'89 R3500 Crew Cab 2wd to 4wd conversion & beyond

[mrk5]

The swap will happen this weekend. Yesterday I got the dust cover trimmed to clear the passenger header.

Kinda fun thinking about my sticker that says this truck is built with recycled parts. I'm going to adding a transmission from a 95 K3500 and the NP205 comes from an 80 K20 with the rear fixed yoke output from a 79 K30.

 

[Truckman4life]

Do you keep a running list of all the vehicles everything is from for future parts ordering?

 

[mrk5]

In my head mostly. The 4l80e is the first thing I've put in that would really matter. Most everything else is covered by a large range of applications.

 

[mrk5]

Didn't get as much done as I hoped but that's not unusual. Always takes me a long time to fabricate a crossmember. Plus figuring out a few things won't work like I'd planned.

For one thing, I need much longer cables for the triple-stick shifter. Going to end up with 8' cables. Mostly because I want the shifters up on the hump to clear the center console and cup holders. The cables have to reach from there back behind the tcase and make a gentle bend back around towards the motor through the bracket bolted to the back of the NP205. 7' cables would work, but JB doesn't have that length.

I was already planning to build a new crossmember but I did get to learn some fabrication lessons the hard way. On the old crossmember, the rectangle tube I used to support the skid plate was not nearly stout enough. A year or so ago I added spacers under the crossmember flange because the driveline brake on the NP241 would occasionally rub the floor, well the caused the flanges to bend.

What really gets me, is I can't think of when I was on the skid plate that hard.

I'm embarrassed about how shoddy that setup turned out to be, but I figure it's a good lesson for others to bear in mind.

The old drivetrain is out. With that 2000lbs Harbor Freight transmission jack it was easy to pull still bolted together.

We took some measurements and confirmed what I'd found on the Internet, the 4l80e is about 2.5" longer from bell housing to the tcase side of the adapter.

Before installing the transmission, I replaced the bolts for the adapter into the transmission. It was a bit tricky to get a torque wrench on them but this was my solution.

So I figured after the failure of my earlier crossmember and skid plate, a SOLID 2x4 would be a much better way to go.

This is what I'm looking at for the crossmember.

There's a bushing under the factory adapter and another tied to the Magnum bracket. I liked the idea of having the transmission mount under the Magnum since the NP205 is so heavy. Down side is you'd need to have a jack under the transmission to support it if you pull the tcase. With a mount under both the Magnum and the factory adapter I should be able to pull the transfer case and the transmission will still be supported by the crossmember requiring the use of just 1 jack. Plus I figure the double design is better considering the design of my mounts.

Earlier in this thread and in other conversations I've had people mention that loosened bolts at the transmission adapter can be a result of the transmission/tcase mounts not allowing for some twist. So that was where my idea kinda started from.

The only problem I have that keeps this from being "perfect" is the bottom stud for the tcase side of the adapter is mostly blocked by the mount under the transmission. The 4l80e adapter is very short, at least it is compared to the 700r4 adapter I'm used to dealing with. The bottom stud ends up projecting under the factory adapter feet a little. Figured that out when I was making the bracket to bolt to the factory adapter and I couldn't figure out what was getting in the way.

The dipstick that came in the 4l80e was broken, the locking mechanism doesn't lock the stick in. The cost of a new stick was almost as much as the entire tube, stick, and grommet assembly so I just went that route. Well the tube I bought that was listed for the 4l80e in the donor truck isn't going to work.

Looks like I'll be using the old one after all.

 

[Bent77]

Are you going to run some plate at the frame where the crossmember will land?

 

[bp71k5]

.

There's a bushing under the factory adapter and another tied to the Magnum bracket. I liked the idea of having the transmission mount under the Magnum since the NP205 is so heavy. Down side is you'd need to have a jack under the transmission to support it if you pull the tcase. With a mount under both the Magnum and the factory adapter I should be able to pull the transfer case and the transmission will still be supported by the crossmember requiring the use of just 1 jack. Plus I figure the double design is better considering the design of my mounts.

As an alternative to using two jacks with the other way, you can put a 2x4 (or some other piece of steel) between the frame rails to hold up the trans while you remove the transfer case. Looks like your solution keeps the trans and transfer case from fighting each other which is a good thing.

 

[mrk5]

Are you going to run some plate at the frame where the crossmember will land?

Yes. This time I'm going with 2"x3"x1/4" angle.

Above is working on adding gussets, but it's pretty much done. Not scrimping on the steel this time.

As an alternative to using two jacks with the other way, you can put a 2x4 (or some other piece of steel) between the frame rails to hold up the trans while you remove the transfer case. Looks like your solution keeps the trans and transfer case from fighting each other which is a good thing.

That is true. I was impressed that we were able to use a wood 2x4 to hold up the trans and some of the NP205 weight. I kept telling Nate we might end up being fools for trusting it to hold. I did finally change out the wood for some aluminum square tube.

 

[mrk5]

Everything is in and we were able to start the truck and run the trans thru the gears.

Plenty of clearance for the front shaft to the crossmember.

