Np-435 + transfercase fluid fluid

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Feb 3, 2006 | 10:35 AM

Rossta86

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Np-435 + transfercase fluid fluid

I have an 86 f-150 4x4 with np435 transmission. Im in the middle of swapping in another np435 because the current one has lost third gear due to extreme play in the input shaft. I'm not sure what type of fluid to put back into the transmission. I've read to use 50 w( i believe) and 80w90? The truck in northern west virginia so its not brutally cold or anything. Which fluid should i use? Also what type of fluid does the t-case take, i've heard atf? Does anyone know approximently how much fluid each holds? Thanks

Feb 3, 2006 | 02:40 PM

big hoss 29

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From: Billings Montana

I would go ahead and put 80-W-90 in your tranny. I have a t-19 tranny which is just about the same and I run that in mine. I think only the overdrive trannies run with ATF. Your transfer case is NP 208 and if I remember right, ATF is just fine. I ran Mercon/Dexron III in my old F-150.

Feb 4, 2006 | 12:57 AM

fordsinair

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From: Hutchinson, KS

Yeah, ATF should work in both the tranny and the T-case. I actually put almost 4.5 quarts of 10W30 Valvoline in my F-150 mazda tranny. Just fill the tranny until the oil level is at the fill hole level. That's kind of your level indicator. Not sure about the T'case.

Feb 4, 2006 | 01:16 PM

82F100SWB

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From: Dryden, ON, Canada

DO NOT put ATF in that NP435 use 40W gear oil, or 80-90 if you must. But, make sure you run a gear oil. ATF will kill the poor thing.

Feb 4, 2006 | 04:17 PM

Rossta86

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so 40 w in the transmission and atf in the transfer case is what i should go with, everyone one agree?

Feb 13, 2006 | 07:55 AM

Pkupman82

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From: Muskegon, MI (home)

I'm partial to 80/90 in the tranny I have an NP435 in my 84, I have been doing a lot of heavy towing lately. Dex/Merc III ATF is fine in the transfer case.