tranny went out on friday so I had to install my FTL lvl 5 thats been setting for a while and notice that the shop that removed the trans removed the cooler lines fittings on the trans. So I pulled the cooler lines off the bad tranny and they dont match up the ones off the bad one are a little bit smaller than the cooler holes in the lvl 5.I went to install them and they wont torque down. My question is are all cooler lines fittings the same size or are do the size differ by year or what?

 

Man I hope you did not mess up the threads in the FLT unit. I'm a little confused on your post as to why you don't have the correct fittings. Maybe I read it wrong. Best I can tell is the trans is a used unit and it was at FLT to be freshened up or you bought if from another member this way. Basically it was not shipped there with the fittings in the case. Is this correct? As you now know there are two types of fittings that have been used. I believe the change was in 08 IIRC and later cases use the larger of the two. 9/16-18 UNF is what is now being used for the threads. The GM # is 24236577 for the 60E. The 80E will use 24236579 for the front fitting and 24236581 for the rear fitting for the factory push in style lines. The early fittings were steel and the later ones are now aluminum. HTH Vince

 

it came new from FLT and the threads are fine. the problem is that when the FLT was removed the shop who removed it removed the cooler line fittings too, and the stock fittings dont fit. after reading the page on FLT website on the lvl 5 I noticed they use -6an male cooler line fittings so that maybe the problem.

 

I would suggest contacting them to get the correct fittings for what you have. The early cases used a 1/4 pipe straight threads from the factory. The AN fittings that most use are not an exact match in thread pitch but do work. I still think you have a late case because of what I'm reading here. You might want to look at the rear bottom side of the trans near the extension housing to get the trans case ID production numbers. You need to look at the first 4 digits to determine what year it is and what it came out of. If the first digit is an 8 I'm pretty sure you have the larger size holes in your case. Look at the picture below to see where to look. I'm sure if you contact them next week with this info they will be able to get you squared away. HTH Vince

 

I got 8L J0049 J 46082608 couldn't really get the last # its either 8 or 9

 

I don't know the answer to your problem, but it would be a good idea to flush out the transmission cooler and the lines before you reinstall everything. I would also recommend just trashing the old cooler and getting a bigger one to help keep the transmission temps down while your at it.