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SAE #3 vs GM Bellhousing

Ok, so I need an allison TPS as well. What is j1850 & j1939? I'm still familiarizing myself with this stuff.

So is the A40 the TCM I need? Does it need to be one off of an 8.1l? Which if so, works out for me as I'm still trying to find a regular cab long bed 8.1. I wanna take the allison out & put a t56 or something behind it & make a hot rod. Swap a 70s chevy body on it or something.

Anyways. So I was talking with a buddy & I was telling him I need a dodge automatic adapter plate so that I can run the Howard's conversions plate to run the sae3 bellhousing. To which he informed me that I should just get a 6bt to sae3 adapter plate. Which to be honest, totally forgot existed. Which route would be better & why? With the straight cummins to sae3, theres a lot I would have to cut off from what I understand? Are these the adapters with the 20 degree tilt or whatever?
 
I know Some had the angle that were used in box trucks like grumans. Others were straight. Depending on what fitment you need ...
My guess would be you want straight, But thats a guess.
 
Always straight my friend, always. Wait, yeah, were still talking about truck parts. Yeah, straight. My buddy has a sae3 adapter that's out of a bus. It has big huge mounts for the industrial motor mounts too which I wont need. Is it going to hurt the structural integrity of the adapter if i have a machine shop eliminate those mounts to fit in my truck? Would using a genuine cummins to sae3 adapter be smaller or bigger compared to using the Howard's conversions parts?

For those unaware, Howard's conversions utilizes a 94 & up dodge automatic adapter plate & flex plate. An adapter is then bolted to the dodge adapter to make it sae3. Same for the flexplate.

So its either cummins to sae3 or Cummins to dodge to Howard's to sae3. Those are my two options.
 
The only adapter that had the tilt was the b series to the GM transmission used on the 4bt in grumman van chassis's with a turbo 400. The 6bt to sae#3 should be super easy to find since they used it in virtually everything except the Dodge trucks. As to the tcm, it doesn't have to be from behind a 8.1l. you can have them flashed to whatever you need easily enough. Just make sure it's an a40 and not an a50. I believe the a40 superceded to an a43, then a46, and now a t14, but just make sure it's an a40 or a superceded version. They were used from 06 to early 09(but there is MANY different operating system's available in that span, so budget the funds to have it flashed if you don't have a way to do it). Then you can have the shift points set to where you want. Otherwise you can get s pcs 2650 I believe it is, and use it as a gateway. It essentially reads whatever info you provide it, translates it into GM electronic signals, and sends that to the tcm. You can also set it up to manipulate the signals to adjust shift points from what I understand. And j1850 is low speed gmlan used up through early 07 for vehicle communications, j1939 is a higher speed data bus signal that was used up to 05 on the duramax and 07 for the 8.1l to talk to the tcm.
 
Oh ok. I'll keep an eye out for a tcm. I went & picked up that trans today. My God these transmissions are massive! I'm second guessing my original idea of utilizing the sae3 in my truck (1996 k3500 crew cab long bed with 6" suspension lift). The 4l80e is holding up pretty good so far. However I haven't beaten on it at all yet. Just babying it. The allison will go in eventually, just taking my time. This deal however was too good to pass up.

I'm thinking of measuring the sae 3 bellhousing & going to a junkyard to measure my same body style that already has the engine & trans out. See if the bellhousing will even fit in the stock trans tunnel. I gotta check out 4bt swaps too, see if anyone has run the sae3 in the gmt400 body over there. Has anyone here done it?
 
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Hmm. I need to find someone that has a GM trans out if a truck that I can butt up the two trannys to to see how much bigger the sae3 is.

From what I gather, the Howard's conversion is the most compact sae3 bellhousing. So I might go that route. Still doing research on this whole swap, havent quite figured it all out yet. Still learning!
 
Alrighty. So I was able to find a 2nd gen dodge adapter plate. Jesus these are hard to find cheap. Still have to get a flex plate & starter, but I will get those new for a reliability standpoint, that's fine. Looking at the gm vs dodge adapter plate, I think the dodge adapter plate is going to fit better than the gm one. Reason being is the corners of the "house" of the gm bellhousing pattern come very close to the floorboard/firewall. The dodge/cummins adapter plate is much more round & I think it's going to fit a lot better. Was doing some rough eyeball measurements today & I think it's going to fit just fine. The allison will be tight due to its beefiness, but that's expected.

