Transmission trouble after engine swap

[Cstoliker]

I had the 4.0 sohc replaced on my 2000 xlt (5r55e) All I know of the donor vehicle is the millage. Since then, under heavy or full throttle the transmission won’t upshift. RPMs go as high as 6k without a shift. It seams to downshift ok (although it may go a gear lower then it needs)
The transmission shifts normally under normal use.
It’s only under hard or full throttle. I do tow with it so this is a real problem.

any help would be appreciate.

 

[410Fortune]

How many miles? on transmission
Any check engine light?
Flashing OD light?
Who did the engine install?

I cannot tell you how many times I have seen an auto trans failure after engine replacement.......due to negligence by engine installer. You CANNOT get any water or debris in the transmission cooler system while engine is out, AND the lines and coolers should be CLEANED before putting back into service.

Hopefully it is something as simple as a missed wiring plug, that is why I asked about any dash lights.....we are looking for trouble codes from the engine/transmission computer

 

[Cstoliker]

How many miles? on transmission
Any check engine light?
Flashing OD light?
Who did the engine install?

I cannot tell you how many times I have seen an auto trans failure after engine replacement.......due to negligence by engine installer. You CANNOT get any water or debris in the transmission cooler system while engine is out, AND the lines and coolers should be CLEANED before putting back into service.

Hopefully it is something as simple as a missed wiring plug, that is why I asked about any dash lights.....we are looking for trouble codes from the engine/transmission computer

Truck has about 130,000 miles. No CEL and Overdrive works fine.
most garages wanted $3-4,000 to do the engine swap. I found 1 small shop called “Phill’s Garage” willing to do it for $2,000. So I did that. They got the job done but had to replace a brake line and The transmission dipstick tube that broke during install. Also, they forgot to recharge the A/C (witch I don’t think needed to be discharged if you keep the compressor)

I hope it’s something simple. Like I said it up and downshifts beautifully under normal driving.

My fear Is that the donor engine came out of a 4 speed. I don’t know if it’s needed to swap an engines “brain” with the engine or plug in the new engine to the original PCM. I have a good code reader and was going to compare the PCM’s VIN to the Trucks to see if they match but I was unable to get the VIN off the PCM. Says “unavailable“

 

[C420sailor]

PCM/ECU/whatever should stay with vehicle, assuming same engine and trans models.

Check engine bay connectors. MAF, crank position, TPS, etc. You can also try disconnecting the negative batt cable and reconnecting. Sometimes a good hard reboot can fix weird things like that.

 

[410Fortune]

Any codes in memory? What does Phils garage say when you tell them about your shifting issue?

I agree to check all connections

 

[Cstoliker]

Any codes in memory? What does Phils garage say when you tell them about your shifting issue?

I agree to check all connections

No codes, no stored codes, no advanced (manufacture codes), no ABS codes and all monitors have run and passed. The PCM is completely unaware of any issue.

it took Phils 3 months to do the swap. When I brought it back for shifting issue it took 3 weeks for them to determine the fluid was a little low due to a broken dipstick tube. Which they replaced. I don’t think they ever drove the truck.
My confidence in them is low and I would like use the truck this year so it’s pretty much up to me to figure it out.

 

[410Fortune]

low fluid due to broken dipstick tube!! Yikes this maybe why the trans developed an issue, it was run low on fluid due to their negligence
You likely have a leaky valve body gasket or shift solenoid issue, shift solenoids do NOT like to be run low on fluid.
Lets start by looking up 5r55e known issues that deal with no upshifts ........

18 Troubleshooting Tips for 4R44E & 5R55E Transmissions | Sonnax

With the proper repair, these cores can be just like money in the bank. Set yourself up for a successful rebuild with these expert tips.

www.sonnax.com

 

[Cstoliker]

low fluid due to broken dipstick tube!! Yikes this maybe why the trans developed an issue, it was run low on fluid due to their negligence
You likely have a leaky valve body gasket or shift solenoid issue, shift solenoids do NOT like to be run low on fluid.
Lets start by looking up 5r55e known issues that deal with no upshifts ........

18 Troubleshooting Tips for 4R44E & 5R55E Transmissions | Sonnax

With the proper repair, these cores can be just like money in the bank. Set yourself up for a successful rebuild with these expert tips.

www.sonnax.com

thanks but it is not a fluid issue..
The issues was noticed when i first drove the Truck home after having the engine replaced. I checked the fluid that day and it was fine. I kept an eye on it and it never got dangerously low. I may have added 1qt in 4 months.
I have replaced the valve body gasket three years ago.

The transmission was working fine up to & including the day I dropped it at the shop. After engine replaced and with fluid still full the trouble started.