examine the inner filter media for unusual debris and accumulation.

Next -now is a good time to replace your trans elec. connector's socket O-rings since the socket needs to come out for valve body removal. Remove the small heat shield and disconnect the trans. elect connector. Reach into the trans. mounted elec. socket with a 7mm 1/4 drive socket at the end of a short extension-unbolt the retaining bolt and gently pull the socket out of the trans. Have a new socket with o-rings ready for later reassembly-part# is 68021352AA (inexpensive and comes complete with the latest black O-rings).

Now, using the same T-30 Torx bit, you used to remove the pan- loosen all the bolts and remove all but 2 (opposing bolts) holding the valve body in place. Supporting the valve body carefully-remove the last 2 bolts and lower the valve body down and carry it immediately into your surgically clean(?) workshop.

Lay the complete valve body on a clean newspaper- elec side up. Refer to your workshop manual diagrams- the speed sensors are easy to spot(on top) and should be carefully cleaned of accumulated metallic filings(they are strong magnets).

Inspect exposed parts of the circuit board and exterior of the solenoids for heavy accumulation-clean carefully.

If things look really clean- you don't need to go further. Skip down to re-installation.

If there's heavy accumulation of metallic debris you can unbolt(again-the T-30 Torx bit) the solenoid retainers and carefully remove the solenoids. The electrical board can now be unclipped(2 push clips) and separated from the valve body.

Inspect the small filter screens under the 2 regulating solenoids(If you find the screens clogged-I would stop here and seriously consider a transmission overhaul-this is thankfully rare) also inspect the o-rings on the 3 shift solenoids and single TCC lock-up solenoid(yes-part of the RSN gang). The o-rings are NOT avialable as (separate from solenoid) replacement parts from DC but any suspect o-rings can be replaced by visiting the local autoparts store and sorting through their collection of quality viton o-ring drawers.

If the circuit board looks hopelessly contaminated -it is available as a replacement part and is somewhat reasonable in price. It's mostly encased in plastic and cleaning can be tedious.

Reassemble the electro and hyd. portions and follow torque specs(71 in/lbs.) for the solenoid retainers.

Carefully lift the assembled valve body back into the transmission sump and make sure you engage the plastic sliding lever of the selector valve into the detent plate post. Torque the 10 bolts to 71 in./lbs. Install your new connector socket, and your new filter and sump seal. Bolt on the sump and fill as usual (I assume you have also drain the torque converter as per previous post). Photos show-1) The complete valve body. 2)Transmission w/valve body removed. 3)Close-up of speed sensors. 4)Disassembled valve body.5)Close-up of the TCC lock-up solenoid. 2008 Copyright by Doktor A

[jdcaples]

Originally Posted by abittenbinder

...

If there's heavy accumulation of metallic debris you can unbolt(again-the T-30 Torx bit) the solenoid retainers and carefully remove the solenoids. The electrical board can now be unclipped(2 push clips) and separated from the valve body.

...

If the circuit board looks hopelessly contaminated -it is available as a replacement part and is somewhat reasonable in price. It's mostly encased in plastic and cleaning can be tedious.

Thanks for the excellent write-up, Doktor A.

What is the source of the contamination? Is this entirely T1N-specific, or all Nag1-transmissions?

Would the system benefit from additional filtration, like a by-pass filter on the trans-cooler lines?

-Jon

[kurt]

[QUOTE=abittenbinder;18330]-Has your Sprinter clocked over 80K miles?
-Does your Sprinter see severe "stop and go" service and clocked 50K miles?

If you answered yes to either question-I recommend you perform this additional procedure during your routine ATF fluid/filter change.

-Are you experiencing transmission related malfunction codes and/or symptoms of transmission malfunction despite having proper fluid level?

-Is your dealer recommending a transmission replacement?

If you answer yes to either of the last 2 questions-don't wait. Perform this procedure immediately.

Here's the procedure that has benefited "severe service" delivery fleets and I'm hoping will help group owners avoid needless transmission replacement.

If you answered yes to any of the above questions- I recommend you drop your transmission valve body (or as DC calls it ,"the electro-hydraulic unit"). It's simple to do and I'm recommending dropping it specifically for inspection and cleaning of the 2 circuit board mounted speed sensors.

Here's the procedure-When you have the pan off and the fluid drained (and inspected) and the filter removed-don't throw out the old filter just yet. It's halves can be uncrimped with a channel-lock plier and you can examine the inner filter media for unusual debris and accumulation.

Next -now is a good time to replace your trans elec. connector's socket O-rings since the socket needs to come out for valve body removal. Remove the small heat shield and disconnect the trans. elect connector. Reach into the trans. mounted elec. socket with a 7mm 1/4 drive socket at the end of a short extension-unbolt the retaining bolt and gently pull the socket out of the trans. Have a new socket with o-rings ready for later reassembly-part# is 68021352AA (inexpensive and comes complete with the latest black O-rings).

Now, using the same T-30 Torx bit, you used to remove the pan- loosen all the bolts and remove all but 2 (opposing bolts) holding the valve body in place. Supporting the valve body carefully-remove the last 2 bolts and lower the valve body down and carry it immediately into your surgically clean(?) workshop.

Lay the complete valve body on a clean newspaper- elec side up. Refer to your workshop manual diagrams- the speed sensors are easy to spot(on top) and should be carefully cleaned of accumulated metallic filings(they are strong magnets).

Inspect exposed parts of the circuit board and exterior of the solenoids for heavy accumulation-clean carefully.

