'93 Cherokee Automatic Transmission Transmission possible issue / How to test?

[johnson7634]

Hey guys, new here but a long time Jeep owner. Fixed just about everything on this puppy but I am stuck because I know nothing about transmissions. Below are the basic specs:

Jeep Cherokee 1993, 224,000 miles

Here is the story: So I'm visiting my fiance who lives 30 miles away (I visit her every weekend), and one day my Cherokee came upon a hill and started to lose power (I was going about 65mph... then 55mph...). My engine was up to 3,000rpm but the speed was steadily decreasing. I eventually hit the nearest off ramp and pulled into a parking lot near by. The Jeep has been making wining noises for about 3 weeks now but I concluded it was the engine (long story short, my dad said to put a quart of transmission fluid in the engine next time I changed the oil. He said it has more detergents than regular oil and would clean out the gunk... sure enough, the wine went away and engine sounds good).

OK back to the original story: Now I let my Jeep cool off in a parking lot for a few minutes and took off again. But as soon as I left, same problem started again, but now I can only go 35mph with 3,000rpms. I was able to drive it the last 10 miles to my fiance's going about 25 to 35mph. When I finally reach her place, I think it decided to give out. 3,000rpm and it's inching along. Now it's sitting outside my place (Thanks to the great people of AAA), runs great but does not go anywhere when I put it in any gear (R,D,3, or 1-2). Doesn't even move

Just to knock out some potential quick answers, I have made several repairs which can make this equation more detailed:
A) When I first bought the Jeep I knocked out the catalytic converter (it's basically a straight pipe now)
B) TPS sensor has been changed a million times (I have lifetime warranty so I change it about once a year)
C) TV cable has been checked several times... It worked perfectly before this tragedy so I'm sure this is not the culpret.
D) Replaced the break pedal sensor because the Jeep was always going into over drive plus the cruise control didn't work. I read on another forum that if those two things are not working on a Cherokee, more than likely that sensor has fried (Changed the $15 part and cruise control and overdrive came right back)
E) Unplugged the TCU to see if I could manually opporate the transmission... no luck
F) Changed transmission filter at least once already (I think at about 200k miles). Also, I checked the transmission fluid levels and color and everything looks good.

So, I have several options/questions:
1. Call a dealership and ask how much they want to take from my small wallet
2. Try to find someone that can hopefully pull some diagnostic codes from it for a decent price (this leads to another question**Q3**)
3. What is an OBD tester and DRB tester :???: I specifically want to get transmission diagonsis codes. Which one do I need? I picked up a AW4 manual online (pdf) and it said I needed a DRB II tester.
4. Should I just take it in and have someone fix the transmission?

Sorry this is so long but I figured I would atleast try to get some help before throwing in the towl. I really don't want to part with my Jeep Cherokee just yet (its loads of fun and I have great memories with that bad boy!). Any help is GREATLY APPRECIATED.

[See attached photo. This thing is a beauty. Hopefully you'll feel sorry for it... LOL]

 

[Bounty__Hunter]

Sounds serious since you couldn't shift the transmission manually after disconnecting the TCU. I'm betting transmission replacement but that's an uneducated guess.

Your transmission is readily available in junkyards and on local jeep forums, for between $100-$300. Sold my last one for $100, hard time getting rid of it because they generally don't fail.

 

[SteelHeadz]

My best Advice: If you want to spend an hour of diagnostics from a Dealership, Who has the DRB Scantool, will be the option i would take. they can scan the TCM for any DTC's and run a few diagnostic test to isolate the cause for your concern. after that, if they tell you that the problem is a sensor or a torque converter, i would just pay for the diagnostic and replace the sensor or torque converter myself granted, that you have the tools to do it. If they say that the problem is in the Clutches, If you have no experience or knowlege of rebuilding an automatic transmission, your better off to let a proffesional do the job for you..BTW, what TV cable? . the Cheapest option is Bounty_hunters suggestion.

 

[johnson7634]

Thanks for the suggestions. Well my dad has helped me change most of these parts. He has almost every tool you can think of for cars. One problem though, I'm at college now and he lives about 3 hours away. What a bummer!

My dad said that he needed to adjust the Throttle Valve cable on my brother's car in order for it to shift correctly. The '93 though has the automatic TV adjustment (push the pin in, push TV cable all the way back, move Throttle manually to wide open when car is off). I'm pretty sure this has nothing to do with this particular situation. It was just something I have already messed with.

