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  #1  
Old January 9th, 2019, 19:20
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Ecomike Ecomike is offline
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Shifting AW4 into reverse while going forward

Family member in a near accident, panic stop freeway, shifted from drive to neutral and thinks it may have gone into reverse (it was dark and the shifter lighting does not work). AW4 Renix 4x4. The engine died when she moved the shifter during the panic stop (reverse???).

What damage might that have done?

How would would check? I am 1000 miles away, so I was asked...feedback
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Old January 9th, 2019, 22:11
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Re: Shifting AW4 into reverse while going forward

Quote:
Originally Posted by Ecomike View Post
Family member in a near accident, panic stop freeway, shifted from drive to neutral and thinks it may have gone into reverse (it was dark and the shifter lighting does not work). AW4 Renix 4x4. The engine died when she moved the shifter during the panic stop (reverse???).

What damage might that have done?

How would would check? I am 1000 miles away, so I was asked...feedback



Was the shift to neutral or possibly reverse intentional?



The AW4 doesn't have any synchros or gears that physically disengage or engage as it shifts. It's all clutches, brakes, and a couple of one-way clutches. If it's still working in all gears and not making funny noises, I don't think I'd worry too much about it.
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Old January 10th, 2019, 07:07
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Re: Shifting AW4 into reverse while going forward

Albeit not good for it, I dont see it really causing any serious damage to the trans unless the engine was at WOT or something like that.
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  #4  
Old January 13th, 2019, 19:55
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Re: Shifting AW4 into reverse while going forward

So far, it has not manifested any AW4 issues. Fingers crossed.
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Old January 14th, 2019, 09:21
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Re: Shifting AW4 into reverse while going forward

Maybe you got lucky, my youngest daughter did that doing around 50 MPH, 6 weeks later the tranny grenaded. A half handful of broken bits and pieces laying in the pan.
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Old January 14th, 2019, 11:15
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Re: Shifting AW4 into reverse while going forward

Ugh, :-( Right now the rig has overheated for the 3rd time in weeks, and just spent 6 hours fiddling with trying to solve a power steering leak...flushing it... 1200 miles away, a day ago. Among other things...

Leaning towards a sticking T-stat...
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #7  
Old January 14th, 2019, 12:15
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kastein kastein is offline
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Re: Shifting AW4 into reverse while going forward

I wouldn't worry about it unless it starts slipping or explodes either. I looped my 98 XJ in a snowstorm (long story short, snow was coming down hard, highway unplowed, had to get home, rear left tire had been victim to a rock a week earlier leaving me with 3 26" studded snows and 1 29" half bald spare tire, had to run it in 4wd to get any traction... it was VERY squirrely) and caught traction while sliding backwards. All it did was stall the motor, I put another 30k miles on it after that.

I have seen a nearly dead AW4 cause severe sporadic overheating at highway speed (it was slipping and dumping a ton of heat into the fluid) but I would suspect other sources for an overheating problem. AW4s are pretty tough. Hell, Team Petty Cash slammed theirs in reverse by accident on the track and all that happened was they slid off course, stalled the motor, and busted the leaf center pin. Trans was fine.

http://www.fourwheeler.com/events/17...d-racing-jeep/ (search for "accidental")
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Last edited by kastein; January 14th, 2019 at 12:22.
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  #8  
Old January 14th, 2019, 12:39
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Re: Shifting AW4 into reverse while going forward

Wowzers. The overheating was first idling in park a year ago, new clutch fixed it, then about 5 weeks ago making deliveries and long idles in park, etc..... it overheated again. The E-fan works, but I do not think the Temp switch is working. Clutch is a year old (from the last time it overheated in park sitting).

Over heated again sitting in park too long again about 6 weeks ago. Then fine for several weeks (but not allowed to sit and idle in park except at stops), and good for many 60 mile drives.

Is there a freeze plug on the rear of the block? Does the tranny need to be backed off to get to it?

Waiting for more inspection, and running data right now....
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091

Last edited by Ecomike; January 14th, 2019 at 12:44.
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  #9  
Old January 14th, 2019, 14:25
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kastein kastein is offline
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Re: Shifting AW4 into reverse while going forward

there is one on the back of the block inside the bellhousing as well as one on the back of the head.

