coolwind57

There's a store chain here in N. Kentucky that I'd never heard of when I lived in S. Indiana two years ago. KOI Auto Parts. They're kind of set up like NAPA, with a counter and older fellas that seem to know what's up. I did have some luck finding a difficult part there once. And they sell KROIL penetrating oil on their counter! Hadn't seen that before. Good stuff if you're not familiar with it. I never need to buy it myself because we use in a lot in aviation at my work, so I have a free source!

PICS: Today, I installed a Bosch coolant temperature gauge. My 89 has the standard idiot lights and after replacing my engine last year, I didn't want to rely on idiot lights anymore. And I didn't want to do a whole dash instrument swap. Placed the gauge in the slot where the old transmission rocker switch was....it was disabled (and useless anyway). I built an engine last year and I used a later model 7120 cylinder head, so I had to use the non-Renix water neck during my build. Since I'm still running the Renix system, I had just plugged the right port of the water neck. Perfect place for a new instrument Temp Sensor! The Bosch sensor was very long, so I had to add a coupler and close nipple. Part store didn't have brass, so I used Galvanized iron pipe. Sure is nice to see where I'm at temperature wise now. By the way, when I built my engine, I was so paranoid that she'd have some sort of oil pump issues at start up/initial break in that I installed a mini pressure gauge near the distributor. It was worth the effort and expense to see that I had good pressure during that initial start up. I left it on. Not really useful anymore unless you have the hood up of course and want to periodically check oil pressure. But anyway, I thought I'd snap a pic of that too for you while I was in there. I have thought of doing the fuel rail gauge. I may look into that later.

Just went through transmission issues like 2 Months ago. Mine just refused to shift. There's several parts that affect your transmission. Shift solenoids, TCU (Transmission Control Unit), there's a speed sensor, and the NSS (Neutral Safety Switch). As DZIMM states, that crank position sensor may have something to do with your problem. I would not replace the shift solenoids till you test them first. There's a continuity test that i performed on mine. I can't remember what Olms they should shoot at so check your manuals. I dropped the pan, tested continuity and i also took them out and hooked them up to my battery (one wire lead on the spade connector to positive and one on the housing to battery ground) and confirmed a clicking noise to mechanically test each solenoid. Mine were good. Saved some bucks. Next on my list, I did a TCU swap after checking that the fuse that feeds it was good and that the TCU was getting juice. Bought a used TCU off ebay and wasted my $100. No change. My original one was good. I was having trouble finding the correct trans shift speed sensor and was in the process of ordering one when I thought I'd go ahead and swap out the Neutral Safety Switch NSS. My NSS was only about 3-years old, so I prioritized it at the bottom of possible causes. NSS are not expensive, I think I bought mine at under 20-bucks. Removed and replaced and the transmission shifted as if it just rolled off the assembly line. Couldn't believe it. Let me know if you come down to the TCU during your troubleshooting and I can send you my spare to help. It's frustrating, I know. I was down for over a Month. Good luck, brother.

I had to braze my sending unit. it was leaking where the tubes meet the disc mount. If your gasket doesn't work for you, you may have to braze. I did Marine JB Weld which worked for nearly a year. Regular JB Weld will not last but a few days. This is your temporary fix. I hope you get dealt the easy hand and have only to replace the gasket. Good luck.

Honestly, I hadn't put the original one back in to try. I've been so happy with having my truck back that I've been delaying trying it. I spent over a hundren dollars for the eBay TCU....Almost want to put it up for sale to get my money back, but then again it would be nice to have it on the shelf as a back up with my luck.

Removed my NSS Neutral Safety Switch, which was only a few years old. Took it apart and it looks fairly new inside. Swapped out with a new one that i got for like $35 and tested my transmission. Shifted normally. PROBLEM FIXED. I thought the NSS was a long shot. Again, internals looks good so I suppose a wiring/connector/harness issue maybe I don't know. Just glad I'm back on the road. Missed my truck. I've confirmed that the SC29 is not on this transmission or transfer case. Even though it shows it fits my 89, it does not. Appreciate your response. This was my next step after the NSS repladement. Glad I didn't have to bother. Thanks for the response.

