My 1967 Chevy K20 Build Thread

[Chaparralman1974]

2/22/2023-2/23/2023
New Spring Hangers and Rear Leaf Springs Installed
I got a call from Valley Spring Services saying that my newly fabricated rear spring hangers were ready for pickup, so I hopped into the car and bolted down to pick them up. These things are beefy and legit! They did a fantastic job in getting them made up. I did have to grind down the leading edge towards the front of the bracket in order to clear the leaf spring shackle bolt, and they neglected to provide for a drain hole at the bottom, but a ½” drill bit fixed that problem in short order. These new hangers are definitely a step up from the factory ones and should provide a solid platform for a long time.

[Chaparralman1974]

2/23/2023
Rear Axle Installed
I was able to finally get the rear axle installed. I still need to fix the rear pinion seal as there is a leak, but this is not critical at this time. I have also ordered all new rear wheel bearings, races, seals, and the disc brake conversion parts so that I can totally ditch the drums.

[Chaparralman1974]

2/27/2023 - 3/5/2023
Frame assembly, Rear Disc Brakes, and Transmission
The past week saw several big wins in the overall truck project. First up, is the rear disc brake conversion for the Eaton HO52. Initially, I was going to go with a drum brake setup using the drums and backing plates off of the GM 14 bolt “corporate” axle, but after doing the math it was abundantly clear that from a time and money standpoint, it was cheaper and all around easier to go with a disc brake conversion. I picked up the caliper brackets from RuffStuff, and the rotors from Amazon. I will get the calipers down the road, but for now I need to put budget elsewhere in the project. Something worth noting in the conversion is that I was able to repurpose the wheel studs out of the 14 bolt axle. They were in excellent condition, so after soaking them in a vinegar solution for a few days, they shined up really nice and should work out very well. There is plenty of threads available and now I have 9/16” wheel studs front and rear. The rear hubs are off of a 71/72 C20 that I found on eBay and were setup for the larger wheel studs. I installed all new bearings, races, and seals for each hub. I do need to go back in later and install Speedi-Sleeves on the spindles as they had a little wear on the sealing surface. I will likely do that at the same time that I replace the pinion seal. I applied a light coat of grease to the bearing surfaces to keep them lubed, and when I do finally button up the rear axle, I will likely use a syringe to shoot in a few CC’s of gear oil directly into the hub as the axle shaft flange bolt holes are not blind.
Moving onto the frame, I was able to get the transmission / transfer case mount along with the engine mount installed. I went with new poly bushings for the mount that goes directly to the frame for the transfer case, but the original mounts that go on the crossmember look perfect, so I will clean those up and get them reinstalled.
I was also able to begin the teardown of the transmission. All in all, it looks to be in excellent condition except for the output shaft splines that are a bit chewed up. This appears to be a common issue with this configuration and I was able to source a NOS output / mainshaft on eBay for a reasonable price, so the plan is to replace the shaft and reuse everything else. The bearings all seem to be perfect, and the inside of the case was pretty clean. The gear oil looked clean and green, and there only appeared to be a small amount of sludge at the bottom of the case.
My process was to take everything apart, and then mix up a solution of oil eater and Arm and Hammer Washing Soda and then soak the parts for a day or two. I then hit the parts with the pressure washer and they came squeaky clean.
I was also able to source a 1967 Chevy K10 transfercase locally for $100. I am hoping that the splines on the input shaft for it are better than mine, in which case I will transfer the shafts. I figured that for $100 I can’t go wrong with having a spare case around.
Lastly, I was able to get the bellhousing cleaned and painted. I have to say that I really like the Chevy Orange color.

[Chaparralman1974]

Here is the transmission before cleaning.

[Chaparralman1974]

Here is the transmission after cleaning.

[Chaparralman1974]

And here is the bellhousing after painting.