The torque converter. Now that has popped into my mind. I would be more than happy to replace that bad boy but I am having a hard time spotting a new one (so It's probably off to the junk yard). The problem I have with replacing the torque converter is I have heard stories when the TC goes out, it usually sends metal shavings into the transmission. Have any of you guys heard of that?

On that same subject of the torque converter, what specific tools would I need (besides your basic sockets and wrenches)?

Again, thanks for the help! You guys have no idea how much this means to me.

 

[SteelHeadz]

Ahh, i see, TV cable = Kickdown Cable.. I agree with you on the Torque Converter Debris ending up in the Transmission . Other than Hand tools to remove a transmission, a Large enough Jack that can handle the trans. will be sufficient to do the job.

 

[Bounty__Hunter]

I don't think the TV cable is like a kickdown cable, is it? I mean it's a cable to the transmission but that's where the similarity ends.

 

[johnson7634]

Here is what I found about the TV... just so you guys know. I'm pretty sure this is correct.

Function of the TV Cable: Many people believe that this is a detent downshift cable and that this is the only function that the cable performs. In actuality, the TV Cable controls line pressures, shift points, part throttle downshifts and detent downshifts. The cable functions similarly to the combination vacuum modulator/cable systems found on other automatic transmissions.

[found on: tciauto(dot)com/Products/Instructions/instructions/gm_tv_cable_adjust(dot)htm --> insert dots where indicated].

I personally believe it controls the idle as well. If this thing is not in the right spot, my engine would idle funny (i.e. to high or to low).

I think I'm going to take my Jeep into a local transmission shop and ask them to JUST CHECK THE CODES. The guy says he will do it for free... I'm going to tell him straight up that I'm not paying him to work on that puppy, I just want the codes and what they mean (& shell out a few bucks for his time). I'll let you guys know what the codes say just in case anyone else has the exact same problem in the future.

 

[SteelHeadz]

Here is what I found about the TV... just so you guys know. I'm pretty sure this is correct.

Function of the TV Cable: Many people believe that this is a detent downshift cable and that this is the only function that the cable performs. In actuality, the TV Cable controls line pressures, shift points, part throttle downshifts and detent downshifts. The cable functions similarly to the combination vacuum modulator/cable systems found on other automatic transmissions.

[found on: tciauto(dot)com/Products/Instructions/instructions/gm_tv_cable_adjust(dot)htm --> insert dots where indicated].

I personally believe it controls the idle as well. If this thing is not in the right spot, my engine would idle funny (i.e. to high or to low).

I think I'm going to take my Jeep into a local transmission shop and ask them to JUST CHECK THE CODES. The guy says he will do it for free... I'm going to tell him straight up that I'm not paying him to work on that puppy, I just want the codes and what they mean (& shell out a few bucks for his time). I'll let you guys know what the codes say just in case anyone else has the exact same problem in the future.

This is From the Service Manual Thru Chrysler.
THROTTLE VALVE CABLE ADJUSTMENT

The throttle valve cable controls throttle pressure and kickdown on 30RH transmissions
Correct cable adjustment is important to proper shifting. The cable positions the throttle valve which controls shift speed, shift quality and part throttle downshift sensitivity. If the setting is incorrect, shift quality and shift speeds will be unsatisfactory.

Transmission Throttle Valve Cable
THROTTLE VALVE CABLE ADJUSTMENT PROCEDURE


Cable adjustment is performed in the engine compartment. It is not necessary to raise the vehicle for access.

1. Shift transmission into Park and shut engine off.
2. Press cable release button
3. Push cable conduit back into cable adjuster body as far as possible
4. Rotate throttle body lever to wide open throttle position. Cable will ratchet to correct adjustment point as lever is rotated
   Throttle Valve Cable Components
   Throttle Valve Cable Adjustment

Line pressure is adjusted at the Valve Body.