Mine just arrived today from Amazon. I've got the AW4 with the NP231. We'll see how it goes. Thanks for sharing. This one does look much better than I imagined. Thick SS plates and looks to be quality fasteners/hardware.

Ok, this thing is $110 and is harder than hell to find. Crown makes it and you can only purchase through an authorized dealer. One dealer showed that the part does not fit my 89 Jeep Comanche. Another, Jegs, says that same part does fit, and can get it but they have no estimate on when they can ship (I'm assuming they'd drop ship from Crown). This thing must be like hen's teeth. Very difficult to find anything about this part on the internet. Anyhow, unless I can find a way to test mine, I'm not sinking that much money on a part that I'm not sure is correct for my application and with me guessing if it would fix my issue. I'm now leaning towards taking the truck to an transmission shop and giving up on troubleshooting and shotgunning parts. Frustrating.

This is an old thread, but I'll revive it for a bit. Anyone ever install one of the Amazon copies of the Azzy shift linkage? How'd it go? My gosh, they're like 1/3 the cost.

Thanks Omn. I did see this part as well, very different from the one that I purchased. I’m assuming I just purchased the wrong part even though application shows it is correct. I will purchase this and see what happens

I think I’ve just got the wrong part.

Thanks for taking the time to respond. I didn’t see anything on the transfer case. I did see a guy on YouTube swapping one out and his was near the output of the transfer case. Mine is not.

I'm suspecting that the shifting issues of my AW4 auto may be caused by a bad speed sensor. I'd already replaced and properly set a new TPS, I bought and replaced my TCU with a junkyard one, and my NSS is only 2-3 years old, so I'm feeling good that it is still good. I tested my shift solenoids and they were all good. My next move is to replace the speed sensor. I recently bought a Standard Products SC129 speed sensor from PartsHawk like the one pictured. I was under the impression that the location of the speed sensor was behind the 4x4 shift bracket. Man, that was a pain to remove. Anyhow, I was either wrong on the location of I just have the wrong part. The part under that bracket looks nothing like the SC129. The part on my truck has what appears to be a rubber line running to it and no electrical connection at its base (see the end of my finger): I've been looking all over the internet but I'm not really coming up with anything to solve my issue. Anyone with experience swapping the speed sensor out? I've scanned all over my AW4 transmission and I cannot figure out another location where SC129 would go. Is the part pictured at the end of my finger the actual speed sensor? Do I have the wrong part? Am I overlooking the area where the SC129 would go?

Thanks for the input. Man, I sure hate to parts cannot this thing but I am starting to feel some pressure here. BTW, I did get a chance to fool around with it a bit longer, checking continuity from the "B" blade of C114 to battery ground. It was good. Did you look into the speed sensor(s) by chance? I'm going to try to read a bit about it next.

Well damn. Pulled my C114 connector and tested female side to the three solenoids. Got 12 olms. Should have 11-15 Olms, so that checks out good. Went ahead and pulled the trans pan and removed each solenoid and tested again. Got 12 Olms each. Shot 12v to each blade terminal to check for mechanical click. They all clicked and so then they all should be good. Looks like I won't be buying solenoids which is good news, but I am frustrated to still be lost as to why my trans is not working correctly. I'm going to regroup after lunch and figure out what's next. Maybe check male side of C114, though I'm not yet sure what I'm checking for. My engine starts just fine, but would the NSS allow for engine starting but at the same time not allow for proper trans shifting?

Oh cool. I am getting a better understanding now, thanks. I'll get the ol' multimeter out hopefully tomorrow and go over what you and Ohm talked about to test those solenoids. If they test good then I'll take my NSS off and clean/lube. If that doesn't work, then perhaps I'll probably be sitting on two busted TCUs unfortunately. That would really suck.

I have not checked resistance of the solenoids. I'll try to accomplish that this weekend. Just sucks that there seems to be no shop to bench test those TCUs. i kind of assumed the trans solenoids were good when I was able to manually shift with the in-line fuse removed...but I suppose there may be electrical/wiring issues going on, so I get what you're saying. Thanks for you help, man. I'll report back when I get some troubleshooting time in the next few days.

