Trans fluid leaking at torque converter ports

swami29

2004 2500 T1N 144 Hi-top
2004 T1N 133,000 miles. Recently changed my tranny fluid, filter, gasket etc including draining torque converter. Everything fine for a couple thousand miles. Tranny smooth and shifting normally. After a recent 600 mile round trip -freeway driving- when approaching home I got a little slippage in the tranny. Checked fluid level and it barely registered on stick.. inspection underneath revealed fluid spraying as far back as the fuel tank. I added about a half quart and realized It was running out fill tube ( filling too fast. So now I have additional fluid all over). Slowed down and added about 3/4 quart. Pulled it into shop and put it in neutral with parking brake on and could see a slow leak coming from torque converter ports. . Seemed to slow after a bit to an occasional drip. Rechecked the fluid level and now appears to be possibly over full. If overfill would I see the fluid coming out in the torque converter ports?. Any other ideas welcomed . I've searched around the forums but couldn't pinpoint this leak location. Tranny gasket and bolts all seem normal and no leak at connector. Thanks:thinking:
 

Goofy foot

sliding left...
It may be that when you first drained the torque converter you left the old washer in. If it was an aluminum crush washer it blends in with the trans housing threaded drain port. You wouldn't know it was there. If you installed a new one over the old, that could be an issue. Just a thought. Have you re-inspected the drain plug ?
 

Dougflas

DAD OWNER
Been there; done that. Make sure you have another crush washer and recheck it. You may need a pick to get the old one out. If you put a new one on and left the old one there, the new one will be distorted.
 

swami29

2004 2500 T1N 144 Hi-top
Checked the plug,its in tight no fluid visible adjacent. Will remove and reinstall with new crush washer again. To be double sure
 

swami29

2004 2500 T1N 144 Hi-top
Replaced crush washer on converter plug even though it appeared dry. To no avail! Still leaking out of torque converter inspection ports. Have been driving and carefully monitoring tranny fluid level. Still running in the zone although defenitly lower. Is there a seal between the transmission and torque converter that could have gone gunny?? Is it time to haul into the repair shop or would a transmission repair place be better? Any responses appreciated.:thinking:
responses appreciated.0
 

lindenengineering

Well-known member
Several things could be wrong!
First there is a seal on the torque converter shaft which is placed on the front pump housing .

This is the most common issue of converter fluid loss!
Ostensibly the seal got hard over time because the fluid before you changed it was in an acidic condition and you ":shocked it by changing the fluid to an alkaline state !

Now that might be fine in isolation and an easy fix! Simply budget about 6,5 hours of labor to recertify it! The seal is $35,00!
Now caution!

The front pump bush might be worn which supports the torque converter, so its doing the samba on the crankshaft and wear (mostly ovality) is stressing the front seal!
Lastly there is "lift" on the crank and shell bearings. The front pump bush is taking all the driving loads and is showing signs of accelerated wear hence the leakage.

All these things need to be checked once the transmission is removed.

Most likely just the seal but be alert for these other conditions.
Dennis
 

220629

Well-known member
...

Most likely just the seal but be alert for these other conditions.
Dennis
:hmmm:

Would this be worth trying before a transmission R&R?

...

Also once you are done add a can of BG's ATC plus transmission additive. Any abnormal burnishing of the lock up internal clutch will be smoothed out by this stuff.
All the best
Dennis
I have no idea if the stuff will "condition" seals, but it does say this: "BG ATC Plus® will help correct and prevent transmission shudder and shifting problems and prevent transmission leaks by keeping seals soft and pliable.".

https://www.bgprod.com/catalog/transmission/bg-atc-plus-automatic-transmission-conditioner/

vic
 

swami29

2004 2500 T1N 144 Hi-top
I guess if Dennis recommends the stuff I'll give it a try. I have to say I was disappointed that possibly doing the service could have instigated a rebuild.... just when Id gotten the bugs worked out of this thing after 4 yrs and 40,000 miles. Ah well I've learned a lot and have taken my amateur mechanicing to a new level thanks to the many stars on the forum! Any one have a quality mechanic in the Portland Or area? I hate to drive all the way to Denver to Lindenengineering.
 

swami29

2004 2500 T1N 144 Hi-top
My mechanic now estimating $2000 to $4000. He pulls tranny hauls to tranny shop they fix he reinstalls?. Driving to Portland and finding another mechanic is a possibility but doesn't excite me. Looking at a used tranny on flea bay for $1000.00 shipped 90 day warranty. Any thoughts, comments or wisecracks welcomed. Can I drop this thing myself and install the used one? I have the shop ,a few weekends and am not in a hurry.
 

220629

Well-known member
Before resorting to a used transmission I would spend a bit more for a Silverstar Transmission rebuild. Silverstar has a good reputation. They mention having have learned some things and have specific parts and procedures for the NAG1 rebuild.

Find out what experience a local shop has with NAG1 rebuilds before going that route.