VALVE BODY

CONTROL PRESSURE ADJUSTMENTS

There are two control pressure adjustments on the valve body;

• Line Pressure
• Throttle Pressure

Line and throttle pressures are interdependent because each affects shift quality and timing. As a result, both adjustments must be performed properly and in the correct sequence. Adjust line pressure first and throttle pressure last.
LINE PRESSURE ADJUSTMENT

Measure distance from the valve body to the inner edge of the adjusting screw with an accurate steel scale
Distance should be 33.4 mm (1-5/16 in.)
If adjustment is required, turn the adjusting screw in, or out, to obtain required distance setting.
[SIZE=+1]NOTE: The 33.4 mm (1-5/16 in.) setting is an approximate setting. Manufacturing tolerances may make it necessary to vary from this dimension to obtain desired pressure. [/SIZE]
One complete turn of the adjusting screw changes line pressure approximately 1-2/3 psi (9 kPa)
Turning the adjusting screw counterclockwise increases pressure while turning the screw clockwise decreases pressure.

Line Pressure Adjustment
THROTTLE PRESSURE ADJUSTMENT

Insert Gauge Tool C-3763 between the throttle lever cam and the kickdown valve stem
Push the gauge tool inward to compress the kickdown valve against the spring and bottom the throttle valve.
Maintain pressure against kickdown valve spring. Turn throttle lever stop screw until the screw head touches throttle lever tang and the throttle lever cam touches gauge tool.
[SIZE=+1]NOTE: The kickdown valve spring must be fully compressed and the kickdown valve completely bottomed to obtain correct adjustment.[/SIZE]

 

[johnson7634]

Long story short. They said the transmission was shot. Now I'm in the market for a new transmission.

Does anyone know what transmissions are compatible with a 1993 regular Cherokee? I have looked on google several times but nothing seems to come up for "cherokee transmission compatibility." I want to pull an AW4 from another Cherokee but I want to make sure I can get one from another year Cherokee if possible (hopefully find a newer transmission!!! )

Any help would be great!

 

[Onkover]

91-96 might be safe years.

 

[johnson7634]

Ok, so I'm going to swap the transmission in my 1993 Jeep Cherokee tomorrow. I have the Haynes Repair Manual but it does not include many pictures.

I have searched Google for 5 or so hours total and can't come up with anything good. Does anyone have advice or some pictures they could share (concerning the removal and installation of an AW4 transmission)?

Thanks for the help!

 

[Bounty__Hunter]

'91+ AW4 will have the same output shaft type as yours. Stick with '91-'95 if you want all the electronic connections to match perfectly.

 

[johnson7634]

Thanks guys for all the help. I just finished the installation of a slightly used AW4. It's running great now.

Just for others to know later, it took me 2 full days. On these Cherokees, there is 2 star bolts at the top of the bell housing. To remove them, I used a standard 12 notched 10mm socket (or 12mm, I can't remember), 2 long extensions, and a wobble gear. My dad helped me remove and insert the transmission and transfer case (I thought I could do it myself, but that sucker is way to heavy for one person). I eventually installed the transmission first, then the transfer case (the shop manual said to do both at the same time, but I had several jacks to help me out).

Best of luck to anyone else that attempts the project. Its a lot of work but can save you tons of $$$. Just to give you an idea, I found a slightly used AW4 for $150 at a local junk yard. I probably spent a total of $200 for extra crap I didn't have (like gear wrenches, towing the vehicle to a spot I could work on it, etc...)

DIY price = ~$350
Shop rebuild price = ~$1,200 to $1,600

If you have the time and right resources, I would say its well worth the time.

If I get the time, I'll post pictures later. Thanks again for all the advice!

 

[johnson7634]

UPDATE (April 19,2009):
After replacing the transmission, my Jeep runs better than when I first purchased it. It may be the luck of the transmission, but now it runs better, gets better gas mileage, and shifts super smooth. The junk yard transmission only had 84,000 miles on it, and came with 90 day warranty (a steal at $150)!

 

[borgnine]

Glad to hear the used transmission worked out.

I just had to replace my transmission in a 1995 cherokee and had it done at a shop just outside Denver. I put in a rebuilt trans and the whole thing cost $1600 with a 12/12 waranty -- so you saved a tone of $$.

To answer your earlier question. When torque converters fail, they typically blow metal into the transmission and destroy it. Thats exeactly what happened to mine. However, my understanding is that torque converters rarely fail before the transmission itself does. They have something like a .5% fail rate.

 

[kaw2000]

I am pulling the transmission on my 93, it however takes the 42RE transmission. Hard to come by in good condition, in my area anyway. I am told you can't interchange it with the AW4. Can anyone tell me the difference between them? Thanks.