[Chaparralman1974]

3/12/2023
Transfer Case Teardown, Cleaning and Painting
I had originally planned to simply clean up the transfer case, install new gaskets, and paint it but after thinking on it for awhile I decided that I might as well do it right and conduct a total rebuild of the gear box. After all, when am I going to have it on the bench again anyway? The tear down was actually quite easy. It was a bit intimidating at first but with the chassis overhaul manual available it really isn’t rocket science. The key is to take your time during disassembly and to put everything out in such a way that it is easy to identify. Also, orientating things on the workbench as they come out of the case should make reassembly easy.
I found that the bearings were so-so on it, so they will be replaced. Also, since the bearings are needing to be changed, I will need to redo all the shims in the bearing caps. I put in an order with Torque King 4x4 to order all of the parts that will be needed to do a complete rebuild. This includes new bearings, races, seals, gaskets, and shims.
I did notice that the input shaft was a little chewed up. Fortunately, the input shaft on the spare transfer case was in excellent condition, so I will be swapping those.
I soaked the case in a solution of oil eater and Arm and Hammer Washing soda for a few hours and then hit the case with a pressure washer. I followed that up by plenty of brake cleaner and compressed air after chasing all the threads in all the bolt holes. I then masked up all of the gasket surfaces and sprayed 3 coats of Glidden Brick Red Satin spray paint. It isn’t perfect, but it is close enough for my needs.

[Chaparralman1974]

3/15/2023
Transmission rebuild and assembly
I finally got the transmission rebuilt and reassembled. All in all it was not a very difficult task. There are several YouTube videos out there that show the overall process and as long as you follow the procedures in the overhaul guide, it is really a no brainer. The synchro’s in the case looked brand new as did the teeth on all of the gears except 1st as that gear is non-synchronized and a bit of wear is to be expected. The mainshaft / output shaft was ok, but the rear splines that connect to the transfer case input shaft were a bit worn, so I was able to source a NOS shaft on eBay. It had a little bit of surface rust on it, but after soaking it overnight in a solution of white vinegar, it cleaned up good as new. The rebuild kit consisted of all new bearings, seals and gaskets and I used all the bearings except for the front countershaft bearing. The reason being that the new bearing looked pretty weak compared to the original. The original was in good condition (as were all of the bearings for that matter) so I reused it after doing a thorough cleaning. I was also able to source a NOS rear countershaft bearing oil deflector (GM Part Number 591652) as mine came out in pieces.
I painted the case with Eastwood Imitation Cast Iron Grey as well as the transmission to transfer case adapter. Regarding the adapter itself, I also replaced the splined coupler with a new one sourced online and I am in the process of ordering the adapter oil seals. These have been rather challenging to source. After watching a YouTube video (Raybuck Auto Body Parts) doing the same rebuild, the guy in the video mentioned that he was able to find the original seals at a local drive shaft repair shop. I messaged him and he gave me the company name https://pointspring.com/ and the part number is Meritor A1805E447. It is a difficult seal to find, but it is out there if you dig for it.

[GAc10boy]

Awesome work! Really looking forward to following along.

[Chaparralman1974]

Originally Posted by GAc10boy

Awesome work! Really looking forward to following along.

Thanks Robbie! It is definitely a labor of love.


Clay

[72 tigger]

You’re very persistent! Keep it up

[Ol Blue K20]

Coming along nicely, keep up the good work.

[KyleSeal]

Love these old K trucks. Looks great.

[Chaparralman1974]