I'm excited, especially since the 4l80e overheated to 250 degrees today sitting in traffic. That rebuild didn't last long. My allergies were killing me. Eyeballs were all itchy & puffy. Could barely see the gauges cuz my contacts were all messed up. I happened to glance down & it caught my eye. 250 degrees! Yikes! Going to try to source a decent remote oil cooler & fan for now, hopefully that'll help it live a little while longer.

Any recommendations as far as a good remote oil cooler with fan? I'm thinking of getting a good heavy duty one to mount under the cab on the driver side behind the transfer case. Thinking of remote mounting the power steering fluid as well so I can eventually fit the ac condensor up front.

Anyways. Any good remote oil cooler kits ya'll like?
 
No help on the trans cooler, but on the new starter you are going to buy Powermaster makes one for the cummins also.
 
Will L. said:
No help on the trans cooler, but on the new starter you are going to buy Powermaster makes one for the cummins also.
Click to expand...

Is powermaster a good brand? With the 4l80e adapter, I have been fighting 6.4 Ford starters. Not sure if they just dont like turning over the cummins, but my dad's old 6.0 starter hasnt let me down yet. I burned through 3 6.4 starters. Not sure if bad luck or what.
 
The OEM Dodge starters are quite good as well. They used a permanent magnet gear reduction nippen denso starter. About the only thing that wears in them is the contacts in the solenoid and the brushes, both of which are available cheap from the aftermarket.
 
Powermaster builds starters and alternators, and can do custom for them as well, like if you need alternator to charge at idle...
and Yes, everything they build seems top notch. The only issue I ever heard of was the 6.5 large post was too long on several and had to be shaved. I called and spoke to tech support, let them know and they called me back a couple days later and had test fit one themselves and made a change going foreword.
 
Scholioso said:
I'm excited, especially since the 4l80e overheated to 250 degrees today sitting in traffic. That rebuild didn't last long. My allergies were killing me. Eyeballs were all itchy & puffy. Could barely see the gauges cuz my contacts were all messed up. I happened to glance down & it caught my eye. 250 degrees! Yikes! Going to try to source a decent remote oil cooler & fan for now, hopefully that'll help it live a little while longer.
Click to expand...

I see no mention of what transmission cooling you have already on your conversion so post that info up ok and let's see what would cause the 250 f Temps in your 4L80 while sitting in traffic first before considering another cooler under vehicle and relying upon a fan for air flow through the coolers core.

Airflow under any truck is well a mess under all conditions requiring a setup that has an air tab aka: spoiler below and on the leading edge of the cooler and the cooler should be mounted flat so air can hit the tab forced under the tab causing air above the cooler core to be pulled through the cooler core at speed if core properly sized the cooler fan will last a very long time.

However; I'm into redundancy and run two 30k gvwr capacity B&M HITECH coolers w/fans thats 60k gvwr up front between the chassis rails and have good airflow through the cores while in motion and way more cooling capacity then needed in stop and go traffic they also have temp sensors which can be changed out to different on/off Temps depending upon your likes. There a few ways to wire the fans which should be on their own separate fuses and relays to turn on manual, temp sensing or an AUTOMETER trans temp gauge with switching capability or any combination thereof.

Anything less than pure synethitic transmission fluid is a waste of money and will afford much better protection than dino fluids can IMO.
 
FellowTraveler said:
I see no mention of what transmission cooling you have already on your conversion so post that info up ok and let's see what would cause the 250 f Temps in your 4L80 while sitting in traffic first before considering another cooler under vehicle and relying upon a fan for air flow through the coolers core.

Airflow under any truck is well a mess under all conditions requiring a setup that has an air tab aka: spoiler below and on the leading edge of the cooler and the cooler should be mounted flat so air can hit the tab forced under the tab causing air above the cooler core to be pulled through the cooler core at speed if core properly sized the cooler fan will last a very long time.

However; I'm into redundancy and run two 30k gvwr capacity B&M HITECH coolers w/fans thats 60k gvwr up front between the chassis rails and have good airflow through the cores while in motion and way more cooling capacity then needed in stop and go traffic they also have temp sensors which can be changed out to different on/off Temps depending upon your likes. There a few ways to wire the fans which should be on their own separate fuses and relays to turn on manual, temp sensing or an AUTOMETER trans temp gauge with switching capability or any combination thereof.

Anything less than pure synethitic transmission fluid is a waste of money and will afford much better protection than dino fluids can IMO.
Click to expand...

