Hot Rods AD_NAPCO's 39 GMC Rocket 324 Build

So, in accordance with my stated mission to get something done every day that I can, I got the trans cross member cleaned up in prep for cutting and modding as soon as my new welder arrived. Also resurrected my commie blast cabinet and tore it down for resealing and a couple upgrades so I can blast small parts without a mess in the driveway. Still not sure if I'll trust it indoors or not but I'm gonna do my best to get it sealed up to that level. Anyone else have one of these crappy HF cabinets they've made into something they're happy with?

 

update on the spring situation...........talked to a bunch of spring guys. No one has a duplicate which is not surprising.. MI company will make them for $623 for 5 units! or you can buy one from a CA company that is the same wire size, .984 top, 1.53 bottom but only 1.50 in length. So I wondered if one could machine a top cap to placed over the spring to compensate for this. Your thoughts guys?

Josh, my son has the same blaster. I mounted it on a roll around platform to getit out in the drive way easily. The light is pathetic. I would stuff a sealed box and a fog light up in one corner to improve the lighting if it were mine. All of that stuff is readily available at the hardware store. Look at TIP's website to get some ideas. They sell a ton of blasters. I have had one for over ten years. Great machine.

 

$623 for 5 units is the kind of price that drives good men down the dark path of the street rod... Best not to entertain such thoughts.
I think the machined cap is the way to go. All you need is a seat in the bottom for the spring and a groove in the top for the pin... Right?
I did run silicone in the seams and upgraded the light in this cabinet back when I got the thing... It was a craigslist acquisition. I need to redo the silicone and seal up all the openings with actual weatherstripping rather than the glorified meringue that HF supplies it with. Stripping that crap off of it was the majority of what I did yesterday. I'll take a look at the site you mentioned and see if I can do any other improvements. Thanks!

 

Worth a try. I have a lathe. Where is the website or ordering info?

 

Well, the commie blaster is sealed up as best I think it can be, and I attempted to make one of the TP style double barrel pickup tubes. See if that helps me or hurts me considering my compressor is not very big.

 

Do either of you have an Olds master parts book that will list necessary bearings and seals I'll need for this trans? I have a 56 shop manual, which I *think* applies from a servicing standpoint, but it does not list any part numbers. I already have the gasket set for the Buick case here. I'd like to have new bearings and seals as well before I tear into it.

 

Frank, Century Spring in LA. Minimum order is 40 bucks on line. Each spring is 5.63. I will have to order 6 units to make the minimum which is not a problem. Tried to order them but it kept kicking me out. Called CS and they say the minimum is now 50 bucks. I complained and they said they could send me one for free as a test item, transferred me into space, after 5 miinutes I hung up. Will try Monday. On a side note....my engineer son out in CA works with these guys all the time in his design work that he does for Valley Engineering. Maybe he can get them for me. I will ask him Sunday.

Josh, call NW Trans and give them the bearing numbers. They will have them and the seals etc. Or run the bearing numbers on the web at one of the bearing manufacturer sites and you might get lucky finding replacements.

 

Walt I'm not sure who or where NW Trans is. I was hoping to get bearing and seal numbers from a master parts book to have them on hand before tearing into the trans. I may have to just take lots of pictures while I disassemble to make sure I get it all back together correctly while waiting for parts if I can't source them locally.

 

NW is in Winchester, OH 937 442 2811. They will need the casting number off of the tail housing to see what vehicle it came from and the bearing numbers. Guess you will have to tear it apart. It is not difficult, one snap ring on the rear shaft and it will come apart.

 

Cool. Thanks Walt!

 

Ok... Got the trans all torn apart. The snap ring holding 2nd gear on the rear main shaft was a nightmare to get off. One side was bound and it took a while to free and then it just didn't want to come out. Took an hour just to get enough screwdrivers in just the right positions to open it up and finally slip it out of the groove completely. Other than that... My only issue is the speedo drive gear. I don't have a press. Maybe I can have it pressed off at the shop I found last week. I'm curious about your opinion of the rear main shaft bearing.. It is shielded on one side only. The rear facing side is open. Do you guys think I need both main bearings to be open on both sides? The bearing number is 47606. The tail shaft seal number is too pitted to read. I'll call NW Transmissions on Monday and see what they can tell me.

 

I wonder if you are missing a small piece.

Under that snap ring, there should be another ring hidden. It looks like very thin hardened wire...never measured it, but lots thinner than 035 mig wire.

I don't know why it's like that. It seems to hold the regular ring up higher in the groove so you can get ring pliers on it easier. If it is missing like one mainshaft that I had, it was harder to do, as I recall..

Also, did you have the rear bearing and mainshaft, pulled out of the case, and angled up in front to get the ring better?

I spotted a mainshaft this week, and I know the rear bearing had a shield at least on one side. No idea what year.

I can't say what to use, but you can ask that trans place.

One more thing; you have a repro gasket set...does it have a round gasket exactly the same size OD as the main bearing? I am not sure, but maybe something should be between the front main bearing and the TOB collar?

