Most of this has been covered in another thread, however, I fear this subject is lost among all the other things discussed there. In addition, at least one member has mentioned the difficulty of downloading the thread due to all the images and his dial-up connection. I thought it best to cover the tranny in its own thread.

We have been working under the theory that the known good heavy-duty tranny donated by Dan would bolt to our 460 engine - a fit check has shown that this is not true. We need a 460 case. Worse, we need one set up for 4wd using a married transfer case.

We have a C6 tranny we bought with the engine, but it is 2wd with the long tail shaft, and appears to be in bad shape. I do not know if it is the heavy-duty with the stronger parts and clutches inside. Professionals have indicated we can move the heavy-duty internals and tail shaft from the known good tranny into this one.

Question one is if we do the work ourselves, or pay a professional to do it for us. It looks like they will charge less than $200 for this.

Question two has to do with the valve body. The known good one is off a diesel engine, thus will have the shift points set for a lower RPM than our 460 needs. With our cam, we will want to shift in the 4500 to 5K RPM range.

I do no know how good the valve body is from the 2wd tranny, or if it has a shift kit installed. I expect it will bolt up, but do not even know this for a fact. It may just be a matter of buying some different springs for the 4wd case.

Question three has to do with the torque converter. I do not know where we stand there - will the one off the diesel engine work with our 460? Do we need a different one and, if so, do we want to go with a new one with heat treated veins? How about stall speed, given the cam we are running?

Question four has to do with the starter - the one for the gas 460 will be different than the one used for the diesel engine. Do we even have a starter? What of the mounting? Will the ring gear we have engage the starter gear?

Lets discuss this some more and come up with a plan.

 

I can assist on some of the questions, as well as some random thoughts...

I think Dan and AJ have spoken up and looks like we'll have someone who's been there/done that do the work.

Regardless of what is/was in our C6 we got with the engine, it will be replaced with the internals that Dan has-sans Valve body.

One issue with the VB we have, it would need to be taken apart, thoughly cleaned to make sure there isn't a speck of grit in it...one little piece of gunk can stick a valve and fry a tranny, I had this happen "way back when", the guy who rebuilt my TH400 gave me two option, clean up the old VB, or replace it, I thought I'd save a few bucks and it cost me in the long run.

Regarding the TC, Dan told me the deisel one has an 1100 stall, or there abouts, way to low for us and what we'd want anyway, even a stock TC for a gas engine would be too low, I think we should look at a 2500-2800 stall for our engine.

I have the starter for the 460 here, unknown condition, but easy enough to check "the shadetree-way", I'll check it out before delivering to Dans.

I'm not concerened about the ALt., I have a few good working ones if need be we can adapt/or may beven bolt right in, Dan has some pwr steering pumps he's sure will work good, and I have a known working one off the 5.0 I won't use, but ity's a serp belt pully, I'd have to lay them side by side to see if they'd be compatabe.

 

I have the alternator for the 72 here - it was a fresh rebuild. The same with the power steering pump.

I am not worried about the starter working electrically speaking, but how it fits into the tranny bell and the ring gear on the flywheel. Will the gears engage fully, or are they different? I understand this can be a problem.

Also, what of the balance weight on the flywheel? does it need a 29 once weight to externally balance the engine, or is the engine internally balanced?

I am just trying to anticipate any and all problems we could run into with this engine/tranny combination.

 

When Dan dropped off the engine and tranny, it came with the flexplate attached...so there shouldn't be any issues using the tranny/flexplate/starter we have on hand

 

flexplate - you are talking about the steel sheet that goes between the tranny and the engine case, not the flywheel, right?

It is not likely to be a problem, but I understand the ring gear on the flywheel can be a different tooth count, and larger or smaller in diameter on these newer engines.

The same is true - that is, some engines are internally balanced, some externally. Your 302 is that way so some have the weight attached to the flywheel, some don't, even though they are the same block (302). Do we have the original flywheel?

Again, I am just pointing out things that have given others problems in the past - I want our swap to go without any more surprise problems.

 

The Flex plate is where the "flywheel" for an automatic transmission is and is what the torque converter bolts to.

We're speaking of the same part

 

Mike, forgive me from being so slow and tedious - they say your mind is the first to go!

This picture shows the flex plate, which has the starter ring gear mounted on it and bolts to the torque converter and the engine crankshaft. It also shows the bottom cover plate.



While this picture shows another plate (what do you call it?)


Now, do we have all three plates? With the cover plates in place will the starter drive gear engage the ring gear mounted on the flex plate?

Are these stock parts (came with the engine/tranny?)

note: pictures are of a 390/C6 combination.

 

First off, yes, we have it all...

But I see there's some confusion in terminology.

A manual tranny uses a "Flywheel", as known from way back when on Johny Poppers, etc,...the flywheel is really a device to keep the engine "spooled", you need the inertia of revolving mass, or the RPM drop between shifts (or lug in a one speed combo) with a light weight "flywheel".

