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Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!ZJ (93-98), WJ (99-04), WK (05+)
All ZJ/WJ/WK specific tech questions asked here!
I'm a new owner of an '02 Laredo, 4.0/2WD. It's super clean with 109K miles and everything works. It has new tires, new radiator, and a new starter. I got it for what I thought was a good deal. But, I'm not so sure any more. When I test drove it, I couldn't get on the highway since it was pretty much stopped due to rush hour traffic. So, I took it through a business park. Other than a valve cover gasket leak and high idle, everything seemed perfectly fine so I bought it. On the way home, I was able to take the interstate. When taking the on-ramp, I pressed the pedal to the point that it should've downshifted, but it didn't. Flooring it made no difference. The only way I could get it to downshift for acceleration is to press the O/D button or manually shift it to 2nd. I also noticed that it felt like it was starting out in a higher gear than 1st. On the way home, I got a CEL and the code was something like a 1736 or whatever, but it was something about the governor pressure voltage. I accidentally erased the pic I took of the scan tool's readout. After much reading here and at other sites, I learned of the few common problems with this trans. and I ordered a kit that contained the upgraded Borg Warner solenoid, a new transducer, Sonnax 3-4 accumulator spring, new filter, Duraprene pan gasket, governor base gasket, and new speed sensor.
The Jeep sat for a couple of days until today. As I was letting the engine degreaser soak, I tightened the TV cable a few clicks. After washing and drying the engine, I took it for a spin. It was now downshifting and seemed to be doing so as it should be. So, I took it back home to swap out the transmission parts.
Upon dropping the pan, I discovered the ubiquitous piece of snap ring in the pan. I also found the 3-4 accumulator spring to appear identical to the Sonnax spring in my upgrade kit. It felt like it had an ever-so-slightly softer spring rate, though. Everything swapped as it should, except the connector on the BW solenoid was inverted as compared to the original. I didn't think much of it and just twisted the wire plug 180 degrees and plugged it in. I cleaned and reassembled everything and got the level where it should be with 5 quarts of ATF+4.
The Jeep now starts off in what feels like first gear and seems to shift through all the gears. Overdrive works as it should with the button pressed on and off. But, it doesn't downshift when floored at any speed over 35-40 MPH. Under 35, it'll damned-near snap my neck when floored. Also, it seems to be holding the gear for too long. When holding the pedal to the floor, it'll bounce off the rev limiter once and then upshift.
Does this tell anyone anything? Should I have unpinned that governor pressure solenoid connector and reversed the wires (to maintain original polarity)?
Oh, I cleaned the IAC valve to solve the high idle issue. At least something was fixed!
That piece of snap ring has me worried. Usually that is the forward clutch retainer located in the O/D housing. When that goes, it allows the clutch piston to ride against the O/D sprag and make metal shavings. My advise is to get it checked out.
I'm definitely concerned about that snap ring. After all the research I've done on this thing, I was actually expecting (but hoping not) to find at least one piece. I'm currently researching reputable trans shops in my area. I just wanna have as much knowledge as possible before I "present my case" to the shop.
Since my first post, I've adjusted the TV cable both ways. I started with it set according to instructions found in a few YouTube vids. The only change I made was instead of it bouncing off the rev limiter before upshifting, it would upshift way too early. One click at a time on the TV cable adjustment only made it shift too early or too late. Also, it still won't downshift when floored if going faster than 30 MPH. When floored at 30 MPH or lower, it'll drop into first and accelerate until redline (or thereabouts depending on how the TV cable is adjusted), then carry 2nd gear until 3,xxx-low-4,xxx RPM and upshift into third, then into 4th soon afterward- all with the pedal still floored.
I may just be my advanced years, but I can't understand why you are beating on a transmission with obvious internal problems. What happens if it goes BANG and you are left with scattered pieces on the side of the road? Did you think about that? I learned the hard way drag racing my everyday wheels and had to be towed home and take the bus to work.
I may just be my advanced years, but I can't understand why you are beating on a transmission with obvious internal problems. What happens if it goes BANG and you are left with scattered pieces on the side of the road? Did you think about that? I learned the hard way drag racing my everyday wheels and had to be towed home and take the bus to work.
