First time swap. LQ9 into 95 OBS

[kewljay223]

I just read this whole thread. Tons of info here. I am new here but should this be a sticky before it gets buried?
Kewljay good job on the swap. Looks like it took you about 2 months? Think you can do it in 6 weeks? Lol. Im gonna try in my 1990!

Did you use your stock radiator?
Also I need my transmission in the same exact spot. Would you go with the 1" setback mounts again? I thouht about some $30 ebay brackets but idk after seeing your issues.
One more thing.. what guide did you use when modifying your harness

yeah its taken me about 2.5 months. i ran into a few issues but mostly the reason it took so long was my work schedule. plus i was still learning things along the way. but if i was to do another, i would be able to purchase more parts before hand, and with the knowledge i have now, im sure i could shave a month off. if this is your first, dont expect that tho! lol not gonna happen.

yes i used the stock radiator and it works fine with the exception of my overheating issue but thats not due to the rad. im not sure if i would go with the same mounts i got due to the extra trimming of the clamshells but i think mickey posted a set that didnt require the extra notching a several pages back. you need the 1 inch tho if you want to keep everything in the stock location.
word of advice. i know you want to do this on a budget as does everybody. but there are things that just make life easier if you pay a lil more and trust me its worth it. im not talking with motor mounts alone. 30 bucks seems cheap to me. i have a funny feeling they wont fit right. its a pain in the ass enough as it is forcing something that it wasnt designed to to. go with tried and proven parts on the major stuff and choose what you can skimp on for the minor things. just my 2 cents from my experience.

as for the wiring, there is no guide... lol every application is different so its up to you to figure it out. if you dont want to or dont trust yourself with it, have your harness reworked. this is the most time consuming part and confusing part. if you want to go through with it, all you need is diagrams from both vehicles, and do one wire at a time. i made a list of everything that needed to be cut and converted and i did them one by once checking them off as i went. but everybody has their own way of doing things. check out http://search.ebscohost.com/login.as...ile=autorefctr for diagrams. username: student
password: watc

good luck!!

[jwang203]

Thankyou so much!

[kewljay223]

i know im still not finished with the motor swap yet but i wanted to get the ball rolling on the 80e swap. im so nervous to punch it with the 60e... i really dont know what this thing can do yet! anyway, so i started looking for an 80e and last night after work i found an add that was posted yesterday for one that was a fresh rebuild with all updated parts and has only 17000 miles on it. picked it up an hour ago for 500 bucks!! i jumped on that deal since they normally go for about 850 with a lot more miles!! plus the guy knows his stuff and owns two smog stations!! craigslist can be scketchy but it can also make you new friends!!! lol. so while i finish cleaning up my engine compartment, i will be looking for the rest of the needed parts and how to's to complete the swap.

a few questions though about it.

1) since these trannys came in the hd obs trucks, i assume there are driveshafts in the yards that will be a direct change over as long as the chassis length is the same correct? should i look for one of these or just get mine shortened? if i shorten it, i will still have to get the new yolk and all. thats why im thinking a used one from an hd truck would be easier and cheaper. any thoughts?

2)anybody have the pinout diagram and which wires i need to change on the round connector? i know you did the 80e swap mickey... im counting on you for this!! haha

3) are the trans cooler lines a direct swap (thread wise) or will i need adapters?

4) mine didnt come with the black shifting module that the rectangle and square connectors plug into. will the one off my 60e bolt up the 80 case or do i have to buy one specifically for the 80? or make my own bracket to use the one i have? i read through the 60 to 80 swap sticky and it looks like it will swap over. but he mentioned something about a tcm... my truck doesnt have that correct? what am i supposed to do?

heres the new tranny. yay!

[Mickeymotormount]

Actually, I went from a 4L80E to a 4L60E. Kind of ass-backwards since the original 4L80E that came with the motor was cooked. I would have liked to stay with the heavier trans but that would mean I would have to find a donor truck with the right driveshafts in order to fit. For me, it was easier to stay with the 4L60E or 65E to keep the same driveshafts.

You will need to change some/add some wires on your trans plug in order to run the 4L80E. Also have to add a smaller harness for the other VSS on the side of the trans. This is not hard but will take time to track down and put all the wires in place.

