69 K5 LS 6.0 [Deleted]

[Coontail]

Has anyone else had this issue adapting a 99-2006 4L60E 4WD transmission to my original 1969 NP205?

When I called the tech at Advanced Adapters, the only advice that was given was to purchase the $800 kit that would have me replace my stock output shaft with their output shaft.
Makes me wonder why they offer the 50-0405E kit if the adapter isn’t long enough to allow the supplied gear to align with the original shaft.
I have a mill & can easily remove the .625” of material from my factory 350 to NP205 so it will fit the 0405 adapter as the supplied directions direct but that doesn’t address the output shaft length issue.

Neither does replacing my stock 13.25” shaft with their 13.25” output shaft...
I already spent $1500 to rebuild the transmission, it doesn’t make sense to buy their $800 kit then pay the transmission shop to replace my output shaft with theirs at this point...

Can anyone shed light on my issue?

Assuming you have a figure 8 np205, I think they made other patterns, all you need is this adapter https://www.offroaddesign.com/4l80e-figure-8-np205-adapter-housing.html

Then you need to mill a flat on the output shaft housing on the transfer case for the speed sensor as well as install a reluctor ring on the output shaft as well

ORD offers it all in a single package as well https://www.offroaddesign.com/catal...1/s/4x4-4l80e-to-figure-8-np205/category/656/

 

[venevidivicci]

That’s for a 4l80e he has a 4l60e. I did this swap before the kit was so expensive. It still wasn’t cheap when I did it.

Ultimately the original shaft for the 4l60e has too much spline too far on the end. The shaft would have to be cut down and by that time you do not have a good enough amount of spline to engage with the original drive sleeve that our adapter uses.

Bothe the adapter And sleeve has to be machined. The adapter flat on the first shoulder to only utilize the “o”ring seal. Then the Drive sleeve has to be machined shorter. Last issue I recall was I don’t think the original output shaft has the correct diameter for their VSS ring to clamp to.

I rebuilt my trans and installed the shaft myself back when I did it. I have more pictures but would have to get them from an old computer.

What tire size and gears are you going to be running? The low range in the np205 is the only thing I’m not happy with in the end. It drives phenomenally but doesn’t crawl as slow as I would like.

I attached the pic I have of the adapter machined down and the red mark on my Steve during mock up showing about where the sleeve was going to be machined down to.

 

[Coontail]

Woops I assumed they would be the same, my bad

 

[19Tim69]

That’s for a 4l80e he has a 4l60e. I did this swap before the kit was so expensive. It still wasn’t cheap when I did it.

Ultimately the original shaft for the 4l60e has too much spline too far on the end. The shaft would have to be cut down and by that time you do not have a good enough amount of spline to engage with the original drive sleeve that our adapter uses.

Bothe the adapter And sleeve has to be machined. The adapter flat on the first shoulder to only utilize the “o”ring seal. Then the Drive sleeve has to be machined shorter. Last issue I recall was I don’t think the original output shaft has the correct diameter for their VSS ring to clamp to.

I rebuilt my trans and installed the shaft myself back when I did it. I have more pictures but would have to get them from an old computer.

What tire size and gears are you going to be running? The low range in the np205 is the only thing I’m not happy with in the end. It drives phenomenally but doesn’t crawl as slow as I would like.

I attached the pic I have of the adapter machined down and the red mark on my Steve during mock up showing about where the sleeve was going to be machined down to.

View attachment 338911

View attachment 338912

Thanks...I have a mill so the machine work on the OEM Adapter & the power sleeve has to happen no matter what.
I guess it would have been nice to have known about the output shaft. Somehow I missed that.
Makes me wonder why they sell the 0405E kit without the output shaft. Seems worthless without it.
They charge a premium for crappy cast adapters that don’t seem to be even the quality of the factory...lol
I now plan to run 411 gears with 33” or 35” tires...
I have a 241C that was behind my 700R that I may look into using.

 

[19Tim69]

Woops I assumed they would be the same, my bad

I guess in the end it may have been about the same cost as going with the beefy 4L80.
I was looking at many changes either way...

 

[TuckerK5]

Thanks...I have a mill so the machine work on the OEM Adapter & the power sleeve has to happen no matter what.
I guess it would have been nice to have known about the output shaft. Somehow I missed that.
Makes me wonder why they sell the 0405E kit without the output shaft. Seems worthless without it.
They charge a premium for crappy cast adapters that don’t seem to be even the quality of the factory...lol
I now plan to run 411 gears with 33” or 35” tires...
I have a 241C that was behind my 700R that I may look into using.

