Does anyone know what is the thread size on 4l30e where you can attach the pressure gauge to test transmission line pressure? In Shop Manual it refers to tool J-29770-A.

sorry i don't. fyi, my helms isuzu manual shows that part number for the set of gauge + 4 or 5 adapters.


btw, what's this test going to do for you?

just want to use it to install temperature gauge instead of going through the lines.

that's weird, because i earlier today came upon this article on fourwheeler's site while researching something else
http://www.fourwheeler.com/techarticles/129_0311_transmission_temperature_gauge/
it's about what you're doing using that same location.

they list some suppliers with telephone numbers and website addresses; maybe they can help. or maybe your gauge's company can help?

or just take out the plug on your trans and match it?

Where exactly is this port? I have a spare tranny and I can go check the port , and also find out what you would need to make the part fit.I think most temp sending units are 1/8 NPT , then they have an adapter to screw onto the T if you use the part they send that you put it on your hard line.In my case that wouldn't work with me having braided stainless lines.

I'm guessing the port has some kind of plug on it?I don't remember seeing any other threaded spots on the tranny when I changed the filters and stuff before installing it.

The plug is on the left side of the transmission right above the small pan.
I suspect that being GM design it will have standard threads, but being European it might be metric.

ok , by left side , I am assuming you are talking the left side when you are facing the engine?The side that doesn't have the shift lever on it.Here are 2 pics of that side , one of the small pan and the other the larger pan.If its the plug just above the small pan , then it must be this huge thing?




The other place that looks like it could be a plug is the one in this other picture just below the dipstick tube , almost on the edge of the pan itself.Neither look threaded , so you must have to pull them out somehow.




I'll have to take a closer look and see how the plug can come out , then I can get an idea of whats needed for size and stuff.

barak, no! -- your other left. <img src="/forums/images/graemlins/lol.gif" alt="" />

check out the fourwheeler link a couple of posts up. the second photo there will give you an idea about the size.

btw, that "huge thing" is the Accumulator Piston cover that wants to leak.

nice guy considering all you're up to to stop and take these pics (but you did make me think i was really going blind with that first one. . . <img src="/forums/images/graemlins/smile.gif" alt="" />

Trooperbc is right, it appears to be on the same side the wiring is.

Ok , I must be blind.On the side with the wiring , and above the small pan , theonly thing there is the black plug for one of the wiring harnesses.Theres not really anything above the bigger pan on that side either except for the mounting points for the shift controller and the wiring.As for the big one on the other side , I found out quick that its not the right spot <img src="/forums/images/graemlins/lol.gif" alt="" /> I took the clip off and popped off that cover.Inside is a big heavy spring , and a plunger that moves the spring.It was a pain to get that clip off as the part where you would normaly use a snap ring plier was broken off , I had to get creative.I will pick up a new snap ring to put back on there , and good as new <img src="/forums/images/graemlins/kewl.gif" alt="" />

I'll look again for a port on the other side , but it must be well hidden <img src="/forums/images/graemlins/scared.gif" alt="" /> Maybe you have a newer style transmission than mine and that makes a difference?