# 1980 chevy 2500 tranny/ transfer case ?'s



## lcncapo (Nov 30, 2007)

hello, i just bought a 1980 2500. how can i find out exactly which tranny and transfer case i have? also what is the correct way to engage in 4wd? last nite i tried to get in 4 low but heard grinding when i put truck in drive.

thanks 4 the help.


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## Sydenstricker Landscaping (Dec 17, 2006)

Count the number of pan bolts on the trans and the shape of the pan. Im not sure on the bolts/type of trans, but I am willing to bet you have the TH400 in it. On the t-case, there may be a build plate up by where the rear driveshaft is. That will tell you what t-case you have. Prolly a NP-203/205/208. When you put it in 4lo, did you put the trans in neutral first? And make sure it is a complete shift on the t-case to ensure proper engagement. It was grinding because it wasnt engaged properly or all the way. Good luck with the truck and post some pics of it Everyone always appreciates old iron


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## William B. (Jul 22, 2004)

The 80 only came with the 205 if I remember correctly. What is the shift pattern on the transfer case?


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## B&B (Nov 4, 2006)

If it's an actual '80 model year 8 lug truck it should have the 400 trans with an NP205 T-case. But GM did some odd combos that year since it was a changeover year from the old body style ('80-back) to the newer style ('81-up). 

To positively identify the trans look at the pan, if it's shaped like a "kidney bean" it's a Turbo 400. 

If it's square shaped with the left rear corner cut off its a Turbo 350.


T-case identification is a little tougher if your not sure how to tell but in a nut shell if it has a shifter that lays almost horizontal and all the way forward when its in 2WD (will also have a plastic console around the shifter with a lighted indicator), it's an NP208.

If the shifter is nearly vertical when in the 2WD position, and perfectly round, it's a 205.

If the shifter stick is almost vertical but slightly forward and is flat on two sides then it's a 203 (full time 4WD).


Never trust the shift pattern on the knob as they can be easily swapped (or even missing).


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## lcncapo (Nov 30, 2007)

thanks for the info!
it is an 80 w/ 8 lug axles. i will crawl under there tom and take a look but it sounds like its the 205 from your shift lever description.

btw i'm pretty sure that the body style is the same as any chevy 73- 87. you had said that they changed it 80-81, is that right?

thanks again.


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## B&B (Nov 4, 2006)

lcncapo;547827 said:


> thanks for the info!
> it is an 80 w/ 8 lug axles. i will crawl under there tom and take a look but it sounds like its the 205 from your shift lever description.
> 
> btw i'm pretty sure that the body style is the same as any chevy 73- 87. you had said that they changed it 80-81, is that right?
> ...


The major difference between 73-80 and 81-up is the front sheet metal but in '81 they also changed many other small things along with it (interior, trans and T-case options, things like that), so the best way to designate them is 73-80 and then '81-87. Less confusion that way.

If it is an actual '80 with 8 lug wheels it _should_ have a corporate 10 bolt front axle, 14 bolt full floating rear axle, 400 trans (should have the extra capacity pan) with the 205 T-case. Should have 3:73 or 4:10's as well.


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## lcncapo (Nov 30, 2007)

hmm i was told by the previous owner that both axles were dana 60 's. is this possible? i just picked it up 2 days ago and havent had time to play w/ it or get it up on a lift will try to by monday.


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## ABES (Jun 10, 2007)

If you posted some pics of the drivetrain parts i'm sure some guys on here could identify them very easily.


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## B&B (Nov 4, 2006)

lcncapo;547852 said:


> hmm i was told by the previous owner that both axles were dana 60 's. is this possible?


 Not possible from the factory. But not to say someone didn't swap them in. Like ABES mentioned, pics will positivity identify them.


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## Detroitdan (Aug 15, 2005)

205 case has a small round cover on the back with three bolts holding it. It is just below the fill plug, and kind of between the big round covers. 205 is a gear driven case and allegedly much stronger and more desireable. I broke mine in two, so I'm not sold on it being bulletproof as everyone says. But I've also broken 203 (chain driven) and 208 (wimpy chain driven). So far I've been unable to break my 241 chain driven case. But I haven't stopped trying.
Trans pan is real easy to ID. Either its square with 1 corner cut off (th350), or it's shaped like Texas (th400). If you have bolt-in axles in the rear its a 14 bolt full floater (should be). Front could be a Dana 44, Corporate 10 bolt (should be).
It's not a 2500, if it's a Chevy it's a K20, GMC it's a K25. Unless the sheetmetal and/or emblems is swapped or missing, in which case it could be darn near anything. If you were lucky it might even be a single wheel one ton (K30/35). In which case it would have the very desireable Dana 60 front axle. If you still can't tell, post a photo of the trans pan, the back of the t-case, the front of the front diff, and the outside of a rear wheel with no hubcap. 
The GMCs were more commonly found with the th400/205, and Chevys th350/203. But I have seen every combination possible with them. I've owned and parted out and rebuilt a few of them.
No matter which driveline you have, it is going to be tough enough for whatever you want to throw at it. As long as you've got 8 lug wheels.


