Jeep YJ Wrangler 32RH Transmission: 2nd to 3rd Shift and Lockup Issue

[zidodcigalah]

Hi all,

I've got this issue for about a year. Transmission will not upshift from 2nd to 3rd when it's cold.It will when engine rpms are above at least 2200 - 2500. After 3 or 4 upshifts it will eventually behave as it should.

I've replaced filter and flushed it. New 8 liters of ATF are in it and still there were no results.

Then, I've tried adjusting TV cable. Results are following - It will shift from 1st to 2nd at light throttle when rpms are in between 1500-1900. 2nd to 3rd shift is also in between 1500-1900 rpm. 

 

But new problem appears now, also when transmission is cold. When it upshifts into 3rd, if I easily press throttle pedal it slips. Like it's shifted into neutral, and suddenly at 1900-2000 rpms it shifts into 2nd (i think). If i let off throttle pedal it will again upshift into 3rd and same story again. This happens ONLY when transmission is cold. If I readjust TV cable again the shift point for 3rd is again high ( about 2200rpms). Is this TV cable related or there is something wrong inside valve body?

There is also one thing I've noticed, I'm not sure if it is normal. When driving some 40mph in 2nd, seems like it first locks-up in 2nd ( about 150 rpms drop) and then upshifts into 3rd.

 
If i drive in 3rd and press throttle a bit harder, it downshifts into 2nd but TC is still locked. Only when I fully press throttle it will downshift into 2nd and unlock. Even when I go uphill it stays locked until I give it a lot more throttle. Is this normal and shouldn't lock-up occur only when in 3rd?

[Moses Ludel]

zidodcigalah...You've made a good accounting of the troubles.  Have you adjusted the bands yet on this transmission yet?  This may not solve all of your troubles, but it is routine service and will help eliminate guesswork.

 

I will walk you through the remaining symptoms and help troubleshoot after the bands adjustment.  Meanwhile, see my article on RH/RE transmission valve body and accumulator issues: http://www.4wdmechanix.com/Survival-Upgrades-for-Jeep-and-Dodge-Ram-Automatic-Transmissions.html.  See if any of these issues sound like they apply.

 

Expect a detailed reply after you adjust the bands and report the results.  Consider the valve body and other issues described in the article. Some may be relevant.  Others may not apply directly to the current symptoms.

 

As for adjusting the bands, I can share the procedure if you are not familiar with the process or do not have access to the service steps.  Since you just changed the fluid and now need to drop the transmission pan again for one of the two band adjusts, I can also share details on how to properly drain, strain and reuse the fresh fluid.  ATF is costly, especially synthetic types...

 

Moses

[zidodcigalah]

Thanks for advice. I've adjusted bands, but problem is still there. I think TV cable is properly adjusted now. The problem happens only after Jeep was sitting for at least 2 hours.

 

Transmission shifts fine into Low and 2nd. Then, at some 25 mph, when I lift my foot off throttle pedal, revs will go down very slow, and it seems like it is somewhere between 2nd and 3rd gear. It's definitely not in 2nd ( I know because revs are higher when I manually move gear selector from D to 2nd), but I'm not sure if it is in third . If i easily press throttle pedal, car behaves like it's in neutral ( revs to some 1500rpm but no acceleration). If I press throttle pedal a bit harder revs will go to 2000rpm (but no more than that) and it will then "downshift" to 2nd. As soon as i get to some 40 mph, it will stay in 3rd speed properly.

 

I've noticed that after driving at speeds higher then 35mph for a couple of seconds, shift problems dissapear. If I stop car and start driving again, it will shift properly all the way, and there is no slippage at all. If car sits for a couple of hours, same problems until it get to 35+mph speeds for a couple of seconds...

 

PS. Happy new year!

[Moses Ludel]

Glad you adjusted the bands, zidodcigalah.   That's a routine service that often gets overlooked and can tie into the symptoms you now experience.  Was there much take-up on the bands when you adjusted them?  Did they seem to be in good condition?

 

I'm curious about the vehicle's model year and mileage plus the history of this transmission.  Do you know whether any minor or major work has been performed on the 32RH transmission or the torque converter?  Any wiring issues in the transmission's electronic circuit?