[kewljay223]

alright thanks. ill search a lil more while i look for the rest of the parts do do the swap.

but i gotta ask how do you get the PRND light working!? thats basically the last thing i need to hook up. i cant find anywhere in either set of diagrams a specific light for the letters. all i can see is that they go from the switch to the pcm so im assuming the pcm controlls it? will the new pcm work on my old cluster? or am i supposed to just piggy back the 4 wires going to the square connector from the old harness? i dont get it.

and the only other issue is when i turn my key off, all my gauges go down except my fuel gauge, it pegs out. the only thing i did to that circuit was splice in the ppl wire to the new pcm. is the new pcm sending a signal or something? do i need to put some sort of diode in there so stop that from happening? ill check it out a lil more. just thought id bring it up to see if anyone else had that problem.

[Mickeymotormount]

After reading your previous thread, I'll try to answer a couple questions you asked.

1)You may luck out and find a 2 wheel drive 3/4 ton that had the 4L80E driveshaft. That should get you close but the rears may be different between your truck and the heavier truck. Something that will have to be investigated. You may be better off adapting/shortening your old shaft. Depends on your search outcome.


2) I have the pinout diagram for a '99 4L60E/4L80E. Hopefully it hasn't changed from this year to your year trans.

3)I don't know about the trans cooler lines. Could be a toss-up. Hopefully you win and you won't need any adapters.

4)As far as I know, they are the same along with the bracket. I will check the wiring schematic to see if the same wires go to each trans "shift switch". I will post them shortly.
My truck doesn't have the indicator light for the gear position. I guess I should say lucky me. As for your gas guage, not sure either since mine doesn't need input from the PCM to work.

[kewljay223]

thanks for the reply mikey. i think im going to go the route of just modifying mine. like you said, even if i get one from a 3/4 truck, the rear will prolly be different and have to modify it anyway so might as well modify mine. and ill see whats up with the trans cooler lines when i get there... lol and i was looking at the bracket the other day and i think it has provisions for both trannys... GOOD JOB GM!!

so i have been trying to deal with my PS pump whining issue and i just cant figure it out. im 99.9% sure i have the hoses hooked up correctly but the pump whines like crazy. i can hear it over my LOUD ASS exhaust on the freeway... im driving around without a hood at the moment but i highly doubt i should hear the pump. it seems to be quiet when i first start up the motor but as soon as i turn the wheel, it starts making noise and wont stop. i have to admit i hooked up the lines, polured fluid in and ran it for a few days without checking.... and when i finally checked it again it was low so i filled it up and its been the same level since. so i know there is no leaks, it was just air in the lines that finaly came out. im worried that i damged it by running it low on fluid for a few days. it steers just fine but i can feel a little vibration when im am turning sometimes. could i have damged it? how can i tell if the pump is bad? its gonna be a pain in the ass to change due to how its mounted so i dont want to change it if i dont have to. what do you guys think? is it in need of replacement even though it seems to be working properly?

[Mickeymotormount]

1) I'm still working on the pinout diagrams for you. I can't seem to get my scanner to scan them correctly. As soon as I get it figured out, I'll post them. Hopefully, your trans is wired the same as a '99.

2)When I had issues with my pump, it would be quiet for the first minute of operation upon startup. After that, she would whine like crazy. It still steered easily, but noisily. That's when I did some checking and found that I was dumping return fluid to the wrong port. I'm not sure if you damaged your pump or not. It may be an issue with your double return hoses you hooked up. As far as I know, and by looking at alot of other pumps, the return is the one on the bottom center of the pump. The top port is the Hydroboost return port. I know it's probably a pain in the a##, but maybe you should try just one return hose before switching out the pump for another one.

[kewljay223]

appreciate you working on the diagrams for me. and yeah, mine is acting the same way noise wise as yours did. quiet at first then i can hear it real bad. ill try your suggestion of just capping the top port and see if that solves it. i sure hope so.

[Mickeymotormount]

As promised, here are the schematics for the 4L80E. These are out of the 1999 GM service manual. Hope these help!!!