Transfer case and transmission... DOA?

naturist · **Posted:** Tue Dec 13, 2011 8:28 pm

Neutral/Park makes perfect sense to me. The key here is that you don't want anything in the tranny to spin, and all it takes for spin to happen is for there to be a rotating piece barely touching one you don't want to spin. A little oil or tranny fluid in that gap, and unless locked down, things are going to spin.

I'm sorry to hear this happened to ya, Geordi, but I'd let the "old man" know he's fulla brown/smelly. Well, ok, be nice, uh-hum, "dad, I'm sorry, but that doesn't work with a KJ."

OldSkull · **Posted:** Tue Dec 13, 2011 10:33 pm

Sir Sam wrote:

If it was a 2x4 it would have needed the drive shaft pulled or the vehicle put on a 4 wheel dolly.

To tow: transfer case in neutral, trans in park.

The last time we tow a car behind a RV it was a "Manual" rear wheel drive Datsun 510 station wagon! :ROTFL:

To be honest I got no memory of what my Dad did to the "red wagon"! Since that all other goes on 4 wheel dolly or on flat bed towing as far I can remember...

I prefer learning your advices reading this thread then the way Geordi learn it... :banghead:

geordi · **Posted:** Wed Dec 14, 2011 11:31 am

Old skull: cute. But maybe you missed the part where I said this was NOT the first time I had towed it this way, I know others have.

The CRD has been pulled over 4000 miles with both in neutral, and possibly some miles with the transmission in park and the transfer case in neutral.

Something different happened this time, this was way beyond just fluid coupling. I suspect somehow the transfer case re-engaged itself, for reasons that I do not know yet.

tjkj2002 · **Posted:** Wed Dec 14, 2011 10:42 pm

geordi wrote:

Old skull: cute. But maybe you missed the part where I said this was NOT the first time I had towed it this way, I know others have.

The CRD has been pulled over 4000 miles with both in neutral, and possibly some miles with the transmission in park and the transfer case in neutral.

Something different happened this time, this was way beyond just fluid coupling. I suspect somehow the transfer case re-engaged itself, for reasons that I do not know yet.

Both serverly overheated this time,most likely due to broken down fluids from other tows the wrong way.That degraded ATF will rise in temp real fast compared to new ATF and degraded ATF can not protect anything let alone lubricate anything.Heat kills ATF real fast,going over 300 degrees on the ATF reduces it ability to lubricate and protect to less then 500 miles and why if you have a in-radiator trans cooler and you overheat the engine you must get a trans flush down also.Then all that heat melted plastic parts like the t-case sensor and most likely the shifter bushings also which explains the lack of being able to shift the t-case afterwards.Don't forget alot of other little gizmos and gadgets in the trans and t-case have plastic parts also.

It was a cascading effect that ended in severe damage this go around when the components could not take the abuse they were not designed for.

geordi · **Posted:** Sat Dec 17, 2011 6:34 pm

Update from the dealer - taken with a BIG chunk of salt:

The transfer case is intact and seems to be just fine, the fluid was not burned OR low. The transmission itself is seized from being spun (possibly in low, but I doubt it) without lubrication, but we knew that already. The fluid in the case was in a condition they would have expected, given the age of both the vehicle and the mileage. (which is hilarious they would say this, as I do not believe that fluid has ever been changed - Ok, so I admit that I did that part wrong.)

So what did they find as the cause? The service writer says that the tech followed the cable for the transfer case shifter and found that the cable sheath is missing sections, and the cable itself seems to be splayed out and damaged where the sheath isn't present. The tech also supposedly was able to shift the case manually between each position and it behaved completely normal. He verified this by turning the input shaft manually. If this is true, then the transfer case simply transmitted the force from the rear driveshaft into the transmission without accepting any damage itself.

To me, this indicates that the cable may have been broken internally. When I pulled the lever into neutral, I did feel the case unlock, but the cable might have gotten stuck against the sheath internally and bunched up creating a pressure point. With the bouncing of the highway, that pressure pushed back against the cable and pushed the transfer case into gear. Possibly 4-full-time, but that doesn't really matter. The trans became mechanically engaged to the rear wheels and spun at some speed without lubrication. I do not see any way that having the transmission in park OR neutral would have made a single bit of difference in this case, the result would be the same either way - destroyed transmission. Tell me why I'm wrong if you think so.

I've already had a cable-in-sheath fail like this on another Chrysler product, and it also failed without any warning by breaking internally in a similar manner to what I described. That was much less destructive however, as it was the hood release cable on a (then) 4 year old minivan. We had to cut the grille out of the front to get into the hood.

