Major trans leak, stranded on road 500 miles from home. Trans went into limp mode while climbing with OD offf. I thought my temps were a bit higher than normal this trip, but didn’t think too much of it.

Pulled off, dipstick dry at idle in park. 2 quarts wasn’t sufficient, added total of 6. That was over full on dipstick at idle. And all the atf I had.

Temps dropped for a bit, then quickly went back to 210 and stayed there. Late at night in western NC, didn’t find a place to get more atf. After about 50 miles, temps went up a bit more, so I pulled over. Dry dipstick again.

So what are my likely leak locations? I’m pretty sure I have some seeps where cooler hoses connect to the hard lines back to the trans, but that’s an awful lot of fluid to lose with the hoses still on the lines. I will tighten those. I have a lot of fluid on the pan, so I will check pan bolts. But it looks like at least some of the pan fluid came from on top of the trans. Would that be the vent and where some of the overfill puked out?

Last and worst case candidate- torque converter shaft seal. Would this be something that would leak quarts per hour? Would a bad seal leak be obvious if I pull the inspection cover with the engine off?

Ah, the fun of tris trip. Selling house and moving in early June, so this trip I’m bringing down 19’ powerboat, canoe and 3 kayaks on the cab racks, 3 kayaks and a bunch of other stuff in the bed, rear seat full, front cargo carriers loaded, and lines from bumper over hood to boats on top. So I have to untie the bow lines to open hood to check transmission, and tools are buried under the rear seat. Oh, and it rained so I’m crawling on wet asphalt to look for leaks. I was too happy with how the hole rig was driving… so karma intervened.

 

My guess would be the front seal. I'd pull the cover. Is the transmission working ok now, just leaking?

 

Got rescued by a buddy not long after midnight. Left truck at a rest stop 45 miles from destinations.

Symptoms are hot fluid, blinking OD, and dry dipstick. Transmission working fine otherwise, except for a few slightly harder shifts. Will be going back this morning to evaluate, and see if I want to try and limp it to a repair shop or need to get it towed.

taking tools to tighten hose clamps and pan bolts, and remove inspection cover. Will be stopping at tractor supply and/or Wally world for ATF, and a rise drawbar so I can tow powerboat away with my Cherokee that’s already down here. If pick up is towed, I need to get the boat trailer, canoe and kayaks on top, and front cargo carrier off it. Wish me luck…

 

give those cooler lines a front to back look over, there's a lot of pressure in them and only need a pin hole and a short time to pump a trans dry, if it's the front seal you will see a super wet spot from inside the bellhousing area

 

My recollections crawling under the truck about 1130 last night on wet asphalt…

Definitely wet around the trans pan, but I suspect that might be excess fluid puking out from my initial overfill. I stopped once, put in about 6 quarts, then drove about 50 more miles before abandoning it at another rest stop. Roughly 2 quarts still had the dipstick dry idling in park. I added the next gallon, and that definitely overfilled. Figuring fluid on the pan could be overflow from top of case. Not spillage, I used a long funnel.

Oil pan is very wet, looks like from stuff coming from farther forward. I just had new steering box installed, so some fluid is from that.

I also know I have seeps around the soft cooler hose to trans hard line connections.That would also blow back towards the oil pan.

trans hardlines and their connections to the pan seemed dry.

We will see what I can find in daylight.

 

good luck man. if in any doubt tow it don't drive it,

 

Also check the trans oil dip stick tube, the tube might of come out the trans.

 

So the leak seems to be… not?

Got back to truck this am, crawled under with hood light, removed inspection cover, and no smoking gun. Now believe no leak, and issue is restricted flow through coolers.

Interior of inspection cover was dry and rather clean. Lip inside bellhousing had some old grimy fluid, but that didn’t overflow into the inspection cover, and I figure is allowed seepage 100k of service.

Some fluid obviously came out of vent onto trans pan. Dipstick and cooler line fittings at case looked good. A few pan bolts could have been tighter, but only one loose (stripped) and no adjacent bolts were issues.

Two hose clamps at end of hard lines from transmission case are suspect. I tightened them as much as I could and will replace them. One or two others could have been a bit tighter, but these seem to be long term seep rather than fluid loss. There are signs of seeps from above at the bottoms of some hose loops.

Oil pan has fluid over quite a bit of it, but I’ve never been good at wiping things off. This could just be age-related minor incontinence over time

We checked fluid level at idle, and after reving engine in drive with brakes and chocks applied. Fluid was more than full, without adding any. My 11:30 pm in the rain check appears mistaken. Pulled negative terminals to clear any codes. I don’t have a reader.

