89 AW4 issues.

Alright gents, I just picked up an 89 2door, 4.0, auto. Bought it off a kid that said the trans was slipping so he replaced it with a junkyard trans out of an 87 (he thinks). After the swap, No forward gears, reverse works perfect. I can however get the rig to move a little forward with it in low range. Trans leaks fluid out of the bellhousing after she warms up. PO replaced the transmission filter when he did the trans. Unplugging the TCS does nothing. Kid said he didn't replace any seals when he did the swap.

I'm guessing a seal or two got damaged or was already damaged when he put the other trans in, but would any of that have anything to do with the extreme slipping in the forward gears? Obviously I gotta drop the trans to see which seal is causing the leak and fix that (guessing front pump seal). Any ideas on what I should be looking at?

I'm no transmission expert, but a "little forward" in low range indicates the trans is putting out very little torque. Maybe torque converter not full when re-assembled?

Also, I don't know the compatibility from '87 to '89.

Sorry, but might ask him if he filled the torque converted when he re-assembled.

Re: Re: 89 AW4 issues.

Flyfisher said:

I'm no transmission expert, but a "little forward" in low range indicates the trans is putting out very little torque. Maybe torque converter not full when re-assembled?

Also, I don't know the compatibility from '87 to '89.

Sorry, but might ask him if he filled the torque converted when he re-assembled.

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Good point. The only way to prove that theory would be to drop the trans I'm assuming, which I gotta do anyways. I would however speculate that there would be no reason for a wrecking yard to drain the TC, unless the kid did it. Is it possible to break the front pump if the trans isn't put back in properly? I thought I read somewhere that can happen.

Is it possible to break the front pump if the trans isn't put back in properly? I thought I read somewhere that can happen.

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Yes, that is very possible, but it does not explain why it works in reverse.

Might take an ohm meter and test #1 and #2 solenoids, the coils should read 14.5 ohms. It may be stuck in OD with dead solenoids, or no ground for them, or busted pins on the electrical connectors. But in 1-2 low, it does not use the solenoids!!!

If the dip stick shows the transmission is full, it is full, including the TC, unless the pump is busted.

Re: Re: 89 AW4 issues.

Ecomike said:

Yes, that is very possible, but it does not explain why it works in reverse.

Might take an ohm meter and test #1 and #2 solenoids, the coils should read 14.5 ohms. It may be stuck in OD with dead solenoids, or no ground for them, or busted pins on the electrical connectors. But in 1-2 low, it does not use the solenoids!!!

If the dip stick shows the transmission is full, it is full, including the TC, unless the pump is busted.

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Alright thanks mike, I'll have to check that today. Can I check those solenoids with the trans out of the vehicle? I'm gonna drop the trans today to check the seals and what not so if that is a possibility it would make it a lot easier. I've always owned 5spd vehicles so working on and troubleshooting autos is not my cup of tea.

You can check the solenoids any time, in or out.

Alright, little bit of an update. Replaced the transmission with a junkyard one out of an 88 with 149k. Now it is slipping in all gears. I can feel it finally grab if I get on it a little then it's fine until I change gears, come to a stop etc. Had to unplug the TCU and shift it manually because it won't come out of 1st. Gonna test the TPS after work but I'm pretty sure it's done for. I've done a little searching on the symptoms of a bad TPS but I'm still unclear if it would cause the slipping like it's doing. Anybody got any ideas? Transmission fluid in the junkyard trans was perfect, drained it out and added fresh dex/merc, fluid is right where it's supposed to be. Fluid checked with it in neutral after drivimg it around for about 20 mins.

Check the fuse the TCU, and the ground for the transmission. Also, disconnect, inspect for bent pins, and clean the bulk sensor wiring connector to the AW4.

Does it shift normally with the TCU disconnected, shifting manually?

Does it slip (more than normal) with the TCU disconnected?

If the answer is yes and no respectively, the hydraulics of the AW4 is OK. If not, the JY AW4/TC combo is bad.

If the hydraulics are OK, then one or more solenoids may be bad, TCU fuse maybe bad, wiring or ground fault, or bad TCU. Bad fuse and bad solenoids are common, as is bad ground or connection in the bulkhead fitting at the oil dip stick to the AW4.

JY fluid may need several transfusions, even if it looks OK? It may be the wrong fluid for all you know?

Ecomike said:

Check the fuse the TCU, and the ground for the transmission. Also, disconnect, inspect for bent pins, and clean the bulk sensor wiring connector to the AW4.

Does it shift normally with the TCU disconnected, shifting manually?

Does it slip (more than normal) with the TCU disconnected?

If the answer is yes and no respectively, the hydraulics of the AW4 is OK. If not, the JY AW4/TC combo is bad.

If the hydraulics are OK, then one or more solenoids may be bad, TCU fuse maybe bad, wiring or ground fault, or bad TCU. Bad fuse and bad solenoids are common, as is bad ground or connection in the bulkhead fitting at the oil dip stick to the AW4.

JY fluid may need several transfusions, even if it looks OK? It may be the wrong fluid for all you know?

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Thinking i found my problem, was probing the grey connector for the trans to test ohms on the solenoids. Terminal E tested at 16.4ohms, Terminal F tested at 18.7ohms, and finally Terminal G tested at 16.8ohms. Read up and they are supposed to read between 11-15ohms so that tells me that all 3 of them are toast. I tested the ohm readings on the transmission that i took out of the thing (front pump was bad). All 3 test high 12's. Placed the COM probe on the case of the old trans for a ground. Probably gonna swap the solenoids over and see what she does.

