512 cid C series on Dakota chassis- build thread

[Plymouthy Adams]

be very careful that the spring you installed for positive return is not binding the selector/kickdown....your spring action would in my opinion be better served at the carb end of the linkage verse that at the selector and kickdown levers...most cables for downshift is reverse connected, I cannot speak for Lokar….they just not my cup of tea.....personally I think if you do not adapt a 94 up downshift cable made by Mopar, the next best thing if you like shelling out coin is Randy Bouchillion…Randy is good people, have know him for years.....

[Radarsonwheels]

With this cable all you can do at the carb side is introduce slack. Here’s a pic of my return spring. It’s gentle enough to not introduce stress to the throttle shaft or make the pedal stiff, but returns the lever nicely to full forward (idle) position. 

 

The cable is doing its job. Taking off in Drive part throttle upshifts from 1 to 2 are quick and heavy throttle shifts hold 1st longer. 

 

I stayed up last night studying the operation section of my transmission book- even re-watched the old mopar master tech movie on youtube which covered the basics I already double checked but was still a good watch. 

 

I’m still very inexperienced as a transmission mechanic but here’s my diagnosis: I have park, neutral, 1, & 2 working just as intended. The one part shared by 3rd gear direct and reverse is the front clutches and since it only has to share duties with the rear clutches in D the line pressure is much lower than in R. Reverse having a intermittant operation and sometimes a violent shuddering that jerks you backward could be explained by the front clutch trying to engage at high psi with a leaking seal. 

 

I still have to really study the valve body again and see if I could have missed something there before I pull the whole

trans.

 

In the meantime I’ve been mulling over whether to drop the trans out the bottom, which could involve the chassis springing from all the frame welding I did when the trans crossmember is unbolted or cut out. 

 

Or I could take off the nose and fenders and pull the driveline from the front. This is probably the best option time wise. It would also offer nice access to my firewall and undercarriage- a great time to finish, paint, and insulate some spots that were hard to reach underneath. 

 

Then the answer hit me right between the eyes. What I really need to do is pull off the nose, cab, and bed. Then I can access the trans from above, and flip the cab and bed up on their rear panels so the bottoms can get nice finish work. This would also be the time to shim up the motor 1/4” for more header clearance and decide if I want to try and seal the rear main or if the leak is livable. 

 

Y’know like the right way to build stuff- make it work, then take it apart and finish it. At least I made everything servicable so it will be easy to take apart. And I know where I’m looking for a ripped seal in the transmission. I already ordered new 727 seals and gaskets- they’re cheap enough. 

[Radarsonwheels]

*not my front clutches* just a youtube clip I found. 

 

This is what I’ll be looking for when I hit the front clutch port in the trans after I pull the valve body.

 

If it seems good I will tear apart and verify the valve body pistons and check balls. If it doesn’t apply or sounds like a hurricane I’ll have to pull it and replace the seals. Hafta try it at high air pressure and low to simulate reverse and drive fluid pressures. If it’s the seal it might look like it applies at high pressure but make a lot of noise and the return will be instant instead of a sigh. Low pressure would be just a rush of leaking air that can’t defeat the return springs.

 

 

Making a lot of work for myself here but I’m actually excited to get the undercarriage nicely finished and protected- most of it was built in place and  some is unpainted underneath. I am also no stranger to taking on big jobs- one step at a time it’ll get done right. 

 

 

Edited March 29, 2019 by Radarsonwheels

[Radarsonwheels]

Here’s an even better video since it shows how I’ll be checking it through the ports in a built up transmission. The first one is more like how to check it before re-installing. 

 

[f_armer]

Just a thought... when i pulled my engine and trans after the cab was on, i thought the easiest way was to take the front clip off, and slide it out the front.  Well it was prob the easiest, but i still fought with getting that deep pan up and over the front cross member, while fighting the engine hitting the firewall. I would think yours would be similar. I got it out, but at one point i considered pulling the pan off for clearance.

Next time i think I'd drop the trans out the bottom first, then pull engine, not both at the same time.

 

Another thing, and i'm no expert on transmissions, i have succesfully rebuilt a 727, but my initial thought was that it sounds like a valvebody problem your having. It would be easy to pull it first and double check everything in it first?

 

Edited to add: after rereading your post, the air pressure test is probably the best place to start, good luck! I hope it is something simple, and you don't have to tear the whole tranny apart again!

