What is there to leak in trans/transfer case - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Leroyswift · 12-08-2012, 01:37 PM

I have a 1978 k10 350 4speed and a 12 bolt out back. the whole area underside is caked in oil and after pulling both plugs in trans and t case not a drop in either. I am curious where are the seals and the difficulty of the replacementof ALLof them. Thanks yall
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bobbybyrns · 12-09-2012, 02:32 AM

Well common leak spots on the trans are side covers or input shaft seal or out put shaft seal and pretty much same for the t case input/out put shaft seals(Tail shaft seal). Depends of where the leaks are as of to how hard it is do do you might have to pull the trans and t case or just pull the t case. Fill em back up and find the leak

High ho silverado · 12-10-2012, 01:03 AM

What tcase do u have? Some cases have a seal between them and the tranny, when that seal goes bad the trans will fill the tcase and when the case gets full pressure will blow out the output seals, also I've seen them leak around the splines for the yikes, there is a little rubber seal in the yoke that goes bad.
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Leroyswift · 12-10-2012, 01:37 AM

I reckon its a Np205 gear type. The truck came with a factory chevrolet parts manual that is full of exploded diagrams and it shows what it calls an "adapter" between the trans and t case. im thinkin thats the source. im the third owner and the guys before me really abused it. There was a 3/4 plate across the frame with a goose neck in the bed, just a glimpse of the shenanigans the truck endured. This was my $400 i drove it home special. Good strong 350 that runs stronger than my 89 k3500 tbi.The last pic with blue bed is as it currently stands with a total all inclusive investment off ~$975
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High ho silverado · 12-10-2012, 03:49 AM

Well if it is a 205 ur lucky, cause if its a 203 ur not so lucky, the 205s are a lot easier to take down to fix the gasket for the stand than the 203s. Ull know if its a 203 or not, they are huge and have the full time 4wd. For example( the shifter will say 4 hi loc-4 hi- N- 4low- 4 Low loc) if its the aluminum 208 then u hit the jackpot cause they are real easy to work with but I'm sure u didn't get that lucky cause they were in the 81 up.stuff
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Leroyswift · 12-10-2012, 10:57 AM

It definately aint all full time 4wd. A guy round here used to work at the huge chevy dealership said the same thing,he also mentioned the 208 but id rather mot have alum cased stuff. Course if it was mt way i wish i had a 700r4 to replace that 4spd. Oh well.
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12-08-2012, 01:37 PM	#1
Leroyswift Registered User Join Date: Jan 2010 Location: Lei, Nc Posts: 52	What is there to leak in trans/transfer case I have a 1978 k10 350 4speed and a 12 bolt out back. the whole area underside is caked in oil and after pulling both plugs in trans and t case not a drop in either. I am curious where are the seals and the difficulty of the replacementof ALLof them. Thanks yall Posted via Mobile Device __________________ Two days ago, I saw a vehicle that would haul that tanker. You want to get out of here? You talk to me.

12-09-2012, 02:32 AM	#2
bobbybyrns Registered User Join Date: Dec 2012 Location: Fulton NY Posts: 9	Re: What is there to leak in trans/transfer case Well common leak spots on the trans are side covers or input shaft seal or out put shaft seal and pretty much same for the t case input/out put shaft seals(Tail shaft seal). Depends of where the leaks are as of to how hard it is do do you might have to pull the trans and t case or just pull the t case. Fill em back up and find the leak

12-10-2012, 01:03 AM	#3
High ho silverado Registered User Join Date: Sep 2012 Location: clearmont mo. Posts: 75	Re: What is there to leak in trans/transfer case What tcase do u have? Some cases have a seal between them and the tranny, when that seal goes bad the trans will fill the tcase and when the case gets full pressure will blow out the output seals, also I've seen them leak around the splines for the yikes, there is a little rubber seal in the yoke that goes bad. Posted via Mobile Device __________________ Dan G Lift it, fat chicks cant jump! 83 Chevy shortbed 4x4: 6.0 ls powered 97 Chevy 3/4 ton ex cab 454: work horse 00 Chevy camaro: daily driver 83 Chevy 3/4 ton: dads old rig

12-10-2012, 01:37 AM	#4
Leroyswift Registered User Join Date: Jan 2010 Location: Lei, Nc Posts: 52	Re: What is there to leak in trans/transfer case I reckon its a Np205 gear type. The truck came with a factory chevrolet parts manual that is full of exploded diagrams and it shows what it calls an "adapter" between the trans and t case. im thinkin thats the source. im the third owner and the guys before me really abused it. There was a 3/4 plate across the frame with a goose neck in the bed, just a glimpse of the shenanigans the truck endured. This was my $400 i drove it home special. Good strong 350 that runs stronger than my 89 k3500 tbi.The last pic with blue bed is as it currently stands with a total all inclusive investment off ~$975 Posted via Mobile Device Attached Images __________________ Two days ago, I saw a vehicle that would haul that tanker. You want to get out of here? You talk to me.

12-10-2012, 03:49 AM	#5
High ho silverado Registered User Join Date: Sep 2012 Location: clearmont mo. Posts: 75	Re: What is there to leak in trans/transfer case Well if it is a 205 ur lucky, cause if its a 203 ur not so lucky, the 205s are a lot easier to take down to fix the gasket for the stand than the 203s. Ull know if its a 203 or not, they are huge and have the full time 4wd. For example( the shifter will say 4 hi loc-4 hi- N- 4low- 4 Low loc) if its the aluminum 208 then u hit the jackpot cause they are real easy to work with but I'm sure u didn't get that lucky cause they were in the 81 up.stuff Posted via Mobile Device __________________ Dan G Lift it, fat chicks cant jump! 83 Chevy shortbed 4x4: 6.0 ls powered 97 Chevy 3/4 ton ex cab 454: work horse 00 Chevy camaro: daily driver 83 Chevy 3/4 ton: dads old rig

12-10-2012, 10:57 AM	#6
Leroyswift Registered User Join Date: Jan 2010 Location: Lei, Nc Posts: 52	Re: What is there to leak in trans/transfer case It definately aint all full time 4wd. A guy round here used to work at the huge chevy dealership said the same thing,he also mentioned the 208 but id rather mot have alum cased stuff. Course if it was mt way i wish i had a 700r4 to replace that 4spd. Oh well. Posted via Mobile Device __________________ Two days ago, I saw a vehicle that would haul that tanker. You want to get out of here? You talk to me.



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