2003 Tahoe 5.3 FLEX :

Here is a link to a write-up by folks removing the nut securing the fuel lines bracket at the upper section of the transmission bell housing:
https://www.gm-trucks.com/forums/top...ge/3/#comments

What is the correct size deep socket?

I read that there was a choice of 13mm vs. 14mm.
Neither are working for me.

I called the tech support at FineLines Company ( bought their SS fuel lines).
Their answer 9/16 inch. The gentleman was very friendly, said that he has done 20 of these.
Not work for me.

I duplicated the long extension with a ratchet as detailed in the writeup and attempted to hold the deep socket onto the nut--> Failed.
I finally fed the long extension along the extreme top ceiling of the work area to minimize the angle spin --> Failed.
Prior to that , I followed the writeup and fed the long extension down by the mid area of driver door. --> Failed.
Sprayed PB Blaster yesterday to assist the removal , more today --> Failed.

Been working on this for 5 hours today w/o success.
Any instructions appreciated.

I believe that the nut is a different size than the remaining bell housing nuts . This one is just for securing the fuel lines bracket.

 

Is a deep socket required to remove the nut ?
New info:
Deep socket vs. Tall socket --
upon quitting this evening, I noticed that my new 14mm socket is not actually a " deep socket", it is merely a tall socket with standard depth of the recessed well for the nut.
Perhaps that is why I cannot grab the nut.

My new 13mm deep socket is both deep recess and taller than my usual socket set.

FYI : 9/16 inch = approximately 14.3 mm

Hope that the forum informs me that :
-- deep socket is required
-- socket size is 14 mm
That would provide a solution to my failed efforts to remove the transmission bracket nut securing the fuel lines.

 

I'd try a 14mm six-sided deep socket. Everything on a 2003 should be metric. Even for GM.

 

To get the correct size you can use a short/shallow socket, preferably 6 point, and set it on there and let the stud stick up through the square hole for the ratchet to attach at. Then you can get the correct working size and go from there. If you lack room, you can unbolt the crossmember ad use a floor jack to lower and support and tilt for more access. Oh, almost forgot, gotta stick the tongue out and clamp with the teeth at just the right angle to add precision to the effort.

 

Issue resolved : 13 mm .

Nut is off, photo attached.
Used 13mm deep socket, then universal swivel , then long extensions PLUS BREAKER BAR to initiate the first turn.