Slowly driving to destination. Trans is acting normal, but temperature slowly climbs, even idling down a hill. Stopping go for cooling beaks before 210 deg fluid temperature. The cooler soft lines are not as hot as I would expect for that temp, and cool to ambient very quickly,


So it looks like it’s a cooling flow issue.

Plan is to drop pan tomorrow, change fluid, and blow out cooler lines with compressed air. Hopefully that fixes the issue. But I also saw somewhere that there is an internal cooler bypass valve that could fail or trip and block cooling flow.

So the story isn’t over yet.

 

Not in an E4OD. There is no internal cooler bypass. That started in 2003 with the 5R110W.

 

I noticed mention of “front cargo carriers”. Were these restricting airflow to the radiator and trans cooler?

 

I don’t believe the carrier was an issue. Engine coolant temps were not out of line even when I was pushing it. Carrier sits well forward of bumper, so there should be good turbulent airflow around cargo and through all cooling devices.

Most telling was that the soft lines connecting the two aftermarket coolers, which I can easily reach, did not get nearly as hot as I expected for 210 deg trans fluid temp (sensor in port on case), and quickly cooled to ambient. The best explanation I can come up with is that there is a major blockage somewhere, and little fluid is flowing through the coolers.

My cooler setup is first through stock radiator cooler, then through two additional fluid to air coolers in series and back to transmission. The additional coolers and connecting hoses are much larger diameter than the hard lines, so additional resistance to flow should be minimal. This setup worked well for years.

 

So I’m pretty sure I’m NOT leaking.

Dropped pan, changed fluid and filter. Disconnected cooler lines, at the forward end of the hard lines from the transmission. Blew 40 psi air through coolers and hard lines back into trans. Coolers and top (feed?) hard lines definitely clear. Bottom hard line spit air and fluid back at me, like it was blocked, then seemed to spit something into the drain pan and freed up.

Fluid looked ok, did not see any glitter or sludge. Some color on the pan, just enough to stain fingers and paper towel. Very little around the magnet. It’s been a while since I dropped pan and changed fluid, so I’m figuring this is normal wear.

Took a test drive, about 30 minutes and 25 miles. Highway speed on hills, and hill-and-dale curvy. 2nd, 3rd, 4th, multiple shifts and torque converter lockup. Temps slowly got up to 180, but that was finishing the drive on a twisty 25 mph back road. Cooler hoses were hot to the touch, which is a change from before.

So… I am going to try and return on Tuesday, 570 miles with unloaded flatbed (~500 lbs) and no load.

 

my 96 f350 was doing this it was a rub on the metal lines to the trans cooler.. just behind the rad those lines rub against the crossmember . I patched in two inches of fuel line and clamped it down. No fluid loss or problems since . Hope that helps

 

I would be interested to know what it spit out. Maybe a rubber line is breaking down on the inside and depositing debris in an area that is flow restricted.

I am glad it is doing better. Hopefully it stays that way. Be careful heading back.

 

So I'm back home with no drama. 570 miles with unloaded 5x8 flatbed. Here's what I think happened, and what I think I learned.

• Almost certain I did NOT have a leak. Level checks in good light not under stress and the amount of fluid I got out of pan when I dropped it and blew out everything did not show low fluid.
• Almost certain I had a blocked cooler line, specifically hard return line to transmission. Under 40 PSI of air, it acted like it was blocked then something spit out the trans end. Also, the cooler soft line that I could easily check without getting under front of truck was only mildly lukewarm and quickly cooled before blowout and with fluid temp gage at 210. After blowout, it was uncomfortably warm at 180 fluid temp.
• Believe that I misread hot fluid level at night and under stress. I'm used to checking cold, when fluid really sticks to the dipstick. Afterwards, I realized that hot, little fluid sticks to the dipstick and you have to carefully check the cross-hatches. That's much more subtle, and I think I misread it several times.
• One-time minor slip can set OD light flashing, so flashing OD light is not necessarily a death sentence for the transmission. I was worried I killed the transmission. Now know that figuring out how often the code event happens is very useful.
• My normal driving style and load usually keeps temps about 155 to 160. "Nervous" highway traffic... a lot of on-and-off throttle (and torque converter lockup) will push 180 even at light payload. Trailer, a lot of air drag, and long climb will push temps higher. So I usually run cooler than most, and observed temps under adverse conditions are still not out of line.
• My transmission probably isn't very robust. Its a Jasper reman, with 100 k to 120 k miles on it. Good enough for most of my conditions, but needs to be babied when I add more load. And my "more load" is still way less than what many of you are pulling. Eventually, there may be a BD or ATS in my future.
• I panic easily when things go wrong... especially late at night, in rain, far from home, and away from services.

Thank you all for putting up with me. Hopefully this helps someone from NOT assuming the worst when the OD starts blinking late at night in the rain.