D300 shaft seal

[EVERYUSERNAMEISTAKEN]

I'm not 100% that the shaft seal is leaking but it sure looks like it. Disclaimer: I have never disassembled a Transfer Case or a Transmission . However I can usually reassemble something after taking it apart with minimal issues. Can someone please give me some insight on replacing the shaft seal on my Dana 300 ? I would also appreciate some input on replacing a AMC 258 i6 / 4.2l rear camshaft seal.

 

[EVERYUSERNAMEISTAKEN]

Motor rear main seal leak

 

[Lumpy Grits]

Check your t'case oil level. Check the vent line connecting on the t'case.
Also-See if it's oil wet at the back of your valve cover.
What weight oil are you run'n in the t'case?
What weight oil in the engine?
LG

 

[EVERYUSERNAMEISTAKEN]

I didn't check the Transfer Case oil level but I did check the vent hose and the oil isn't coming from there. It looks like the oil is coming from the shaft. Which kinda makes sense Bc I recently installed my new CV drive shaft. Maybe I damaged the seal when I did this?

I also recently put the following oil in the Transfer Case :

As for the engine oil leak. I checked the back of the valve cover and wiped it the best I could. I was hoping that this would be the issue but I didn't find any fresh oil. Here a thought though.. the vacuum line/breather on the top rear of the valve cover is blocked off. Should this be vented to my carb air cleaner?

Thanks for help with this Lumpy!

 

[Lumpy Grits]

This is what you want it to look like. Make sure your PCV valve is clean.
The PCV System

What weight oil do you run in the engine? How many miles on the engine?
LG

 

[EVERYUSERNAMEISTAKEN]

This is what you want it to look like. Make sure your PCV valve is clean.

The PCV System



What weight oil do you run in the engine? How many miles on the engine?

LG

Thanks!! I'll check the PCV setup when I get home. Can't remember the motor oil weight off the top of my head. The motor was rebuilt about 6 years ago and then it sat for several years. I would say that there is less than 2miles on the rebuild.

 

[Lumpy Grits]

How long has that oil and oil filter been on/in the engine?
LG

 

[Hedgehog]

It is amazing how quickly synthetic can find its way OUT of an old Transmission /Transfer Case .

 

[Belizean]

I don't run synthetic in anything !

 

[Lumpy Grits]

If you run a T-4 /T-5 tranny, you had best run syn 75W-90 gear oil.
LG

 

[Belizean]

If you run a T-4 /T-5 tranny, you had best run syn 75W-90 gear oil.
LG

Got 1 with over 235,000 miles using only Castrol 80-90 . Non syn

 

[Lumpy Grits]

Got 1 with over 235,000 miles using only Castrol 80-90 . Non syn

Go buy some Lotto tickets-

Std gear oil was never recommended buy Borg-Warner or AMC for the T-4 /5.
Hope your luck continues.
LG

 

[Belizean]

Already bought my mega millions ticket

 

[Hedgehog]

But he's running a Dana 300 and that is what is leaking.

 

[Lumpy Grits]

But he's running a Dana 300 and that is what is leaking.

I know A bit of 'thread-drift' took place.

LG

 

[Belizean]

But he's running a Dana 300 and that is what is leaking.

Mines (Dana 300 ) been leaking since early on, just not enough to remove and work on it. I just add some fluid once in awhile. When I pull my engine I'm hoping to do the 4 to 1 and then fix the leak. When it was new I didn't trust the dealer enough to let them work on it. My buddy and I both bought 84s new and were BSed about problems when new by the dealer and never went back to them.

 

[Lumpy Grits]

Try that power steering stop leak.
Ya got nut'n to loose.........
LG

 

[EVERYUSERNAMEISTAKEN]

How long has that oil and oil filter been on/in the engine?

LG

That's a good question.. the answer is too long! It needs to be changed.

 

[EVERYUSERNAMEISTAKEN]

I'm going to try and find sometime today to remove the inspection cover on the bell housing and see if that is where the oil is coming from. The motor oil leak is an issue but has only been an occasional tiny drop until my highway run the other day. I'd like to fix the output seal on the Transfer Case and then fix my vacuum lineup and see if that helps.

 

[EVERYUSERNAMEISTAKEN]

Alright, I have made progress! It took forever to get a Transfer Case output shaft seal but it finally came in and I installed in. This was very simple. I removed the driveshaft and yoke, pulled/pry'd the old one out using a long screw driver. Cleaned the area, put a little grease on the new seal and pressed the seal in with a piece of 3" PVC pipe and a few tapes on my 10lbs sledge hammer. Ok maybe joking on the size of the hammer. Simple as that!

Hoghead hooked me up with some vacuum hoses and I ran a hose from the breather on my valve cover to the unused port on my Weber Carb. Idk why we had that blocked off originally.

Anyways so far I've driven 15 miles and didn't see any oil!

I also removed the bellhousing inspection plate to see if the rear main seal was leaking and found it to be pretty clean.

I've printed off a bunch of vacuum diagrams and Weber carb instructions. I plan to dig into this more this weekend. Thanks for your help!