79' GMC C15 - Spruce Caboose

[bix]

At a minimum I would triple check the proper direction and assembly of those sprags and check twice the direction and lockup when you are done with the subassembly. You have to be 100% confident they are correct before you continue.

You likely already know this, but I believe the rounded corners in this picture (green arrow) are supposed to be in contact, not the more squared corners (red). Also, if the direction is 180 from correct it will not work and you will be tearing it all apart again.

You can see some of the dog bones circled in red are rolled wrong, but they should correct if you rotate the inner race the correct direction while you install it.

Don't take my word for this, confirm with the book pictures and orientation.

View attachment 474874

Thanks for the reminder on how badly i do not want to take this thing apart. Humping it up and in once and removing it twice by myself is enough work that i want to triple check everything i can.. I did follow the astg manual in regards to inserting it into the outter race from a certain side going counterclockwise with the visible notches pointed up, and then inserting the inner race while turning it clockwise and also verified the orientation of how it rotates a few times, but im going to check everything one more time since its easy enough to do so at the moment before the band and valve body go in.

Since there was some fine debris in the pan and I couldnt really see where it was coming from when i tore down the case i decided to split the pump and make sure it wasnt the pump eating itself or debris stuck in it. All seemed good but i still took the vein guides out and made sure it was good, cleaned it all out and put in two new bushings which didnt need to be done necessarily, but when youre on your second go around you might as well just fuggin do it.

One thing i didnt do last time until i had it fully assembled was check the endplay on the input shaft and it was a pain in the ass with the band installed along with almost every bushing in the transmission being new. So this time around i decided to do this now while theres no band installed and i could pretty easily change the selective washer. I never checked this when i got the transmission so i dont have any previous numbers.

With the two last bushings in the pump change it was still tough to get any easy movement while checking this clearance so i tapped the input shaft down with a rubber hammer to ensure it was seated all the way towards the rear assembly and then put some band clamps on the splines of the input shaft, and clamped some vice grips to them so i didnt mess up the splines. I then rotated the input shaft a little as i lifted up and basically took the full weight of the transmission once or twice. Then with calipers i measure the distance from the top of the input shaft down to the top of the bushing on both sides. Nice to have the splines vertical so you can tell the calipers are plum with the shaft and I got a reading of 2.180. I then tapped the input shaft back down with a good wack or two of the rubber hammer and measured again, which gave me a reading of 2.168. Sonnax calls for the same clearance as OE spec which is .005 -.035". And i have .012 which i would think will probably open up a bit as bushings wear but im on the tight side of the middle range so that should be good. The pump gasket measured .015" and i contemplated not putting that in but since its all nice and dry i decided to anyway before measuring.

I replaced all 4 teflon rings on the input shaft again because i had some laying around, but i didnt put the teflon rings on the reverse input stator side of the pump because i knew i was going to check endplay and it would all be coming out again. So i got that done and the resizing tool is on there for the night. Also re stacked the overun and forward clutches, as well as the Zpak 3-4 clutches, and this time didn’t put in the load springs to give me a little more clearance and it only seems recommended if shifting above 5000 rpm will be a normal thing.

Ill keep going through my checklist before assembling the band and pump for the final time.. then on to the valve body which should go quick..ish and then maybe itll actually end up in the truck soon..

 

[centexk5]

And this is the reason I pay someone for transmission work. Kudos for doing it yourself.

 

[imiceman44]

And this is the reason I pay someone for transmission work. Kudos for doing it yourself.

I used to do mine and like you I started giving it to the professionals when I was working.
Now I am unemployed and I am contemplating doing one since the professionals failed me last time

 

[bix]

And this is the reason I pay someone for transmission work. Kudos for doing it yourself.

I hear ya on that one. Im just on a seriously tight budget and 1100$ or so in parts is alot better than 3500$+. Now time is valuable and costs productivity in one way or another, but im a stubborn A hole... and although i may never choose to do this again, its incredible how much less daunting it is this time around and the knowledge is invaluable even if i do decide to pay someone next time. The biggest skill im learning is like how art is made, up until now my skills have sufficed on just learning how to put things together from a friend or a book, which is still the case but im learning how much of an art there is to putting it together the "right" way. Im the kind of person who if im not failing 20% of the time i dont think im trying to learn enough.. so hopefully this will give me a good stock pile of failure to sit on for awhile..

