97 tahoe 5 speed swap

[#1taho]

 

[87carl]

If everything goes according to plan I will pull the axle bumper and tail lights off the z71 and cut the drivers side of its frame the rest of the way we're it's cracked and remove the entire back half off that truck tomorrow.


Has anyone ever seen anything about someone shoving an 80s single cab shortbed truck frame under a 90s tahoe? I am tempted to try it because it will give me a straight axle it will fix all the frame rust issues I have. The wheel base is the same and motor tranny mounts will line up perfectly drive shafts can be used. Only issue I can see is transfer case is passenger side drop so I would have to use the np208 out of an 80s truck but question is can I use the 32 spline input shaft from the z71 transfer case in an 80s transfer case? Also would have to figure out something with the fuel tank body mounts can probably be cut from the Tahoe frame and welded to the 80s frame. I am trying to decide if I should try to do that or keep patching the rust on the Tahoe frame? I know were an 80s single cab shortbed parts truck is sitting just don't know if I have enough money to buy it and don't know if I should try to do it? Spent today loading scrap in my dodge I will take that in in the morning see what I get for it then maybe go see what they would want for the 80s truck.

 

[87carl]

They want 600 firm for the 80s truck forgot to ask what year. It's got a running 350 engine no transmission no fenders doors bed or hood but I won't need any of that I just need the frame axles suspension and drive shafts transfer case and probably steering box could probably get 300 back selling its motor but idk that's more money than I have rite now and will have to sell a bunch of parts to get that much so I don't know. Tempted but not sure if I should. I will take measurements off the Tahoe frame tomorrow then go look at the 80s truck and measure it's frame.

 

[87carl]

Weather has been ****** snowy windy and freezing so haven't been able to do much but I started pulling small parts off the inside of the z71 today. In hooked the shifter almost got the 4wd shifter out but the bottom bolt is being stubborn turns easy most of the way but locks up tight when it's almost all the way out. I left it to soak in pb blaster then pulled dash bezel and gauge cluster then the steering column started pulling the clutch pedal out but there's one bolt that is being blocked by the wiring harness and still trying to figure out how to unhook the harness so I can move it and get that bolt out not much progress but it's atleast 's start. didn't get any pictures using the phone as a flashlight to see under the dash killed the battery.

 

[87carl]

Can't wait till warm weather so I can get more done on this project. Hopefully the weather idiots are right and next week will be in the 60s. Till then I keep doing little things on it. Changed the computer to the z71s computer changed the gauge cluster so it no longer says prnd321. And changed the steering column. Also removed the electric 4wd buttons from the dash

Ignore the lines in the picture my phone does that when battery gets low.

After I changed the computer and gauge cluster I started it and let it run for a while before I changed the column. Only thing I did after that is change the column. After I changed the column it won't start it's got power to everything and everything else works but it won't crank over. My best guess is there was a safety switch in the old column that used to tell it the truck is in Park or neutral to let it crank. And by switching columns it's not getting that signal? Does that make sense or could it be something else? If that is the problem should I figure out what wires are causing it to do that and hook them to the clutch pedal switch or neutral safety switch? The automatic steering column had a little box with a rod that connected it to the shifter and had two wires that go into the main plug. Is that the park/neutral safety switch or the reverse light switch?

 

[87carl]

And I know it is filthy I will clean itit when I am done swapping everything

 

[87carl]

Oh and most of the cut wires on the dash were either on the steering column or were on a trailer brake controller that's being removed this tahoe will never need to pull a trailer that's what my truck is for. The rest are splices tied on the main start wires looks like some previous owner put a remote start in it and later cut it back off. So at least the wiring ain't as bad as I thought. Swapping columns fixed more than half of the cut wires.

 

[bluex]

That's an nv3500 trans in your pickup. No half ton came factory with a 4500 I believe. The 3500 should be plenty for a daily driver.

 

[xanatost]

Is any the dash in good shape on the parts truck? If so would you be willing to sell it? I'm looking for a good dash because mine is all cracked up. Good progress so far. Keep the post and pics comming. I'm starting to get parts for my hoe when I change her over to manually transmission.

 

[87carl]

From what I read online You could special order the nv4500 in a half ton but not many got it. So I figured this was probably the nv3500. Couple days ago I looked under a friend's Truck I know has a nv3500 and it look identical to mine verifying mine is the nv3500. And ya they are plenty strong enough for what I will do with this tahoe. My friend beats the piss out of his truck and that nv3500 has held up. I won't be off roading the Tahoe or hauling heavy loads. My dodge does all that. The Tahoe is just for regular driving with the family it's hard to fit 2 carseat and 2 big dogs in our subaru or the dodge.

