TCM Swap

warp2diesel · **Posted:** Thu May 23, 2013 7:24 pm

LS12FAST4U wrote:

I'm reviving this thread. Just wondering what years of Rams your using? 04-07 or something?

'03 with a 5.7L Hemi

Dennis MacGyver · **Posted:** Thu May 23, 2013 8:39 pm

Read viewtopic.php?f=5&t=70718

Part of the 1st post of that thread

From what I gather,
The part number for the Ram TCM is 56029053AD or ending in AE too.
This TCM is designed to work with the 5 speed transmission, ATS 545RFE.
This TCM was designed for the 5.7 Hemi engine, some say from an '03 made truck (mine came from an '04)
This TCM will lock-up into 5th gear as low as 47mph IF you are a "feather footer"
This TCM will cause problems IF you race our CRD above 3800 RPM's

The objective of using the Ram TCM is to lower the shift point rpm's and hold 5th gear at lower engine speeds/rpm's.

LS12FAST4U · **Posted:** Thu May 23, 2013 10:20 pm

I mainly drive freeway and hills. Occasionally tow and off road. I don't floor it very often.

JieselDeep · **Posted:** Thu May 23, 2013 10:28 pm

Newer than 03 and it might have the programming to recognize the Liberty via ECM VIN...then you're stuck with the preset shift points instead of being able to 'teach' it the shift points.

warp2diesel · **Posted:** Fri May 24, 2013 8:54 pm

groelzj wrote:

Newer than 03 and it might have the programming to recognize the Liberty via ECM VIN...then you're stuck with the preset shift points instead of being able to 'teach' it the shift points.

Newer than 03 & 04 5.7L /545RFE RAMs went to the PCM instead of a separate ECM & TCM. The PCM looks nothing like either the ECM or TCM and can not be hooked up.
The part number for mine is 56029053AE a 56029053AD will also work.
Another option that works is the TCM from a 4.7L with 545RFE Grand Cherokee , sorry I don't remember the years for the GC.

The reason the older TCMs work in the 05 & 06 CRDs is because they can not figure out what it is hooked up to.
The TCM learns to adapt to the engine and how you drive. I guess the TCM thinks you slapped a turbo onto a 5.7L Hemi engine and lost some chassis weight and starts learning new line pressures and adapts to the boost instead of vacuum.
If you drop a CRD stock TCM into an "02 gasser that has the neutered 545RFE made to act like a 4 speed, it continues to shift like a 4 speed. With the 4.7L Dakota that has a neutered 545RFE, a GC 4.7L/545RFE TCM will transform it into a 5 speed.
Now you know how I figured out the TCM swap trick.

Hoosier CRD · **Posted:** Sat May 25, 2013 9:12 am

LS12FAST4U wrote:

I mainly drive freeway and hills. Occasionally tow and off road. I don't floor it very often.

If you swap out the TCMs, then I would not suggest that you floor it all. The Ram TCM will not shift at 4000 RPM like the CRD one will. This will cause the engine to over rev and nasty things can happen. HOWEVER, you can rev it nicely in (I believe) third gear up to the 4,000 mark and then lift the throttle for a shift to occur. This can keep the mongrel breathing and functioning well, especially the variable veins in the turbine housing of the turbo.

racertracer · **Posted:** Sat May 25, 2013 9:37 am

I am pretty sure that an other member (who I wont mention his name) threw a rod due to this TCM.

He accidentally allowed the engine to spike past the 4000 rpm mark, while accelerating trying to pass a slow poke going up hill....... and Bang.

Be careful with your heavy foot on the fuel peddle when using this TCM.

warp2diesel · **Posted:** Sat May 25, 2013 12:03 pm

racertracer wrote:

I am pretty sure that an other member (who I wont mention his name) threw a rod due to this TCM.

He accidentally allowed the engine to spike past the 4000 rpm mark, while accelerating trying to pass a slow poke going up hill....... and Bang.

Be careful with your heavy foot on the fuel peddle when using this TCM.

The member you mention with out stating his user name had a lot of other issues with his CRD and multiple repeat catastrophic failures.
To use an analogy, his CRD was like someone infected with advanced untreated HIV, bubonic plague, getting shot up with multiple rounds from gangbangeers, and then getting stung by a wasp.
Blaming the TCM is like blaming the wasp sting.
I am sure there were multiple bets going on as to how many broken anvils and hammers were in his scrap pile.

arengant · **Posted:** Sun May 26, 2013 3:05 am

Do any of you who swapped for this have your CRD TCM that you want to sell?

JieselDeep · **Posted:** Sun May 26, 2013 4:31 am

So, what kind of MPG's do you get after this swap? The 5th gear lock really appeals to me where 95% of my driving is below 50mph. The highest speed limit on this island is 55. When I'm driving one of those highways, I sometimes push it up to about 60. Whatever the traffic around me is doing.

If I could lock in 5th gear at 47mph, I'd be a happy camper!

Jon

arengant · **Posted:** Sun May 26, 2013 6:01 am

groelzj wrote:

So, what kind of MPG's do you get after this swap? The 5th gear lock really appeals to me where 95% of my driving is below 50mph. The highest speed limit on this island is 55. When I'm driving one of those highways, I sometimes push it up to about 60. Whatever the traffic around me is doing.

If I could lock in 5th gear at 47mph, I'd be a happy camper!

Jon

My mpg has dropped on the island because it will shift into 5th too soon. Some steep hills on my commute.

TCM Swap

Who is online