The Diesel Stop banner
1 - 7 of 7 Posts

· Registered
Joined
·
45 Posts
Discussion Starter · #1 ·
Two days ago, mid day and 95 degrees, a friend and I drove from DC to Western MD to pick up some hardwood lumber. We were cruising along fine and engrossed in conversation for about 60 miles, when I noticed a haze of smoke behind us. I realized we were headed over what passes for a mountain in this part of the world and I was pushing along at 70-75. I figured I was pushing the truck too hard and backed off. All the gauges read normal, but I was thinking engine, so we turned off the AC, eased up and kept going. 20 miles later, I start to feel an occasional slip. We take our exit and pull up to a stop light. Light turns green, no go.

I rolled it backwards down the hill to a gas station and hopped out to find the transmission hemorrhaging from the breather tube (is that what it is?) between the engine and trans pans. It dumped maybe a gallon or a bit less, then started to slow down. I added 2 quarts I had in the truck (I had meant to check the trans fluid level before we left and forgot) and limped 50 yards into the gas station parking lot. It spilled a little more fluid, which boiled when it hit the gravel/grass.

We let it cool for a couple hours, added 3 more quarts till it registered on the dipstick and went about our business. I took it a lot easier on the way home, now with 600 or 700 lbs of lumber in the back. It did OK, but I was pretty paranoid and it still feels a little funny. The other oddity: the oil pressure gauge went from it's normal position at about 33% to about 55%. Makes no sense to me, but it happened at the same time.

The really bonehead part is that I remembered that the truck had randomly gone into limp mode a couple times in the last few weeks. If I shut it down and restarted, it was fine, and I basically forgot about it for the last week.

I changed the tranny fluid about 18 months/5000 miles ago, but I'm assuming it's pretty cooked so I'll do another fluid/filter change this week. Anything else I need to do?

Was I really pushing it too hard to go up a 5 mile hill on a hot day at 72ish MPH and empty? I'm more accustomed to modern vehicles where that wouldn't really be a thought, and if I were towing with the 20 year old truck I'd understand, but empty? Do I need to look for a deeper problem, or was I just being dumb?
 

· Registered
Joined
·
658 Posts
If the fluid was leaking out the dust cover between the trans and engine, that is not a breather tube, it's a drain tube.
What happened was the seal on the shaft from trans pump to converter melted causing fluid to leak. The seal is only about 1/8" x 1/8" and only one wrap on the shaft. The newer seals are Teflon and take a higher temp.
If the seal has not healed itself, which they will, then the trans will have to be pulled or just backed up about a foot to replace that seal.
Any E4OD should have an auxiliary cooler, especially hauling or in Mountainous areas.

Low or overfill fluid level will cause high trans heat. Always check fluid level with engine running in Park and HOT.
Regular Dino oil is good for ~260*, Synthetic oil is good for ~360*.

The normal trans temp is around 180* to 190*. Usually the coolant temp is close to the trans temp, the radiator fan clutch should kick in at ~235* and quickly cool the rad coolant down.

You where probably running in OD, anytime the trans starts to hunt gears (OD to 3rd) take it out of OD.
 

· Registered
Joined
·
45 Posts
Discussion Starter · #3 ·
If the fluid was leaking out the dust cover between the trans and engine, that is not a breather tube, it's a drain tube.
What happened was the seal on the shaft from trans pump to converter melted causing fluid to leak. The seal is only about 1/8" x 1/8" and only one wrap on the shaft. The newer seals are Teflon and take a higher temp.
If the seal has not healed itself, which they will, then the trans will have to be pulled or just backed up about a foot to replace that seal.
Any E4OD should have an auxiliary cooler, especially hauling or in Mountainous areas.

Low or overfill fluid level will cause high trans heat. Always check fluid level with engine running in Park and HOT.
Regular Dino oil is good for ~260*, Synthetic oil is good for ~360*.

The normal trans temp is around 180* to 190*. Usually the coolant temp is close to the trans temp, the radiator fan clutch should kick in at ~235* and quickly cool the rad coolant down.

You where probably running in OD, anytime the trans starts to hunt gears (OD to 3rd) take it out of OD.
That's helpful, thanks. I don't see any leakage at this point, so im hoping I don't have to replace the seal. I'm wondering if I've got a small leak that eventually got low enough that it caused a problem. Pretty dumb on my part, but I certainly wasn't thinking I was driving outside the reasonable performance expectations for the truck.
 

· Super Moderator
Joined
·
9,147 Posts
The front seal gets soft when it gets hot. Then it leaks. Once it cools it seals again until the next time it gets hot. The only way to fix this is to replace the seal with an aftermarket seal. I don't know about Teflon seals, the good seal is made from Viton, not Teflon.
 

· Registered
Joined
·
658 Posts
Yeah Mark, my boo boo, Viton is what I should have said. Thanks for the correction.
 

· Super Moderator
Joined
·
9,147 Posts
I have never seen one pour fluid out of the vent after shutting off the truck. I can't imagine how that would happen.

Where do you see the fluid coming from?
 
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top