3/12/2023 - 3/30/2023
Transfer Case Rebuild and Installation of Transmission and Transfer Case Into Chassis
The rebuilding of the transfer case was a little more challenging than I initially thought that it would be. First off, Parts are very difficult to come by, and when they do come along, they are expensive and if they are used, not much better than what you are starting with anyway. I was lucky to find a transfer case out of a 1967 K10 that, as luck would have it, was only 5 minutes away from me. Moreover, I was able to get it for $100, so I totally scored on that one!! I am very lucky to have run across that deal due to the fact that there was a lot of wear in my transfer case. My initial plan was to use the original case that came in my truck and scavenge the other one for parts, but seeing as how the one out of the K10 was much, much better I altered course and opted to use that one instead. This was of course after I put in all the effort to clean, paint, and prep everything in the original case for rebuild. Oh well….I will just rebuild the original case in time and will have it for a spare. Also, the other case came with an adapter for the transfer case, so it is really good to have another one of those seeing as how they were only produced for the 1967 model year.
As stated, parts are terrible to come by. This includes the oil seals in both the transfer case and the adapter. 1967 was the first year of the "married" transmission to transfer case setup in the K10 and K20 series 4x4 pickups. It was also the last year of the SM420. After 1967, the SM465 came into being. That essentially makes the adapter that mates the SM420 to the Rockwell T-221 transfer case kind of a unicorn of sorts. The coupler that connects the output shaft of the transmission to the input shaft of the transfer case is also unique to the 1967 model year. Anyone who has been down this restoration path probably has found that the seals are difficult to come by if not downright impossible. Well, after digging around the inter-webs and YouTube, I have found the seal and it is still in production! It is super hard to come by no doubt, but I wanted to share it all with you in the event you need to source it as well. This is the same seal that is in use in the T-221 transfer case by the way. While there is an alternative seal solution (SKF 17381 being one), it is not of the original opposed double lip design. It is however likely a superior seal due to the higher temperature rating, but the opposed lip seal, IMHO, is better for the adapter due to the need to keep gear lube opposed in both the transmission and the transfer case. At any rate, if anyone is looking for it, I found the seal at Point Spring and Driveshaft Company (https://pointspring.com/). The part number is an Axletech (or Meritor) A1805E447.
I ended up using the Meritor/Axletech seal in the adapter, and the SKF seals in the transfer case at the yoke outputs.
Another challenge with the transfer case rebuild for me was the process of shimming the bearings to set end play. This was the main cause for concern with the original transfer case as well. I followed the manual and it says (depending on which one you go by) to put on the rear bearing cap and shims for the input shaft, tighten down the cap and set the end play on the shaft to .015". The problem was that the bearing on the rear, under the bearing cap seemed to move in and out of the bore an awful lot. It would not go all the way into the inside of the case but it would go just below the mating surface which caused the front bearing to move out a good 3/8" or so. At this point, I went ahead and hooked up the transfer case to the transmission and adapter and bolted it up. The adapter didn’t allow the bearing to move in and out, and I tried to move the shaft forward and backward from inside the transfer case, but there was no way for me to measure end play doing it this way. I concluded that the bores for the bearings in the original case were likely worn as there was also indications that at some point, the bearing was changed out (it was not the original bearing) due to a failure. The rear of the input shaft was tore up, and the bearing cap itself was cracked.
For comparison, I took a telescoping bore gauge and did a comparison with the other case that I have and it seemed to be tighter. I didn't put a mic on it, but the bore was definitely a bit smaller on the other case. It was at this point that I opted to just use the other case as the gears, shafts, and components all looked better anyway.
I did have difficulty in setting up the end play on the other bearings, but after some messing around with it, I eventually got it configured.
Another problem that I had was with the threads for the nut that secures the yoke on the rear output shaft. When I disassembled the case, I put the nut on the shaft and used a hammer to tap out the shaft. Well, I didn’t have the nut all the way down (important safety tip for next time!!) and I mushroomed the threads on the shaft slightly as well as on the nut. During the assembly process when I was installing the rear yoke, I foolishly tried to force the nut on using my impact wrench….super bad idea. I tore up the threads in the nut, stripped it out and made the threads on the shaft worse. At this point I stopped for the night (it was 11:30PM) to revel in my stupidity.
After determining that the threads in the nut and on the shaft were 7/8x14, I order a tap and die and got them cleaned up on the shaft (I had another nut from the other transfer case).
From that point on, the assembly went well. I did notice as I was putting the top cover on that the original springs for the balls that lock the shift forks were smaller on the original case. After closer inspection it looks as if they were cut down at some point. I put the longer springs on from the replacement case first and the shifting was extremely tight. I put the smaller springs in and the shifting seems to be much nicer. I concluded that this was a “mod” probably done at some point due to the lever being too tight to pull when shifting into 4WD.
The gasket kit that I ordered for the transmission did not come with any adapter gaskets that go between the adapter and the transfer case, so I had to make my own. I ended up using extra shims that I had as templates and they fit perfectly.
Finally, I was able to lower the transmission and transfer case into the frame and get it bolted up. I also filled both gear boxes with gear oil. Having the body off is nice….all I needed to do is pour the oil in from the top of the transmission where the gear shifter goes and I took the top off of the transfer case and did the same. On the transmission, you just fill until it comes out of the fill hole on the side. Same goes for the transfer case, but I ended up putting the plug in and adding about an extra ½ quart of gear oil to hopefully allow for additional lubrication of the upper end.

[Chaparralman1974]

Transfer case tear down pictures

[Chaparralman1974]

More transfer case pictures.

[Chaparralman1974]

Transfer case completed.

[Chaparralman1974]

Transmission and transfer case installed into chassis.

