8 speed swap

[TheEnder]

My 2013 with the 5.7 did have the OE 8-speed shifter wiring behind the dash - there was even a little cutout within the support structure to secure it for vehicles with the 65RFE not utilizing it.

You will need the OE 8HP70 transmission bracket (68147349AB) and the insulator (68147348AB), which gets bolted to your factory transmission crossmember support between the frame rails - not 100% sure that crossmember is the same between all models but I think so - you may need to check specific 4.7 swaps. Depending on where you buy your transmission, many from junk yards and LKQ come with those (2) parts listed above, the bracket and the insulator.

The real part you will need to fabricate is the driveshaft carrier support cross-member (680550980AB). I am pretty sure that part is now discontinued. Even if it isn't discontinued, you will need to weld it in or fabricate some way to secure it to the frame in the correct location.

I have Russell's kit but my Tow/Haul does NOT work, but I also haven't tried to get it to work, yet. He told me in my first email correspondence with him that it would NOT work. That is a problem I will address way down the line, if needed.

I would get real familiar with sites like moparonlineparts that have the replacement parts catalogs with diagrams and PNs where you can search various vehicle configurations and compare parts to make sure you have what you need.

If Tow/Haul doesn’t work it’s not the biggest deal. I’ll just keep my foot on the gas and prevent it from shifting.

 

[TheEnder]

There was something on the right side but I am 99% certain there was the shifter wiring harness on the left side behind the radio/HVAC controls.

I don’t think i have that. I’ll have to look later but all i have is the 12v outlet supply wire i’m pretty sure.

 

[TheEnder]

My 2013 with the 5.7 did have the OE 8-speed shifter wiring behind the dash - there was even a little cutout within the support structure to secure it for vehicles with the 65RFE not utilizing it.

You will need the OE 8HP70 transmission bracket (68147349AB) and the insulator (68147348AB), which gets bolted to your factory transmission crossmember support between the frame rails - not 100% sure that crossmember is the same between all models but I think so - you may need to check specific 4.7 swaps. Depending on where you buy your transmission, many from junk yards and LKQ come with those (2) parts listed above, the bracket and the insulator.

The real part you will need to fabricate is the driveshaft carrier support cross-member (680550980AB). I am pretty sure that part is now discontinued. Even if it isn't discontinued, you will need to weld it in or fabricate some way to secure it to the frame in the correct location.

I have Russell's kit but my Tow/Haul does NOT work, but I also haven't tried to get it to work, yet. He told me in my first email correspondence with him that it would NOT work. That is a problem I will address way down the line, if needed.

I would get real familiar with sites like moparonlineparts that have the replacement parts catalogs with diagrams and PNs where you can search various vehicle configurations and compare parts to make sure you have what you need.

Yup. I don’t have it.

 

[TheEnder]

Spam posts galore today but i do have the brown PCM.

 

[1SLwLS1]

Yup. I don’t have it.

Probably for the best, I think Russell's kit is probably a bit easier and has tons of online support from several who have done it.

 

[TheEnder]

Probably for the best, I think Russell's kit is probably a bit easier and has tons of online support from several who have done it.

Yeah, i’m gonna save up and buy it. Should be here within the next couple months then. I really don’t wanna buy a new truck.

 

[TheEnder]

My 2013 with the 5.7 did have the OE 8-speed shifter wiring behind the dash - there was even a little cutout within the support structure to secure it for vehicles with the 65RFE not utilizing it.

You will need the OE 8HP70 transmission bracket (68147349AB) and the insulator (68147348AB), which gets bolted to your factory transmission crossmember support between the frame rails - not 100% sure that crossmember is the same between all models but I think so - you may need to check specific 4.7 swaps. Depending on where you buy your transmission, many from junk yards and LKQ come with those (2) parts listed above, the bracket and the insulator.

The real part you will need to fabricate is the driveshaft carrier support cross-member (680550980AB). I am pretty sure that part is now discontinued. Even if it isn't discontinued, you will need to weld it in or fabricate some way to secure it to the frame in the correct location.

I have Russell's kit but my Tow/Haul does NOT work, but I also haven't tried to get it to work, yet. He told me in my first email correspondence with him that it would NOT work. That is a problem I will address way down the line, if needed.

I would get real familiar with sites like moparonlineparts that have the replacement parts catalogs with diagrams and PNs where you can search various vehicle configurations and compare parts to make sure you have what you need.

How would the driveshaft thing work? I just tried looking for everything and i couldn’t find a single thing on the carrier bearing support.

 

[emjohn4]

I reused my driveshaft. It probably needs shortened by 1/2 inch to be extra cautious, but had no problem fitting it. If you currently have a 2-pc drive shaft, I'd wager you keep it; if you have a 1-pc drive shaft, I don't see a reason to switch to a 2-pc one.