I had 3.73 on 33’s with LS motor and 4L60. It was awful at 60 mph. It lugged the motor really bad.
I put in 4.56 gears and it was great. The LS really liked 2,000 rpms at 60 mph. It cruised with very little throttle and got way better gas mileage.
I switched to 35s and lost a little but it’s still a million times better than it was with the 3.73s on 33s.
Point being I don’t think you’ll be as happy with the 4.11s as you would with 4.56s and especially if you do go up to 35s.

 

[venevidivicci]

If you already have the 241c I would look into that for the gearing.

I have 4.10’s and run 35” BFG KO2. I’m very happy with how it cruses. I pull a pop up camper with it and I can pass people at 85 on the highway. It does good off-road but when I go crawling the 4x4 low is just a little faster than I would like.

here is a webpage I have played with a lot and suggest to people. Put in and compare different combinations.

http://www.grimmjeeper.com/gears.html

 

[TuckerK5]

If you already have the 241c I would look into that for the gearing.

I have 4.10’s and run 35” BFG KO2. I’m very happy with how it cruses. I pull a pop up camper with it and I can pass people at 85 on the highway. It does good off-road but when I go crawling the 4x4 low is just a little faster than I would like.

here is a webpage I have played with a lot and suggest to people. Put in and compare different combinations.

http://www.grimmjeeper.com/gears.html

You're pulling a camper 85 mph with a K5?

About 70 is as fast as I want to go in mine without towing anything. And I think I'm being a little reckless at that.
And it drives and handles as good as new vehicle. It just doesn't have the safety features of a new vehicle and if I roll mine with the soft top and no cage my head will be the first thing that hits the road.

Your are right though. It depends on what your typical cruising speed is going to be.
I'm normally doing 60 around here on curvy and hilly roads just using mine as a DD.
If I were going to be doing 85 on a regular basis I would want 4.10s on 35s.

 

[19Tim69]

You're pulling a camper 85 mph with a K5?

About 70 is as fast as I want to go in mine without towing anything. And I think I'm being a little reckless at that.
And it drives and handles as good as new vehicle. It just doesn't have the safety features of a new vehicle and if I roll mine with the soft top and no cage my head will be the first thing that hits the road.

Your are right though. It depends on what your typical cruising speed is going to be.
I'm normally doing 60 around here on curvy and hilly roads just using mine as a DD.
If I were going to be doing 85 on a regular basis I would want 4.10s on 35s.

Mine will see more pavement than crawling hills except those weekends hunting & camping...I’m not sure I ever thought about 85 MHP with my suspension but my original idea was 373’s because it’s a good combination with my 01 Sierra but that was with the 350/350 that I was going with.
The HO 6.0 has more hp than that other combination....the 456’s do sound like an idea I can toss around but 35” will likely be the biggest rubber I’ll consider.

 

[19Tim69]

If you already have the 241c I would look into that for the gearing.

I have 4.10’s and run 35” BFG KO2. I’m very happy with how it cruses. I pull a pop up camper with it and I can pass people at 85 on the highway. It does good off-road but when I go crawling the 4x4 low is just a little faster than I would like.

here is a webpage I have played with a lot and suggest to people. Put in and compare different combinations.

http://www.grimmjeeper.com/gears.html

I like that link. Thanks, I’ve got to solve my transmission adapter issue but I have 373’s now with a set of 411s on the shelf so I have time to think about what I’ll do after

 

[19Tim69]

I had 3.73 on 33’s with LS motor and 4L60. It was awful at 60 mph. It lugged the motor really bad.
I put in 4.56 gears and it was great. The LS really liked 2,000 rpms at 60 mph. It cruised with very little throttle and got way better gas mileage.
I switched to 35s and lost a little but it’s still a million times better than it was with the 3.73s on 33s.
Point being I don’t think you’ll be as happy with the 4.11s as you would with 4.56s and especially if you do go up to 35s.

What engine where you using?
I’m using a LQ9, by the time I strip the accessories that aren’t needed & put the long tube headers without the cats it should be around 400HP. I guess I’ll have to wait & see at this point but your 456s could be in my future

 

[TuckerK5]

What engine where you using?
I’m using a LQ9, by the time I strip the accessories that aren’t needed & put the long tube headers without the cats it should be around 400HP. I guess I’ll have to wait & see at this point but your 456s could be in my future

I have the GM Performance LS376/480 495HP Hot Cammed.

https://www.gmperformancemotor.com/...MI9e-gj-yk6QIVgp6zCh2eRAxXEAYYASABEgL7d_D_BwE

When I had 373s on 33s it lugged bad (took about and inch of throttle and got 12 mpg) at 60 mph and sucked gas. I think you'd be in about the same place with 410s and 35s
Also with that ratio anytime the engine started to breath a little it was trying to run away. 80 mph is where it would start to free up and stop lugging. I did not want to go that fast on 2 lane Alabama roads.
Now it takes about 1/2" of pedal and gets 20 mpg at 60. Edit: Also it has no problem with 70 mph either.
The other benefit of gearing low like that is it takes stress off your entire drivetrain (assuming everything is smooth and no vibrations) so it doesn't just free up the engine.
Think how much less strain is on your transmission, and driveshaft / ujoints.

