AW4 Transmission not shifting when hot

[TheOoz]

Once at operating temperature, my AW4 doesn't want to shift anymore. I can use the T bar and it all works okay, but it doesn't appear to be shifting automatically. Originally I thought it just wouldn't downshift, but now I think it isn't shifting automatically at all.

Once cold, it goes back to expected operation.

I have checked the fluid level and quality, both okay

I have replaced the TPS which made no difference.

Thoughts on this, or recommend a transmission specialist who knows Jeep?

Is it possible to plug in a tester and monitor the signals the transmission is receiving to see if there are any dodgy signals causing this fault?

[junglejuice]

What year model is it?

[TheOoz]

1995 Limited

[TheOoz]

I'm still working through this. There are wires running next to the trans dipstick coming off the main harness and down to the transmission. The point in question includes 3 large plugs.

Mine have been routed incorrectly, so I'm wondering if someone can share pics and a description of how they should route, whether there is any heat shielding, and whether they are cable tied/secured to anything?

[TheOoz]

Wiring now re-positioned, but the problem was still evident.

I pulled out the NSS and it was full of gunk. One of the contacts was also pitted. I cleaned it, re-lubed, and put it back in as per Go Jeep's approach. I ordered a new one due to the pitted contact. New one has arrived so I'll be putting that in shortly.

Since cleaning the NSS I haven't had the same problem, but the weather is also getting cooler so that may also have something to do with it. I've had it nice and hot after some long drives, so it could also be fixed. Ah well. Next summer might hold the key.

[warmapple]

what was the best price on the NSS you found?

[TheOoz]

$108 plus delivery from Rock Auto. I had a few other things delivered with the same order (of course). I can give you a 5% off discount code if you plan to order anything. PM me for that.