I used to do mine and like you I started giving it to the professionals when I was working.
Now I am unemployed and I am contemplating doing one since the professionals failed me last time

I am currently unemployed although im a full time stay at home dad which is tough because im constantly job hunting and taking care of 2 acres and the house... but it does give me some more free time than working all the time. And yea, ive always worried about how easily it is to make a mistake and even the best have bad days or an absent mind due to life, which then could lead to lots of annoyances later on , like if they will cover the cost of redo-ing it, or think you messed it up after receiving the truck back ect.. It sounds like youve been down that road before, hopefully they fixed it all for you with little troubles.

 

[imiceman44]

I hear ya on that one. Im just on a seriously tight budget and 1100$ or so in parts is alot better than 3500$+. Now time is valuable and costs productivity in one way or another, but im a stubborn A hole... and although i may never choose to do this again, its incredible how much less daunting it is this time around and the knowledge is invaluable even if i do decide to pay someone next time. The biggest skill im learning is like how art is made, up until now my skills have sufficed on just learning how to put things together from a friend or a book, which is still the case but im learning how much of an art there is to putting it together the "right" way. Im the kind of person who if im not failing 20% of the time i dont think im trying to learn enough.. so hopefully this will give me a good stock pile of failure to sit on for awhile..




I am currently unemployed although im a full time stay at home dad which is tough because im constantly job hunting and taking care of 2 acres and the house... but it does give me some more free time than working all the time. And yea, ive always worried about how easily it is to make a mistake and even the best have bad days or an absent mind due to life, which then could lead to lots of annoyances later on , like if they will cover the cost of redo-ing it, or think you messed it up after receiving the truck back ect.. It sounds like youve been down that road before, hopefully they fixed it all for you with little troubles.

Nope, didn't even go back to them.
They were great with dozens of transmissions through 15 years but in the past few years they downsized and were overwhelmed with the amount of work and I was promised 3 days turn around, ended up 30 days, and the transmission failed within 20 miles.
I just found a good deal on a low miles transmission from a member here and replaced it.
It still works a couple of years later.
Now I have a few transmissions needing a rebuild but I will tackle the 4l80E first.
I am hoping to step up to an nv4500 next.
I haven't done manual transmissions yet, only automatic

 

[bix]

Nope, didn't even go back to them.
They were great with dozens of transmissions through 15 years but in the past few years they downsized and were overwhelmed with the amount of work and I was promised 3 days turn around, ended up 30 days, and the transmission failed within 20 miles.
I just found a good deal on a low miles transmission from a member here and replaced it.
It still works a couple of years later.
Now I have a few transmissions needing a rebuild but I will tackle the 4l80E first.
I am hoping to step up to an nv4500 next.
I haven't done manual transmissions yet, only automatic

Id think an nv4500 would be easier than an auto, just because of the mechanical linkage of all the gears making more sense than these automatic mystery boxes... but im not one to talk.. i have a t5 transmission sitting in pieces up on the shelf i wanted to rebuild and decided to do this one first.

Is the 4l80 the same thing as these 4l60s but just with way more beef to handle increased torque? When you do tear into it , it would be cool to follow along and see the guts for comparison.

 

[folkenheath]

Id think an nv4500 would be easier than an auto, just because of the mechanical linkage of all the gears making more sense than these automatic mystery boxes... but im not one to talk.. i have a t5 transmission sitting in pieces up on the shelf i wanted to rebuild and decided to do this one first.

Is the 4l80 the same thing as these 4l60s but just with way more beef to handle increased torque? When you do tear into it , it would be cool to follow along and see the guts for comparison.

It's not the same design no, but the controls and theory are similar.

@1-ton has a build thread for a 4L80E with pictures....I never took the time to do that with the units I've built, props to these guys for that extra mile they went.

Rebuilding My 4L80E Transmission

I got my 4L80E transmission out of my 1991 V3500 Crew Cab. It had about 300,000 miles on it, and was starting to develop a wine. Also at 300,000 miles I am sure the clutch bands and bushings have to be starting to wear out. I got a top of the line rebuild kit from Jakes Performance transmission...

ck5.com

 

[imiceman44]

Id think an nv4500 would be easier than an auto, just because of the mechanical linkage of all the gears making more sense than these automatic mystery boxes... but im not one to talk.. i have a t5 transmission sitting in pieces up on the shelf i wanted to rebuild and decided to do this one first.