Both are proper bastards to get at... found a pic but haven't bothered to upload it so I can embed it here.
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My yard looks like Sanford & Sons.
Please do not PM me about the AW4 info thread unless you have a truly unique question that is not covered by it or info to add. I do not respond to questions answered by the thread.
Definitely do not hunt down my phone number at 3AM, text me about it, and then threaten violence when I am not helpful. It will not get you what you want.
CTeunuch: Sometimes I really wonder if this sport makes you insane, or it just attracts the mentally unstable.
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  #10  
Old January 14th, 2019, 15:24
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Re: Shifting AW4 into reverse while going forward

OK, she just ran a test. Started out with temps around 39 F. Upper radiator hose and T-stat housing hit about 100F at the same time, making me thing the T-stat may be stuck open (some or all, no idea which).
T-stat housing was under 180 F, maybe even 160 F max when coolant started blowing out the bottle (cap was off to try and add coolant). Ambient (Colorado Springs was about 39 F ish?)

I am thinking the block has air in it. Hope its not a head gasket leak.

She thinks (not verified) that the bottom hose/nipple on the coolant bottle may be leaking now, but that is not the main issue!!!!

Plan to pull the upper rad hose at the T-stat this weekend. Then fill the block and radiator from the coolant bottle and vent air through the radiator and upper Rad hose. And then rerun the test to see what happens.

Hoping the air already in the block is the only real problem. Tranny fluid and oil are normal.
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #11  
Old January 15th, 2019, 18:57
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Re: Shifting AW4 into reverse while going forward

You may have already checked, there may be a flow issue. When it gets up to temperature, squeeze the top hose. If it is rock hard you likely have a flow issue. When everything is working well that top hose should collapse with two fingers and a thumb, if it isn't really stiff with age.

Flow restriction is often the radiator, sometimes a hose separates internally.
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Old January 15th, 2019, 20:42
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Re: Shifting AW4 into reverse while going forward

What I am hearing is with the coolant cap off, just as soon as the T-stat seems to start to open it blows massive steam/coolant mix out the coolant bottle.

This is not a radiator issue.

I also do not think it is a head gasket issue.

But on Renix, the radiator is a trapped loop with no air exit.

I think the bottom of the coolant bottle feeds the water pump inlet (3/4-5/8 hose) and the second hose by passes the T-Stat (driver's side) and lets hot coolant from the head(?) under pressure from the pump pushing coolant to the radiator then to engine block feed/flow, and then through the head, and then to the heater valve Y that splits flow/diverts flow to the bottle or heater core?

So why does it suddenly blow steam out just as the T-Stat gets in the 180 to 190 F range and starts to open?

I am trying to plot the path of the steam eruption through one of the 2 hoses to the coolant bottle to make sense of how it can do that.

Keep in mind I am getting second descriptions from 1200 miles away. I was on the phone step by step, but my data is not perfect with out being there.
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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  #13  
Old January 16th, 2019, 04:36
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Re: Shifting AW4 into reverse while going forward

The coolant hose going to the heater valve/coolant tank and the return have a secondary function. It allows coolant to bypass thermostat so the hotter coolant get to the thermostat. That loop helps make the thermostat much more responsive.



Way back in my racing days we'd plug that bypass and had heating issues, the motor seemed to run either too hot or too cold in cycles. We learned to make a loop instead of plugs to bypass the heater. It was most prevalent in the first start up cycle on a cold motor. Just a thought, but I've seen some really gunked up heater valves.
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Old January 16th, 2019, 04:40
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Re: Shifting AW4 into reverse while going forward

Another thought, if you've replaced the thermostat you can't use the supplied (universal) gasket. The Jeep gasket is the only one that will work, it has a cut out for that bypass.
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Old January 16th, 2019, 12:20
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Re: Shifting AW4 into reverse while going forward

Just had an idea. It may be that the engine block needs to get to a critical temp, say 190 F +/- for the trapped air and or ( and or trapped coolant from a stuck T-Stat?) to boil and steam up (pressure) thus blowing coolant and steam out of the heater hose on the side of the coolant bottle into the bottle and out the bottle hole top side.

Also now wondering if the bottom coolant bottle hose ( it may not be sealing, not sure yet...., but it was starting to look like it might not be sealing there in the last minutes of the tests) may be letting air into the coolant pump that then pumps air bubbles into the block.

Or the bottle emptied when the T-Stat opened, and drained and pushed air into the block in seconds, that led a blow out seconds later?

I have never ever in 45 years seen what she says it did. So I know it is not any of 101 known coolant issues we all know all too well.

Nothing on the entire cooling system has been changed in 24 months, except the heater 3 way valve about 4+ months ago.

I see no way the heater valve could be involved. It is under pressure feed from the coolant pump outlet.
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Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
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