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#1 |
Registered User
Join Date: Jun 2013
Location: N/A
Posts: 218
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What transmission/transfer case do I have?
Its a 1980 Chevy K20, 10 bolt front axle, 14 bolt rear. For the transmission I've got L, 1, 2, 3, R and the transfer case has 4LO, N, 2HI, and 4HI in a straight pattern. What oils should I use to replace on each?
EDIT: Also what is the best oil to use on a worn Chevy 350 5.7L w/ ~80k miles. |
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#2 |
Registered User
Join Date: Aug 2004
Location: Eastern Shore VA
Posts: 366
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Re: What transmission/transfer case do I have?
I assume its a 4 speed manual? in that case Id bet that its an SM465 granny gear 4 speed and a NP 205 tcase.
If it were mine I'd use a name brand gear oil in both. I'm sure that somebody will pipe up with the recommended weights but 75w90 or 80w90 should suffice. both of those components are well made gear to gear heavy duty units and will tolerate a lot of abuse. So far as engine oil I like Rotella 15w40 in older engines. I run it in my 67 and my 86 with no problems.
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-j-rod '06 3500 LWB CC 4wd, 8.1 Allison |
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#3 |
Registered User
Join Date: Oct 2014
Location: Tell City, IN
Posts: 637
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Re: What transmission/transfer case do I have?
I also run 15w40 and 80-90 gear oil. Been doing fine since I got the truck a few years ago.
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Big Nate Carp. Local 224. Buy made in the USA! 03 F350 6.0 Daily Race Truck. 79 C70 366 Project Dump. |
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#4 |
Registered User
Join Date: Jun 2013
Location: N/A
Posts: 218
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Re: What transmission/transfer case do I have?
Yes it's a manual. Thanks!
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#5 |
Registered User
Join Date: Aug 2012
Location: Oklahoma City, OK
Posts: 2,539
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Re: What transmission/transfer case do I have?
If the engine truly has only 80K miles, use 10W-30. 80K isn't that many miles unless the motor has been abused or ignored. Now if the odometer has rolled over a few times, a heavier oil can slow the leakage and help with oil pressure until the motor is overhauled or replaced.
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#6 |
Registered User
Join Date: Jan 2009
Location: Louisville,Ky
Posts: 5,811
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Re: What transmission/transfer case do I have?
Or you can crawl under your truck on the t case theres a round metal tag that will tell you witch t case you have.
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#7 |
Registered User
Join Date: Oct 2009
Location: Buhl, Idaho
Posts: 1,438
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Re: What transmission/transfer case do I have?
I recall 1980 models only having the np205 case.
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86 c30 crew cab dually 454/400 4/6 drop SOLD 1-8-11 1981 chevy K10 short Bed Scottsdale SOLD 10-26-2020 67 GMC Stepside Straight six/3 on the tree "The Peach" 2020 Silverado Double Cab LT Z71 5.3 8 speed Daily Driver K10 build http://67-72chevytrucks.com/vboard/s...d.php?t=671934 The Peach build http://67-72chevytrucks.com/vboard/s...d.php?t=733903 ![]() |
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#8 |
Registered User
Join Date: Jan 2009
Location: Louisville,Ky
Posts: 5,811
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Re: What transmission/transfer case do I have?
I think your right 80 was np205 only but its a old used truck someone could have swapped t cases over the years its best to know for sure what you got.
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#9 |
Moderator
![]() Join Date: Oct 2008
Location: Wentworth, NH
Posts: 4,950
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Re: What transmission/transfer case do I have?
The only stock case in the 1980 is the NP205 that uses 85W90 GL-5 gear oil. Some K30 with Auto Hubs got synchronized gearshifts. Use GL-4 in the Synchronized cases.
The 1979 & prior NP203 uses SAE30W non detergent The 1981-1988 NP208 uses AC Delco 10-4033 or GM 88861800 Manual Transmission Fluid. Mobil1 ATF with GM 88861800 listed on the label or Pennzoil Synchromesh fluid will work. Usually the Delco fluid is cheaper unless you're buying from the dealer.
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1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...
And please let us know if and how your repairs were successful. |
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