Big stumbling block is the driveshafts. I was hoping that changing the NP205 rear output yoke to 1410 and not having all the driveline ebrake stuff (flanges and rotor) would let the rear driveshaft work.

However it's still 2" too long.

And of course the front shaft is too short by about 3". My wife said she hates it now whenever I mention the word "driveshaft" because it means we're dropping hundred dollar bills at the driveline shop.

The NP205 ended up a little more than an inch below the frame. This is where I have the studs on the Magnum out of all the position options available.

I thought we could get it higher, but it started to cause quite a bit of interference issues with the floor. If this was a dedicated trail rig I might have started cutting up the floor pan, but it's not that critical for how it's going to be used. The NP241 was about an 1" below the frame so this isn't much different.

I mentioned previously in the thread I needed longer tcase cables. 6ft probably would have done it but after 5ft, the next length up is 8ft. However I'm happy with how they worked out.

The old carrier bearing support works perfect for tucking the cables up. The extra length will give me freedom to locate the shifters where I want them and also keep all the bends nice and gentle.

I did have trouble with the lever for the Art Carr shifter to connect to the 4l80e. The pattern plates on the shifter are the same. I found a part number from Winters (since Art Carr doesn't so the shifters anymore) for the bracket and lever that are supposed to be used with the 4l80e. At first we thought the bracket was wrong, but we figured out is the lever that's wrong. It needs to be clocked further forward. When the lever is in 2nd gear it's in-line with the cable which means it can't pull into 1st. So this was my solution:

Welded the lever from the 700r4 to the lever that's supposed to be for the 4l80e. I did check the 700r4 lever first to see if it would work, but it was worse. So now the 4l80e lever is bolted to the shift shaft and the cable is attached to the 700r4 lever welded to the front of the other.

We still ended up with a little extension on the bracket that holds the cable.

At this point I don't know if I got the wrong part number or if I was sent the wrong thing or if the difference is Art Carr vs Winters and trying to mix & match their parts. That's why I just made my own fix because I don't want to spend money trying to order another part that may or may not be correct again.

The only other picture of interest that I have is the cooler lines.

I put red stripe on the hot/outlet line so I'd know which is which. Also have blue on the cold/inlet line. Aren't I a fart smeller, er I mean smart feller. Had to do some internet searching to find on the 4l80e, the top line is hot-out. Looks like most every other GM trans has the outlet on the bottom. There are the newer 4l80e (97 and newer I think) that have the ports positioned in a front/rear orientation.

As long as I can get the driveshafts back by the end of the week, I should be able to drive the truck this next weekend.

 

[mrk5]

Oh and this was my to-do list I started the weekend with.

 

[454Sub]

Shortening one is cheap.

Lengthening on the other hand isn't.

 

[nvrenuf]

I like that trans mount you made.

Any pics of the tcase shifter installed? Did you do anything special when passing the cables through the floor?

 

[skunked]

Nice progress Scott.

 

[LNielson]

You got a lot done. Nice pics too, It's fun to follow along with your build.

 

[LNielson]

Oh and that sucks about your driveshafts.

What are you doing for an e-brake now?

 

[AgDieseler]

Nice looking crossmember solution. You're moving along quickly toward moving very slowly.

David

 

[mrk5]

I like that trans mount you made.

Any pics of the tcase shifter installed? Did you do anything special when passing the cables through the floor?

They are just floating in the cab for now.

I drilled 3 holes about 3/4" diameter and 1" on center. I put a steel rod thru the holes that's about the same diameter and lever down on the rod to kind of angle the holes more in line with the cables.

I used 1/2" hose to keep the cables from chaffing.

Oh and that sucks about your driveshafts.

What are you doing for an e-brake now?

I never did have the driveline brake fully setup so I'm kinda used to it now. I carry some big wheel chocks in the bed.

I think I'll rig up a line lock type setup. My ideal scenario would be a new 14b with the ebrake in the rotor hat.

 

[mrk5]

Earlier I posted my new dipstick tube fail.

I put the factory tube back in the 4l80e. The primary reason I wanted a new dipstick was because the end didn't lock in place anymore. I found the entire setup with tube, stick, and grommet was not much more than just the stick and a grommet. It occurred to me I could still get my new locking end. Then ends are just riveted on.

The old and new ends are the same length and have the same hole locations.

I drilled out the rivets and put the new end on the old stick. I was lucky to find small rivets in our collection.

 

[mrk5]

So I'm probably doing a new front shaft. Thinking about 1310 CV versus 1350. Tom Woods website makes a good case for 1310. Costs a lot less than 1350.

 

[mrk5]

Here's how the shifters sit with the console in.



Probably gonna end up further forward and up a little.

 

[DickeysK5]

So I'm probably doing a new front shaft. Thinking about 1310 CV versus 1350. Tom Woods website makes a good case for 1310. Costs a lot less than 1350.

I have been running the 1310 CV since I got Poco Loco nine years years ago. I have two shafts, so I can change one out when I bend it. Then get it re-tubed. No problems with joints or yolks so far.