Well, a "it works" TCU from E-bay didn't solve the issue unfortunately. I'm gathering thoughts on what to do next. I may fool with the NSS next, I suppose. Give it a good cleaning and lube and reinstall. My truck acts the same with either TCU...starts off great in D. But doesn't shift. i pull the in-line fuse and I can shift throughout each gear manually. That in-line fuse tested good, btw as did the 7.5a fuse in the fuse box, driver's side. TPS is now new and had no issues getting it adjusted. Numbers looked good. Any ideas? I'm so limited in time so shooting wires would be my unfavorable last option....just was hoping it was something I could discover relatively easily. Am I overlooking something that's easier than shooting wires?

Thanks my friend. I think a speed sensor on the tranny is sometimes the issue for some guys. I was not expecting $150+ for a TCU! Man, I hope this is the issue.

Thanks for sharing the info. Today, I replaced my TPS with a new TH67 and with spray electrical contact cleaner, cleaned the two trans connectors near the trans dip stick. No corrosion and pins looked fine. I then set the TPS output to 83% of the input and took her for a spin. and....No-Go. Still not shifting past 2nd gear. Unplugged NEG battery cable, and looked for corrosion/issues with battery cables. All good. Replugged NEG and tried again, with fantasies of the trans actually shifting. No such luck. I replaced my NSS maybe two years ago, so I should be fine there. Layed down and did a visual inspection of wiring on both sides of transmission and all looked well. I suppose based upon your results, a TCU may be my next step. I can really respect all of the wire-shooting you did with Ohm's guidance but I think I'll go with an R&R of the TCU and see what happens.

Yesterday before work, I was able to properly pull the ECU fuse and test drive in each gear successfully. The moment I plugged that fuse back in, the shifting issues returned. I suppose that makes this an electrical issue and likely not mechanical. I appreciate all the help, fellas. I look forward to having some time to dig into this issue this weekend.

I've got a Standard Motor Products TH67 (not the inferior TH67T) TPS on order that I found at a great price, so that's what I'll replace next to see if that'll take care of the problem. Maybe I'll find some time in a few days to go test the old one. If this is not the issue, then at least I'll have a backup TPS on hand for the future. just an update for those interested in following this issue with me.

I've had limited time to look into this so far but I'd like to go ahead and toss this at you guys to see if I can quickly remedy this with your experience and knowledge for the next time I can afford a few minutes. My 89 AW-4 Automatic (paired with 4.0L) began shifting erratically and within a few minutes stopped messing around and refused to budge past 1st gear. I had to drive 3 miles back home in 1st. This occurred only 2-3 minutes into the drive. I parked and didn't look into it for a few weeks. Today, I got into it and ran it. Same thing, worked great for a couple minutes and began shifting funny--like it was searching or something, then it lost it's ability to leave 1st gear. I got home and reset the transmission shift cable (using that little button reset method found near the throttle body). I checked the fuse that likely goes to the TCU--yellow wires, in-line 10amp fuse at passenger foot well. The fuse and wiring looked great, btw. Next thing I did was pull the fuse and attempted to drive. Without fuse, it reeeeaaaalllly didn't want to move at 1st gear and the truck crept along. I replaced the fuse and it moved via 1st gear normally. What's the next check? Maybe TPS? Should I swap in a new one? Any other troubleshooting you can think of to narrow this down? Sound like a bad TCU maybe? It's my understanding that the AW-4 is overall pretty hearty. Appreciate your thoughts.

I'm happy with my build. I really had no need for a long range rifle. At the time, I lived on a steep hill with a long private driveway. My thought is that I could practically stop a Sherman tank from approaching the house if I had to. I live in a subdivision now, so I still have no need for long range. I have no regrets. It's an expensive round to buy, but you can't go much cooler than this bad boy.

Did my first AR15 build a couple years ago. Went with .50 Beowulf. Powerful short-range cannon.