Edited March 30, 2019 by f_armer

[Radarsonwheels]

Thanks Farmer

 

I put my engine in the chassis with the cab on but no doghouse and cut out my firewall and floor so it would go in, then once the mounts were all done I built the firewall and floor around the driveline. In theory the motor and trans will slide right out the front- it does have plenty of room to work on the motor now but it’s tightish around the trans. It’ll feel good to have the bottoms all nicely finished and protected from the elements.

 

I still might not pull the cab right away but since I have another set of hands on the way I’m thinking it’d be a good time to pull and upend the cab and bed. Plus I can get the whole chassis painted too.

 

I will look over the VB but I will be surprised if the air check doesn’t sound good on the rear clutch (called the forward clutch) compared to the front (R/3rd) clutch. At least the front clutch is right there behind the pump and won’t need a lot of digging to get to like the sprag.

 

If it stops raining I’ll get some work done in an hour or 2

[Radarsonwheels]

It sorta cleared up outside but my reinforcements came and we got busy for a bit. The doghouse came off pretty easily and the bed came off with the cherry picker on the back and a guy on each corner. It’s pretty heavy with the wood installed and the mounting bolts are going to be fun to get lined up when I re-install. 

 

I’m glad I flipped the bed on its back- now I can finish the welds on the bottom, paint the frame, and wirebrush & paint the insides of the tubs etc- it would have given years of service as it but was really 3/4 done and will last much much better with some finish work. The struts behind the tires that stabilize the rear fender lips will be easy to weld in now too. 

 

Still gotta pull the cab but that’ll be easier too now that it’s not butted almost to the bed and I have easy access to disconnect the steering wiring and oil sender. Gonna take the opportunity to paint the frame where it’s still crusty too. 

[Radarsonwheels]

I got all the bottom joints of the bed floor frame welded in, power wirebrushed and vacuumed the whole undercarriage including inside the tubs, and painted everything with por15. And I didn’t even get dirty!

 

[Plymouthy Adams]

no dirt...somehow I feel you did not enjoy this job to stay so distanced from it you did not even get dirty.....

[Radarsonwheels]

I’m thinking about getting a gallon of oil based rust treatment gloss enamel to paint the frame. There isn’t really any real rust on it but I’d hate to trap anything under regular paint. I’m thinking the stuff you’d use on wrought iron fence? I used a whole quart of por15 so far. It is spendy and it works but it’s not a miracle or the only way. 

[RNR1957NYer]

I've used POR 15 in the past, even using it with fiberglass mat to rebuild small areas of rust out in floor pans, but they recommend top coating it as it is not UV resistant (it also dries so glossy I think you need to sand it to get a top coat to stick).  And when I use POR 15, I manage to get it on myself so you clearly are neater than I! 

 

For a more paint -type product I like Eastwood's Rust Encapsulator - it comes in black, grey or silver, in spray cans, quarts and gallons, and can be sprayed or brushed and does not need to be top coated.  Check out Eastwood's website for more info.  I keep a spray can of gray around to use as a primer when I can't completely grind away all traces of rust.

[Radarsonwheels]

I only used the por15 where the sun don’t shine so I think it’ll hold up fine. Still gotta do the back of the dogouse- the rears that clamp to the cab have some surface rust that needs attention before I squeeze it back together. And of course the whole bottom and front of the cab need attention.

 

I’m thinking I can roll the cab on its back on some wood & towels with the windshield pointing at the sky and handle all that. Probably done for today though. Probably spray rubberized undercoat on the insides of the tubs tomorrow am before work if it’s gonna be sunny. That stuff also doesn’t hold up in the sun but does fine in wheelwells. 

 

My transmission seals and gaskets should be here by weds. I’m anxious to finish my undercarriage work so I can dig back into the transmission. 

Edited April 1, 2019 by Radarsonwheels

[ggdad1951]

You should top coat the POR when it is tacky...nothing short of nuclear war will get the paint off.  Be careful, it's not "nice" stuff to your body, make sure you use the right PPE when using it.

[Radarsonwheels]

Thanks! I just brushed it on outdoors wearing nitrile gloves- no spraygun action yesterday. I did have a bandanna over my nose like a bandit during the dirt & rust removal in the tubs. It was pretty crazy I probably looked like pigpen- dirt tornado included.

 

I would have sprayed undercoat last night if I had por15 brand but I was worried my 3M rubberized undercoating would not be simpatico with the por15 solvent or it would seal in the por so it would never dry.

 

I put a spraycan of the 3M in each tub, spending extra time around the back to dampen thrown rocks and pebbles. 