But, go ahead. It's yours to beat on.
I get what you're saying. I know my previous posts sound like all I'm doing is keeping this thing pegged at all times. I'm not. I just know that there will be times when a full throttle pass will be needed during normal driving. (Ever driven through urban Louisiana?!) If not full throttle, there will be times when the trans will need to at least downshift to accelerate, as when merging. My posts were written from my observations when testing these basic functions. I know it has obvious internal damage and I realize the risk I'm taking by driving it. This Jeep was bought for me to use as weekend transportation while my personal truck is off the road for an engine swap. After the swap, it will be to replace my girlfriend's dying Montero. It is in no way a daily driver at this point. I drive a company van five days a week, and I usually run my personal errands during the day as I can fit them into my schedule. So, I rarely need to go anywhere on the weekends.
Before this Jeep is commissioned, I'm somewhat leisurely giving it a good once-over to tend to the maintenance/repair points so it will be 100% ready for our uses. My "testing" has been kept to the few roads around me that see more tractor traffic than anything, as I'm in the country and surrounded by crop fields.
I've read up on the broken snap ring issue, and it seems that mine isn't "that bad" yet. But, I WILL have it repaired soon. In the meantime, I'd like to handle the other odd issues that I know aren't related to the snap ring, such as the not shifting when needed/shifting when not needed. On that note, some more reading has prompted me to check the throttle position sensor. I'm currently tracking down an analog Ohmmeter to be as accurate as possible for this.
Last edited by s10xtremist; 05-13-2015 at 06:01 PM.
I apologize for jumping on you. I'm just used to guys that are just interested in how fast it will go. One guy wanted to put a supercharger on a 4.0!
My WJ's tranny can't make up it's mind sometimes on an on-ramp either. I'll give it some throttle expecting it to downshift and all it does is moan, give it a little more and it downshifts to FIRST and starts screaming. I've gotten to the point of manually downshifting it when I need it to and not waiting for it to make up it's mind. It's better than having a semi run over you!
No worries. Like I said, I know how my first post sounded. I belong to a lot of car forums and I know how it goes- a new kid shows up knowing nothing about the type of car, yet wants to tweak everything about it. It's a 6-cylinder mid-size SUV with a straight front axle and 4-speed slushbox. It is NOT a performance machine. One of my Jeep's purposes is to serve as periodic weekend transportation while my S10 gets a hopped-up 6 liter. THAT's my performance machine. I have enough projects and I just want the Jeep to perform all of it's factory functions as intended from the factory. although, I'll admit I did think about how easy it would be to throw on that centrifugal supercharger I have leftover from my S10's past life...
To get back on topic, I can't have it needing to be manually downshifted. This will soon be my girlfriend's car, so it needs to be as easy to drive as her Montero (just not as dangerous/unreliable!).
The TB gasket, spark plugs, valve cover gasket, hood support struts, and fuel filter were delivered today. I went to remove the TB to give it a good cleaning as well as test the TPS, and the TPS cracked and fell to pieces upon attempting to unplug the harness. I just got back from town with a new TPS, and both elbows, grommets, and hoses to replace when I crack those into shrapnel tomorrow while removing the valve cover.
I'm hoping the TPS is the unexpected fix for the trans shifting issue. I'm still holding hope that it was faulty because the high and unstable idle problem returned soon after cleaning the IAC valve and seat inside the TB. If it doesn't fix it, I'll leave it in the transmission shop's hands as I'll be out of ideas at that point, and I need them to fix the snap ring, anyway.