 

That's interesting... I certainly didn't see a ring that small behind the snap ring. It was the snap ring, and then a thrust washer with an indexing tooth to keep it from spinning on the shaft.
I'll check the gasket set and see if it has one like you mention.

So, after my last post I went out and decided to pull the reverse idler and counter shafts... Man. I'm almost regretting that now. I didn't realize that the counter shaft was full of needle bearings! That's gonna be royal pain to get back together.

Second thing is this... When I was taking the countershaft out, I pulled out a large bronze thrust washer at the front of the case that had a dent in one side, almost like it was damaged in the taking apart...But it also looked kind of perfect. Well, I convinced myself that I had somehow screwed up and banged this washer out of shape. Now I just went back and read your tech article and you mention a thrust washer with a locating dent in it... I think that was the washer. Mind you, I read this AFTER I flattened the washer in my vice. Well, Seeing as how this is the Buick case, and it doesn't have provision for the locating dent anyway... I'm thinking that flattening the washer will end up being the right thing? I freaking hope so.

So now my case is completely bare. Next step will be to thoroughly clean it and prep for prime and paint. Putting that countershaft back together with all those needles inside the sleeve has me a bit freaked out. I'm thinking if I can get them in place and suspended in some grease that's about my only shot since the shaft has to go through the needles blind.

 

that's exactly right, clean the races and bearings then use grease to hold the needles in place, not that big a deal

LaSalle input here but you get the idea..

 

you need to look real close to see it in the bottom of the groove, it might be up against one side. Easy to miss it as it is stainless color.

Did I forget to address that in Fedco's thread? ... if you have spare heater hose laying around. I have one cut to the exact length of the cluster. I even use it on disassembly ... I get the shaft to start to move with a long punch, and then slide the hose into the bore to follow the shaft, as the punch keeps moving the shaft. I just hate to chance breaking a needle with the punch as they fall out without a hose.

On assembly, put the hose in the cluster, then pack the needles and the "needle-thrust washers". Drop the cluster in, and the shaft will push the hose out and needles stay put.. (I always worried that if I used just grease, is there a way that one or two needles could get knocked loose, and remain in there trapped? Not sure if they could even fit alongside the spacer tube, but i use hose anyway. Maybe it's not needed.)

I cut the last post short as my son and a friend showed up to help tow the 32 from deep dark storage, to the work bay. No promises though....have not touched it in 27 months Also put a complete J2 off the floor dolly and onto a tall engine stand for cleaning, I hope.

 

Heater Hose! Very clever Frank. I was out there scrounging for a piece of bar stock that was hopefully within a few thousandths of the right diameter. I found a piece of aluminum bar that would be a bit smaller than the heater hose... Anyway, no need for it now! Awesome idea. I'll be using that for sure! Just gave the case it's first real degreasing. Maybe I'll get it taped up and blasted tomorrow. Thanks!

 

Josh, I use a piece of conduit in place of the hose trick Frank mentioned. Both work slick as heck. Curious about that rear shaft. Can you post pic of it. Mine has the usual pia ring and another located on the shaft. I did not find the small spacer ring either. Only seen one ever and that was on a 37 Lasalle that had been rebuilt by a po. NW will have new snap rings if yours is torqued out of shape. Think they are $3 or so. I believe they have them made as they are narrow. Just had to get one for the 37 lasalle last week. Seems all the aftermarket bearing are sealed on one side. Never thought to ask John last week about that at NW. He is the go to guy there regarding the old trannies.

And on reassembly stand the case on end when installing the cluster gears as it makes it a lot easier holding the thrust washers in while you insert the shafts. End play on the cluster should be around 12-25.....according to John.

 

Yeah, conduit make sense as well. Is there anything in particular about the rear shaft you'd like to see? I will probably order snaprings as I'm sure mine is tweaked at this point. It was a total pain to get free. Been outside blasting the case in the commie box... That damn thing is too small. My compressor is too small... Sometimes I think this hobby is for rich people. I think I'd need a massive compressor to be able to run even a medium sized blast cabinet for any length of time.

 

Here are some pics of the case after it's bath. Some pretty ugly stuff going on htere... Any thoughts on the lead plug at the front of the case around the front main bearing surface?
I wonder what all the extra plugged holes were for around the tail shaft housing?

 

Frank, I just opened up the gasket set, which you can see here:

http://www.bestgasket.com/dt_pop_up_picture.asp?PartNumber=10213&SortBy=parts&Order=DESC

#2799 is the same diameter as the front bearing and I'm guessing would go between the bearing retainer and the bearing? 6061 does not match up. I'm guessing I need the right Olds gasket. I could probably make one. 9027 must be for a different case. 9228 fits the face. I'm not sure what 4138 is meant for. It is notably thinner paper than the rest.

 

If I recall correctly, the old gasket sets for these transmissions, fit the Buick back to 1936 and up to the last buick stick in 1960, as well as 51 to 64 Olds, and not sure about Pontiac 56-7 Selector. So, the old sets would have the correct tail housing gaskets for both the old Buick, and the Selectors too.

