NV4500 Swap

[Dneel81]

So I got the reverse light wiring figured out. The pink wire on the prnd321 harness hooked right up but I didn't know which green wire to use. I found out by shoring them out and walking to the arse end of the truck with the key on. Voila!





Got her running again and hooked up. Clutch feels like there'a a touch of air in the system but it works well enough to drive around the land a bit. Thanks to SunLitComet, I figured out the wiring to the 4x4 actuator switch. Drove around the land a bit and had a ton of fun. 4x4 high, 4x4 low, 2Hi all work well.


Thank you to all of you for all the help you've contributed to me and any poor soul who attempts this in the future. All that's left is to get the truck tuned. Well sortof...when I started the truck and drove it, feels like the driveshaft might be a bit out of round or something is wrong that makes it vibrate when I get on it. But I feel no wobble when I'm coasting. And when I hit the door locks on the door itself, the interior lights come on. And the keyless entry doesn't work anymore. Electrical gremlins I'm assuming are responsible for that. Maybe I got some brake fluid where it didn't need to be. I'll tear into the dash and figure out WTH is going on. But she drives and shifts great. I love the NV4500. Heavy duty tranny that shifts just a little worse than the wife's mustang (above). Anyway, thank you guys again!

Dave

 

[SunlitComet]

BURN THE FORDS!!!!

 

[Dneel81]

Nah, I'm gonna swap a ZF6 into the truck and wire in a new Coyote Motor (like what's in my wife's GT) and then let that thing run loose. Ideally I'll get a 6.0 together for the Tahoe and be set to go.

 

[SunlitComet]

then get a plymouth roadrunner to play with the coyote.

 

[Dneel81]

I'd rather have a Raptor. Another Ford, I know. I've put 600,000 miles on a ford and GM tahoe/yukons. Cant say either is any better than the other. Wish Ford would have given me a bigger motor with my 5 speed 4x4 pickup, but that coming from a guy who just ripped out the tranny and put in the one he wanted in the Tahoe. Otherwise they're both good trucks.

 

[Dneel81]

So I've been driving the Tahoe around with it's new driveline. Getting lots of vibrations from the driveline when I'm accelerating and the tranny feels like she's moving around alot in the tunnel. This is new since all of my "work" on the truck. The auto had no vibrations or weird clunks. I thought it was the u joints but took them all down last night and they're all fine. Good and snug, needles look good, grease is even fresh. The difference in my driveline lengths has about 1/2 of fresh steel exposed on the slip yoke. Splines are well engaged between shaft and the NP241. I'm exceedingly naive (ask SunLitComet, he knows) when it comes to this crap. Best thing I can figure out is 1 of 3 things.

1. Bad motor mount: I let the trannies (both outgoing and incoming) sag a bit to help me get my 2' ratchet extension in place for the bellhousing bolts. Could I have warped/fractured a motor mount and that's torquing my drive line when I get on the accelerator? I put lights in from above and below and can see/feel no fracture on the motor mounts. Also looked at the motor under load and couldn't see any obvious lurching or rolling of the motor that you see on those perfect Youtube videos...

2. Second option is bad driveline pinion angles that are not playing nicely together. That's all I've got and that's just from scouring the internet searching "nv4500 vibration." I used the same transmember mount that the 4L60e used (on the tail of the tranny). All those bolts are snug. I have nothing else even remotely intelligent to say about that. I think I'll take her in to a driveline shop and see what they can do. I need to figure this out as my other truck has a cylinder misfire (bring on the bad Ford jokes...now!) and the Tahoe is the DD for the time being. I'd love to not screw up my transfer case and NV4500 I just paid $$$ for.

3. Transfer case output shaft bushing. The guy I bought the NP241 from never started his jeep rocker build so no idea if that's bad. If the NP241 is from a 1997 K2500, I have read they both did and DID NOT have bronze bushings in the xfer case tailhousing. would make it easy to rule that out if it didn't have one to begin with...

Thanks guys

Cmon brain trust...

 

[Dneel81]

The latest installment of the driveline vibration saga continues. The main link is on Pirate4x4 but I figured this might help out some poor bastard in the future on this forum. I figured out my drive line pinion angles were off by about 3-4* so I bought some shims. I got the F150 running again so I could play with the Tahoe some today. Took the wheel off and stared for a minute at what I saw...

Here's the block/spring set up I found after taking the tire off. This is looking at the right rear side from the forward side of the wheelwell. Note the two sets of perches. The original bumpstops were closer to the rear differential (more medial) and I assume the lift kit welded new perches and left the old perches and bumpstops there.



