66RFE Not Shifting Under WOT?

[tvizzle]

Any idea what I should check?

It drive great under all circumstances, except WOT, especially on up hills.

The tach will max out, RPMS will hang up high, and my speed will remain the same. Unless I let off the throttle. Than she'll shift and I can continue my WOT. Sometimes it's second gear, sometimes 3rd or 4th.

I've been tuning with J Greene, he suggested my ping sensors were too high on the engine. But. I just put in a 2017 junkyard engine, and it's doing the same thing. I've checked for places where the frame is touching the engine/exhaust, and I couldn't find any.

Has anyone else ran into this issue?

 

[TheEnder]

Any idea what I should check?

It drive great under all circumstances, except WOT, especially on up hills.

The tach will max out, RPMS will hang up high, and my speed will remain the same. Unless I let off the throttle. Than she'll shift and I can continue my WOT. Sometimes it's second gear, sometimes 3rd or 4th.

I've been tuning with J Greene, he suggested my ping sensors were too high on the engine. But. I just put in a 2017 junkyard engine, and it's doing the same thing. I've checked for places where the frame is touching the engine/exhaust, and I couldn't find any.

Has anyone else ran into this issue?

Any codes for solenoids? I’d check that first. When was your last trans filter change?


Sent from Blue Onyx

 

[tvizzle]

Would codes show up w/ OBDII/ engine light? If so, theres none.

The trans filter was probably never changed. I suppose I can get greasy and try that. The fluid is a nice normal looking red though.

 

[TheEnder]

Would codes show up w/ OBDII/ engine light? If so, theres none.

The trans filter was probably never changed. I suppose I can get greasy and try that. The fluid is a nice normal looking red though.

Trans codes only show up if something has gone bad to the point where it’s in limp mode (stuck in 4th.) How many miles are on your truck? My truck doesn’t show any CEL for low pressure in the trans, it’s something you have to check for manually, with a code reader.


Sent from Blue Onyx

 

[Burla]

2012 and sounds like you have a heavy foot? Valve body probably leaking everywhere. You should stop whaling on it til you fix it.

 

[TheEnder]

2012 and sounds like you have a heavy foot? Valve body probably leaking everywhere. You should stop whaling on it til you fix it.

This too, i wouldn’t be surprised if you had a few burnt out clutch packs too. This is what the 65-68RFE is KNOWN for, and if you haven’t changed the fluid, oh boy you’re asking for issues.

If it’s shifting fine aside from the WOT issue, i wouldn’t say burnt out clutches, but these valve bodies are notoriously ****. Cracked from small line pressure increases, warping which causes massive leaks which causes burned clutches etc.


Sent from Blue Onyx

 

[Lyle Longboat]

I heard somewhere that an 8 speed could be switched with either a 5or6 speed? Is there some truth to this info? I may bite on this if it’s doable! Fabrication of course!

 

[TheEnder]

I heard somewhere that an 8 speed could be switched with either a 5or6 speed? Is there some truth to this info? I may bite on this if it’s doable! Fabrication of course!

It’s doable, but it’s also up into the 10K range the last time i heard, with the trans included in that. I could get a used 8 speed on eBay for like 600$ so idk it id ask him to source the trans, but i definitely wanna do that swap too. I ******* hate how i have to baby the 6 speed when it’s in a TRUCK.


Sent from Blue Onyx

 

[Lyle Longboat]

Well your doing better than myself, stuck with the 5 speed. It’s rebuilt though and the Circle D torque converter going in next. I was thinking of having the 545 monster in a box Installed the same time to help it move Along better. Idk though as this swap has got my attention.

 

[TheEnder]

Well your doing better than myself, stuck with the 5 speed. It’s rebuilt though and the Circle D torque converter going in next. I was thinking of having the 545 monster in a box Installed the same time to help it move Along better. Idk though as this swap has got my attention.

I think the guys name or the name of his company is german sound automotive, check him out on FB. let me know what you find. Mines fully stock and she loves to show her age LMAO


Sent from Blue Onyx