My 71 Duster work in progress

Thanks to @69.5CUDA and @Dr.Jass for the info. I've got plenty of description to make this happen.

I'll figure out the least amount of parts to disconnect before I start. My biggest concern is still (always has been) pulling the engine mounted on elephant ears. Those are bolted to the frame rail so I can take the k-frame out and the engine won't move.



I guess I could drop it right out the bottom too, if I drop the K-frame first.

I asked on FABO about welding up the cut for the oil pump and got some good photos of how to weld it up and found out that 16 gauge is plenty so my welder is good to go for that. Plus the welding there isn't really structural, so I don't worry so much about it.

This is that thread if you're curious Welding after Schmacher/Trans-Dapt biscuit mount mod
 
b-body-bob said:
You're right, I will definitely have to swap the water pump housing. The pulleys and PS brackets *should* swap straight across to the new engine.
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Forgot that since the WP housing lines up with everything now, it must have been milled to allow for the thickness of the ears. I will probably end up buying a replacement. I think I've got a couple laying around but they are both for an earlier b-body so they have the lower hose on the driver's side.
 
doc thats EXACTLY how i did it on my 67 after cranking out both tubes entirely...well i wouldnt call em cracked at that point they were SPINNING!..that was the first one i did...the others i refined how to do it easier

bob ..assuming you can get to the ears..i would leave the member in place and remove the ears and drop it out the bottom even if it just "rests" on the k member

even still i swear by the HF wheel dolleys..dropping an engine oilpan into one and a strap over the engine they stay put even on ROUGH asphalt..i have dozens of those things laying around mostly under engines and transmissions
 
I've got 4 wheel dollies that I've used for various things but don't remember using them to wheel a motor around.

I'm thinking I might drop the 400 out the bottom, but don't know if I'm bold enough to just let it rest on the k-frame and drop it all at once. I worry that the engine would roll over and make a mess of things. Seems it would be more secure to put it down on a wheel dolly or some kind of rolling cart where I can strap it in place.
 
Seems like I'm .030 too tight on both clutch packs. That would probably explain the car creeping in neutral. The last time I had it apart I replaced and checked everything but remember thinking "Yeah that ain't right but it was working good enough before. Of course it also creeped before, but it was a race car too so I let it go.

I'm not 100% sure I'm measuring the front pack correctly. The pressure plate has that step at the edge. I'm measuring flat across the top of it to under the lock ring, disregarding the extra space from the step.

It's got a 5.0 lever in it but I'll be danged if I can figure out how to get the pivot out. Yes I removed the plug from the front of the case. It still doesn't want to come out. The new VB calls for a 3.8.

I'm gonna have to go to the parts store to borrow a valve spring tool to get the servos out unless someone has a home made tool in mind that will do the job. I don't remember messing with them the last time, so either I rigged something up or I didn't take them apart. Probably didn't take them apart.

I need to be sure the servos are set up right since those are the only things that change for the LBA VB. I'm mostly sure they're already modified but need to check to be sure.

No governor


Clutch packs


New red band


The accumulator is blocked


Cheetah RMVB for sale
 
Continued

The front drum is full of clutches and steels. Six of each, and it has a bunch of springs too but I didn't take that apart.


Clutch clearance
 
Well this just keeps getting more confusing.

The Coan VB instructions calls for
"The clutch pack for the High/Rev. must have .070”-.080” clearance. The forward clutch pack must have .030”-.040” clearance in it. "
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The Munro book calls for .015 clearance per disc in the front, so with 5 that means .075. For the rear pack, he says it doesn't really matter because that's not a "shifting" clutch, so .030-.040 is fine with the standard 4 disc pack. Per the illustrations, that means the front is the front most drum that the kickdown band rides on and the rear one is the one with the input shaft in it. Or the front is the one with 15 springs in it and the rear is the other one. That agrees with the FSM.

First, that makes me wonder if Coan is using different terminology to ID the clutch packs. Seems like they're directly opposite of each other. Maybe Coan is talking functional position, Munro is talking absolute position.

Going forward, when I say "front" I mean the drum that's directly behind the pump, and when I say "rear" I mean the other one.

