4L80e with no reverse or netural

[blazing816]

Hey All,
  I am looking at purchasing a 91 crew cab with a 350TBI and a 4l80e/np205 tranny with dana60 and 14ff w/4.10. Supposedly it has no reverse and no natural, but shifts through the forward gears just fine. Is this a common issue with the 4l80e?? or does anybody know what causes this most of the time??

He wants $3000 and it has no A/C and no power windows or locks and needs rusty floor pans replaced. Because of the trans issue, I was thinking about low balling him at 1750 or 2000, but I kind of was hoping I could some info here first.

And is the 4l80e a good trans, I know it was only in the 91 crews or 91 burbs, so curious if it is worth keeping or not. I like the fact that it has the dana 60 and 14ff and not the 454 (will being doing an LS swap eventually). But I do not see a lot of 4x4 crews around me that often, so just seeing my options and others opinions. Thanks

[ehjorten]

The 4L80e transmission is not unique to the '91 3rd gen. GM trucks.  It was around for a long time!  What is unique to the '91 is the combination of the 4L80e coupled with the NP205 transfer case.

The 4L80e is basically the electronic version of the THM400 with overdrive.  It is a solid transmission.  It has been used since 1991 until as latest as 2013.  I don't know if any 2014 vehicles use it.

If you are not getting reverse then there is something wrong with the Low/Reverse Band.  It is the only thing that applies, coupled with the Direct Clutch to provide you with Reverse.  I am not not sure what would be wrong with Neutral?!  How did you get it started if it won't go into Neutral?

[blazing816]

The 4L80e is basically the electronic version of the THM400 with overdrive.  It is a solid transmission.  It has been used since 1991 until as latest as 2013.  I don't know if any 2014 vehicles use it.

Well that is nice to know, so it is a "beefy" version of the 4l60e (700r4).

If you are not getting reverse then there is something wrong with the Low/Reverse Band.  It is the only thing that applies, coupled with the Direct Clutch to provide you with Reverse.  I am not not sure what would be wrong with Neutral?!  How did you get it started if it won't go into Neutral?

I haven't looked at it in person, he just stated that both reverse and neutral act like forward gears.

Would it be intense work to work on the low/reverse band??

Thanks

[ehjorten]

A full teardown of the transmission would be likely, but i would check fluid levels and electronic connections first.  The 4L80e is capable of around 440 lb-ft of torque.  The successor is the 6L80e which is a 6-speed double-overdrive with a much steeper first gear.

[Irish_Alley]

im tring to piece a 4l80 and 205 together. so far i think i have everything except the adapter. a dump bed that came off the truck with the 4l80e that i could sell for 1500-2k and without selling the bed i have 900 (600 for the dump truck and 300 for the 205). so you would be buying a rusty crew cab for 2k. too much imo never seen one with just the floor being rusted without the rockers or corners.

[manualburb]

I just had the 4L80E in my 1996 2500 4x4 rebuilt and it cost me $2300.00. That being said the truck has 177k on it and has hauled campers and trailers ect....... so I wasnt to suprised when it started acting up.  And now I will keep the truck forever because it has a new Transmission

[blazing816]

Well thanks, I am not much on the knowledge base when it comes to trans, but I assumed it would prob have to be torn into, I think I will pass on it. Plus this one does have air, if I buy another truck to travel (camper) and it does not have air, I think the wife would kill me (I know I can add it, but that's a PIA, to find everything and put it in).

Thanks again for the help.

[ehjorten]

Go scoop it up Irish and you got your adapter! 

I hear that you can make one from a NP241 adapter.

[Irish_Alley]

i have heard that also or a th400/205 adapter will work with a little work. have a friend near me that tried a 4x4 nv4500 and th400/205 adapter he said it was too long. so idk if my plan will work with stock parts or i have to make one up

[ehjorten]

Hope it is okay to post a link from another forum...

http://www.pirate4x4.com/forum/chevy/1176113-4l80e-np205-again.html

You have probably read everything, but here is a good thread.

[Irish_Alley]

thanks i had that page booked marked already but im still a little bit confused. when he mocked it up did he use the 241 adapter and found out it needs to be spaced out a little? im trying to do this cheap if i can and by cheap i mean if i dont have it already ill try to make it in the shop.

[Irish_Alley]

blazing hes getting 2.3 right now on ebay
http://www.ebay.com/itm/Chevrolet-C-K-Pickup-3500-Sierra-1991-GMC-Chevrolet-3500-1-ton-Crew-Cab-4x4-Dana-60-NP205-/301260431039?forcerrptr=true&hash=item4624855ebf&item=301260431039&pt=US_Cars_Trucks