Ok, so the 4l80e itself has like a 1500/1600 stall converter is what the guy said he made it to. Also has alto red eagle clutches, transgo shift kit, sonnax shift kit. For cooling, it just has the factory gmt400 6.5 auxiliary cooler up front. It doesn't integrate into the radiator or cooling system. Had to delete the dodge factory trans heat exchanger due to starter placement.

I found a really heavy duty trans cooler in the junkyard the other day. Flushed it out twice, seems good. I then got a small radiator fan at oreillys for a good deal (friend works there). So I mocked it up under the truck. I think it's going to make a big difference. I reversed the fan per the directions to make it a pull instead of a push. Here it is mounted under the driver side passenger. Please keep in mind, my truck is lifted 6" on 37s, so I'm not overly worried about gunk accumulating.

But, so I currently have the tranny hooked directly to the aux cooler in front of the radiator. Which cools great when on the hwy but doesn't do anything at idle or low speeds in traffic. So I'm debating. Do I add this rear cooler to the existing system. Or do I completely replace the cooler in front for this rear setup? Ideas? I was thinking of having both, but that's a lot of lines to run. I'm kinda thinking of just using this rear setup
 

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Scholioso said:
I found a really heavy duty trans cooler in the junkyard the other day. Flushed it out twice, seems good. I then got a small radiator fan at oreillys for a good deal (friend works there). So I mocked it up under the truck. I think it's going to make a big difference. I reversed the fan per the directions to make it a pull instead of a push. Here it is mounted under the driver side passenger. Please keep in mind, my truck is lifted 6" on 37s, so I'm not overly worried about gunk accumulating.

But, so I currently have the tranny hooked directly to the aux cooler in front of the radiator. Which cools great when on the hwy but doesn't do anything at idle or low speeds in traffic. So I'm debating. Do I add this rear cooler to the existing system. Or do I completely replace the cooler in front for this rear setup? Ideas? I was thinking of having both, but that's a lot of lines to run. I'm kinda thinking of just using this rear setup
Click to expand...
OK, I suspect you already know the factory aux cooler is too supplement the fluid to fluid heat exchanger in the GM radiator. The fluid to fluid cooler you removed from the Cummins was too cool down fluid exiting the converter to engine coolant Temps then from there an air to fluid cooler is used to bring the Temps down even further. With real estate behind the grill being non-existent for a big trans cooler you have to find ways to efficiently cool the transmission fluid this is why I went dual myself.
A much better layout of the cooler under the truck "if you don't do off road" is instead of angled mount like in the image mount it flat and have a tab attached at the leading edge that can catch the airflow which in turn will cause air to be pulled down through the top of cooler at speed the other benefit is that you dont have much of the cooler core exposed to impact damage from flying objects.
 
The trans cooler out front on these trucks is just about useless below 40mph I've found. I have a MASSIVE Earl's cooler on mine, but below 40 it doesn't do much of anything. I've actually had to speed up going down a grade to bring trans temps down on mine because of it.
 
Ok. So I do sometimes off road the truck. Not rubicon/moab stuff, but more like driving dirt roads/fields when going camping or hunting. I mounted it at that angle due to it being a heavy duty/ thick cooler. But ya'll are saying I should mount it flat like almost against the cab? With like a 1" spacer or so? Thought about this too, but wasnt sure about mud or dirt accumulating on top of it. Mounting it this way makes it much easier to clean off if anything did get stuck in it. That was my thoughts.

Also, still not sure whether I should delete the gm factory cooler in front then & just run this one? Or should I keep both? When I put the allison in, I'll look into reinstalling the dodge factory trans heat exchanger as well.
 
The Allison needs a SERIOUS cooler. Several have found that dual 10x14 earls coolers on electric fans were bearly big enough to manage temps on them. They really need a liquid to liquid cooler to knock the bulk of the temp down in them.
 
THEFERMANATOR said:
The Allison needs a SERIOUS cooler. Several have found that dual 10x14 earls coolers on electric fans were bearly big enough to manage temps on them. They really need a liquid to liquid cooler to knock the bulk of the temp down in them.
Click to expand...

Hmm. Ok so what about running the dodge heat trans exchanger & this bigger remote cooler with fan? Delete the front one completely? Gives me more room up front on the swap since I'm already tight for space.
 
Keep in mind the ALLISON needs a high flow cooler. It uses -10an cooler lines which are 5/8" id. Most radiator coolers cannot flow enough fluid for one as they move a couple gallons a minute of oil through them.
 
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