So, if they are using opposite terminology and the .030-.040 is correct for the rear clutch pack, I'm OK with .047, but the car definitely creeped in neutral, and everything points to a tight rear pack as the cause. But, if I go with the .015 rule of thumb, I need .060 there for 4 discs, and based on that it really is too tight so I need to use a thinner something somewhere (split ring, disc, or steel).

Next, everything I see describes checking the clearance by just jamming a feeler gauge between the pressure plate and snap ring. My front pressure plate has been machined, so it is stepped and there is no way to come straight at the gape to measure it with a feeler gauge. It always ends up at an angle. I decided to use an allen key to check it, and was able to get a 7/64 (~ 0.110) to fit, so that's close enough. But going back to the .015 per disk rule of thumb, that's .035 too much.

In the end I'll probably end up just putting it back together as is, so this will have all been a waste of time and money and I won't be able to let the car idle in neutral when I work on it. (y)
 
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I see per the FSM that the front clutch pack is active when the car is in reverse. The rear clutch pack is not. The front clutch pack is also active when the car is in drive-direct (high?). I think that cracked the code. "High/Rev" means the front clutch pack, and "Forward" means the rear pack.

While doing that I also realized the difference between "forward" and "front"

Still need to know if I'm measuring the front clutch clearance correctly - but at the same time I don't see how measuring it with an allen key would be wrong.

So, for the time being anyway, it seems like I need to add about .020 clearance to the rear clutch pack, and remove about .035 from the front clutch pack.
 
I don't pretend to know much, if anything, about the internal workings of TorqueFlites. I read some articles probably 30 years ago in Mopar Action since, y'know, I had an automatic at the time so I cared. I didn't retain much, apparently. However, it seems to me I've repeatedly seen reference to only using 9 springs in the front drum, in three groups of three.

Barring the possibility of dragging out Mopar Action tech articles from February of '92 and (maybe) October of '89, I'd suggest trying to get in touch with Rick Allison. If it's been tried with a 727, he's seen it. If it's a problem with one, he's diagnosed and fixed it. I'm sure I have the aforementioned technical articles, but at the moment I just haven't the time to sort through stacks of magazines to find 'em.
 
No problem. I'm pretty sure I'll need to get on the phone with someone about it anyway. Have you looked at A&A's website? Holy cow it lists every part and type of part known to man. There's no way I trust myself to make the right choices.

I checked my stash of old steels and clutches that I took out of it and they're the same thickness as what I've got so there's no help there.

I managed to get a reply on FABO from a guy who says the rule of thumb is all crap - just put the pump upside down, put the two drums on it and air check it to see how much clearance you've got. Yeah I know you can do that, but how do I know when it's right? Some people think they're comedians I guess.

I started out thinking the creeping behavior could be the VB but after taking it apart years ago there didn't seem to be anything wrong with it or anything that could go wrong with it for that matter. It may turn out to be that after all if I get confirmation that it shouldn't be doing that based on the clearances I've got. I might get a chance to call tomorrow, hopefully before the weekend anyway.

I've still got to decide what to do with the engine - run it as is or pull the pan and check the bearings. I don't recall having any oil pressure problems or smoke so I'm leaning toward running it as is. But dang I don't want to put it in just to pull it out again.
 
One other thing that I recalled: In the Black Bitch, I had too much front clutch clearance after a few thousand miles of driving. This caused a runaway situation in third gear... it would engage for a second or two, then the engine started to free-rev like I'd put it in neutral. That transmission had the extra clutch pack in it, but neither myself nor the guy who built it for me--who knows 727s very well--were aware that the wave-washer snap ring is a no-no on a performance transmission. I'm assuming your trans has a flat snap ring in that position, considering all the other work that's been done. Anyhow, I think too much clearance is far more of an issue than not enough. I'm also wondering if it isn't (wasn't) valve-body or shifter related. The reason I say that is because in neutral, the front pump is pumping. Hence, any "overlap" between positions, in this case neutral and drive, could possibly allow partial fluid flow to a passage or orifice that should not receive flow (pressure) in neutral. It's a thought, and one that has no particular basis beyond my supposition. Were a guy so inclined, he could look in an FSM with its fancy color fluid-flow charts and exclude this possibility... or potentially verify it.

