Transmission output shaft blown from new fluid

Isla

Member
This has to be one of the heaviest nights of my life, which probably means I've had a pretty cushy life... but still the pain is visceral. Changed the tranny fluid on my 2003 sprinter with 200k yesterday and 400 miles into a 1400 miles trip it looks like that produced major leaks in my output (correction, input**) shaft seal. The leak is coming from the two rubber plugs below the torque converter, I checked the torque converter drain and it really does not appear to be coming from it, also it is coming faster than I would imagine a leak around the washer could. I ended up getting ahold of the local sprinter mechanic and he told me from the description i almost definitely damaged the seal. Besides being stranded i'm in shock. I guess I'm just looking for consoling words or advice. Im stranded new Benton Illinois if anyone with knowledge wants to take a look for me. Other wise I'm just gonna try and keep feeding her fluid until i make it home. I sure hope this isn't it for me and this forum, you guys of been beyond helpful and patient with the 70 questions I've asked over the last two months. Can't tell you all how much I appreciate it. If anybody's got extra send some good juju my way, I'm gonna need it.

-Alex


Sent from the first city on the Mississippi.
 

Isla

Member
Was too frazzled when I wrote this to realize I said output shaft when I meant input shaft


Sent from the first city on the Mississippi.
 

220629

Well-known member
Re: Transmission input shaft blown from new fluid

Sorry to hear.

What that you did would damage the input shaft seal?

Even incorrect fluid won't damage a seal that quickly... maybe over the very long haul, but I question even that.

Are you certain that it isn't the TC plug copper washer being missing or damaged? The TC is under quite a bit of pressure. It can spray out. Why is the input shaft seal under that much pressure and leaking so badly. It should only see the very low sump pressure. If bad, I would expect that seal to more just seep.

If you find that the copper washer is damaged or missing, any fiber or composition washer should work for the short term. Even a small piece of dense cardboard from a paper pad cut to shape will crush down and seal for the short term.

Above all do not run your transmission low on fluid if try to limp home.

:cheers: vic
 
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smiller

2008 View J (2007 NCV3 3500)
I also don't see how you could have possibly damaged the input shaft seal just by changing the fluid. More likely you have a leak at the TC drain plug and if it's just a missing gasket ring as above then that will definitely be your good news for the day. :smilewink:
 

220629

Well-known member
Re: Transmission input shaft blown from new fluid

As to fluid in your emergency situation. I would use MaxLife™ without hesitation. I know some T1N owners who use it exclusively for the their fluid changes and they are still on the road with many miles under their belt.

...

You will typically not need to top off. If you need to add because of some leak/emergency the Valvoline MaxLife™ DEX/MERC ATF is formulated to MB236.10 specification. It is readily available and will work just fine.

vic
 

MikeP

Member
If you have not gotten that Sprinter guy you wrote about in first post or a transmission shop to check it out, please do! Or if you can get at it check everything you touched, clean dry best you can and see if you can spot where exactly it's leaking.
We had a transmission rebuilt in a Chevy van right before a 1200 mile trip. Going we went at night got daylight and noticed we had transmission fluid covering backend of van. Looking under van had fluid all over underside of van, too!
My first thoughts were very bad! Spent money on rebuilding transmission and more than likely have to buy a rebuilt one to get home.
Stopped at AAMCO Transmission Shop. The cheap shop I got it fixed in Oklahoma had not properly tightened the pan bolts. AAMCO had it fixed and back on road in matter of acouple hours and a few dollars for fluid.
 

Isla

Member
Basically I don't see any other option for where it's leaking from. I don't buy TC drain because I've lost 3 quarts in 600 miles. The TC drain washer that I used had only been used once before and had not been over torqued to my knowledge. The diagnosis on the input shaft was given to me by a mechanic like I said near Effingham Illinois. Said he had been a mechanic for 40 years and worked on every sprinter out there. Said that out of 100 vehicles that get a tranny service 70 of them go out within a month. Basically the idea is that Input seal is slightly worn and with the introduction of clean fluid that is much thinner, moves faster and thus gets hotter, cracks can turn in the leaks. With the amount that I'm losing and the location is coming from this seems rather plausible. That said i'm all ears with other possibilities.


Sent from the first city on the Mississippi.
 

220629

Well-known member
... Said he had been a mechanic for 40 years and worked on every sprinter out there. Said that out of 100 vehicles that get a tranny service 70 of them go out within a month.
...

Sent from the first city on the Mississippi.
One guy's opinion? :idunno:

He claims a 70% failure rate of Sprinter input seals within a month of transmission service? :hmmm:

If that were true then I would expect to see many, many posts (with warnings) here and in the Jeep forums complaining about NAG1 transmission seal failure after a fluid change. I don't recall ever reading about even one input shaft seal with a major leak. Most any NAG1 fluid leaks I've read about are related to the electrical connector in one way or another.

Good to hear you have things under control.

Good luck. vic
 

smiller

2008 View J (2007 NCV3 3500)
The diagnosis on the input shaft was given to me by a mechanic like I said near Effingham Illinois. Said he had been a mechanic for 40 years and worked on every sprinter out there. Said that out of 100 vehicles that get a tranny service 70 of them go out within a month. Basically the idea is that Input seal is slightly worn and with the introduction of clean fluid that is much thinner, moves faster and thus gets hotter, cracks can turn in the leaks.
That statistic is outright silly. If a mechanic told me that I don't think I'd be inclined to trust anything else he might have to say.