The parts trucks dash is cracked thru the defrost vents and I used it's radio/cluster bezel to replace the broken one that was on my hoe. If you do a manual transmission conversion I strongly recommend buying a complete parts truck buying it peice by peice gets expensive quick. I paid 400 for my parts truck and should be able to sell its motor for 500 and sell the Tahoe auto trans for another 300 or 400 axles for another 200 and sell other parts and end up completely covering the cost of the swap plus put a little extra in my pocket. Plus it's alot easier to go back to the parts truck for more parts if it's ten feet away rather than 20 miles away at a yard.
Most of it is pretty simple just unbolt automatic junk and bolt in new parts. Hardest parts so far is getting to the one bolt on the clutch petal bracket. Stupid wiring harness and everything else is in the way. Other hard part atleast for me is the electrical stuff. I will keep posting pics and details as I figure it out and get it done. Hopefully we get warm weather next week so I can at least get the manual Trans in the Tahoe and can start to figure out wiring.

 

[87carl]

Another kinda hard part will be drilling the hole for the clutch master cylinder the spot for it is stamped in the Tahoe firewall but there is no way to get a drill and hole saw straight on it without removing a bunch of other stuff like the fuse box computer/abs bracket and possibly master cylinder first. Cutting the floor for the shifter and 4wd shifter will be easy the spots for them are already stamped into the floor. Doing 5spd swaps on early 90s chevys alot of the threads I have read said that they had to weld the upper bracket for the clutch pedal in place because it wasn't there. (were the bolt that's hidden under wiring harness that I keep fight with is) but I am about 80% sure I see it up in there on the Tahoe still gotta move stuff like the wiring harness to get a good look of that.

 

[xanatost]

All I would need is the dash it's self. Don't need any of the other stuff. If it is something that you would be interested in sell would you mind sending some pics? I might be able to fix the broken defrost vents if there not too bad and there are no other cracks running through the dash. My email is rodneypowell01 (at) yahoo.com. also it might be easier if you remove your dash too to get to some of the harder to reach areas and if you have to weld anything would definitely be better too.

 

[87carl]

Were do you live I am in western NY

 

[87carl]

I am not sure of how you would ship a dash without it getting broken? Do you know? I can get Pics of the z71s dash tomorrow

 

[87carl]

I have been searching online the thing on the right side of the automatic steering column that connects to shifter and has 2 wires going into main connector is actually the shift interlock that makes it so you can't shift out of park without pressing the brake pedal. The 4l60e has a neutral safety switch on the left side of the Trans just above the shift linkage. From what I am reading I need the purple and yellow wires from it to connect to the nv3500s neutral safety switch. Hopefully I just pulled the linkage slightly out of park when changing steering columns and that's why it won't crank now I will climb under it and make sure it's fully in Park tomorrow if it still won't crank I will connect the purple and yellow wires I just mentioned to bypass neutral safety switch and see if it will crank over. If it still won't start I will have to keep searching. Hopefully purple and yellow are the rite colors.

 

[87carl]

Just found a thread from 2012 about a guy doing a 5spd swap with nv4500 in a 99 tahoe.

http://www.tahoeyukonforum.com/threads/nv4500-going-into-99-2-door-tahoe.37537/

Another 5spd conversion thread is 88gmctrucks thread on fullsize not a tahoe but still lots of good info

http://www.fullsizechevy.com/forum/...torations/410690-88gmctrucks-nv4500-swap.html

Anyone know of any other good 5spd conversion threads most I find googling are people asking will it work not much detail on doing it

 

[87carl]

Despite being 2 am curiosity got the best of me so I went out to check. Turns out the shifter on the 4l60e won't lock into Park without the cable being connected to the column so I pulled it into neutral and the Tahoe started rite up perfectly. So that's awesome

 

[87carl]

Made some progress today. We got the nv3500 out of the z71 and cut the z71's floor out to use as a template so i know exactly were to cut the Tahoe floor.

 

[87carl]

One other thing i want to fix on this truck is that if you leave it off for more than an hour she won't start unless you prime it by cycling the fuel pump 3 or 4 times then she fires rite up what can cause that?

 

[87carl]

That is the wiring printout for the 4l60e range selector / neutral safety switchs 7 wire connector. There's also a 4 wire connector but none of those wires are needed. For a 5 speed conversion we need pins C E F and G on the seven wire connector. Pins G and E are for the neutral safety switch or clutch pedal start switch you can either can connect wire to them and run it into the cab and connect it to the clutch pedal switch or pull them back out of the loom then thru the firewall and connect to clutch pedal switch. Pins C and F are the reverse switch wires the reverse switch is on the left side of the nv3500 mines wires are the same colors green and pink cut the wires off the 4l60e range selector plug and connect them to the nv3500 reverse switch plug. That's what of the wiring i have figured out so far. Still got to figure out if the wires on the transfer case are the same or if different. On the transfer case is the vss sensor for the speedometer and a 4wd indicator sensor that tells the front diff to engage and turns on the 4wd indicator lights in the cab telling you its in 4wd. I am hoping the plugs will be the same between transfer cases but if not i will post what i have to do to get them hooked up.