My center crossmember worked, but the holes needed slotted rearward by 1/2 inch. It fit (barely), but it fit.

 

[TheEnder]

Figured I would throw together a brief list of info for swapping in the 8hp70 in early 4th gens… I couldn’t find a lot of this out there so some was trial by fire and then leaning on others (thanks to Alex LaBrash), as they were the biggest help. The process would be similar in earlier models but part numbers and custom work may have to change up.

8 Speed Parts List:

8hp70 Transmission -
Used - $500-$900

Torque Converter -
Comes with JY Trans - $0

Torque Converter Bolts x6 - $1.10 (6509361AA)

Flex Plate (Flywheel) - $43 (4752574AB)
Flex Plate Bolt Spacer -$5 (4736613AA)
Crankshaft Pilot Sleeve - $14 (4736283AA)
Trans Mount Bracket - $72 (68147349AB)

Trans Mount Bracket Bolts x4 - $2 (6102400AA) - (M10x1.5x30)

Trans Mount - $70 (68147348AB)

Trans Mount Nuts x3 - $5 (6502979) - (M10x1.5)

Drive Shaft - Size Depends on Cab - $75-150 Used

Drive Shaft Bolts Trans Side and Diff $5 Each (6506497AA) (8 in total, can reuse old diff bolts)

Drive Shaft Carrier Crossmember - $300 (68055090AB)

Drive Shaft Carrier Bracket to Xmember - $6 (52105587AD)

Drive Shaft Carrier Bolts x 4 - $5 (6101060)
Driveshaft Carrier Nuts x 6 - $3 (6504728)

Transmission Vent Hose - $16 (4627854AB)

Dial Shifter or Console Shifter - Dial (Part# Varies on 2wd/4wd) - $300 New ($50 Used)

Engine to Trans Bolts (Pass Thru Block and Thread into Trans)x2 - $2.55 (6101985) (M10x1.5x45)

Engine/Converter dust Shield (Bottom 2 bolts, thread into Trans) x2 - $2.55 (6101985) (M10x1.5x45)

Sound German Automotive wiring/tcm and Recalibration - $1250

Fluid - Walmart.com Best Cost Option for Mopar Fluid - 6qts deal x2 ($110 Each - 12qts total)

Lines:
3/4-16 Tap - (8an)
2 - 8an ORB to 6an Fittings
2 - 90 Degree 6an to Hose Barb Fittings
5 Ft - 3/8 ID Transmission Hose
4 - Hose Clamps
Cut Factory lines near block and flared the end with flare tool for a raised lip

Misc:
Wire to Run Brake Feed to SGA Harness.

File to File Down tab on Can Bus Line on SGA Harness (purple connector) to Fit Can BUS C Star Connector (under steering wheel area, star connector with yellow wires)

Bolts/Screws to Mount SGA Computer and OBD Port Connector (I went under drivers seat)

Zip Ties - To Clean up Wiring

Grommet if you pass Harness Thru Cab (I Used 1.5" ID (1 3/4 Inch Cut Out) From Amazon, This same grommet can plug the shifter cable hole in firewall as well, if you opt for no neutral cable. (will need 1 3/4 hole saw for this grommet)

Solder / Crimpers For SGA Harness Install
Add a fuse (micro fuse) I tapped into fuse 99 (climate control) - make sure power remains constant in accessory, run, AND crank - goes to yellow wire in sga harness)


Reused 6 Speed:
Transmission Crossmember - No Modifying was needed
Engine to Trans bolts (Bolts that pass thru trans and go into block (top 4 bolts)

Flex Plate Bolts
Trans Mount Nuts
Starter and Bolts
Trans lines and Cooler (after modifying)
Cable Brackets (frame)

Optional Items:
PPE Trans Pan
Performance Converter
Transmission Tune
Trans Heater
Trans Oem Lines

Trans Oem Coolant Lines (won’t be able to use valve)

Rear Main Seal (add RTV to List if Doing Seal)
Neutral Cable - $51 (68211076AG)
Neutral Cable Bracket on Trans - $8 (68149025AB)
Neutral Cable Bracket on Trans Bolts x2 - $6 (6510721AA) - (M8x1.5x18)
Neutral Cable Bracket on Frame (Reuse 6 speed Bracket - 68080743AA)
Neutral Cable Bracket to Starter Bolt and Plastic Clip (Reuse 6 Speed)
Steering Column Shroud - $36 (1GE44DX9AC)

Tips:

1.) sga harness only needs brake input, power, ground, accessory power, can bus(purple connector, and shifter wires …. Using the can bus reduces the need to use a lot of the wires (kit can be used in non can bus vehicles, these would need the other wires)

2.) the driveshaft carrier crossmember I used is the oem one and I welded it in…. You could use a piece of square tubing (1x4) just measure your frame rails for length. If you can’t weld you could riv nut some angle iron into the side of the frame to bolt the angle iron to frame then the angle Iron to your crossmember.

the recalibration sga does made my dash work like stock, trans temp reads out, no cel lights, and P,R,N, D all are in sync with dial shifter.