And, after typing all that out, I checked the FSM just for funsies because let's be honest, it's not doing it because it's a hootchie-pow race transmission, it's doing it because it's misbehaving Torqueflite.

Survey says:

BobTrans.jpg

Stop looking at the front drum. That ain't the problem.
 
Dr.Jass said:
One other thing that I recalled: In the Black Bitch, I had too much front clutch clearance after a few thousand miles of driving. This caused a runaway situation in third gear... it would engage for a second or two, then the engine started to free-rev like I'd put it in neutral. That transmission had the extra clutch pack in it, but neither myself nor the guy who built it for me--who knows 727s very well--were aware that the wave-washer snap ring is a no-no on a performance transmission. I'm assuming your trans has a flat snap ring in that position, considering all the other work that's been done. Anyhow, I think too much clearance is far more of an issue than not enough. I'm also wondering if it isn't (wasn't) valve-body or shifter related. The reason I say that is because in neutral, the front pump is pumping. Hence, any "overlap" between positions, in this case neutral and drive, could possibly allow partial fluid flow to a passage or orifice that should not receive flow (pressure) in neutral. It's a thought, and one that has no particular basis beyond my supposition. Were a guy so inclined, he could look in an FSM with its fancy color fluid-flow charts and exclude this possibility... or potentially verify it.

And, after typing all that out, I checked the FSM just for funsies because let's be honest, it's not doing it because it's a hootchie-pow race transmission, it's doing it because it's misbehaving Torqueflite.

Survey says:

View attachment 24715

Stop looking at the front drum. That ain't the problem.
Click to expand...
Yeah I know it's not the front drum. I'm only looking at that to figure out how to measure clearance with that modified pressure plate.

The rear drum spec is .030-.040 and it's got .047 - it's straight-forward to measure that. The shifter was adjusted and re-adjusted and ... so it's not that. It almost has to be the valve body at this point.

The front pressure plate looks like this, so it's impossible to take an accurate measurement with feeler gauges. The stock part is flat.

1671108164697.png
 
b-body-bob said:
It almost has to be the valve body at this point.
Click to expand...
I would tend to agree. Shift-linkage adjustment ain't exactly rocket surgery, and while the rear clutch clearance is outside of spec, I have to doubt .007" would render it "inoperative" in the context of the FSM. The FSM spec is for production-line stuff, so I'm not sure how it translates into gitchasum race parts. I know that on the front drum, the TH400 snap ring is required because there is more clearance with the TCI race rebuild kit, and the wave washer snap ring provides just enough extra clearance that third gear can dash off into the distance and wiggle its ears at you.
 
Also the creeping would be caused by the clutches being too tight and it's +.007 to spec so it's actually looser

Coan specs .030-.040, the Munro book specs the same, and the 71 FSM specs .025-.045. There's nothing wrong with the rear drum clearance. I was led astray by the confusing terminology but that's cleared up now.

I didn't mention it before but yes, it's definitely got flat snap rings in both drums. IIRC they're about .080", both are the same.

I'm going to do what needs done to the servos this weekend and just put it back together. Can't order the gasket kit until I pull the servos out, in case parts are needed there. I will probably order a thicker snap ring at the same time to try to bring the front drum clearance into spec. Coan specs .060-.080, the book specs .075, and the FSM specs .033 to .075 for hemi and 440+6 with 5 clutches.
 
I had a suggestion to check the spring and the rear clutch piston. No problem. The rear drum will clunk a little but I looked at it closely and the cause of that is the clutch retainer (drum) sliding about .020 on the splines of the piston retainer (the big gear inside the drum). It's designed that way.
 
This video explains the likely culprit



Jass you were right, call Rick Allison. He would've pointed that out pretty quick since he makes it.

Gotta go take a proper measurement to figure out which of 4 heights I need.
 
I'm trying to follow this adventure & learn something, now it's deeper than I'll ever go but I give you guys credit for even venturing in there!
 
I think it's interesting and there's less chance of screwing up than there is building an engine LOL. An A/T basically just stacks up and is held together with snap and lock rings.
 
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