First Swap LB7 to LBZ, possibly

[tripleD]

I have a 2003 Duramax Quad Cab with an LB7 and am looking at a motor/Allison combo that the owner is not quite sure what model he has LLY or LBZ (he bought it used and only has the motor/trans).

I was able to do some digging with the Bosch ECM number: 12606127. When I looked up this ECM it showed that it belongs to an LBZ. In addition the MFG date on the ECM is 10/10/2006 which would again lead me to believe its an LBZ.

This is critical because the LBZ ECM and the LB7 TCM are not compatible. I would need the whole motor/trans combo in order to make it work in my 03 Max.

The last part of the equation is if the rear housing on the trans is a 4x4 or a 4x2. I am not sure from the picture I have seen. If you could take a closer look and tell me what you think. I believe the rear housing can be swapped with my 03 and it should work if it is a 4x2.

Thanks,

Andrew

 

[rfletes79]

Hard to tell from that pic but it looks like that is a speed sensor in the tail housing which would make it a 2wd tranny.

Yes having the motor and tranny LBZ/6 speed would make the swap much more straight forward. But you would need the truck side harness for that motor/tranny combo, even if it were an LLY you would need the truck side harness.

 

[tripleD]

Hard to tell from that pic but it looks like that is a speed sensor in the tail housing which would make it a 2wd tranny.

Yes having the motor and tranny LBZ/6 speed would make the swap much more straight forward. But you would need the truck side harness for that motor/tranny combo, even if it were an LLY you would need the truck side harness.

Parts Summary for LBZ Swap in 03+ LB7:

-btdieselworks wiring harness 2003-2004-lb7-to-lbz-conversion-harness *(Optional)
-LBZ engine *Check
-LBZ 6-speed Allison transmission *Check
-LBZ ECM *Check
-LBZ 6-speed TCM *Check
-LBZ "on engine" wiring harness (the harness with the fuel injector connectors on it) *Check
-LBZ "underhood" wiring harness (the harness with the LBZ ECM/TCM connectors on it, as well as the long tail that goes down to the transmission)

For complete compatibility, a throttle pedal conversion is necessary:
Petal PN#15233970
Petal harness PN#15233968
Shift indexer PN#15866124 (*optional)
Shifter PN#15860125

4x2 to 4x4 conversion:
Swap out the Tail housing and shaft from the 4x4 to the 4x2. This is an extra step because the LBZ's Allison is a 2wd. You will need to swap the P3 carrier along with the shaft and housing.

*Detailed P3/Housing Info: http://www.atraonline.com/gears/2009/2009-09/2009_9_4.pdf

**See This thread/Post: https://www.duramaxdiesels.com/forum/threads/first-swap-lb7-to-lbz-possibly.72330/page-3

To polish off the install:
A gauge set from an LBZ installed with the programmed Vin. (plenty on Ebay).

Swap Tips:
Provided by RPM Motorsports
1. You will also need to figure out what way you want to go with the lower radiator hose, and cold side boost tube.

Provided by 036.6Turbo
2. I had no VATS issues, because Idaho Rob did my tuning. I had him disable the VATS, eliminate the EGR, flip the fuel gauge polarity and set it up with DSP 5. He did all that for the same price as a regular DSP 5 tune. Good people.

-I used the LB7 lower rad hose, it was quite a challenge to get it on the LBZ water pump, but I did get it done.

-Charge hoses are different story, I used a mis mash of hoses from the LBZ and LB7, of anything on this swap I'm not 100% happy with, it would be that, I may revisit them after some research.

-Getting the plastic cover back over the underhood fuse block was fun.

-The IP from the donor truck has no DIC interaction with my steering wheel controls. Not surprising as it was a work truck without that option.

 

[RPM Motorsports]

No need for any aftermarket harness, it's literally moving a few wires and adding a couple.. I have a write up somewhere on here what's needed and how to do it.

Your 03 4x4 tail shaft housing will not interchange with the 6spd housing without changing other trans internals, but can be done.

You will not need to change the shift indexer, just the handle.

You will also need to figure out what way you want to go with the lower radiator hose, and cold side boost tube.

 

[tripleD]

No need for any aftermarket harness, it's literally moving a few wires and adding a couple.. I have a write up somewhere on here what's needed and how to do it.

Your 03 4x4 tail shaft housing will not interchange with the 6spd housing without changing other trans internals, but can be done.

You will not need to change the shift indexer, just the handle.

You will also need to figure out what way you want to go with the lower radiator hose, and cold side boost tube.

I had found this thread noting it was possible to use a 01-2005 tail shaft and housing from my 2003 on the 2006 2wd. It was supposed to be a straight swap from the research I did.

https://www.duramaxdiesels.com/forum/threads/6-speed-allison-2wd-to-4wd.42054/

Do you have any other threads I can look at on this subject?

Thanks

 

[RPM Motorsports]

Nope, but if only changing shafts it will not work. The 5spd P3 planetary carrier assembly is not the same as the 6spd P3 planetary internal ring gear. You will need to swap the P3 carrier along with the shaft.