At this point, I'm cautiously optimistic that they are correct about all this, but I will be looking for myself on Monday when I can get there. More to come.

retmil46 · **Posted:** Sun Dec 18, 2011 11:31 pm

Ummm, from what I've been told, the type of plastic they use for the electrical connectors on the tranny has a melting point of around 500 F. :shock:

Are they checking out the engine as well? That little mention of starting the engine, then getting huge cloud of white smoke and the stench of burning fluids doesn't sound good. IE - tranny may have reached somewhere close to 500 F - tranny bolted directly to engine, metal to metal heat transfer - engine not running, no oil flow and no coolant flow.

geordi · **Posted:** Sun Dec 18, 2011 11:44 pm

I agree with you about that Mitchell, but the smoke / smell was from the burnt clutch and the trans fluids. I only ran the engine for a few seconds, but it sounded fine and started right up without argument. I also took the time before attempting the start to check each of the fluids, and the oil dipstick tube wasn't smoking... The trans tube was.

Don't forget that the bell housing and the torque converter separate the trans casing from the engine, so while some heat may have transferred, it shouldn't have been as much as all that. According to the service writer, the sensor that melted off was the speed sensor, which (IIRC) mounts near the back of the transmission near the output shaft. It makes sense to me that the hottest area would have been back there.

I am making arrangements now to extract it from the dealer tomorrow and drag it home (sans driveshafts) to the mechanic / transmission shop that did the labor to replace the engine.

geordi · **Posted:** Thu Dec 22, 2011 2:23 pm

OK, here is a link to the pictures I got today after dropping off the replacement transmission to the shop. Sorry, they are iphone pics, that was all I had with me and my iphone doesn't have a flashy light.

http://www.dropbox.com/gallery/5447172/1/trans?h=bc5e80

The first 2 pics are the entertainment in the pan. "Chunks" or "steel oatmeal" are both apt descriptions of the carnage in there. The mechanic who pulled the pan described it as "The entire transmission is IN the pan" to me. They also are all of the opinion that the dealer did not even drop the transmission pan during their "diagnosis" and simply charged me whatever they wanted. Avoid Jacksonville Chrysler like the plague.

The pictures of the innards of the pan, look at the spin-on filter! The heat was so intense in there, I think the fluid boiled and cooked the coating on that filter. Wow. Picture #5 is where the speed sensor melted off, the hole is plugged with plastic carnage. The last picture is the transfer case shift cable, which is out of its sheath... But does not really look "splayed out" like the dealer suggested. It is the opinion of this shop (who I know and trust) that the dealer did nothing more than visually inspect it from (or on) the ground.

racertracer · **Posted:** Thu Dec 22, 2011 4:33 pm

Geordi,

You need an excorcism.

geordi · **Posted:** Thu Dec 22, 2011 6:01 pm

If it wasnt for bad luck, I might not have any?

Just left the mechanic, he called me b/c he wasn't sure about something with the TC... I'm glad he did. The TC is going to be sent out to a dedicated TC shop now, but it looks like the cable is another result, not the cause... And there is yet another thing the dealership lied about checking. They claimed that the tech shifted and rotated the driveshafts and all was normal. Not when the front shaft wont lock to the rear in any mode, and only "binds" like it is locked, but falls away from the motion of the rear shaft with just hand pressure. That was in PT and 4LO.

The saga continues, but it is looking now like something in the TC came apart and pushed it back into gear, which may have moved the handle and did kill the trans.

tonycrd · **Posted:** Fri Dec 23, 2011 10:44 am

Geordi, you need a rabbitsfoot, a horseshoe and a 4leaf clover in your KJ.

On the topic of putting it in P or not, imo if you put it in P and something like this happens you would at least feel it, the tires would lock up. (dunno for how long and if or when the lock pin in the gearbox gives)

You must notice that, it will slow down your tow rig big time.

:2cents:

geordi · **Posted:** Wed Dec 28, 2011 1:00 am

Tony, I'm not sure that I would feel the bump, OR that the parking pin could hold enough that the wheels would lock up from turning at 50+ mph. I think the parking pin would just shear off and be another casualty.

I have just gotten an update today from the transfer case shop - The case is toast, but it *could* theoretically be rebuilt. I have not decided whether to rebuild it or just replace... That will depend what I can find in boneyard options.

According to the shop, the fluid was black. There's another thing that the dealer lied to me about, they said the fluid was "normal" and what they would expect. The fluid should be red, like normal ATF+4.

I don't have a complete idea of what happened yet simply b/c I have not yet seen the damage in person and taken any pictures.
It would appear that the one of the two sets of gears that are used by the selector has been damaged, such that half the teeth were ripped off of one gear. At the same time, there are several collars as part of the selector system, and at least one of them is now at an angle and badly worn away out of round to about a 45 degree angle. I don't know if that is something that could have happened in just the 30 or so miles of this tow, but according to the tech, if the shaft moved and re-engaged the stationary gears to a 50mph spinning set (the output sets) it could easily do that kind of damage, but would feel like hitting a pothole - So not terribly obvious when in a truck.

