Another 4l80 swap.

[chris989]

Hello all,

I have searched and most threads are either hijacked or fizzle out.

I have an 89 4wd 5.7 TBI 400 turbo suburban. I want to put in a 4l80. Does anyone have FIRST HAND knowledge of the swap?

I know the 91 2500s came with a 4l80. There is one at my pic a part but 2wd.


question, what do i need to harvest from it. Wire harness, computer etc???

I know i need to change the output shaft if the donor is a 2wd. What and where can i source an adapter for a 241???

I am sure there are many questions i am leaving out so if you can walk me through this i would be indebted.

Thank you in advance

Chris

[chris989]

PS,,

What gear would have come in a 91 5.7 4wd if it had the 4l80. I found an entire truck but the owner has no idea what gear is in it.

[bilfman]

I did a 4l80e swap from a 1991 crew into my 79. Here is my swap.

http://67-72chevytrucks.com/vboard/s...d.php?t=537481

[andrewmp6]

Which 91 is it is it the crew cab square body or is the 88-98 body style?If its the 91 crew cab buy it that has a 4l80e np205 combo plus you could use both axles if you wanted them.To know the factory gears look at the glove box sticker and decode it http://www.sierragear.com/gm-rpo-axl...ation-codes-3/ just remember its a old truck so they factory gear ratio might not be the same as what's in it today.

[chris989]

Originally Posted by andrewmp6

Which 91 is it is it the crew cab square body or is the 88-98 body style?If its the 91 crew cab buy it that has a 4l80e np205 combo plus you could use both axles if you wanted them.To know the factory gears look at the glove box sticker and decode it http://www.sierragear.com/gm-rpo-axl...ation-codes-3/ just remember its a old truck so they factory gear ratio might not be the same as what's in it today.

The donor is a 91 square body,,

my 89 and 96 burbs both have a 241. was it only in 91 for a 205??

[chris989]

Originally Posted by andrewmp6

Which 91 is it is it the crew cab square body or is the 88-98 body style?If its the 91 crew cab buy it that has a 4l80e np205 combo plus you could use both axles if you wanted them.To know the factory gears look at the glove box sticker and decode it http://www.sierragear.com/gm-rpo-axl...ation-codes-3/ just remember its a old truck so they factory gear ratio might not be the same as what's in it today.

I am going to post on your other thread.

[andrewmp6]

Yeah the 4l80e np205 was 91 only in the crew cab.

[chris989]

Andrew,

Do you know if the adapter from a 92 and newer will bolt to my older 241? Mine is a passenger drop and all of the newer ones are driver drop. Is there a clocking issue?? If the adapter is the same those transmissions are easier to find.

Thanks,
Chris

[wildwilly4x4]

I bought a 5/8 spacer adapter that northwest fab makes for my 400 to 4l80e/ 205 swap. It should eork fine with your 241 setup. It adapts the 400 size index ring to the 4l80e size index ring. I think the adapter was around $150

[andrewmp6]

http://www.pirate4x4.com/forum/chevy...e-adapter.html

[chris989]

Thanks for the help. I wish the search feature worked a little better on these sites. All the information is always available but finding it sometimes isn't so easy.

Chris

[andrewmp6]

I use just google between pirate 4x4,pavement sucks and few other 4x4 forums most stuff is covered somewhere.

[wildwilly4x4]

The only part i still havent found much info on is the shifting linkage. I made a linkage adapter out of a piece of 2" strap that bolts to the old linkage pivot mount on the frame. I also welded on a piece of round stock to extend my original shift linkage. Problem is, i cant shift it manually down past drive(3rd). I read somewhere about putting a "J" bend into to the linkage, but i havent experimented with it too much yet. Also i read that a 700r4 steering column might be needed.

[bilfman]

A company called lokar makes many trans linkage adapters try a google on that. I believe they have something.

[chris989]

Hello all,

I thought i would share my 4l80 swap conclusion with the board.

First, It was worth every penny.

here is the list of things i know to be true now that i did it.

1- my cross member slid back exactly the distance of the bolt spacing. I only had to drill one new hole per side.

2- the 400 turbo trans case adpater will not work, you will need one from a 4l80

3- throw all your linkage in the trash and buy the Lokar rod linkage set up (not cable). worth every penny

4- there are two stock convertor for the 4l80, SB and BB. Use the SB for higher stall speeds. if you trans came from a big block donor it will stall to low for you SB to work well.

5- finding a SB 4l80 dust cover is next to impossible. i had to cut and tig two different covers together.

6 you will need to cut both the trans case shift linkage and the trans case support rod. Easy to do with a few inches of DOM tubing and a welder.

7 the 4l80 dipstick tube from my 93 donor cleared my firewall.

8 the EZ TCU trans controller works well but the programming is archaic and should be an embarrassment to FAST.

9 you can use the rear output speed sensor on the 4l80 for the EZ TCU. I bought a dakota digital but have not installed it. it would only make a difference in low range not using the transcase output.

10 with my two inch lift, i think my original rear driveshaft would have worked. I installed a SYE so i had to make a new rear shaft.

11 you will need a new front shaft.

12 the speedometer cable reached, the 4wd shift indicator wire did not.

13 throw away the steel transmission lines. I used USA made rubber transmission hose and simple automotive hose barb fittings. i used a straight and a 90 on the radiator along with two 45s at the trans. easy, simple if there is a problem any parts house will have more hose.