I was always been a fan of higher gears is better gas mileage before this setup. I was wrong! You really want the setup that gets you the least throttle effort at your most common cruising speed. Never mind engine RPMs.
The only problem with my setup is that every time I start off it's hard not to drop the pedal about half way down and launch like a rocket off the line. It's like the pedal is calling my foot a p-word the whole time I am driving it. Way fun!!


.

 

[TuckerK5]

With my old setup it was stressful driving it because I was constantly having to work the throttle up and down with every little rise in the road.
Now it just pretty much stays in the same place up or down hill.
People piss me off when they slow down going uphill in front of me and they get sh_t scared out of them when I drop the hammer and blow by.

 

[19Tim69]

I have the GM Performance LS376/480 495HP Hot Cammed.

https://www.gmperformancemotor.com/...MI9e-gj-yk6QIVgp6zCh2eRAxXEAYYASABEgL7d_D_BwE

When I had 373s on 33s it lugged bad (took about and inch of throttle and got 12 mpg) at 60 mph and sucked gas. I think you'd be in about the same place with 410s and 35s
Also with that ratio anytime the engine started to breath a little it was trying to run away. 80 mph is where it would start to free up and stop lugging. I did not want to go that fast on 2 lane Alabama roads.
Now it takes about 1/2" of pedal and gets 20 mpg at 60. Edit: Also it has no problem with 70 mph either.
The other benefit of gearing low like that is it takes stress off your entire drivetrain (assuming everything is smooth and no vibrations) so it doesn't just free up the engine.
Think how much less strain is on your transmission, and driveshaft / ujoints.

I was always been a fan of higher gears is better gas mileage before this setup. I was wrong! You really want the setup that gets you the least throttle effort at your most common cruising speed. Never mind engine RPMs.
The only problem with my setup is that every time I start off it's hard not to drop the pedal about half way down and launch like a rocket off the line. It's like the pedal is calling my foot a p-word the whole time I am driving it. Way fun!!


.

Okay, I live in the Tahoe National Forest, I drive from 1500 elevation to 4500 in the last 30 miles of my Trek home so what you are telling me makes sense. I certainly don’t like the constant shifting that my wife’s newer Denali does. It’s also hard to imagine my old iron driving like her luxurious soccer wagon. Lol

 

[19Tim69]

With my old setup it was stressful driving it because I was constantly having to work the throttle up and down with every little rise in the road.
Now it just pretty much stays in the same place up or down hill.
People piss me off when they slow down going uphill in front of me and they get sh_t scared out of them when I drop the hammer and blow by.

That LS3 is a monster!
I think my LQ9 is only rated at 350ish HP. If I do decide to cam it, I think I may go with a high torque cam but this isn’t supposed to be like my ol Chevelle.

 

[19Tim69]

Okay, now that I have figured out my main malfunction (with help from some good guys here on ck5)
I have ordered a Advanced Adapters 50-6900 output shaft...
Which in my opinion after my ordeal should be included in the 50-0405E kit.

A quick look at the way AA does business seems to be misleading to a point. I’m a KISS guy that goes all the way back to my Basic Training days...Keep It Simple Stupid
Even the main description leads me to believe a OEM 4L60E shaft...

Nevertheless, it should be easy to install myself now that I found out the valve body doesn’t have to be removed to get to it

 

[19Tim69]

If you already have the 241c I would look into that for the gearing.

I have 4.10’s and run 35” BFG KO2. I’m very happy with how it cruses. I pull a pop up camper with it and I can pass people at 85 on the highway. It does good off-road but when I go crawling the 4x4 low is just a little faster than I would like.

here is a webpage I have played with a lot and suggest to people. Put in and compare different combinations.

http://www.grimmjeeper.com/gears.html

when you had your adapter machined, did you put the bearing back in?
It looks like it will not go back together the same. The milling may erase where the snap ring goes...
I borrowed a pic of one done & there is no bearing in his

 

[venevidivicci]

I used the later model with the inner snap on the inside of the splines. So no I did not use the bearing. After about 1975 they omitted the bearing altogether.

 

[venevidivicci]

Here’s a few images I found from another build.

 

[19Tim69]

I used the later model with the inner snap on the inside of the splines. So no I did not use the bearing. After about 1975 they omitted the bearing altogether.

I pulled out a couple of snap rings then the bearing & spud adapter.
After looking closer & taking measurements, I realized the machine work will eliminate the surface that the bearing rides on so now it is beginning to make sense.
I’ll mill the adapter tomorrow & post some pics.
Did your spud adapter look like this?
I’m assuming I’ll mill the side with the recessed area...