If things look really clean- you don't need to go further. Skip down to re-installation.

If there's heavy accumulation of metallic debris you can unbolt(again-the T-30 Torx bit) the solenoid retainers and carefully remove the solenoids. The electrical board can now be unclipped(2 push clips) and separated from the valve body.

Inspect the small filter screens under the 2 regulating solenoids(If you find the screens clogged-I would stop here and seriously consider a transmission overhaul-this is thankfully rare) also inspect the o-rings on the 3 shift solenoids and single TCC lock-up solenoid(yes-part of the RSN gang). The o-rings are NOT avialable as (separate from solenoid) replacement parts from DC but any suspect o-rings can be replaced by visiting the local autoparts store and sorting through their collection of quality viton o-ring drawers.

If the circuit board looks hopelessly contaminated -it is available as a replacement part and is somewhat reasonable in price. It's mostly encased in plastic and cleaning can be tedious.

Reassemble the electro and hyd. portions and follow torque specs(71 in/lbs.) for the solenoid retainers.

Carefully lift the assembled valve body back into the transmission sump and make sure you engage the plastic sliding lever of the selector valve into the detent plate post. Torque the 10 bolts to 71 in./lbs. Install your new connector socket, and your new filter and sump seal. Bolt on the sump and fill as usual (I assume you have also drain the torque converter as per previous post). Photos show-1) The complete valve body. 2)Transmission w/valve body removed. 3)Close-up of speed sensors. 4)Disassembled valve body.5)Close-up of the TCC lock-up solenoid. 2008 Copyright by Doktor A[/QUOTE

Doctor A

No blah blah blah or BS excellent and best posting I've seen on this forum for a long time thanks.
Already bought the connector socket $12 and was recommended (MB service tech).

Upscale made my first transmission oil and filter change at 55K,now close to 100 000K will execute my next oil and filter change myself,see below why.

<<<<My experience with Upscale !!!!!!

<<<<Simple transmission service,oil and filter change.

<<<<There are 6 transmission oilpan retainers,2 where missing,2 of the remaining retainers where <<<<loose.The 2 rubber bellhousing covers missing (provide exes to Torqe Converter oil drain plug)

<<<<After 3 trips (4hr driving and $30 in diesel) to retrieve all missing
<<<<parts the arrogant """BITCH""" behind the counter told me,"ACT OF GOD"
<<<<not there fault.

[northener]

Kurt: could you please name the dealership that gave such poor service. We need to pin point stealership problems as well as vehicle problems.I wander about quite a bit but some areas like south Florida offer many choices. Thanks paul

[kurt]

Originally Posted by northener

Kurt: could you please name the dealership that gave such poor service. We need to pin point stealership problems as well as vehicle problems.I wander about quite a bit but some areas like south Florida offer many choices. Thanks paul

Sorry Paul but Upscale is not a dealership,a independent autoshop in Portland,Oregon specializing in German cars including Sprinters. Positively and continuously pluging itself on all Sprinter forums.

Happy day to you.

Kurt.

[kurt]

Originally Posted by northener

Kurt: could you please name the dealership that gave such poor service. We need to pin point stealership problems as well as vehicle problems.I wander about quite a bit but some areas like south Florida offer many choices. Thanks paul

To add to your posting I use *****http://www.fivestardealers.com/ronto...th=&bid=&rid=u ****and always got service and courtesy.

[tegimr]

Originally Posted by kurt

To add to your posting I use *****http://www.fivestardealers.com/ronto...th=&bid=&rid=u ****and always got service and courtesy.

Kurt - just curious: you use and are happy with Ron Tonkin; but went to Upscale instead, and since unhappy with Upscale you are now going to do the work yourself. I'm not certain that I can follow your point. Why not return to Ron Tonkin?

Tim

[bikerjoe]

That is some scary looking stuff. I don't know if I am brave enough to get into my tranny like that just yet.

[abittenbinder]

Originally Posted by jdcaples

Thanks for the excellent write-up, Doktor A.

What is the source of the contamination? Is this entirely T1N-specific, or all Nag1-transmissions?

Would the system benefit from additional filtration, like a by-pass filter on the trans-cooler lines?

-Jon

The contamination we're most concerned with are the minute ferrous filings that can accumulate on and disrupt functioning of -the speed sensors(curiously- one in particular).

These sensors are very strong magnets and protrude directly into the trans housing chamber where all the rotating elements and friction elements are housed. The torque converter with its "lock-up"(slip mode most of the time) clutch are also prime suspects in shedding fine ferrous hairs.

There is a small, weak, magnetized grid "dropped" into the sump but these sensors are unfortunately much more effective in picking up these filings(and not by design).

This is not T1N specific. The NAG1 in the new generation has a V6 specific bellhousing but it's still an NAG1.

Filtration has benefits but also its risks-quality and integrity of plumbing and hardware being the ones I would be most concerned about. Doktor A

[abittenbinder]

Originally Posted by bikerjoe

That is some scary looking stuff. I don't know if I am brave enough to get into my tranny like that just yet.

True-this is not as simple as an engine oil filter change but it's much less intimidating than it appears.

If you're nervous about doing this procedure then why not just keep it in mind and do this inspection and cleaning -if and when you ever suffer from transmission codes or symptoms.

More importantly, don't let someone talk you into performing expensive repairs or replacing your transmission without checking this first. Speed sensor (in this case false signals) related failure codes are suggestive of serious internal problems -can be misinterpreted. Doktor A