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Old 12-05-2012, 07:39 PM   #1
tgoatman
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Leaky NP 205

OK, so when I restored my truck, the NP205 was in great mechanical shape, but leaked like a seive. I went through the whole thing, replaced every seal and gasket, and refreshed whatever else needed refreshing...

but it still leaks like crazy. Anyone have a suggestion on how I can get this thing to stop? Is it a total rebuild???

TIM
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Old 12-06-2012, 10:04 AM   #2
SunSoaked
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Re: Leaky NP 205

Where is it leaking from?

If you have already replaced every seal/gasket, it sounds like you already did a total rebuild.


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Originally Posted by tgoatman View Post
OK, so when I restored my truck, the NP205 was in great mechanical shape, but leaked like a seive. I went through the whole thing, replaced every seal and gasket, and refreshed whatever else needed refreshing...

but it still leaks like crazy. Anyone have a suggestion on how I can get this thing to stop? Is it a total rebuild???

TIM
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Old 12-06-2012, 12:07 PM   #3
tgoatman
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Re: Leaky NP 205

I can't tell where it's leaking - it's weird - there's dripson teh bottom of the case, but you can't really see a trail. My guess is that it's coming from the speedo cable or the shifter-shafts on top.

When I freshened it up, I didn't do anythingwith bearings or the gears. I was afraid maybe one of the bearings was bad and it already thrashed a new seal...

Are these prone to leaking? It was covered in an inch of goop when I took it out to clean it up...had obviously been leaking a long time.

T
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Old 12-06-2012, 12:19 PM   #4
psuedopimp
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Re: Leaky NP 205

is it leaking gear oil or transmission fluid? mine is leaking transmission fluid from the shift shafts and it runs along the bottom and makes it look like it is leaking from the rear
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Old 12-06-2012, 12:20 PM   #5
Redcap
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Re: Leaky NP 205

Quote:
Originally Posted by tgoatman View Post
I can't tell where it's leaking - it's weird - there's dripson teh bottom of the case, but you can't really see a trail. My guess is that it's coming from the speedo cable or the shifter-shafts on top.

When I freshened it up, I didn't do anythingwith bearings or the gears. I was afraid maybe one of the bearings was bad and it already thrashed a new seal...

Are these prone to leaking? It was covered in an inch of goop when I took it out to clean it up...had obviously been leaking a long time.

T
I'd pull it and de-grease/pressure-wash it, then see if you can isolate the leak.
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Old 12-06-2012, 01:51 PM   #6
RLONG
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Re: Leaky NP 205

I have had quite a few 69-72 4x4 all leaked from transmission and filled up transfercase with atf and leaked. When i bought my 71 blazer i had the transfer case pulled and new seals and new seals in tranny. 6 years and still holding.
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Old 12-06-2012, 02:51 PM   #7
tgoatman
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Re: Leaky NP 205

It is all cleaned up. I have new trans and all new seals, so no trans fluid in transfer case. The fluid leaking is definitely gear oil. Maybe I should use a heavier oil???
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Old 12-06-2012, 03:25 PM   #8
RLONG
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Re: Leaky NP 205

Still will leak maybe not as fast best to find wherethe oil is coming from.
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Old 12-06-2012, 04:26 PM   #9
72longbed
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Re: Leaky NP 205

Just my .02 cents here, but there is an inner sleeve that the speedo gear runs inside of that has an O-ring in it. These are notorious for leaking oil and pumping it out the case to run right down to the bottom of the case. GM still has the part available at dealerships or online ... I would check to see if that is where your leak originates. It comes out with a 15/16 or 1" socket right where your speedo cable attaches.

Check it out.

72longbed
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Old 12-07-2012, 01:02 AM   #10
csb#356
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Re: Leaky NP 205

Tail housings can crack too.
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