Is the 4l80 the same thing as these 4l60s but just with way more beef to handle increased torque? When you do tear into it , it would be cool to follow along and see the guts for comparison.

I was never the type to document things as I go.
I didn't even document my trucking trips until I had to, on the road or at the office.
I am trying to get better at this and I hope I remember to document the nv4500 build but no promises

 

[tRustyK5]

I did a NV4500 many years ago. Need a few special tools, mostly really good and big snap ring pliers...other than that it's lego in comparison to an Automagic.

 

[imiceman44]

I did a NV4500 many years ago. Need a few special tools, mostly really good and big snap ring pliers...other than that it's lego in comparison to an Automagic.

I have those.
I have pretty much any tool I need and if not I buy it.
The last time I was going to rebuild an sm465 but then I ended up with a couple good used ones from trucks I parted so I have yet to say I rebuilt a manual
The furthest I went was to remove the top cover, rebuild the forks and reinstall

 

[bix]

@folkenheath this is how my input sprag is aligned after checking it. The ASTG manual doesnt show any pictures of the dog bone but just the procedure for installing it. I see why another book besides the ASTG manual would be useful like mentioned in the 4l80 build you linked

 

[folkenheath]

@folkenheath this is how my input sprag is aligned after checking it. The ASTG manual doesnt show any pictures of the dog bone but just the procedure for installing it. I see why another book besides the ASTG manual would be useful like mentioned in the 4l80 build you linked

It looks correct on the inner surface where it's riding on the middle of the dogbone end, but the larger surface looks close to the corner, yet under load it should be centered better.

As long as both diameters are correct with a good finish and it slips and bites the correct direction then you should be good to go.

 

[bix]

- Last night when i air checked my over run/ forward drum/ and 3-4 clutch paks with air i realized i might have had the thrust washer upside down. The ASTG manuals do a pretty unclear job at showing you these. They have close ups but the picture is always unclear which side of the photo is the edge of the assembly or shaft, and which side is the case. After ensuring the selective washer was orientated correctly with the numbers down ( i went from a #71 @ .103", to a #70 which measures @.094 " ) i then made sure the thrust washer was orientated the right way on the input drum. The larger surface area of the thrust washer sits on the input drum side and the narrower side has the reverse input drum sitting on it which isnt very clear because the sonnax thrust washers are not like the OE ones which are clearly identifiable.

- I then checked my endplay again today but measured from the input shaft end to the pump splines , as this was easier to measure off of than inside at the bushing but measured both ways to be sure. I got .019 on average +/- a few thousands here and there. Online people say .005 -.035 is good, the ASTG manual says never go below .015 because of aluminum expanding when its hot, some other sources say .005 - .036" is fine but should aim for .010" and higher because of gasket crush, and for maximum life it should be set below .025" . I think the difference in my two readings was the thrust washer being potentially upside down. I am happy with .019 because its suitable for all these opinions..

I am now moving on to the valve body after getting the band, anchor pin and pump installed. The rest "should" go quick because i dont believe there to be any issues with the valve body but i will be going over the valve orientations again to double check things since its apart.

 

[Blue85]

Isn't it weird how I can smell your pictures?

 

[bix]

Isn't it weird how I can smell your pictures?

Id think so... but only slightly weirder than the comment itself.

 

[bix]

well here goes nothin'

- Got the valve body assembled, Only took out the main valves and left all the ones with a roll pin in this time, everything moved well and returned to position
- Ohm'd out all the components.
- I ended up making two dowels out of m6x1 threaded bolts to align the valve body as i put it down onto the case. This time i put the check balls on the case instead of using something to retain the checkballs in the valvebody. Used 1 steel in the case side and 7 of the plastic sonnax ones.
- Ohm'd out the selector switch to ensure the N/O ones are working, along with the N/C ones.
- Torqued everything down to 120"/LB from the inside out.
- Did end up using a slightly longer spare bolt on one of the selector switch holes (One of the two shorter bolts ) because the one that came out had some dinked threads. I made sure the hole was blind and nothing would be caused by this slightly longer bolt.
- New filter, gasket, and also tossed in 2 extra magnets because i have no faith in this working haha..
- Confirmed 4th gear sonnax servo travel without orings and d rings. Spec is .075" -.125" And I have .090"

































Now i just need to make some sort of makeshift transmission cradle for my jack because i do not want to hump this thing in again myself.. atleast not in any annoying and wrench throwing sort of way. Then cut a hole in a floor.. and if she goes then ill make some sort of shifter for it.

