89 Cherokee AW4 2nd Solenoid Override Switch Install 

Yes, is acts like an Overdrive kill and will shift into 3rd as well. My throttle position sensor harness was messed up so the transmission wasn't getting any throttle input. If I hit WOT, the engine would run as if you were only pushing down 1/3 of the way which sucks if you are trying to pull out or merge. I could manually shift it and it would speed up correctly but I was tired of having to shift from 1st to 3rd so I didn't work my engine to hard. Now that I replaced the harness, everything works normally so I only use the switch if I'm trying to race or pull out fast.

Nice. I was looking at kits like that but don't really have a need for one yet. It's pretty cool that you can turn an AW4 into a manually shifted auto with full control. Would make a nice trail shifter if the TCU ever burns out. There were a few projects I've seen where a digital display was included to see what gear was selected in real time. Here is a really fancy version: scontent-lga.xx.fbcdn.net/hphotos-xap1/v/t1.0-9/1424297_251242441696706_187435092_n.jpg?oh=420c3ee9de9b2ecb6ed160794a7c6c1c&oe=5579517D

The link that you submit has expired , could you pls send it to me . Or tell me what was that project .

I honestly don't remember, couldn't track it down as it was from someone's facebook. I think it may have looked something like this but i don't really remember: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4mpHWQcDjWE.html

Thanks Anyway Sir

BTW ,I wanna to do shift to my 4th gear b'4 the TCM do . b'cos TCM shifts to the 4th gear after 60 km/h . So I did manually override the solenoid A and shift manually to the 4th gear when the vehicle reach to the its comfortable speed rage (45 - 50 km/h thats the speed normally I'm driving most of the time.) so it save my fuel 25% . But the problem after I manually shift to the 4th gear , TCM does not shift even if after vehicle reach 60 km/h (even 70 km/h) , To get it back to normal I have to trun the ignition key off and reset the TCM . Any idea why is this happening ?

Engine speed, wheel speed, throttle position. Mine switches to 2nd if I'm offroading, trying to climb a sandy hill. So high engine rpm, almost full throttle.

You would need a 3 way switch. 1 that passes through for auto, 1 that is off for first, and 1 that feeds 12v for 2nd.

I did a quick search but nothing turned up. It sounds like the AW4 doesn't have bands to adjust. www.jeepforum.com/forum/f11/aw4-band-adjustment-1451045/ Now if you have a Chrysler A904 3 Speed (1984-1986) or Chrysler 30RH 3 Speed (1994-2000) then you have bands to adjust. Not sure which 3 speed trans my Haynes manual refers too but here are the torque specs it lists for those: 3-Speed Front Band - Adjusting Screw (w/ adapter): 36 in-lb - Adjusting Screw (w/o adapter): 72 in-lb - Locknut: 30 ft-lb 3-Speed Rear Band - Adjusting Screw: 41 in-lb - Locknut: 35 ft-lb

Well I know it has bands because i've seen two band adjustment screws/nuts. I haven't really looked at the tranny too much. I can hear reverse engage when I shift but it just won't grab (not even a little). The fluid's full and not leaking. I did that self adjusting kick-down cable trick to no avail. I brushed off all the linkage of dirt and it seems rather clear for travel so i'm left with: 1. Tranny is totally shot 2. Band adjustment 3. The pipe that delivers pressure to the reverse inside the tranny is broken. 4. God knows what. I tried to pull it up today to hose the underside off but my starter is out whomp whomp. Thank god this thing isn't my daily driver lol. Thanks for the help.

NickInTimeFilms Also someone told me that a lift kit can sometimes effect the linkage but I don't believe them. Not on a two inch lift anyway. Oh, and I read that forum. I was told to put in ATF+4. I haven't ran it much as i've spent the last year just getting it running & idling correctly, gauges & instrument all that. Anyway i've had problems with slippage a little in forward and totally in the back. Maybe I can get away with just changing the fluid. Then again when I got the Jeep both of the cooler lines where cut & connected (not flared) with vac hose & cheap hose clamps. I don't know. I guess i'll figure something out when I drop the pan tomorrow. Thanks again.

Andrew Roby Just want to verify, what vehicle do you have? If it is a Cherokee with a 4.0L Auto then you have the AW4. I've read several forums that say there aren't any adjusting bands. The AW4 is electronically controlled with solenoids, which is how I'm able to active 2nd/3rd gear with this switch I made. A lift kit by itself will not affect any of the trans shift linkages. If there is a drop Crossmember then you may have issues with the Transfer Case linkage, but the Transmission has flexible cable linkages. I've done a lot of reading on what fluid to use and this is the conclusion I've come to: Use Dex/Merc. Aisin-Warner specifically says the AW4 should use Dexron II(2) fluid. Dexron II(2) hasn't been available for decades since the licensing has expired. Dex II(2) was superseded by Dex III(3), and then again by Dex IV(4). Dexron and Mercon ATF fluid is very similar so eventually they were just combined to make Dex/Merc Blends. Dexron VI(6) is a totally different blend and is not suitable for the AW4. Chrysler back in the day was tired of having Dexron for their AW4 Jeeps when the Chrysler Transmissions used ATF+4 so eventually they released a bulletin saying it was okay to put ATF+4 in all their Transmissions. ATF+4 has more grip additives that will slowly eat up AW4 Clutch Packs so I recommend Dexron IV or Dex/Merc. My jeep also has rubber hose lines that connect the metal trans cooler lines to the radiator. It may have been a factory thing to let the system flex a bit. Here is the AW4 Service Manual. It should have everything you will ever need to know in here: www.pirate4x4.com/tech/billavista/PDFs/AW4_manual.PDF