While it is possible for hydraulic systems (brakes, transmission, etc.) that have gone far beyond proper maintenance intervals to develop deposits that new fluid can act to dissolve and cause subsequent problems that certainly isn't the first place I'd look in your case. Going from not leaking at all to an enormous leak instantly and solely as the result of a fluid change is just unlikely in the extreme.
 

talkinghorse43

Well-known member
Gotta say I agree with the TC drain plug being the probable culprit. Whenever I do any work on my van and something unusual happens after, I've learned to automatically assume I did something wrong. After all, you removed and reinstalled the drain plug, but you didn't actually touch the input shaft seal. Think about it, what's the likelihood that something you didn't touch would fail? Plus, you can't see the drain plug while the engine is running (pressure inside the TC is high), so it may not leak when not running (no pressure inside), but could easily leak while running.
PS - it's not an easy place to access, so I would consider that the drain plug might have been cross-threaded when installed, resulting in non-parallel seats
 
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Isla

Member
The statistic does seem silly and when he told me that I felt like he was exaggerating, but I've also heard a lot of mechanic say things about if you don't know the service record of the transmission you shouldn't just jump into changing the fluid. If I'm hearing you all the only option is the drain plug and I'm happy to believe that. I'll let you guys know what it turns out to be once I get this thing home.


Sent from the first city on the Mississippi.
 

talkinghorse43

Well-known member
Thinking more this AM, I wondered what the pressure of the fluid might be inside the torque converter when operating. So, I went to a centrifugal force calculator on the web and plugged in a radius of 8 inches (don't know what the diameter of the torque converter is, but 16" doesn't seem unreasonable) and a rotational speed of 2000 rpm. The calculator spit back a g-force of 1000 g's. So, if the pressure of the fluid (due to its density alone) at rest at the inside surface of the torque converter is only a fraction of a psi (don't know the liquid depth, but 30" deep would be ~1 psi), it's still going to be ~100 psi (assuming 4" depth) at the drain plug when operating at even that low rpm. So, the TC drain plug needs to be well-sealed - it's not like the tranny sump drain plug (or the engine sump drain plug) where the pressure is basically nothing.
 

Isla

Member
Wow. Awesome math. The whole centrical force thing got me thinking that when I looked at the drain to see if that's what was leaking I didn't account for how a drip would look from something spinning. A drip while spinning would i assume instantly get thrown off the converter onto the walls of the bell housing leaving the converter dry.


Sent from the first city on the Mississippi.
 

220629

Well-known member
Wow. Awesome math. The whole centrical force thing got me thinking that when I looked at the drain to see if that's what was leaking I didn't account for how a drip would look from something spinning. A drip while spinning would i assume instantly get thrown off the converter onto the walls of the bell housing leaving the converter dry.


Sent from the first city on the Mississippi.
It isn't at all a static environment.

Hydraulic fluids including ATF are fairly thin. My general experience with hydraulic fluid leaks and spinning equipment is that, between the spinning parts and air currents, the fluid gets thrown all around. That makes tracing leaks sometimes difficult.

vic
 

MercedesGenIn

Mercedes-Benz Resource
The only time I haver known a trans fluid change to damage TC front seals is when a back street garage did a 'flush' on an acquaintances S class saloon and the engine was left running too long without the correct quantity of fluid - basically the heat built up in the TC to such an extent that it simply fried the front seal. If you filled to the correct level I would just put it down to bad luck, as nothing you could have done in dropping the pan and servicing the box could have caused damage to the TC seals in my opinion.

Isla/Vic's, comment regarding the reported high number of failures of trans units after fluid changes - I have often wondered if all the clutch particles and other grime that builds up in the fluid actually plays an active part in helping to mask failing clutch parts within auto gearboxes. Changing the fluid and removing these suspended microscopic particles just tips the box over the edge. (this is of course attributed to slippage and shifting and not leaks) Its true to say that carbon particles that naturally build up in engine oils soon after it is changed, do actually form part of the lubricant, being surrounded by 'spirals of lubricant' and themselves becoming a component part of the lubricant. I wonder if the same can be said of transmission oils. - Interesting muse.

I do realise that I am probably putting my head on the block here, but MB did move stance from their once 'sealed for life auto gearbox/transmissions' to big-mile fluid changes on their passenger cars etc. Perhaps there was some original basis for this thinking, that modern oil and manufacturing technologies changed (or even perhaps marketing/service trends!) - Maybe the adage 'don't repair what aint' broke is maybe really not the thing to say in hindsight of the OP's tranny service.

Talkinghorse43 is correct, in tranny pressures can be highish plus fling. - A bit of reading revealed that the TC oil charge pressures range from 207 kPa to 1241 kPa ( 30 to 180 psi ) across a few different transmission models. This is a very good read if you are interested - http://what-when-how.com/automobile/torque-converter-automobile/

All the best
Steve
 
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talkinghorse43

Well-known member
The article referenced above states that the TC is completely full of fluid when operating as well as being under pressure from the transmission oil pump, so the pressure the TC drain plug sees is substantially greater (>2x) than my estimate. So, it pays to be very careful with the TC drain plug when changing tranny fluid.
 

Isla

Member
Made it home, lost 4-5 qts on the way. Checked ever 50 miles and kept the level good. Still waiting to get someone over to help me with the cranking procedure so i can check the tc drain.


Sent from the first city on the Mississippi.
 

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