The weirdest mechanical failure I’ve experienced (1 Viewer)

[Just Diddly]

Just wanted to post this up in case it happens to anybody else as I couldn’t find a thread on this anywhere.

Currently, my 93 FZJ80 has the front driver tire removed and is on a stand because I have to drain the coolant to replace my thermostat and PHH and am going to be changing out some other hoses as well (I posted about it all a few days ago) and I started the rig up as it hadn’t ran in a few days and when I turned off the rig I looked down and I was quickly leaking a lot of transmission fluid from my dipstick tube (I need to replace the o-ring) and I pulled the trans dipstick out hoping to relieve some pressure BUT transmission fluid starting shooting upwards, out of the dipstick tube. So I quickly put it back in and just had to wait it out until the leak stopped. Suspecting it was a ventilation issue we figured it’d be worth a call to our mechanic to get his thoughts. He said he hadn’t seen it before but also suspected it was a vent issue.

And sure enough, after a lot of looking, feeling, and cussing we were able to find the transmission breather plug (it is not easy to access at all and impossible to see without a camera / small mechanical mirror of some sort) and we found that the transmission breather hose had gotten kinked at the plug causing the pressure problems. Once we got the hose removed we started the truck, let it run, and turned it off, and the leak was gone. Still have no idea how it happened, how it could have happened, etc. as it had never been an issue before. Thankfully, it happened when the truck was already on stands for the other work and was just a hose, not the tranny itself. We’re going to use this opportunity to replace that hose and extend the transfer case & transmission breathers and fit them into ARB breather set up I did with the differentials a few months back.

Hopefully if anybody else ever has this issue they can find this, just figured I would try and provide something useful to this forum as so many of you have helped me already.

 

[Kernal]

Interesting discovery: anyone know which direction that pipe nipple (what the vent hose attaches to) is supposed to point? Or conversely, which direction should the vent hose be routed? ie: how did it end up getting kinked like that??

 

[EvanD]

I'm not familiar with the hose in question but it seems far to short for the bend it's supposed to make (as Kernal said, assuming it's located correctly).

How long is this hose overall/any idea if it's OEM?

My only guess would be, if it isn't original, that when installed the newer tubing barely made the bend without a kink and over time heat/elements/whatever else softened it enough to kink? Edit- I suppose that could be possible even if it is original.

Shrug, that looks like a mess and serious PIA but thanks for sharing!

 

[Just Diddly]

Interesting discovery: anyone know which direction that pipe nipple (what the vent hose attaches to) is supposed to point? Or conversely, which direction should the vent hose be routed? ie: how did it end up getting kinked like that??

That's my question, there are no moving parts nearby that could have induced a kink like that and it is so inaccessible I don't believe it could have been anything environmental or brought on by the elements (like splashing through water). In the diagrams for the A442F Transmission it appears as though the plug and nipple is supposed to face forward, however, my plug does have a little bit of play from straightforward to front right, I don't believe anywhere near enough to create a kink though.

 

[Just Diddly]

I'm not familiar with the hose in question but it seems far to short for the bend it's supposed to make (as Kernal said, assuming it's located correctly).

How long is this hose overall/any idea if it's OEM?

My only guess would be, if it isn't original, that when installed the newer tubing barely made the bend without a kink and over time heat/elements/whatever else softened it enough to kink? Edit- I suppose that could be possible even if it is original.

Shrug, that looks like a mess and serious PIA but thanks for sharing!

I don't have a picture, but the hose itself is over a foot long. However that whole hose system vents out at the transmission dipstick tube. I believe it is OEM as it is identical to the transfer case hose it is connected with. It definitely was a PITA.

 

[Rifleman]

I'd say you were very lucky to have discovered this problem in your drive way. If this had happened out on the trail, leading to a large lost of fluid like what's on your driveway floor, could of caused permanent damage to your transmission. I guess i now need to crawl under my truck to check out my transmission vent hose, just to make sure it's not kinked.

 

[EvanD]

I don't have a picture, but the hose itself is over a foot long. However that whole hose system vents out at the transmission dipstick tube. I believe it is OEM as it is identical to the transfer case hose it is connected with. It definitely was a PITA.

Interesting. (I know we say interesting when we read about it and cuss up a storm when we deal with it).

I still wonder if heat/age of rubber could have caused it.

As Rifleman said, I'll def be checking into mine so thanks for the heads up and glad you caught it when you did!