[clay68c10]

Nice work, and kudos for having the persistence to get the TC done right.
My friend in Wyoming swears by those T221's. They're pretty stout.

[KyleSeal]

Love this thread! Not a huge 4Wd guy (even though I have a 84 K30 and 4WD Toyota ). But the transfer case rebuild brings back memories of when I did it on my 84 (NP205/SM465)! It was meticulous but it was gratifying! Tracking down pieces and parts can be tough as well.

[Chaparralman1974]

Originally Posted by KyleSeal

Love this thread! Not a huge 4Wd guy (even though I have a 84 K30 and 4WD Toyota ). But the transfer case rebuild brings back memories of when I did it on my 84 (NP205/SM465)! It was meticulous but it was gratifying! Tracking down pieces and parts can be tough as well.

It has been indeed a lot of fun! I have received a lot of help from this forum...I have to call out Chuck (cbeerman) as he has helped me a ton on getting the rockwell back together. It was a challenge for sure, but I hope that I can get another 50+ years out of it. The only real snag in the rebuild was the rear output shaft....the manual calls for close to zero end play. After I got it all together, there is a very small amount of end play in it. I may have to take stuff apart again and remove some of the shims, but we will see.

I also plan on doing a rebuild on the other transfer case as well so that I have a spare. If nothing else, it is relaxing to work on this stuff.

I also did an about face on the front axle. I decided to go back to the original closed knuckle front axle. I have it about 90% rebuilt and it is installed on the frame. I will be updating the thread with pictures shortly.


Clay

[72 tigger]

You’re really doing things right. You’ll be thankful that you went through everything correctly

[Chaparralman1974]

4/4/2023 - 4/23/2023
Front Axle Swap…..Again!
I have come to the conclusion that I am a glutton for punishment and enjoy repeating work efforts….NOT!
After a lot of thought and back and forth, I have decided to stay with the original closed knuckle front axle on the truck. I had to sit back and rethink what my overall project goals are. First off, this truck will never be a daily driver….nor will it ever be driven off road. Moreover, it is unlikely that it will be driven more that on the weekends to go get ice cream or maybe to a car show or maybe to Home Depot to get a bag of grass seed. The point is, I realized that what I want is an original 1967 K20. So, out with the Dana 44 front disc brake axle and in with the closed knuckle original axle.
The original axle did have some issues. The driver side axle shaft was snapped in half, there was a huge dent in the front cover, and the ring gear had a chipped tooth. The tooth wasn’t a big deal to me. I simply ground down the rough edges with a small DA. The inner axle seals were clearly toast as well so I replaced those and did a complete and thorough cleaning of the inside of the axle.
The spindles were ok, but there was a slight groove on each of them where the grease seal rides. This was remedied by an SKF Speedi-Sleeve (99253). The bearings and races were all in good condition after cleaning in kerosene, so I reused those.
The brakes have been a bit of a challenge. First off the drums are Unobtanium! While I was able to have my original drums turned, the driver side has a warp in it. I can only think that this warp is my own fault as I beat on it pretty hard to get it off before I realized that you need to rotate the adjuster star inboard in order to bring the shoes in so you can get the drum off. I am going to try to get it straightened out somewhat, but I am on the lookout for a new set of drums.
The shoes were easy to find at rock auto, as well as some of the springs, but the rest of the brake hardware is a bit of a challenge to find as well. I know that the springs are fairly standard, and I imagine that I could search through bins of springs to locate ones that matched, but all in all, mine were not too bad, so I cleaned them up and decided to reuse them as there was no rust on them. Just grease and dirt.
All of the knuckle bearings were ok, save one so I replaced that one and picked up some new king pin shims. After getting the new wipers installed, both sides were filled with corn head grease.
I installed the spicer locking hubs and cleaned up the front tie rod and installed new ends.
Also worth noting is the lug studs for the front hubs. Originally, the truck had ½” studs. I wanted to upgrade to 9/16” studs. As it turns out, the knurled holes for the original studs is .625”. I found that the Dorman 610-181 studs have a .623” knurl and are only slightly longer. They fit like a glove and now I have updated studs for the front and rear.

[Chaparralman1974]

Here is the housing after cleaning showing the new seals and the chipped tooth on the ring gear.

[Chaparralman1974]

Here are the brakes after cleaning and reassembling.