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I have a 86 F150 manual with a 300 inline. Some of you may remember I had an issue where my transmission mount snapped and the drive line was hitting against the fuel tank. I replaced the transmission and motor mounts. Now I am seeing a new leak from the transfer case. I have tried tightening down the bottom bolts but still leaking.
I've circled in the attached picture where the leak is coming from. Do I need to replace a gasket or just try to bandaid it?
Also I know the transfer case fluid hasn't been changed since before I've owned it (5 years), so I plan on replacing that. However I've seen a few arguments in other posts over what type of fluid to use. Any suggestions would be appreciated!
Just a few thoughts.
Are you sure the fluid is not coming out the front seal and being blown back to that area ?
You could pull the bolt next to the leak and put a squirt of RTV in the hole and reinstall the bolt.
How bad is the leak ?
@hobohilton the leak is slow. Maybe a quarter sized stain every day?
Also didn't consider it coming out the front seal. I'll have to wipe everything down real good to double check
Get a flashlight and look that area over carefully. There should be a nipple up in that area with a hose on it. It is a vent. If the hose is gone and the nipple is out in the open, the leak could be coming from that. If you take that drip and put it on your finger and look at it, it should be red. That is because the transfer case these years takes Dexron automatic transmission fluid.
That's good detective work.
A few more thoughts... Not specific to this transfer case but just general mechanics.
That location where the oil is leaking appears to be above the "over flow port" that is observed when filling any transmission or gear box. You mentioned the oil has not been changed. Perhaps the case has been over filled and oil is covering that area rather than draining away when the truck is parked or when the gears in the case are not turning. Pull the plug from the over flow port and see if any oil runs out.
The next purely mechanical situation could be the case is building pressure and forcing oil past any type of seal. Is the case vented properly ? I have had situations where a gear box would build pressure just on normal temperature changes and would force a bit of oil out of a seal.
I am not sure this is the model transfer case you have. But they all have a vent somewhere with a hose. In the middle of the picture below, find the number 78106. Follow the line down from the number to the arrow on the end of the line. Then look at the broken line that the arrow is sitting on. Follow that upward, it leads to the nipple on this particular model transfer case vent.
Thanks for the reply @hobohilton and @Franklin2 . I see the vent hose is connected to the transfer case but where does it go to? It's just kind of free floating currently. There isn't a leak from the nipple on the transfer case.
I do not see any where else the leak could be coming from other than where the nut attachs the shifter
Thanks for the reply @hobohilton and @Franklin2 . I see the vent hose is connected to the transfer case but where does it go to? It's just kind of free floating currently. There isn't a leak from the nipple on the transfer case.
I do not see any where else the leak could be coming from other than where the nut attachs the shifter
What is the "tube looking" thing with a hole rusted in it for ?
I would look a little closer just above where the leak is showing up.
That's a tight area and will need an inspection mirror.
Make sure the vent tube is not puking some oil above where the leak is showing up.
@Max Capacity I don't think they make Dexcron II anymore. @hobohilton are you referring to the tube itself? I had it up in the cavity where the shifter and 4x4 shifter were so there was no way fluid was coming out. Also it has been dry.
They had Dexron II when the manual above came out. Then they updated it to Dexron III. Then IV the V then I think the latest is VI. All backward compatible. Walmart still sells Dexron III https://www.walmart.com/ip/Super-Tec...T&from=/search
Dexron VI is a semi-synthetic and is backward compatible with all the older Dexron fluids.
I see the vent hose is connected to the transfer case but where does it go to? It's just kind of free floating currently...
IIRC, the upper end of the vent hose is clipped to the transfer case shift lever. It's tucked up inside the bellows at the floor.
In one of your pics, there appears to be a rust stain about an inch from the end of the hose. That mark is from the clip on the shift lever. If the clip is missing, there may still be a rust stain on the lever, too.
