Hi all,

Greetings from Holland! Just a short introduction. I have always been a fan of American Cars pre 1990. After my chevrolet Caprice 1984 I decided to buy a 1978 Chevrolet 1978 K5 Blazer. As I am not a technician I need some help of experienced people and I found this forum so I am trying my luck here.

I recently bought the car and drove it home. When getting home I saw that there was some fluid on the driveway. After spending some hours underneath the car and tightining some bolts I still have a small leak in my transfer case. The leak is not big but the drop is at a place a really cannot determine where it is coming from. Enclosed you will find a picture of it. I am also wondering if I am missing some bolts?

Please take a look and let me know what you think. Thanks!

 

You are looking towards the rear of the vehicle in that picture. You can see the TH350 transmission pan in the top with the vacuum modulator to the left side connected to the hard line with what looks like clear vacuum tubing.

The transmission will have a seal at the output to keep the transmission fluid inside the transmission.

The bolts you have circled should be used for the transmission mount if it was used in a 2wd vehicle instead of being installed to a transfer case.

Between the transfer case and the transmission is an adapter, it is what supports the transmission and transfer case on the cross member. There should be no fluid exchanged between this adapter.

The transfer case in a 78 should be a NP203, this case will use SAE30 oil, same as what you would put in the motor. There is a seal on the input shaft for the transfer case so there should be no fluid leaking out.

Which are you leaking, transmission or 30 weight oil? Might pay off to get a pressure washer out and clean stuff up down there.

 

Hi

Thanks for the quick reply.

It is leaking a bright red oil so I guess it is transmission fluid. I thought the part I made the picture from was already part of the transfer case but is it then the adaptor?

I will clean it up and check it again.

Also found that when changing from high to low gearing and back it seems only to get in locked mode. I feel it when I take a sharp corner as the wheels "bump". I assume it is because all wheels want to turn at the same speed. Or could this be normal because of the big wheels?

It also leaks oil in the front. Need to take a picture from it. Always nice when you buy somebodies "project".

 

70-k5 pretty much summed it up.

i actually had to look at those two bolt holes for a minute to figure out what was going on.

just to warn you ive had a k5 blazer with that np203 transfer case and it is a awkward heavy case to lower and raise in and out of a vehicle, ive always had to use two jacks and have people help due to the way its designed.

yeah just double check that the trans isnt leaking out of the pan or somewhere else and just rolling back onto that adapter.