If the shaft then stayed engaged, linking the output shafts to the transmission, either driveshaft (whichever one that didn't have the gear teeth ripped off) could easily provide enough force to spin the transmission to its death.

The real question is was this something that could have been prevented or was it a freak accident. At the moment, with 4000 miles of towing successfully and less than 40 leading to disaster... It leans toward freak accident. Nothing was in the vehicle to fall onto the selector (I did check that first on scene!) and the only plausible answer is the rings on the selector shaft within the transfer case. If they were already worn and allowed the shaft to slide past the forks... That could easily explain how the casing re-engaged itself.

More to come when I can take the pictures.

bunkermonkeycw · **Posted:** Wed Dec 28, 2011 7:57 am

PM one of our members, USAFCOP. He has one, was for me but I don't need it now.

tjkj2002 · **Posted:** Wed Dec 28, 2011 8:31 am

geordi wrote:

The real question is was this something that could have been prevented or was it a freak accident. .

100% preventable if you had flat towed it correctly from the start.Don't come back and say "well I towed it for 4000 miles like I did before without issue",it took 4000 some odd miles of towing it wrong to blow everything apart.

T-case in "N" and the trans in "P".

geordi · **Posted:** Wed Dec 28, 2011 2:37 pm

tjkj2002 wrote:

geordi wrote:

The real question is was this something that could have been prevented or was it a freak accident. .

100% preventable if you had flat towed it correctly from the start.Don't come back and say "well I towed it for 4000 miles like I did before without issue",it took 4000 some odd miles of towing it wrong to blow everything apart.

T-case in "N" and the trans in "P".

I will ask you this question again, since you failed to respond before. How would having the transmission in park have changed ANYTHING about this, since the failure STARTED in the transfer case which was properly in neutral?

As I suspected and had confirmed by the transfer case shop, the internals of the transfer case are not in working order, thus passing the rotating force from the wheels back through the engaged gearset to the transmission.

The transfer case should not have been engaged at all, since I put it into neutral as is correct.

So answer my question: if the damage started in the transfer case, how would the position of the transmission make any difference at all? Or you can ignore me, and just continue proving you are a troll. Your choice.

bunkermonkeycw · **Posted:** Wed Dec 28, 2011 3:08 pm

Because DC says so. I'm sure physics do also, Im thinking you were just lucky the first time around...

Edit: Thinking more with both in neutral there is nothing stopping them from spinning up on their own... makes sense I'd say.

geordi · **Posted:** Wed Dec 28, 2011 6:03 pm

Missing the point. Think about this logically: the transmission is only held in park by a small pin, just enough to restrict the force of inertia when the vehicle is parked. This is the same in every automatic transmission, the pin is maybe 1/4" wide.

You ever sheared off a bolt with too much force on a wrench? That would be exactly the same result if the transmission was suddenly connected to the rear wheels while they were 50mph apart in speed. I understand the concept of "fluid coupling" within the transfer case causing the transmission to rotate if it was not in park. This wasn't fluid coupling, this was mechanical, plain and simple. What do I believe the result would have been, had it been in park "as the DC manual says"?

Broken transfer case (what it is now), sheared parking pin... And still a burned up transmission. The position of the transmission does not matter when the transfer case is no longer in neutral. DC has no answer for this in the manual because towing is never supposed to happen with the transfer case in anything BUT neutral. Mechanical damage in the transfer case caused this.

tjkj2002 · **Posted:** Wed Dec 28, 2011 9:16 pm

geordi wrote:

Missing the point. Think about this logically: the transmission is only held in park by a small pin, just enough to restrict the force of inertia when the vehicle is parked. This is the same in every automatic transmission, the pin is maybe 1/4" wide.

You ever sheared off a bolt with too much force on a wrench? That would be exactly the same result if the transmission was suddenly connected to the rear wheels while they were 50mph apart in speed. I understand the concept of "fluid coupling" within the transfer case causing the transmission to rotate if it was not in park. This wasn't fluid coupling, this was mechanical, plain and simple. What do I believe the result would have been, had it been in park "as the DC manual says"?

Broken transfer case (what it is now), sheared parking pin... And still a burned up transmission. The position of the transmission does not matter when the transfer case is no longer in neutral. DC has no answer for this in the manual because towing is never supposed to happen with the transfer case in anything BUT neutral. Mechanical damage in the transfer case caused this.

Yeah and that little pawl keeping the trans from spinning is key.I would not have happened if you put the trans in "P" like you are supposed to.It's really that simple.Once the trans started spinning internally the ehat produced was tranfered directly to the t-case which then self destructed due to overheating.

That parking pawl is far stronger then you think,it will hold your vehicle in place on a steep hill.No way to damage that pawl when flat twoing with the t-case in N and trans in P.

Transfer case and transmission... DOA?

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