 

I've printed out the entire troubleshooting chart for the 30RH/32RH transmissions plus additional information that is relevant.  Here is the troubleshooting chart information in PDF format: 30RH-32RH Jeep Transmission Troubleshooting.pdf.  I have also scanned each of the hydraulic system schematics.  You can study these and learn about the fluid flow and how to troubleshoot by knowing the systems and components involved in each and every shift mode of a 30RH or 32RH transmission: 30RH-32RH Hydraulic System Schematics.pdf.

 

Having rebuilt these units in their several forms over the years (the 904/999 first appeared in the early 'sixties and evolved into the 30RH-32RH Chrysler 3-speed automatics), I would note that there is very little in the troubleshooting chart that matches up with your transmission's symptoms.  The only possibility is the shift solenoid valve that is unique to the 32RH and not found on the 30RH.  That device and its functions can be tested with a DRB-III dealership level scan tool or equivalent. 

 

Though this solenoid could cause troubles like you describe, solenoid "sticking" or faulting is less likely when the transmission shifts okay after complete warm-up and driving for a while.  You share that the transmission then works without any faults until it has parked for over two hours.  Solenoids typically either work or don't work, although temperature can be a trigger for a sticky valve or malfunction.  If you have concerns about this solenoid, check wiring circuits, test the device or consider a DRB-III transmission code scan and device driver test.

 

I know you're looking for a simpler fix than a complete transmission rebuild.  When the transmission can still perform "normally" under certain circumstances, I perform a complete diagnostic sequence before considering a teardown.  For now, I'm not going to suggest a rebuild, though that prospect is still a possibility.  Let's stick with what can be tested and fixed in the chassis. 

 

Caution: It is damaging to the transmission to drive the vehicle while the transmission slips or acts erratically, so finding a fix and avoiding further damage to the transmission are immediate goals.

 

Taking your transmission's symptoms and assuming there is no major damage to the unit yet, I would focus on these key areas.  Here's how my next troubleshooting steps would go:

 

1) First I'd consider that the malfunction is when the transmission is cold.  Transmission cooler systems are notorious for clogging at the radiator's transmission cooler, and Chrysler's historic A727/904 RWD and RH/RE transmissions have a legacy of anti-drainback valve troubles.  I would run the cooler flow test and pressure test outlined in the PDF material I have provided.  Make sure the anti-drainback valve is functional, and if in doubt, replace the anti-drainback valve.  These valves are not easy to clean and restore.  See the guidelines in the troubleshooting PDF attached.

 

2) A sticky shift solenoid is a possibility, though I'm not likely to replace that without proof it is defective.  This, again, requires testing with a DRB-III scan tool, which can also gather stored trouble codes thrown by the transmission's electronically controlled system.  You would want to test the solenoid with the transmission cold, that's when the transmission acts up.

 

3) The valve body throttle pressure settings on these transmissions are critical.  Here is the procedure for checking and adjusting throttle and critical line pressure:  30RH-32RH Throttle Pressure Adjustment.pdf.  Before performing this adjustment, I would test the transmission pressures as detailed in the troubleshooting PDF attached.  Clutch air apply and hydraulic pressure tests are the only in-chassis diagnostics that can pinpoint minor or major problems.  If the trouble is either line pressure or throttle pressure, this will turn up during the hydraulic pressure tests.  Follow the adjustment guidelines. 

 

Note: Again, the fact that your transmission shifts "normally" once it warms points more to a restriction in the hydraulic pressure rather than an actual pump or line pressure malfunction.  A transmission cooler restriction can affect line pressure and throttle pressure.  It can also create shift malfunctions.  The "neutral" sensation can be a torque converter unable to fill properly, and this can be due to a restriction in fluid flow or even a defective anti-drainback valve.  Anti-drainback valve trouble is addressed in my article that I shared earlier, review here:  http://www.4wdmechan...nsmissions.html.

