Transfer case seal leaking Help

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gmac

gmac

10 Year
Joined
Jul 16, 2013
Threads
16
Messages
305
Location
Montana
So, it looks like suddenly I have a lot of transmission oil leaking from what appears to be the extension housing oil seal, where the front diff shaft connects to the transfer case.
Question is, do I need to pull the transmission/transfer case for this work or can I do it with the transmission/transfer case on the truck.
Any advise on how to do it, would be much appreciated.
Attached is photo showing here the oil appears to be coming from.
Transfer Case Leak.webp

Thanks
Guy
 
I'm not sure, but if there is a nut that holds the front flange on, then you can probably change the seal without removing the transfer case. Stating things like the year help, but it seems that it is later than '79.
 
if it is the front output, it can be changed without taking the transfer apart, if it is the seal only, if there is bearing play you should rebuild the transfer

it could be leaking from the front drive shift also. which would be a rebuild to fix that.
 
gmac said:
Thanks Paul.
Any specific advise/directions on how to pull the seal?
Click to expand...

it would be easier to block up the trans or transfer, drain transfer oil, remove the crossmember, remove driveshaft, remove nut holding flange, remove seal, reverse order.
always make sure you can get the fill plug loose before draining any oil.
 
Nothing to it with a split case. Drop the drive shaft, remove the stake nut, yoke that connects to DS pulls off. Than use a seal puller to remove the lip seal. Install the new seal with sealant, and reverse other steps. Took about twenty minutes. Get a new stake nut.
 
Thanks for the info Paul and Cruisernerd. Will try to start on it this weekend, to see exactly what I need to order, then I can work on the oil pan gasket, side cover gasket and Knuckle rebuild, while I wait for part. Will keep you posted.
 
I'm thinking all those parts can be found in Helena.
 
Sounds good Paul. Will send you a PM, probably tomorrow or Sunday.
So I got to the seal, it took quite a bit of work, as one of the welded nuts in the frame, attaching the cross member started spinning on me.

Now I need to go buy a seal puller, that thing is in there tight.
One other question, not sure if I'm going blind or what, but I cannot find the fill port to add the new gear oil. Where is that thing?
Also, what is recommended oil to put in the transfer case.

Thanks
Guy
 
Have you checked if your breather is clear? If you are building pressure in your transfer case it will make a small leak much worse, you will still have to replace the seal but it could buy you more time.
 
Ok, thanks. Will check the breather. Found the fill plug. Is it normal to have a hose from the transfer fill plug to the transmission fill plug? For breathing? Just in case a breather gets plugged?
 
That hose is an aftermarket way of dealing with a bad seal between the tranny and TC. The bad seal between the tranny and TC is a common problem. The TC will gradually push oil into the tranny, eventually leaving the TC very low on oil. The hose allows excess oil in the tranny to migrate back to the TC.

Many people, including me, will install the hose before there is any evidence of a bad seal just to keep from unknowingly running the TC dry.

Don
 
I do group buys on the hose which is a stainless steel braided hose. Go to tranny transfer case hose on market place for pics or pm me. Or you can make one your self. I have sold about 60 of those hoses as a group buys.
 
3_puppies said:
if it is the front output, it can be changed without taking the transfer apart, if it is the seal only, if there is bearing play you should rebuild the transfer

it could be leaking from the front drive shift also. which would be a rebuild to fix that.
Click to expand...

Paul, So if it's leaking from the front drive shift. 4wd and 4wd low selector, up on the photo (above) from the front output shaft, the transfer needs to be rebuilt?

It is still leaking, although very little compared to what it was, before I changed the front output seal.

Thanks
 
Ok, so I replaced the seal in the front housing. Drove the troopy around for a couple of day, and notice that it appeared to still be leaking just a bit from the front selector and maybe the rear seal, but was happy to see that the front seal was not leaking. Yesterday (a couple of days of more driving), I noticed that is once again leaking quite a bit from the front housing seal. I then remembered that I forgot to check the breather per BEE-JAY42 above. Could a blocked breather cause a new front seal to start leaking really bad? Also on the photo above (on my first post) you see the front selector. Is this for the hi/low or the 2wd/4wd. Look like I should be able to replace that seal without too much trouble. Any advise?
Thanks
Guy
 
Yes if the breather is clogged the internal pressure can and will cause a new seal to leak as the fluid temp increases.
 
CarDude,

The image below shows the breather plug. Item #36111H. You can at least see the location of it. Right where the transfer bolts to the transmission.
I'll try to get a photo of it when I get home tonight.

81-84-3609.gif


81-84-3609.gif
 
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