Before you do that, make sure that the extra ohms is not the ground you used in the test. If you test from the solenoid case (ground) to the hot wire then yes they are high (and may be even higher when hot), but if you tested from the wires at the TCU or the bulk head fitting near the oil dip stick, it may be a little wire connection losses or a poor ground (2-4 ohms loss in old wires and ground connections is common)!!!!

I have read where they tested OK cold, and way too high when hot at operating temp.

Re: Re: 89 AW4 issues.

Ecomike said:

Before you do that, make sure that the extra ohms is not the ground you used in the test. If you test from the solenoid case (ground) to the hot wire then yes they are high (and may be even higher when hot), but if you tested from the wires at the TCU or the bulk head fitting near the oil dip stick, it may be a little wire connection losses or a poor ground (2-4 ohms loss in old wires and ground connections is common)!!!!

I have read where they tested OK cold, and way too high when hot at operating temp.

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Alright so it would seem the solenoids are testing correctly out of the trans, but at the bulkhead connector they are reading 1-3 ohms over with them installed in the trans. Tried finding the ground for the trans in the bulkhead wiring but according to my multimeter there are 3 of them in the grey plug, none in the black. Me and wiring do not mix, it's like trying to read Chinese.

Have you removed and cleaned all the main ground contacts and post, on the post at the oil dipstick? It is Renix 101 rule #1, the main ground and often the source of many renix control issues.

I mention this, because a 1-3 ohm ground loss should not be a problem for the solenoids, unless it changes and gets worse (loose ground wire?), but 3 ohms is a lot for the TPS, ECU and some of the sensors.

Also, be sure to adjust the throttle cable that goes to the AW4 on the throttle body, it controls fluid pressure!!!

Re: Re: 89 AW4 issues.

Ecomike said:

Have you removed and cleaned all the main ground contacts and post, on the post at the oil dipstick? It is Renix 101 rule #1, the main ground and often the source of many renix control issues.

I mention this, because a 1-3 ohm ground loss should not be a problem for the solenoids, unless it changes and gets worse (loose ground wire?), but 3 ohms is a lot for the TPS, ECU and some of the sensors.

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Cleaned all the grounding contacts real good and put it all back together. No change whatsoever.

Try this next:

http://www.naxja.org/forum/showthread.php?t=1015963&highlight=cable+adjustment

Ecomike said:

Try this next:

http://www.naxja.org/forum/showthread.php?t=1015963&highlight=cable+adjustment

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I've adjusted the TV cable properly, i even tried every adjustment possible with little to no change in the slipping. Tested my TPS with my multimeter, even adjusted on the high side i can't get the WOT voltage to read over 3 volts. I believe the max was 3.08v at WOT adjusted all the way up, which in turn made my idle RPM's jump up to around 2k-2.5k. I'm assuming that means the TPS is bad but would that cause the slipping? If not I'm leaning towards a bad TC. On a side not, I'm now noticing a weird noise that SOUNDS like it's coming from the bellhousing area when the transmission finally engages properly while laying into the throttle a little aggresively. I can't really explain the noise other than it's not a metal on metal/grinding noise.

TPS problems can make the AW4 do screwy stuff, so do this next:

http://www.naxja.org/forum/showthread.php?t=1072534&page=14

Verify that both sides of the TPS have a ground wire with less than ohm of resistance, then verify that both sides have a 5 volt (4.8 to 5.1 is OK) supply voltage (they come from separate sources!!!!), then if the TPS output voltage is as far off as you said, it must be replaced next!!!!!
Once you have know good grounds (they are separate grounds!!!!!!, one can be good and the other bad!!!!), good 5 volt sources and properly adjusted voltages at idle and at WOT on both sides, then see what you have. Don't do any thing else or make any assumptions until that is all done!!!!!

If one of the supply voltages is too low, it is bad wiring or the respective computer, TCU or ECU, or the power to them or ground to them that is bad!!!!

I wasted 3 years screwing with my engine and AW4 before I discovered the TPS grounds were off and the TCU side of the TPS was way out of spec at WOT.

Google my old thread "The RenX Files" the sordid story and step by step tests I ran here in this forum.

Mine would shift to 1-2-3-4, and hit 4th gear at WOT by the time I got to 10-15 MPH, took 3 minutes to get to 55 mph at WOT , LOL!!! I had a bad TPS, one bad ground and one poor ground, but the 87 FSM test procedure said it was good (ECU side), TCU side was junk.

Well I did notice that the 4 prong connector wasn't getting ground. Was gonna start digging into figuring that out and got a call so I had to jet down the road to my buddies house 2 miles down the road. Got there, shut the jeep down. Started it back up and it completely lost Reverse, but all the forward gears were acting like they should. Positive engagement, no slipping, perfect. Turned it off and hunted around with the gear selector, fired it back up, and now absolutely no forward gears but Reverse works just fine. Back to square one when I first got the thing. Whiskey Tango Foxtrot...

For some reason it won't let me edit my post. Forgot the mention i checked all linkage, everything is adjusted properly. When it lost reverse the gears were acting funky on the shifter. Park and Neutral were acting like they were getting forward power. I could still only start it in Park or Neutral like normal. With only having Reverse now like before and no forward gears. If i give it a little gas and go down into 1st-2nd. The trans jerks a little and acts like it wants to go in reverse, I'm stumped. It's possible that the slipping was just this transmission on it's last leg but the symptoms of getting forward gears properly and losing reverse, then losing all forward but getting reverse back is weird.

Sounds like the shifter linkage is out of adjustment to me.