4.) the factory 8hp70 tcm is in the trans, you will have two ports on the sga harness for diag/tuning….. the obd port is for tuning the oem tcm, the 3 wire gm style connector is for adjusting the new tcm from sga.

5.) the flywheel is bolted to the crank , welds facing toward rear of vehicle, DONT NOT FORGET TO INSERT THE CRANK PIOLT BUSHING.

View attachment 470173View attachment 470174View attachment 470175View attachment 470177

Where did you weld the driveshaft crossmember?

 

[1SLwLS1]

How would the driveshaft thing work? I just tried looking for everything and i couldn’t find a single thing on the carrier bearing support.

You mentioned the two-piece driveshaft in your first post from today, the middle carrier bearing of that driveshaft needs a cross-member for support, see the first post in this thread with pictures of that cross-member and the instruction to either use the factory (68055090AB) or fabricate your own. However, I believe the factory part is discontinued and you would need to fabricate your own.

OR you can use a custom 1 piece driveshaft.

 

[TheEnder]

I reused my driveshaft. It probably needs shortened by 1/2 inch to be extra cautious, but had no problem fitting it. If you currently have a 2-pc drive shaft, I'd wager you keep it; if you have a 1-pc drive shaft, I don't see a reason to switch to a 2-pc one.

My center crossmember worked, but the holes needed slotted rearward by 1/2 inch. It fit (barely), but it fit.

Oh. So there’s nothing really to worry about then. Gotcha.

 

[1SLwLS1]

I reused my driveshaft. It probably needs shortened by 1/2 inch to be extra cautious, but had no problem fitting it. If you currently have a 2-pc drive shaft, I'd wager you keep it; if you have a 1-pc drive shaft, I don't see a reason to switch to a 2-pc one.

My center crossmember worked, but the holes needed slotted rearward by 1/2 inch. It fit (barely), but it fit.

How did you manage that? Do you have pictures?

 

[TheEnder]

You mentioned the two-piece driveshaft in your first post from today, the middle carrier bearing of that driveshaft needs a cross-member for support, see the first post in this thread with pictures of that cross-member and the instruction to either use the factory (68055090AB) or fabricate your own. However, I believe the factory part is discontinued and you would need to fabricate your own.

OR you can use a custom 1 piece driveshaft.

Honestly, i’ll just get a cheap welder and weld the new crossmember on. I don’t think i need to worry about it being perfect as it’s not supporting much.

 

[1SLwLS1]

Honestly, i’ll just get a cheap welder and weld the new crossmember on. I don’t think i need to worry about it being perfect as it’s not supporting much.

Okay, what crossmember are you talking about?? You just mentioned sticking to a 1 piece driveshaft, why would you weld in the carrier bearing crossmember?

On the factory 8HP70 setup, there are (2) crossmembers being referenced, one under the end of the transmission and one supporting the carrier bearing.

 

[TheEnder]

Okay, what crossmember are you talking about?? You just mentioned sticking to a 1 piece driveshaft, why would you weld in the carrier bearing crossmember?

On the factory 8HP70 setup, there are (2) crossmembers being referenced, one under the end of the transmission and one supporting the carrier bearing.

Yes, i am aware of that. I’d rather it be factory after further evaluation and just weld in the 2nd crossmember for the center carrier bearing support on the 2 piece driveshaft. Apologies, a bit all over today. Thank you for the clarification.

 

[1SLwLS1]

Yes, i am aware of that. I’d rather it be factory after further evaluation and just weld in the 2nd crossmember for the center carrier bearing support on the 2 piece driveshaft. Apologies, a bit all over today. Thank you for the clarification.

I don't think you can find the factory piece, I believe it is discontinued. You may have to fabricate a custom cross-member, like the first post options.

 

[TheEnder]

I don't think you can find the factory piece, I believe it is discontinued. You may have to fabricate a custom cross-member, like the first post options.

I found the factory piece on eBay for 224$.

 

[1SLwLS1]

I would order it now, there are people on the FB group that cannot find it.

 

[TheEnder]

I would order it now, there are people on the FB group that cannot find it.

Sounds good then, i’ve been meaning to buy the 1st part to do this swap. Mine as well have it sitting there waiting for me.

 

[emjohn4]

Seems kinda anticlimatic.

You can tell from the pic with the transmission crossmember, that the trans mount is a bit rearward of center. It's because the 8HP70 is about 1/2 inch longer than the 65RFE.

That means the transmission mount needs to slide backward an equal distance (and if you're 4x4, the front driveshaft needs a spacer to make up the distance that has now increased by the transfer case being moved 'backward' 1/2 an inch).