:2cents: vic
 

swami29

2004 2500 T1N 144 Hi-top
After watching a couple YouTube videos I think it's time to roll up my sleeves and drop the tranny myself. Worst case scenario I have to call a flat bed and have it hauled in. What's the point in having a sprinter and a shop and not trying it myself��. So I have all winter ahead of me and will consider the rebuilt tranny from Silverstar. Won't know until I see what's going on there. Figure I may as well finish my trailer wiring project first and continue with the remodel of the inside when it's laid up when pulling the transmission. Can't get the time off to go to Arizona anyway so may as well fire up the wood stove and get greasy.. I went thru this same thing with Volkswagen and you would have thought I learned my lesson with German engineering but nooooo I get to do it all over again....
 

swami29

2004 2500 T1N 144 Hi-top
I got the transmission out without too much difficulty now reaching out for help. How do I pop out the old seal between tranny and torque converter? Also do I need to remove torque converter? Or should I just try and replace the seal and refit transmission?
 

Luc

Member
Several things could be wrong!
First there is a seal on the torque converter shaft which is placed on the front pump housing .

This is the most common issue of converter fluid loss!
Ostensibly the seal got hard over time because the fluid before you changed it was in an acidic condition and you ":shocked it by changing the fluid to an alkaline state !

Now that might be fine in isolation and an easy fix! Simply budget about 6,5 hours of labor to recertify it! The seal is $35,00!
Now caution!

The front pump bush might be worn which supports the torque converter, so its doing the samba on the crankshaft and wear (mostly ovality) is stressing the front seal!
Lastly there is "lift" on the crank and shell bearings. The front pump bush is taking all the driving loads and is showing signs of accelerated wear hence the leakage.

All these things need to be checked once the transmission is removed.

Most likely just the seal but be alert for these other conditions.
Dennis
Is it possible that this situation (front bush pump) is what is causing my intense rattle when accelerating under load in 1st gear? I get this awful loud metal rattling in just this situation. And no, it'S not RSN, because I also have that...

I also noticed leakage from the TC plug cover, but today I realized that the Stealership overfilled my transmission with a full quart of oil... This is when I sent it in to drill out 2 trans oil pan bolts... So wondering if the leakage is from overfilling (I also get leaks front the rear seal of the transmission on the propeller shaft), or from the worn pump bushing?
 

swami29

2004 2500 T1N 144 Hi-top
Got the seal out by building a mini slide hammer. Behind the seal was a ring which I assume is the pump bushing. There is a little bit of play where the bushing rides in the case but the bushing fits nice and tight on the torque converter shaft. The torque converter shaft that drives the oil pump shows a little bit of wear near the slotted end also. The inner drive spline (small) has some play which I assume is normal. I assume these were the points Dennis wanted me to examine. Does this wear seem acceptable and I can I tap in the new seal and refit the transmission at this point? Is it better to remove the Torque converter which is still attached or better to just refit the tranny to the torqe converter in place?:thinking:
 

Dougflas

DAD OWNER
Not to change the topic but did you use a lift or just raise the Sprinter up on jack stands? One person job or did you need help?
 

swami29

2004 2500 T1N 144 Hi-top
Jacked up vehicle and placed on wheel ramps. Made a cradle for floor jack to lower tranny. A little marginal would recommend a trans jack. Will probably rent a trans jack to reinstall. One man job
 

RileyC

2002 140 shc, 2005 158 sh
I think it’s better to disconnect the tc from the flywheel. That way you can make sure that it seats all the way into the tranny. I’ve only done it once as part of An engine swap, I think there’s a write up in the t1n write ups section.
 
There are a number of posts on this forum that indicate that the torque converter is not easy to get properly located on the transmission shaft and FULLY seated. I think the manual gives a dimension from the bellhousing face to the TC flywheel mounting pad faces, it is imperative that this be checked, or you will damage the flywheel/flex plate, suffer leaks and damage the converter. I am sure that Dennis can elaborate on this but from what I have read (and having no personal experience) I would be extremely careful with this. You always want the converter on the transmission and properly seated (on any automatic) before installing it. Never attempt to install an automatic with the converter on the engine. You are just wasting your time and possibly your money.

Charles
 

Ron2109

New member
Got the seal out by building a mini slide hammer. Behind the seal was a ring which I assume is the pump bushing. There is a little bit of play where the bushing rides in the case but the bushing fits nice and tight on the torque converter shaft. The torque converter shaft that drives the oil pump shows a little bit of wear near the slotted end also. The inner drive spline (small) has some play which I assume is normal. I assume these were the points Dennis wanted me to examine. Does this wear seem acceptable and I can I tap in the new seal and refit the transmission at this point? Is it better to remove the Torque converter which is still attached or better to just refit the tranny to the torqe converter in place?:thinking:
Hello. Did you ever figured out what was wrong? I'm having the same issue. I replaced the seal and put it back in and same problem. Now I didn't see that orange you said. Is it inside behind the seal?
 
Here are a few pic's from when I replaced the transmission input shaft seal on my 2006 van. The orange I believe is the bushing surface behind the seal.

Like you, replacing the front seal fixed the leak, for only a short time. So, for now I have a "Drippy" transmission. Which I've been told is something that comes with age...

Jokes aside, this didn't fix the problem only eliminated the idea that it was an old hardened or worn seal. Van and transmission have 200K miles.

Drives and shifts perfectly. For now....

I have not figured out what is wrong, or causing the leak. I do know that the solution is going to be $$$.

Transmission Seal.jpg
 

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