1991 4l80e/np205 combo question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bilfman · 06-15-2012, 11:22 AM

Hi all,

I am again pulling from the mass wealth of information that the peeps from this site hold. I have a 1979 crew dually 4x4 with a th400/np203. I recently found the hard to find 4l80e/np205 combo and am wanting to install it. It comes with the cpu, front driveshaft and crossmember.

I have little experience in this new style of tranny but have changed many many motors and trannys in the past 30 years. I was wondering if any have done this and is there anything to look for problem wise. Such as, shifter linkage, cpu controller (I understand the 4l80e has one) etc. Any help before I start wrenching would really be appreciated.

Thanx in advance!

obijuan · 06-15-2012, 01:13 PM

Driveshafts will be wrong lenght now, your new trans is longer but the 205 is shorter than the.203.
Shifter hole may work if you have the 205 shifter from 1991. But you're going from the tall adapter to the short so that may change your shifter hole as well as crossmember location. 85+ its a direct swap.
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06-15-2012, 11:22 AM	#1
bilfman Registered User Join Date: Dec 2011 Location: Regina, SK, Canada Posts: 622	1991 4l80e/np205 combo question Hi all, I am again pulling from the mass wealth of information that the peeps from this site hold. I have a 1979 crew dually 4x4 with a th400/np203. I recently found the hard to find 4l80e/np205 combo and am wanting to install it. It comes with the cpu, front driveshaft and crossmember. I have little experience in this new style of tranny but have changed many many motors and trannys in the past 30 years. I was wondering if any have done this and is there anything to look for problem wise. Such as, shifter linkage, cpu controller (I understand the 4l80e has one) etc. Any help before I start wrenching would really be appreciated. Thanx in advance! __________________ 1979 Chevy Dually Crew 4X4 454, D60 Tru-trac, D70 Detroit Locker, 3.73, 4L80E/NP205 1971 GMC 3/4 Ton 4X4

06-15-2012, 01:13 PM	#2
obijuan Registered User Join Date: Jun 2012 Location: cibolo tx Posts: 1,033	Re: 1991 4l80e/np205 combo question Driveshafts will be wrong lenght now, your new trans is longer but the 205 is shorter than the.203. Shifter hole may work if you have the 205 shifter from 1991. But you're going from the tall adapter to the short so that may change your shifter hole as well as crossmember location. 85+ its a direct swap. Posted via Mobile Device



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