 

[bix]

Well i should have known that by build a transmission cradle ... i really meant man handle this thing alone until midnight with a combination of scissor jacks, floor jack and levers like a scandinavian architect drunk on brandy... but got it in. I really hate these headers as the drivers side it so tight to the block, and being mid length they are just a pain in the arse to maneuver around. Got the transmission in, torque converter bolted up and then went about getting the crossmember bolted in. I made some brackets that sit on the frame rails and cut off the extension i had previously made since it fully wasn't square and didn't sit too perfectly. Confirmed my TC gap was above 1/8 and under 3/16 and no washers were needed.

I set the transmission at 4.9* down, the driveshaft is sitting at around 3* down, and the rear pinion is was set at 4.9* down so i should be good for a vibration free ride, but time will tell. I didn't feel like taking my spring perch shims out, but i can raise the transmission a bit more and it seems like my motor mounts are mainly what's causing the high than normal angle. ( that's another project for another time )

Got the exhaust wheeled and cleaned up a bit. With the crossmember sitting higher, I was able to tuck my exhaust further up into the frame. Relocated the hanger i had around the muffler and got that installed. The other half of the exhaust piping is still off ( over the axle and out the back ) as im trying to not do things I dont have to because im not 100% out of the black berry transmission bush just yet. Hooked up the trans cooler lines to the aux cooler and put 6 qts in the pan and crossed my fingers..

Fired the truck up and immediately added 2 qts. Then i noticed it blew the line clean off the cooler... Shut the truck off but hey, the pump works again this time. I had switched to a secondary cooler because i had stripped the threads slighty in the one that's built into the radiator when using an AN adapter. I did not want to go through the bullchit of making a new line this close to firing it up, so i just put them back onto the radiator cooler and figured a small leak is better than a colossal one. Fired it back up and no major leaks at the cooler this time but i had coolant leaks at the heater core connections and a small fuel leak at the return line around the regulator. Id love to just get a nice 3 core aluminum radiator for this truck but its never gotten even close to hot yet and i dont have enough pennies for that so this one will do for now.

I have read that 6 or so qts should be put in the pan and 1 or so in the TC, then fire up the truck and add 2 qts and run it through all the gears including reverse, as this circuit is quite large and uses a bit of fluid to actuate. Then check the dipstick and fill it to the full mark. Another thing is when using these aftermarket dipsticks, they fit but the marks on them will rarely be right and they usually allow you to adjust via set screws in the filler somewhere , but mine wouldnt adjust enough. It also seems like Hot/Full mark should be about where the gasket sits or the top area of the pan, so i marked my dipstick with the ol pocket poker at that height and went through P-R-N-D-2-1 and had movement of the tires in all gears! I have not yet gone into 3-4 yet because i wanted to look at the data log since a lot has been done since this truck has been driven on the road with any confirmation its not missing 1/4 of the pieces.

Data log so far seems good and im going through the tune file because again because i cant remember a whole lot from when it was just abandoned in the car tent. I also need to fix the sweating return line at the regulator, the hot coolant coming out of heater core at the firewall and also my dipstick is leaking ( should have replaced the double O rings or Rvt'd it.. )

The to do list only got longer now that all the things i was ignoring need to be done, but im glad they are short tasks and should be easy enough to go through over the next couple months of tinkering.

 

[bix]

And yet another realization that staying true to this sticker means constantly making mistakes but choosing to learn from them rather than being butthurt… although tbh my butt does hurt after that thrash sooo who’s to say..

 

[bix]

Got it up on jack stands again last night and ran it through all the gears. Seemed to shift good from first to fourth with no harsh shifts or anything.. Only went through them once as my eyes were watering from exhaust in the shop.... so I guess its time to get some plates!

 

[bix]

Well I’ve been working out of town but managing to get some cruises in the truck so far on days off. I’d say I’ve probably put about a few hundred km on it so far without any issues yet.





I managed to fab up a mount on the door side for my sons child seat, and used the middle belt male end doubled up on the inside so the regular belt has the female end and the car seat can buckle into the male end.