Ok, the front leaded plug. I don't get what they were doing, as that is the factory oil return from the input main bearing. Why did they plug it, because it does line up with the olds bell oil pocket hole. So they cut an oil path in the bell to drain any oil that got past the sealed bearing? Why? Did they not know there is a full face gasket?

I don't know why they plugged the old 36-38 TOB/bearing retainer holes, unless they did not want a gasket???



Ok, the back. Yes one plug is needed to fill an exposed hole that used to be one of the four tail studs. One must be moved and then plug the old location. One of the studs is shorter, so that it can't protrude into the case, and tangle with the gear. If yours uses bolts instead of the old Buick studs, make sure you prefit them with the tail. Some Selectors also had studs, but many were bolts.

The other half plug. I believe that is the oil return from the tail housing. I think I added info on that. When you use the Olds tail, a tiny spot of the oil hole can be exposed, if the castings vary. I assume they dry fit the tail and saw a gap, then plugged and redrilled?

The next one I do, I am going to try to rotate the tail, to see if that would help. I, and probably everyone back then, starts the tail fitting by elongating the two top holes in the tail in opposite directions, equally. It's just easier I guess. But I want to see if I can do the first of the top holes to favor that oil hole coverage. Might be more filing, but should work. I'd have to see about the lower right side though, before I start.

 

HMM, I will have to look at my case to see how much different it is compared to yours. Looks like there have been a bunch of mods on yours. Don't know why they would have filled that front with lead. Who knows what these fellas did back in the day.
On the shaft.....I was curious if yours has two snaps rings or one on the rear shaft.

 

My 56 Olds tail was way off when trying to align with the oil hole even after adjusting the stud holes in the tail casting. So, I filled the area in question with jb weld and filed it to match the case surface. Looks like it will work out ok now.

 

Ok, the front leaded plug. I don't get what they were doing, as that is the factory oil return from the input main bearing. Why did they plug it, because it does line up with the olds bell oil pocket hole. So they cut an oil path in the bell to drain any oil that got past the sealed bearing? Why? Did they not know there is a full face gasket?

So, I'm thinking I'm gonna take that out... Seems like a bad idea.

I don't know why they plugged the old 36-38 TOB/bearing retainer holes, unless they did not want a gasket??

Are you referencing the 6 plugged holes around the front mainshaft hole? Seems like your case as seen in Fedco's thread didn't even have those holes at all...

So, next thing... I got the case and the tail shaft housing washed, taped up, and blasted today. While washing the tail shaft housing, I noticed the machined surface where the rear bearing seats is cracked. However, I think it's a secondary lip. I think the primary thrust surface, which the bearing snap ring is captured against is above it. So, the question is, should I take that cracked section of the cast out with the dremel and grind it all smooth? Or try to have it repaired? As you can see, it's curling down, almost like a spring. I don't see any way to repair it considering there is so little material there and no way to grind out the crack since it goes all the way through, and is almost more like it's peeling away from the case. Thoughts?

Finally... Does this rear main shaft seal look familiar to you guys? The number is too far gone to really read. Possible candidates are National 6010, 6013, 6015, 6016, 6018, or 6019... None of which seem to cross! I'm wondering if you guys had this type of seal on yours or not.

 

I'm sure I had an update on the cracked tail housings on that thread. I looked at quite a few here, and it was caused by casting core shifts. I had spare good ones with plenty of material backing up the bearing.

Yes, it is now supported mainly by the ring....at least on the one side that is broken.

The seal looks familiar. I can look up the GM number if you need it

I did not go look at the thread pic that you could not see holes in my case. I just don't recall, but I do know that trans came from a cutdown doodlebug as a second trans which had no TOB /retainer. I think the seller said it was bolted to a huge flat plate and a small hole for the input shaft. I just can't recall if they plugged the small holes and used the 4 big holes...or not. That trans is in my 32, so I can't look at it

 

The GM number would great, Frank. I will look at your thread closer to see if I can find what you wrote about the cracked tail housing. In the meantime, Walt, here are a couple pics of the tail shaft. It has two snap ring grooves as you can see... As well as yet another sign of some kind of grinding by a PO.

 

Ok... Just spotted the part where you discussed the exact thing I referenced. So... Would you just cut that part and grind it all smooth to stop the crack... Hopefully you're not thinking I should scrap this one.

 

On my Buick top shift tranny with the olds tailhousing I found a metric seal was a perfect fit as the OD of the original is non-standard . I ordered rubber coated seals off Ebay. The seal number is in my build thread, but I will try to dig it up.

Finally... Does this rear main shaft seal look familiar to you guys? The number is too far gone to really read. Possible candidates are National 6010, 6013, 6015, 6016, 6018, or 6019... None of which seem to cross! I'm wondering if you guys had this type of seal on yours or not.[/QUOTE]

 

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Thanks, Roadsir!

 

Josh the seal is available from NW. Just received one and it looks like a factory item. It came in the rebuild kit for the tranny that I ordered.
What is the casting number on the tail. I have some good spares. Also the length end to end and the distance from the front of the casting to the center of the speedo gear opening. Most all of these are interchangeable so long as the lengths match. If I have a match you are welcome to it for the cost of the postage.