14 Enjoy the OD. I now run 456 gears and still can cruise at highway speeds.

Chris

[slimneverdies]

Originally Posted by chris989

Hello all,

I thought i would share my 4l80 swap conclusion with the board.

First, It was worth every penny.

here is the list of things i know to be true now that i did it.

1- my cross member slid back exactly the distance of the bolt spacing. I only had to drill one new hole per side.

2- the 400 turbo trans case adpater will not work, you will need one from a 4l80

3- throw all your linkage in the trash and buy the Lokar rod linkage set up (not cable). worth every penny

4- there are two stock convertor for the 4l80, SB and BB. Use the SB for higher stall speeds. if you trans came from a big block donor it will stall to low for you SB to work well.

5- finding a SB 4l80 dust cover is next to impossible. i had to cut and tig two different covers together.

6 you will need to cut both the trans case shift linkage and the trans case support rod. Easy to do with a few inches of DOM tubing and a welder.

7 the 4l80 dipstick tube from my 93 donor cleared my firewall.

8 the EZ TCU trans controller works well but the programming is archaic and should be an embarrassment to FAST.

9 you can use the rear output speed sensor on the 4l80 for the EZ TCU. I bought a dakota digital but have not installed it. it would only make a difference in low range not using the transcase output.

10 with my two inch lift, i think my original rear driveshaft would have worked. I installed a SYE so i had to make a new rear shaft.

11 you will need a new front shaft.

12 the speedometer cable reached, the 4wd shift indicator wire did not.

13 throw away the steel transmission lines. I used USA made rubber transmission hose and simple automotive hose barb fittings. i used a straight and a 90 on the radiator along with two 45s at the trans. easy, simple if there is a problem any parts house will have more hose.

14 Enjoy the OD. I now run 456 gears and still can cruise at highway speeds.

Chris

Do you have any pics of your line run to th transmission? My understanding is that the 4l80e uses push connect fittings...

[slotard]

91 3/4 Suburbans are about like hen's teeth, you're lucky that you found one that still had the parts you needed.

For what EZ TCU costs I'm surprised it's so archaic. Why did you choose it over Microsquirt? You can get that for a few bucks less, plug n play, and I've heard good things about it.

I really need to get around to engine/tranny swap in my C20, just need to find the right deal and time to do it.

[chris989]

Originally Posted by slotard

91 3/4 Suburbans are about like hen's teeth, you're lucky that you found one that still had the parts you needed.

For what EZ TCU costs I'm surprised it's so archaic. Why did you choose it over Microsquirt? You can get that for a few bucks less, plug n play, and I've heard good things about it.

I really need to get around to engine/tranny swap in my C20, just need to find the right deal and time to do it.

the ez tcu does a good job, just the menu driven features are the kind you have to click, click, click through each screen and then when you hit enter it takes you back to the main menu and it requires ~20 clicks to get bak to where you last were. also there is no way to read all of the setting from a main screen. The user has to click through each setting to see what is is. A real pain,,, if the performance is the same, i would recommend any other unit unit the have a better menu platform.

my trans came from a 1993 k3500. Don't even bother hunting for the 1991. there is no need. I had the linkage from a 1991 and still tossed it because it interfered with my exhaust.

the dust cover was the no find part. i cut the oil pan section from the 400 turbo and welded it to the 4l80 cover.
you could use the big block cover, it is just real big around the oil pan.





My rebuild for the whole truck is here
http://67-72chevytrucks.com/vboard/s...50#post7469050

[1968vetL-71]

i Just parted out a 91 V3500 crew cab with a completely rebuilt 4l80 trans/vss205 with factory adapter and shifter, and have every drive shaft (all 3 ), bracket, nut, bolt, dash cluster, shifter, everything! to do a swap into an older crew. I was going to put it in my 76 crew but i decided its gonna stay original.

Gotta love an OD with 4.56's!! Nice

Oh... i think i've got 2 of the 91 dust covers. I'll check that out this weekend.

[chris989]

Originally Posted by 1968vetL-71

i Just parted out a 91 V3500 crew cab with a completely rebuilt 4l80 trans/vss205 with factory adapter and shifter, and have every drive shaft (all 3 ), bracket, nut, bolt, dash cluster, shifter, everything! to do a swap into an older crew. I was going to put it in my 76 crew but i decided its gonna stay original.

Gotta love an OD with 4.56's!! Nice

Oh... i think i've got 2 of the 91 dust covers. I'll check that out this weekend.

If you have a SB 4l80 dust cover i would buy one if you do not need it. Mine installed ok but the heat did get to it and i can not get the top bolt in near the starter. Also, I would rather have something original and not my frankincover.


let me know,, PM me

Chris

[chris989]

Originally Posted by slimneverdies

Do you have any pics of your line run to th transmission? My understanding is that the 4l80e uses push connect fittings...

here are the pics of my trans lines. i believe my 4l80 was 1/4 mpt. There may be some push type connector but the threads in the trans housing should be MPT. ( I COULD BE WRONG) but my 1993 was nothing special.


The top line has the 90 out of the radiator


i ran along the inner fenderwell using the insulated strap clamps.



same type clamps to the underside of the body



I ran one 45 forward and one aft. the picture does not show well but they were fighting with my fuel lines and i could not keep the rubber from laying on the steel braid. (and my braid is rough, i was afraid it would eat through the rubber)




I know it is not as pretty as AN stuff but it was easy to work with, easy to inspect and easy to replace.