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## derekbroerse (Mar 6, 2004)

lcncapo;547852 said:


> hmm i was told by the previous owner that both axles were dana 60 's. is this possible? i just picked it up 2 days ago and havent had time to play w/ it or get it up on a lift will try to by monday.


GM trucks didn't use the Dana 60 rear end, ever to my knowledge (EXCEPT the Quadrasteer trucks but thats not a normal rear end!). Thats more of a Dodge thing. A Dana 60 front axle is K30 one-ton 4x4 gear, not common nor cheap. A K20 should have a Corporate 10 bolt, though some late 70s early 80's trucks seemed to have used leftover Dana 44s.

A lot of people (on ebay for example) seem to think these trucks use Dana axles front and rear, but they don't. There are too many self-appointed 'experts' out there that think they know everything, I had a guy here tell someone about 'all the dana 60 front axles I had laying around' so they got all excited and came running.... only to find out they were all Dana 44's I have... same thing, right?  Yesterday I was told about a supposedly factory documented '70 Chevelle with its 'original' Chrysler 440 hemi in it.... 

Thats not to say someone couldn't have made it fit, its just not original hardware if thats what it is.

If you're taking pictures of the axles try to get a closeup of the differential cover. Number of bolts only goes so far, but the shape of the cover tells volumes.


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## B&B (Nov 4, 2006)

derekbroerse;548416 said:


> Yesterday I was told about a supposedly factory documented '70 Chevelle with its 'original' Chrysler 440 hemi in it....


Thats a good one there Derek. I hear those same types of stories from time to time. Reminds me of the guy that claimed of selling an original # matching COPO '68 Camaro.....with a 454 in it.

He failed to realize that 454's weren't built until '70...

Theirs some real knowledgeable people/owners out there.


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## Detroitdan (Aug 15, 2005)

Probably built by the same aftermarket company that makes Blazers with 351s in them.


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## derekbroerse (Mar 6, 2004)

Detroitdan;548469 said:


> Probably built by the same aftermarket company that makes Blazers with 351s in them.


I've seen one of those... pretty rare!!!


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## 1980chevyguy (Oct 24, 2012)

*question about my transfer case*

i have an 1980 chevy with an all time transfer case, i want part time transfer case but don't know what I'm am looking for in a transfer case. i have the t400 trans and a small block 350 what would be the best transfer case for my truck. i also do alot of off roading and mudding so i need one to hold up to that if someone can help me out that would be awesome. thanks


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## tuney443 (Jun 25, 2006)

1980chevyguy;1504807 said:


> i have an 1980 chevy with an all time transfer case, i want part time transfer case but don't know what I'm am looking for in a transfer case. i have the t400 trans and a small block 350 what would be the best transfer case for my truck. i also do alot of off roading and mudding so i need one to hold up to that if someone can help me out that would be awesome. thanks


Would be glad to help you out.I happen to have the NP205 TC that was behind my TH400 in my 88 V30.It will certainly hold up to anything you can throw at it.Also have the front Dana 60 axle from same.Not supposed to talk price here I think so PM me.


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## 1980chevyguy (Oct 24, 2012)

i have no clue how to do anything on this site besides this. i am new to the site so if you could post on here and let me know how to do this or just pm me and i will figure it out from there
thanks.


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## sweetk30 (Sep 3, 2006)

th400 has few diffrent tail shaft lengths for tcase style. 

if you had a 203 on it and want other will need to swap tail shaft . and that = full tear down to swap shaft. 

if case is working and just want part time get conversion kit for it. 

or if you want best option keep 203 rangebox front half and get a doubler kit to mate the 205 part time behind it for extra low 4x4 off road use. 

but any swap from stock combo will require drive shaft mods for length . and diffrent shifter setup also needed for the case swaping in . 

you want some great info on freidly site try ck5.com for the 73-87 trucks. 

hope my info helped . Thumbs Up


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