I scrubbed the TB, replaced the TPS, reassembled, and reinstalled it with a new gasket. Then I replaced the valve cover gasket, along with scraping/vacuuming out the built-up crud from around the injectors. All new bolt grommets and CCV/PCV/breather/vent thing/WTF-ever anyone wants to call them plastic elbows on the top of the valve cover, along with their new grommets were installed. I replaced the rubber hose end pieces on the rear vent tube (there actually was a Dorman kit for this ), and replaced the front hose with about 8" of 1/2" ID fuel vapor hose. Before resecuring the throttle, cruise control, and TV cables, I popped off the coil bar and replaced the spark plugs with the Champion OE replacements. I'm pretty sure the plugs I took out were original since they averaged .073" gap. Even the ground on them was worn to a knife edge! They all looked evenly worn and the colors seemed normal and expected. I reassembled everything and let 'er rip. After a few minutes to warm up, the idle settled to around 700, and stayed there even with the A/C cycling. Test #1: PASS. I took it down the road and got it cruising in OD at 50MPH. I floored the skinny pedal and... IT DOWNSHIFTED!! I let it wind out to see where it would upshift, which was around 4700. Good enough. I gave it throttle and even floored it from various highway speeds in OD and it seemed to be downshifting appropriately. So, I'm gonna call Test #2 a PASS.
If the weather holds out tomorrow, my girl and I will take it for an easy highway cruise and I'll see if I can beat the current 19 MPG @ 75 MPH average (as indicated by the overhead info center).
Then, since I now know everything else with the trans has been addressed, it's going to the trans shop to get that OD unit snap ring replaced before the other 90% of it falls out.
I'm actually starting to enjoy this thing now. It's refreshing to have something so easy to work on.
Put almost 300 miles on her yesterday. When we left my driveway, the MPG was at 15.6, which was due to the previous hard driving and extended idling during the repairs/testing. After driving relatively easily (but not excessively "abnormally easily") all day, the MPG hit 19.1 as we were coming down my street. When I first took it out about a week ago, the MPG climbed rather quickly from ~16 and slowly settled around that 19.5 figure I mentioned before. It took almost 300 miles with it SLOWLY climbing to the 19.1 that it finally reached. Either I just need to test it over a few tank fulls or the first average was inaccurate. I am going to calculate it myself at my next fill-up. The only thing different this time that could affect the MPG is the spark plugs. I figured they would've made a notable improvement since being new and having the factory spec'ed gap versus worn plugs with more than twice the spec'ed gap. Maybe the old plugs weren't affecting it so much because the extra gap provided more spark? Should I open up the gap a little (.045"-.050"?) on the new plugs?
Since I'm done with the trans part of this project, I'm gonna end this thread and do some research on the expected MPGs and altered plug gaps on these things. Of course, my research will start with my own calculations after a fill-up.
Last edited by s10xtremist; 05-18-2015 at 08:37 AM.
So... The WJ was doing great for a while, during the very rare occasions it was driven to the farmer's market up the road. One day, it felt sluggish again and had a CEL on. The code was "governor pressure sensor voltage low". After stopping and restarting the engine after a quick grocery store run, the problem went away. I'm guessing that either that sensor I put in with that upgrade kit is defective, or there's an intermittent connection in the internal or external wire harness. Either way, I'm done with it cuz I ain't dropping that pan again! I KNEW I should've put in a drain plug kit when I had it apart! I was turned onto a reputable trans shop by a friend, so I'll let them diagnose the intermittent stuff. I now have another project to be concerned with:
2001 with 160K unmolested miles. Rust doesn't exist here and the body has two almost non-existent dings. The worst of the scratches appear to be in the clearcoat only
Original leather- no cracks or rips. All power accessories work, too!
But what I REALLY like is this:
NO 42RE issues to worry about!
I have plans for it and it does have it's issues. I'll have to start a thread in the appropriate forum.
05-09-2015, 10:16 PM
More 42RE issues
), and replaced the front hose with about 8" of 1/2" ID fuel vapor hose. Before resecuring the throttle, cruise control, and TV cables, I popped off the coil bar and replaced the spark plugs with the Champion OE replacements. I'm pretty sure the plugs I took out were original since they averaged .073" gap. Even the ground on them was worn to a knife edge! They all looked evenly worn and the colors seemed normal and expected. I reassembled everything and let 'er rip. After a few minutes to warm up, the idle settled to around 700, and stayed there even with the A/C cycling. Test #1: PASS. I took it down the road and got it cruising in OD at 50MPH. I floored the skinny pedal and... IT DOWNSHIFTED!! I let it wind out to see where it would upshift, which was around 4700. Good enough. I gave it throttle and even floored it from various highway speeds in OD and it seemed to be downshifting appropriately. So, I'm gonna call Test #2 a PASS.
