Working up the nerve to go WOT.

maroonandwhite

Junior Member
Joined
Mar 14, 2026
Posts
21
Reaction score
23
Location
Moscow, TN
As some may have seen in my newbie intro, I just bought a 2008 GT with the 5r55s. One owner in good shape with right at 200k miles. The engine seems to run great with no weird noises, no codes, etc. The trans does seem to shift normally at with normal driving habits but shifts into 2nd and 3rd a bit more firmly when I give it a little more throttle. The throttle body was mostly clean and couple with the extensive service records, seems to be well taken care of.

I have it in my head that I’m finally going to do a full WOT pull once I change out the spark plugs this weekend but I’m still a bit nervous that I will pull the pin on a grenade! No timing chain or trans work has ever been done but again, seems to be operationally fine.

I know anything could happen to any car at anytime but, am I just being paranoid?
 

maroonandwhite

Junior Member
Joined
Mar 14, 2026
Posts
21
Reaction score
23
Location
Moscow, TN
It’s either going to go or blow! lol

Ok seriously change the fluids get on the highway or safe long back road and slow get into her… from there you can test holeshots and rolling stomps. Enjoy :)
Yeah I can’t really believe I haven’t done it yet but I just want to enjoy it at least a week before she blows.

I am researching a fluid check/fill on this odd transmission and it seems easy enough.
 
Joined
Sep 11, 2022
Posts
167
Reaction score
255
Location
Dover, PA
I know your predicament all too well unfortunately! Only mine is a new engine that I built myself and I’m hesitant to go WOT!

I would think that as long as you have fresh fluids in yours you’ll be fine. Like stated above, test it out little by little and if there’s anything strange back out of it. A month from now you’ll be laying into it regularly and smiling!
 

StockishS197

Member
Joined
Dec 24, 2024
Posts
434
Reaction score
378
Location
Houston
I had the same concern with my 07, and mine only had 50k miles when I bought it.

I can assure you that mine sees WOT now on every drive and it seems to have only made it run better ;) my car now has every bolt on imaginable and aftermarket cams, spinning it up to 6800 RPM and it loves it.

Enjoy the car for what it’s for. If it lets go during a WOT run, it wasn’t for long anyways. The Italian tune up is the way.

If you want to be overly analytical just as I was, pop a valve cover to check out how it looks underneath, change your spark plugs (perhaps check compression while you are in there) and check hot idle oil pressure. Once those all check out, you are golden.

I have had four separate 3vs, 2 4.6 and 2 5.4s. Both 5.4s had 250k miles when we sold them, all original and are still running today.

My first 4.6 was cammed and ran really hard up to the 140k miles when I sold it. Not a single complaint. My 07 is working up the same magic.
 
Last edited:

JC SSP

Senior Member
Joined
Nov 8, 2022
Posts
2,283
Reaction score
1,351
Location
FL
“Italian tune up” LMAO haven’t heard that phrase in 20 years!
 

maroonandwhite

Junior Member
Joined
Mar 14, 2026
Posts
21
Reaction score
23
Location
Moscow, TN
So funny thing happened this afternoon. Headed home from work and I had it in my head that when I got to the straight section of road right when I turn on my street, I was going to let her rip. :D About 5 miles before that I was coming out of a 45 mph zone into a 55 zone and there was a car leading the pack going about 30 mph. I decided to pass and as soon as I pulled out I see that there were about 5 other cars in front of me and a car coming towards me came into view......so I had no choice but to floor it. :cool: She did fine! No check engine lights, no parts left behind, no funny shifting, just downshifting and flowmasters screaming. Needless to say I had fun the rest of the way home with a grin from ear to ear. The band aid has been ripped off!
 

Kev555

Member
Joined
Dec 12, 2021
Posts
374
Reaction score
170
Location
Ireland
From memory and 4 years since I serviced my transmission, I hope I'm not getting this mixed up with any other transmissions I've worked at since. I needed a little oil pump and a thermal temperature gauge to make it handy to change the fluid in my 5R55s. You can access the transmission temp through diagnostic software but the temperature gun is a lot easier.



These or similar items
 

maroonandwhite

Junior Member
Joined
Mar 14, 2026
Posts
21
Reaction score
23
Location
Moscow, TN
From memory and 4 years since I serviced my transmission, I hope I'm not getting this mixed up with any other transmissions I've worked at since. I needed a little oil pump and a thermal temperature gauge to make it handy to change the fluid in my 5R55s. You can access the transmission temp through diagnostic software but the temperature gun is a lot easier.


I think you are spot on. I watched a guy in YouTube use Forscan for the temps. You have to get it between 80-120 F then cycle through each position to “fill” each gear. Then top it off. He rigged up a little pressurized container from Walmart and used an air hose.
 

Kev555

Member
Joined
Dec 12, 2021
Posts
374
Reaction score
170
Location
Ireland
I think you are spot on. I watched a guy in YouTube use Forscan for the temps. You have to get it between 80-120 F then cycle through each position to “fill” each gear. Then top it off. He rigged up a little pressurized container from Walmart and used an air hose.
Yes I used the forscan or similar on mine but iirc I had to keep putting the 2 post lift up and down to read the temp on the diagnostic screen. I have since used the infra red thermometer that we have for checking the kids temp instead which is similar to the one I've posted above. That pressurised container should have a connector that screws into the bottom of your transmission bung for filling although its not the same model I bought years ago
 

JC SSP

Senior Member
Joined
Nov 8, 2022
Posts
2,283
Reaction score
1,351
Location
FL
I think most modern transmission are serviced like what you posted... Wife's R/T Durango has a similar procedure. Now my question is for Ford and Dodge engineers... which moron decide to leave the trans dip stick out of the manufacturing process?
 
Back
Top