NickInTimeFilms It's an 88 XJ with a 4.0. The previous owner dubbed "the tweaker" has done a lot of dumb shit. From what I can tell it looks exactly like a AW4 but you never know whit this jeep. Maybe those set screws where for something else but they look exactly like band adjusters i've seen online. Does the AW4 have a solenoid for reverse? Because that could be a good starting point. No, those tranny lines looked like they where cut with children's safety scissors. I had to file them, flare them and get better clamps on them. I've ordered up a few feet of tranny fluid resistant hose to replace the vacuum hose that's on there now. Tomorrow morning i'll read through that manual with my coffee, then i'll drop the pan and check for chunks/flakes. Then I'll replace the hoses on the cooler lines. After that i'll maybe check the things that I can figure out like the solenoids & connectors. If I can't find anything wrong i'll just pull out as much ATF as I can and fill it with Dex4 or Dex/Merc. I remember doing some reading on that a long time ago but totally forgot. I asked someone who "knows jeeps" while I was at Napa and they told me ATF4. Oh well. If that's all it takes to fix it I'll be lucky. My brother just spent the value of his car to have his tranny rebuilt :/

Andrew Macias I'm having the same problem with mine. It's a 1989

@@jessicapeyatt5582 tcm or the tcm fuse is

fujidude1 If you get 3rd then solenoid 2 is still working. This switch will force the solenoid on if it works properly. Check your tcu connector and the fuse the is next to it if you are having shift issues. bad grounds and bad TPS could also cause issues.

Fuse? Sorry I for for to say it's a 97. Mine is under the dash on the driver side right of the steering column. There's not much wire to work with and I looked for the fuse

fujidude1 my wiring harness for the tcm is routed directly through the firewall no fuses between

fujidude1 not sure then, I don't know much about the newer cherokees. If it's the same tcu and wiring you could still do this mod if you want. But maybe tcu fuse is in one of the fuse blocks

NickInTimeFilms ok thank you so much. I'll be sure to let you know how it works

No it’s different

+Dan Ctibor First you need to check the basics. Do you have enough ATF and does it need to be changed? A clogged filter may cause pressure issues. I would check the Throttle Valve Kickdown Cable on the Throttle body to see if it needs adjustment. Sometimes they fall out of adjustment and can cause big issues. Adjustment vid here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-c0di1z5j1fU.html

My XJ has a reman tranny with 51,000 miles; 96,000 miles on the engine and body.

Throttle/chick-down cable has also been checked.

Hmm. The TPS does cause a lot of trans shifting issues. Mine is starting to crap out on the trans side so it doesn't shift until like 4k. You could try resetting the ecu to see if it relearns anything. If the Kickdown cable is adjusted properly, the TPS is reading ok on both connectors, then there ain't much else. How's the fluid, TCU Fuse, how is the engine side of the tps harness, grounds all good?

Check tps sensor and possibly replace Trans controller

That's the tricky part of this setup. I actually installed to help upshift, not hold it in lower gears. The 2nd solenoid controls 2nd and 3rd gear, so you're probably noticing it shift to third. I built a full blown shift controller recently to hold any gear you want.

@@NickInTimeFilms I connected a switch panel with LEDs and I found that the tcm is pulling my 12v to the 2nd relay so essentially its trying to down shift I'm in the works of making a electronic circuit with an arduino when I shift into 1-2 it will shift into second and then with a momentary button on the shifter it will downshift to first. Then press the button and it will upshift to second the circuit will only work when the shifter is in the 1-2 position so I'll have 1st and 2nd hold with the push of a button.

My jeep wont hold 2nd gear when shifted into 1-2 which is horrible when trying to hold 3200 rpm climbing a mountain.

@@JACKOFALLTODD I feel your pain. I have a '98.

@@JACKOFALLTODD Do you know when the selector is in 1/2 under what conditions does it shift to 2nd? I've never been able to get mine to shift out of 1st, and it would be nice as you say climbing a mountain or even going downhill to be able to use 2nd gear to gain some speed, but not too much speed.

I'm unfamiliar with a transmission "shift governor." I know the Aisin-Warner AW4 transmission uses 2 solenoids to control what gear is selected along with a TV-cable to adjust for WOT. The solenoids are located In the pan. Check my AW4 Fluid and Filter change video to get a quick look inside the pan. Hope this helps.

Thanks!

@@NickInTimeFilms the TV or throttle valve cable controls line pressure.

You could yeah. I've been working on a more complete shifting system now called the Nifty Shifter to allow any gear at any time.

NickInTimeFilms great job!

NickInTimeFilms would this be possible on the newer xjs 97-2001

@@mmeza620 "Yes" The concept is the same as the solenoids still function the same, but with the newer XJs you've got more computers to worry about. If you start messing with them yourself, it will set a check engine light for a solenoid fault and may even put it into limp mode when you turn your override switch off. I build a 97+ version of my nifty shifter which takes care of the basic check engine light issues. The only issue left has to do with the computer detecting when the speed sensors "look" out of sync when you are grabbing manual gears that the TCU did not request and you're really flooring it. That doesn't pop up very often though. Little too smart for their own good.

NickInTimeFilms i got a 97-01 was teally thinking of doing that for "racing" haha but as u say it may have issues i might aswell not even try it cuz im not quite the mechanic haha but thanks for replying really appreciate