Modified diff vent and exhaust

[MUTT Vet]

Uh no, he's got another crazy idea!!!

I took my front diff to my mechanic so he could change the seals and sleeves for me as i don't have the necessary tools. He drained the fluid and noticed that some water was still in it from when i went fording (without the fording kit).

We got to talking and we came up with an idea. Take the diff vent off and replace it with a water tight 'T' coupling and then run stainless steel tubing from it up the inside body and out the wheel well and then encase the end so dirt can't get in. The other side of the 'T' would be capped and used with the actual fording kit.

The front diff line could be ran up into the engine compartment. It would be necessary to make both lines at the same level as the air intake.

I told him that i keep getting leaks in my exhaust pipe underneath where it bolts together because i keep hitting it on stuff when i'm off roading. He said it would be simple to weld the sections together. I have the stainless steel exhaust.

He said the tail pipe could be relocate to route up inside the body through the wheel well and come out right next to the trailer connection. It wouldn't stick out but be flush with the body. We could fabricate a shroud that would hide it and not allow too much debris from entering. The body would have to be cut into a little but it could be welded back later if i wanted to change it.

With the diff vents and tail pipe at the same level as the air intake, i could ford about 32 - 34 inches of water without the fording kit.

Feasible?

To ease everyones mind, i plan on buying another A2 and restoring it to military specs for shows and parades so i will feel better about myself at night about modifying my current MUTT. Plus i won't have to worry about any of you guys from sending a "cleaner" after me!


This isn't covered in any TM so I'm asking the pro's and yes even 'k8icu'!

[Horst]

Eric,

My fording kit has no connection to the differentials at all and also the TM coming with it did not show anything. Maybe there is a later version having that but I doubt that.

What the fording valve does is creating a small pressure in the engine so that water would not enter. I would believe if you would have a source of pressure and connect that to the differential vents, that would be even better than your current idea of bringing the vents above the fording depth. Some trucks like the Unimog have it done that way.

[MUTT Vet]

Horst,

My fording kit has no connection to the differentials at all and also the TM coming with it did not show anything.

Here's what Rick said earlier:

You got water in the vent. The Fording kit should have a line from you diff vent to the air intake, before the filter. Water is heavier than oil and it displaced it.

The diffs in these vehicles get very hot very fast due to the low ratio. When you dive into cool water the diffs cool of very quickly which means the fluid and air in the diff contracts and has to pull in fresh air. If it is under water it will pull in water instead. Even with a fording kit if the vent is clogged or if you go deep enough or even just as I said about the cooling. If it tries to pull air faster than the vent will allow then it will pull water past the seals.

I would believe if you would have a source of pressure and connect that to the differential vents, that would be even better than your current idea of bringing the vents above the fording depth. Some trucks like the Unimog have it done that way.

What would i use to set up that pressure inside the diff? Would i use a vacuum line from the engine or would it have to be a separate device?

[rickf]

Eric, I didn't write the first quote but if you extend the lines as mentioned to a high enought point to stay out of the water then that would solve a lot of the problem. Putting vacuum to the diff would just pull water in past the seals. A very small amount of pressure would also work. The fording valve on the engine closes off the PCV valve so now the blowby from the pistons pressurizes the engine. Thi will not allow water in but it will cause some seals to leak a little. Nothing to worry about because you only have the valve closed while fording and open immediatly afterwards. If you are mashing the exhaust then you are also mashing the driveshafts! The exhaust is above the shafts just about the whole run. If you have stainless exhaust then it was made aftermarket and probably not in the stock location. If you are going to modify it then go all out and mount the exhaust on top of the fender! Man I hate to say this but it sounds like I am trying to build a hybrid rock crawler / mud buggy online without touching a torch! I think I have covered everything on this mutt in the way of modifications from the suspension to electrical to the engine to the exhaust and fording possibilities to skidplating!

Rick

[MUTT Vet]

Sorry Rick, I mis-quoted you. The first quote was from 'cstaup'.

If you are going to modify it then go all out and mount the exhaust on top of the fender!

If i mount it on the fender then that will definitly change the look, it's important that any of the mods i do still keep the stock look of the MUTT as much as possible. If i run the exhaust up the body into the wheel well and out by the trailer adapter then it will be hidden.

If you are mashing the exhaust then you are also mashing the driveshafts! The exhaust is above the shafts just about the whole run.

Where i keep finding the leaks are right where the exhaust bends around the rear end area. That's the only place i've found any major leaks. I guess that when the pipe gets hit there it might pull the pipe a little and make it leak where they bolt together. I don't have any sign of significant damage to my driveshaft.

If you have stainless exhaust then it was made aftermarket and probably not in the stock location.

The exhaust came with it when i bought it at Nellis AFB. It was still sealed in the package and it said stainless steel and it definitly looks like stainless, i've had it one for about 5 years and i don't have any major corrosion problems on it. I put it on myself.

Man I hate to say this but it sounds like I am trying to build a hybrid rock crawler / mud buggy online without touching a torch! I think I have covered everything on this mutt in the way of modifications from the suspension to electrical to the engine to the exhaust and fording possibilities to skidplating!

You've been an awesome help Rick, i really appreciate it. I've taken just about everything you've suggested and gone with it. I am slowly modifying it, but only after i've gotten semi-approval from you guys. I just want to have a unique vehicle that i can pass off to my kids and that they can keep maintaining it with less hassle.

Since i'm being sentimental and have that warm fuzzy feeling (i'll try not to let it happen again), thanks to every one else that has helped me out and given me advice. You all have kept me from make huge mistakes and helped me understand the limits of my jeep. My knowledge and bag of tricks has gotten bigger. I finally feel like i'm starting to fit in here at the 838.

Thanks everybody!

[rickf]

Well while you are warm and fuzzy why don't you take some cool and clear pic's of this thing so we can all see what we are working on.
Rick