Take a look at a real aircompressor for instances, ever wonder why they use so much metal just to spin the compressors?

Okay, so now Auto trannies came out, I think way back when in the early 40's (maybe earlier), when torque coupling devices were introduced (know now as torque converters) originally they were put n "flywheels", what manufactures found ere that with the weight of the TC and the "flywheels" spinning, the engine speed never slowed down enough btween shift and genereally over revved.

The light bulbs came on, and "Flexplates" were introduced...the flexplate was a thinnish, stamped metal unit that the TC could bolt too, so the main rotating mass was the Torque converter.

I Think had they (all auoto manufacturrer that used a "Flywheel" back in the day, just listened to Newtons law of physics about "an object in motion, tends to stay in motuion", they would have caught on sooner...

Anyway, since the TC has "mass", it does not need help to stay in motion, btu7 add another 25-+ pounds of rotating mass to one, and you can easily see why it becomes too much for mosy of us (exceptions are lighter duty deisels, etc...low RPM, and only a few gears, they run a really heavy flywheel to keep things close to a mild RPM drop).

So, when there now became a difference between auto tranny and manual tranny, the terminolgy changed...Manual tranny's continued (as really spec'ed by laws of physics"continued with a "flywheel"...but what to do about these thin, basically "holders" for a Torque converter?

Unknown who or how the phrase was coined, but "flexplate" has been the common term for 40+ years.

Ya, I know, a long diatribe, but my fingers are friskey...sure hope there's not too many typo's, as I surely won't proff this reply before I hit...

 

ALso we have "cover plate 2", Dan explained to me that it's thickness is important for starter to ring gear contact...cool with me as I'd shimmed too many starters back in the early GM engine block days.

A Flex plate (which the TC bolts too)

That bottom plate you show in the firt pic, I've no idea, as we don't have one...might be a different desing (my guess better) as I don't see why Ford didn't do it like GM did and make it simple...i/e the TC Inspection cover on a GM TH 350/400, just unbolts and you can get a good look at it, Ford though they'd just cover it all up with an AL bellhousing on the tranny

I dunno, I've found goo vs. bad since we started t6his project, but all in all it's been a great experience

 

BTW, the gms use a tin pan to cover the bottom of the torque converter for good reasons - first, you are going to be inspecting and working on a GM tranny a lot more than on a Fords,

And second, the pan is not sturdy enough to protect the bottom of the torque converter should you get into rocks or rough country. GMs should never be taken off-road!

As to all the goo you have found, it must have been left by a GM project!

 

Lol, I'm just speaking from street cars, offroading and 4x4'ing has never been my cup of tea...until now that is.

But think about it for a minute...do you really want to drop the tranny because you think the flexplate is cracked?

Doh!

 

OK, to recap:

1. Dan is going to take the tranny to a professional and have the case changed. This has to be done now, before he can locate the engine/tranny in the truck and finish the mounts. It will cost about $200 labor.


2. The "flex plate", ring gear, starter, and cover plates are all from the original stock engine and should work in our application. We are missing the bottom cover plate, which is not needed to build the truck but must be replaced before we run the truck in the mud. It can be replaced with the tranny in the truck.

3. We will need a torque converter. Since we are replacing it anyway, we want one with a better stall speed (matched to our cam) and heat treated veins. The transmission shop Dan found can get one for about $300.

4. We will need either a shift kit or even a different transmission valve body. This needs further research/discussion as to the cost/benefit of our options, and a decision must be made before the tranny goes to the shop.

5. We need "X" quarts of tranny fluid to start the engine, will we need to replace this fluid after it has run a bit?

6. Anyone want to estimate how much all this is going to cost? We need to take up a collection. I will start with a $150 donation, where and how do we send the money?


Any other ideas, discussion needed? Have I missed anything to do with the transmission/transfer case?

 

We can get a TC through Summit for about 250, let me check another place too.

I'm out of "fun" money for a bit, I'll have to put a few things on Ebay to build the account back up.

 

I did a goggle and $250 seems to be the low end for a custom torque converter, but I am not comfortable ordering something for "racing" without more knowledge. I know stall speed is not a firm engineering number, it varies with application. Mostly it has to do with the weight of the vehicle and the final gear ratio.

Also, what stall speed do we want? That is governed by the horsepower curves of the engine which are set by the cam we used. Which cam did we wind up with? A name brand and grind number or series number equivalent is needed.

Also too, remember that while mostly we will be using this truck for mud bogs, we also want it drivable on the street, and will use it on the trails too.

As to money, you did not say where or how to send it. My guess is that we are going to need more that $600 -Several members have offered to contribute. I don't think you or Dan should have to, let the rest of us do our bit towards this project.

How about those willing to send some money posting here - if you want the amount to remain confidentual, send an email to Mike stating the amount. We need to know what we have to work with.

 

I'm in with a good solid donation. Is there a paypal account or something?