Electroshop

I seem to have a serious problem shifting from 1st - 2nd. I have a 42RE with fresh Mopar ATF+4. It has shifted bad ever since I bought it. Originally the trans fluid had water in it and turned the fluid a milky light pink. I decided to do the 'poor mans flush' and ran 14 quarts through it and installed and external cooler. I have proper fluid level and I have VSS signal according to my OBDLink S and ScanXL. This thing shifts into 2nd very roughly (almost scary hard) like I'm dropping the rear end out of it kinda scary, unless I use a very light foot, then it shifts fine. All other gear engage just fine under heavy foot. Could this be the results of a failed Governor Pressure Solenoid and/or Sensor? or could this be part of my current dreaded electrical problems. I am going to pick up a PCM today at the salvage yard as a last effort to fix my current electrical gremlins (hopefully). Is my 42RE Shot? I love Jeeps and this is my second one and don't want to give up on them but I'm at the end of ideas and wits. I have been working on this dang thing day and night for over a month trying to figure out all of these problems this thing has and I need help. Please!

Ralph77

Can you adjust the cable on a 42RE in a GC like we can in our XJ's? If so you should to it. No cost and take about 5 minutes. Figure what do you have to lose.

https://www.cherokeeforum.com/f2/free-quick-fix-41821/

Electroshop

I have adjusted the TV cable to the recommended position but I have read that maybe by adjusting the cable out (away from the TB) by a click, it will allow higher pressure to change the shift point up a bit. I will be trying this a little later today when I wake up. LOL Ain't been to bed yet. as every night of researching the troubles that I bought.

Electroshop

OK.. I pulled the TV Cable out just a bit farther (a couple notches) than instructed by the service manual and it shifts about 90% better. I would pull it out more (another notch) searching for a 100% improvement, but I am worried that it might cause damage to the trans. I don't think it would, but nervous just the same. Does anyone know if a TV cable that is not adjusted in sync with the throttle would cause any damage? The 1st to 2nd shift point is at 1800 RPM. I does down shift well and shifting is smooth. It does bump slightly from 2nd to 3rd (barely noticeable though). When I get on it, I do still have some shutter from 1st to 2nd but not nearly as bad. Before the adjustment, it would shift as if it was grinding teeth down or something like that. Banging, bumping, grinding and jerking as if I am tearing the jeep apart and its about to self destruct! But its much, much better now.

munyanb

Have you ever adjusted the bands? I think the one for first to second is the external band adjustment but I could be wrong. How're your U joints?

Electroshop

Actually, I just bought this bundle of problems. The first thing I did was flush the tranny but I have not adjusted the bands yet. I do plan on it though, So, your thinking band adjustments? I was thinking that was what is needed as well. I almost did that, but after reading some nightmares of people posting bad things, I was a little hesitant. I will be changing the governor pressure solenoid and sensor soon and I will take your advice on band adjustment. Can you share some insight on band adjustment? I have rebuilt manual trans but never did anything on automatic trans before besides shift kits, fluid and filters. I am mechanically inclined, so I am not afraid of any project as long as I have it planned out first. U-Joints appear fine. No slop or play and seem pretty tight. You mentioned external band adjustment?? I can do a band adjustment without dropping the pan?

munyanb

Well when you adjust the bands, make sure you have the right socket to fit the square head on the adjustment bolt, and a wrench to tighten the jam nut as you hold the bolt in place, find a way to mark your socket or extension so you can count turns, make sure you look up the proper year, the adjustments changed from year to year depending on some of the internals. I used some fiberglass tape I had laying around and a marker to make a line on my extension and made sure the socket did not come off of bolt. The one on the inside is much easier to get to. Mine is a 97 with a 42 RE, if I remember correct its supposed to be torque it down to 72 inch lbs, then back off 3 5/8 turns , The one inside the tranny is the same torque, but back it off 4 turns, double check this, research is free, a tranny rebuild is costly, lol. I adjusted mine 5/8 turns less out on both, because I researched this forum here for several hours and found a guy that did his own and he gave the results. Mine works better than I ever remember it to have worked, Oh the external band adjustment is covered by all your shift linkage, sorta hard to find. I would not go buying or messing with sensors or governors until I tried the bands. A code reader does go into tranny on jeep, not sure how accurate or in depth, ive never had anything come up on mine, but id think a bad sensor or governor or solenoid would.

97grand4.0

Fluid changes, filter obviously, band adjustments, and def new solenoids and pressure sensor. Those are before you even start to talk about adjusting the TV, which should be right by book, no tighter. Once you get past that then adjust the line pressure and throttle pressure and good to go.

munyanb

That is the first ive heard anyone ever say to buy all them parts right off, why would someone do that without knowing ? You don't work in sales do you? I would go on and do the bands and see how it works out first, although it really sucks that you already changed fluid. That stuff gets expensive. But yeah in theory them parts could be bad or it could just be bands, like is often the case, judging from the forums I read.

97grand4.0

Currently and over the last 7 years have two 4.0s on the road, one with the 42re, other with the AW4, which has 160000 on it and the RE has over 200k on it. Both have had shift problems, both ended up needing solenoids. For the price on Ebay, you can get the sensor and two solenoids for the RE for about a hundred, but if you go to the AZ or napa they are like 100 each. Like nike says, just do it. Sure you can spend a day troubleshooting and maybe find just 1 bad, but, when you drop that pan unless you like doing it three times, ..do I make the point

munyanb

That is correct, the tranny fluid alone costs to much to keep doing it , unless you have a good way to catch the fluid. But still this guy should have went on and adjusted bands the first time, And there are some good tranny shops that rebuild 42RE for around 700. And that is with the factory oversites fixed. Supposedly. Ive heard it said even the 44RE can be fixed to hold a lot more power and be dependable. That is what I will be running into soon with a 96 Grand Cherokee I transplanted a 95 truck 5.9 into. When I stomp it , it revs free, cant tell where its slipping yet, for all I know it could be burning the tires off and then the 4x4 kicks in, but mine sounds like bands maybe also or governor like you say. Its almost easier to pay 700 once and be good for several years without wondering..... You know that when one tranny part screws up it effects all other parts too.

97grand4.0

Bands and line pressure and throttle pressure. Those adjustments are in the fsm, if you dont have a pressure gauge there are articles where guys just give them a turn or two. Thats what I did, cruises like a Cadillac now. I mean, it has 200k on it, so there’s quirks, but night and day improvements can be had.