From the rear of the right rear axle. Just another shot of the perche setup


This is what she looked like when I loosened the front u bolt. Notice the bolt through the springs without a nut on top. What kind of slack jawed half ass did this lift kit work? I know blocks are dangerous but WTF. Also if you notice, I think the bolt head is supposed to sit in the middle round recessed area of the block. NOT HOW I FOUND IT. The bolt was sitting in the front square-shaped recessed area on the block. I have a feeling the driveline had shifted toward the back of the truck about an inch. Scary to say the least. The bolt head upon further inspection fits perfectly inside the block circular recessed area, lending more creedence to the idea that I think it fits in the round hole on the block. Moreover that would let things sit flush and theoretically be more stable. Just have the shim there for length/width measurements. (i.e. I realize it is backwards from what's necessary to make the pinion more flat).


I know the shim is in backwards for what is required to lower the pinion but as far as size, this is correct. It's the proper length and width.



Notice the hole in the spring pack and the block do NOT line up. Maybe they're not supposed to line up? There is not a picture to demonstrate this but the bottom of the block has a "nipple" that protrudes about 1/2" that fits into a hole on the top surface of the perch.



The piss poor state of the "bolt" in the spring pack...

Another picture of what I'm thinking.


So at this point I'm thinking I have a fair bit of work ahead of me.

I need to replace the bolt in the spring pack with a new complete bolt with some washers (grade 8). I need to figure out the bottom part. I'm thinking if I bring the bolt in from the top and have a locking washer and a nut on the bottom that would protrude into the recessed area on the block. I could include the shim in that bolt.... Further, I'll have to include the shim in the mix somewhere too. The shim is 4* and thick enough that it doesn't really leave enough "nipple" to go into the top of the perch if I put it there (between the perch and the block). Then it seems the block/perch relationship would be unsteady. I thought if I put it on top of the block and drilled a hole big enough for the nut to protrude I could still have the bolt-nut from the spring pack mated to the circular hole in the top of the block. OR I could bolt the shim to the underside of the spring pack and let the rest of the bolt stick into the circular hole on top of the block. I'm naive as to how the lift kit is supposed to be put together. I'm fairly certain, despite me being a lift retard, that this is incorrectly assembled as I found it. And yes I did fail out of engineering school (calculus III) prior to medical school.

Another thought was to bring the bolt up from the underneath side, first through the shim, then the spring pack, then the top U bolt bracket thing and put a lock washer and lock nut on the top of the whole leaf spring assembly. That way the head of the bolt on the underside of the shim could sit in the center of the block on the underneath side and still have the shim in a good spot. Then I think I'm going to brush the u bolt threads, strip the rust, and locktite them all on. I'm not sure how much to torque them but I figure as hard as I can wouldn't be a bad place to start.

Another problem: If I'm going to have the head of the spring pack bolt in the center of the lift block (centered on the perche) then the whole freaking axle is going to have to move toward the engine by about 1 inch if my guesstimates are correct. The center of the spring pack bolt is NOT the center of the perch hole.....see below.

I've got the clearance just looking at the wheel wells. Ironically there is rub evidence on the rear part of the wheel wells...maybe an inch toward the front wouldn't be a bad thing.

Again, sorry this is so involved. There's lots of info and even more questions. I want to do this right, including scrapping the whole kit and buying a new one that fits correctly. I'd rather not, but I want a safe ride for my wife and kids to come with me and not worry about the whole damn rear axle falling the frick off the truck.

Thank you for any suggestions/tips on how to fix this catastrophe.

 

[SunlitComet]

notice the bolt. http://www.gmpartseast.com/chevy/co...wd_springs-rear-tc070150107-l31m30k10706.html

 

[SunlitComet]

and the axle. http://www.gmpartseast.com/chevy/co...-rear-complete-tx0510140105-l31m30k10706.html

 

[Dneel81]

So got the shims in correctly and the pinion angles are right under 1 degree (static). Driveline vibration is better but still not tolerable under acceleration from a stop/romping on it. I'm not convinced a short drive shaft will be the culprit. I tend to lean more toward the transfer case tail house bushing or the output shaft bearing being the issue. I'm not convinced that looking at the output spline shaft spinning while in 1st gear with the driveshaft off is going to show me anything even if it was out of round. I think under load would be the only way to see that. Doesn't seem particularly difficult AT ALL to replace the bearing and the bushing. But it does mean throwing parts at a problem in hopes it will fix it without knowing what's actually causing the problem...thoughts?