 

I also found a handful of rivets on the rear top inside edge of the fenders (original gasket hold downs I’m guessing) that I air chiseled off so they can’t shake like moroccas. 

 

I found my first antique treasure tucked in the corner of the stake pocket area- an old pull tab from a 70’s beer! All the slamming and shaking this thing’s done I’m surprised.

 

I got some oil based rusto ‘rusty metal’ primer and satin black oil enamel to paint the hidden areas for some longer lasting rust protection. Hopefully once she’s back together this time I won’t be pulling the bed or fenders off again for a long while.

 

Gotta go open my shop in a bit but I hit the bed front that butts to the cab and the pocket under the tailgate with the wire cup and some oil rust primer tthis morning so it’ll be ready to topcoat tomorrow. 

[Radarsonwheels]

Today’s cab pulling day. I am going to make a stand to suspend my brake master cylinder so the lines don’t bend.

[Radarsonwheels]

I got some help for an hour and a half this morning. I got the stand for the m/c and 90% of the disconnecting done before he got here. We got the cab off clean and decided it was a bad idea to lean it on its back since the lower panels are not structural and all the weight is in the front. So we put it on some beefy jack stands where I can still get underneath to do the finishing work. The transmission is sitting right there, ripe for the plucking, and my gaskets and seals are here for it too. 

 

Taking a lunch break right now trying to rally to get more work done today. The firewall, floor, and frame are going to keep me busy for a week or two in the driveway. Hopefully I can get the engine shimmed up by the oil pan so I can pull the trans while the sun is shining and I can make noise wheeling the crane around the driveway.

 

 

Edited April 3, 2019 by Radarsonwheels

[RNR1957NYer]

I dunno - since you've got it all apart again, maybe it's time to slip in that 6.1 you're keeping at the end of the driveway....

[Radarsonwheels]

Why would I swap an 8.4 out for that dinky 6.1? It’s only got 425/425 hp/tq haha the six speed is nice though. The ‘09 srt is really comfy on trips and fun to drive but it ain’t a stroked big block.

 

I got the transmission drained and pulled and actually remembered to hit the torque converter and flexplate with a shot of spraypaint so I can index it on reassembly- one of the four bolts is offset. 

[Radarsonwheels]

Figured out the sticky steering at idle- one of the set screws in the middle universal joint was hitting the header. Time for more torch and hammer work. I kinda want to skip the screws and weld it on but then my spherical bearing support can’t ever come off again so I’ll just ding the tube. 

[Plymouthy Adams]

would it not be easier just to get the correct length set screw.... I like hitting things with hammers as much as the next guy but enough is enough...

Edited April 4, 2019 by Plymouthy Adams

[Radarsonwheels]

6 minutes ago, Plymouthy Adams said:

would it not be easier just to get the correct length set screw.... I like hitting things with hammers as much as the next guy but enough is enough...

Yeah the screw is just proud of its locknut so unless I can figure out how to space the whole situation another 1/4” outboard it kinda is what it is. I wouldn’t be dinging the headers just because I couldn’t get or make a shorter screw. It really just needs a little relief, nothing crazy like on the other side.

 

Didja ever see the enginemasters episode where they hammered the crap out of a set of headers to see what it did to the power? Crazy stuff- it did almost nothing to the dyno curve! So of course I’d rather have stuff just fit right without caveman smashing technology but now that I’ve done a complete mock up and disassembly it’s time to make sure I fix any problems while I have 360° access to the mill.

 

Maybe I will throw a couple strong tacks on the double D to universal after it’s installed instead of the loctited set screws into dimples. I don’t expect to wear out the spherical bearing any time soon so if it’s captured I can deal with that and no more sticky spots on the steering.

[Plymouthy Adams]

beating a header full of ding probably does about as much as a pair of skivvies restricts a fart....but then its all hot gases...

[Radarsonwheels]

And because I never saw my firewall from this side here’s a pic of how it came out. I have some work to do on it but not a ton mostly paint and a little grinding. A few seams on the square tube frame that were never welded underneath. 

[Radarsonwheels]

Looks like my seal installation was ok after all but the steel ring seals that ‘looked good’ on the reaction shaft behind the oil pump were not so good. Guess I’ll replace them both. I think the feed for the front clutch apply piston comes from between these metal ring seals. 

 

Started smoking the front clutch pack too but I have some spares. 

[Radarsonwheels]

I got the exterior cab floor and firewall primed with the oil based rustoleum, patched a hole that was behind some bondo, and stripped a ton of flaking paint and bondo off the running boards.