 

[TheBac]

Moved to Repower/Transplant

Please listen to Russ and Rick. They've done a large number of these swaps.

 

[tripleD]

Definitely not disagreeing, I would like to know what parts I would need to make this a clean 2wd to 4wd trams swap.

My fear is the cost....

 

[RPM Motorsports]

Definitely not disagreeing, I would like to know what parts I would need to make this a clean 2wd to 4wd trams swap.

My fear is the cost....

You will have everything needed if you have both transmissions sitting in front of you..

 

[036.6turbo]

Moved to Repower/Transplant

Please listen to Russ and Rick. They've done a large number of these swaps.

They walked me through mine, not that bad of a job.

Details here;
https://www.duramaxdiesels.com/forum/threads/first-swap-lb7-to-lbz-possibly.72330/

 

[onebaddmaxxx]

I swapped from a lly to lbz. Literally followed all the same lb7-lbz swap threads. One wire was different but it was all 100% plug and play and moved a handful of wires and added 2. Fired up and been driving it ever since. Lbz over everything else!

 

[tripleD]

They walked me through mine, not that bad of a job.

Details here;
https://www.duramaxdiesels.com/forum/threads/first-swap-lb7-to-lbz-possibly.72330/

OK, on page 3 Post # 38 you mention doing the tail housing and shaft swap per the below step:

#4. Stand the (5) and (6) speeds on the bellhousings next to each other. Then convert the (6) speed, to 4wd, using the tailhousing and output shaft from the (5) speed.

Then on Page #4
https://www.duramaxdiesels.com/forum/threads/first-swap-lb7-to-lbz-possibly.72330/page-3
Here is a picture of the transmissions and the Output shaft along with part numbers (will add to my original post).

What I am hoping to do is accumulate all of this into one post/thread for future reference.

According to Russ and Rick the tail Housing and output shaft look to be the major components swapped and in addition I will need to swap the P3 carrier along with the shaft. This should work.

Thanks!

 

[036.6turbo]

OK, on page 3 Post # 38 you mention doing the tail housing and shaft swap per the below step:

#4. Stand the (5) and (6) speeds on the bellhousings next to each other. Then convert the (6) speed, to 4wd, using the tailhousing and output shaft from the (5) speed.

Then on Page #4

03 LB7 swap to LBZ

EGR blocker plates are fabbed up. May need to add a support for the one that blocks the exhaust. Sent from my iPhone using Tapatalk

www.duramaxdiesels.com

Here is a picture of the transmissions and the Output shaft along with part numbers (will add to my original post).

What I am hoping to do is accumulate all of this into one post/thread for future reference.

According to Russ and Rick the tail Housing and output shaft look to be the major components swapped and in addition I will need to swap the P3 carrier along with the shaft. This should work.

Thanks!

The only reason I had to buy a new shaft and bearing, is because mine was showing odd scoring. If that had not been the case, I would have just swapped them over.

I like the idea of having the info all in one place.

 

[RPM Motorsports]

Moved to Repower/Transplant

Please listen to Russ and Rick. They've done a large number of these swaps.

They walked me through mine, not that bad of a job.

Details here;
https://www.duramaxdiesels.com/forum/threads/first-swap-lb7-to-lbz-possibly.72330/

According to Russ and Rick the tail Housing and output shaft look to be the major components swapped and in addition I will need to swap the P3 carrier along with the shaft. This should work.

Thanks!

Some clarification on something here, as some things may get confused from what I'm reading. There is no connection to "Russ and Rick" being from my shop. Rick drove my Nova for me while my knee was injured, and I had my motor/trans in his car for a while after and before he went back to LB7. He opened his own shop about a year ago, with no connection to RPM. He has obviously done conversions in the past thought, just an FYI two separate places.

 

[rfletes79]

Moved to Repower/Transplant

Please listen to Russ and Rick. They've done a large number of these swaps.

Mainly Russ, I'm just trying to keep up. And when it comes to the tranny that is all Russ.

I've done the LB7-LLY swaps in the 01-02 and the 03-04 with Russ' help and with the thread he has posted. We have however tackled the 01-02 LLY conversion harness (modded truck side LLY harness making this swap plug n play), which is working well so far. I know your going with an LBZ but just tossing it out there.

Follow the thread and hit him up when needed. I will put in my 2cents when I can help.

 

[rfletes79]

LOL, now that is funny. We were both typing the same thing at the same time!! Thx for clearing that up Russ...

 

[TheBac]

My apologies on the confusion. I did not know the relationship had changed until just now.
Still, both people can be of help when it comes to Dmax swaps and their help is appreciated.

 

[Moonlight Auto]

I am needing help doing a 03 lb7 to 06 lbz conversion, I do have the full 06 donor truck to complete this but don’t know what wires to swap or add to make it work. Any input would be much appreciated!

 

[Bdsankey]

@TheBac @Chevy1925 the links in these posts do not work on the web side.

 

[Chevy1925]

@TheBac @Chevy1925 the links in these posts do not work on the web side.

done