 

4) A torque converter issue cannot be ruled out.  My only hesitation about condemning the converter is that it does seem to function okay once the transmission passes through the malfunctioning phase.  The solenoid for the converter is more about converter lockup.  You can see from the factory troubleshooting flowing chart that the lockup issues are distinct, and you're not experiencing anything consistent that points to the converter.  Still, the converter does play a role here, we can't rule it out.

 

5) The torque converter stall speed test is simple and can be performed readily.  I included the stall speed test in the PDF material.  Beware of the cautions when testing the converter.  You do not want to overheat the transmission or damage the converter and other parts.  A stall test with the transmission cold could be revealing, as this is when the transmission acts up. 

 

In troubleshooting order, my first step would be a stall test cold, followed by testing the radiator cooler flow and anti-drainback valve.  You want to make sure that the torque converter is filling properly.  If a clogged cooler or defective/clogged anti-drainback valve is not the issue, I would test the hydraulic pressures as outlined in the PDF troubleshooting guidelines attached.  Test the hydraulic pressures both cold and warm to pinpoint the trouble.

 

If pressure is normal for each gear and test mode whether cold or warmed up, I would then question the torque converter, the clutch frictions, the bands condition and the band apply servos.

 

Note: In my RE/RH upgrade article, you'll see that I did replace the accumulator piston.  This alleviates the risk of a malfunction at the servo apply piston.  The OEM piston is plastic and can cock or bind.  This upgrade is in-chassis with the transmission pan dropped.  See illustrations 77-82.

 

The last in-chassis testing is an air apply test at the clutches and band servos.  Those steps are also outlined in the troubleshooting PDF attached...

 

Moses

[zidodcigalah]

First, thanks a LOT for this detailed post. I'm really amazed, and thank you a lot for your time and patience.

It is 1995 wrangler YJ with 32rh. Don't know what PO did, i replaced fluid 2 years ago until now.
I've did already stall test and some other procedures you described here. The problem is only tool availability for now. I'll check documentation you have provided and perform other test, and inform about results here. Thank you a lot!

[Moses Ludel]

You're welcome, zidodcigalah...If you decide to perform the transmission pressure tests, make sure the vehicle is safely blocked and secure.  Get assistance to prevent injury, someone who can follow your directions.  Be safe when performing a transmission pressure test...

 

The transmission pressure gauge is not expensive.  Here's an example:  http://www.summitracing.com/nv/parts/otc-5610/overview/.  You may be able to get just the high pressure 0-400 PSI gauge and hose for less cost.  Or find a used test gauge kit at eBay, Craigslist or elsewhere.  You can even make your own "kit" with an oil resistant pressure gauge and high pressure oil type hose. 

 

I once built a transmission and pump test gauge with an inexpensive hydraulic oil pressure gauge (rated for use with hydraulic oil) available from a tractor supply.  I added a section of high pressure rated, oil resistant hose and used common fittings as adapters to the transmission.  If you attempt to make your own gauge, make sure the gauge, hose and fittings will each withstand the pressures described in the Jeep 30RH/32RH transmission tests.  Allow an additional safety margin.  Transmission fluid can get very hot during testing!  Protect your eyes and skin.

 

Moses

[zidodcigalah]

Hi,

Recently I tightened the bands to proper factory settings, replaced fluid et voila, no more slippage! It shifts now fine through all gears (sometimes shift to 3rd is delayed until i fully release throttle pedal, but this only happens when its cold and there is no slippage, it only stays a 1-2 sec in 2nd speed). 

However I still have an annoying problem like before ( this problem was here even before slippage). I notice it going uphill, it starts around 40-45mph. On light throttle (or throttle released), it will shift from 2nd to 3rd speed, and then it seems to lock up, rpms being around 1500. When I apply more throttle, rpms go to 2000-2100 and it takes a lot of time to accelerate. Only when I apply full throttle it would fully downshift into 2nd with rpms around 2500 and then I have the power I need. I dont have this problem on speeds less then indicated (then it immediately shifts from 3rd to 2nd).
Knowing this my suspect would be some malfuctioning of TCC solenoid, like it keeps it locked even in 2nd speed until i press full throttle or get to lower speed. Could these be the symptoms of it?

Thanks a lot for the help and advices!

[Moses Ludel]

Congrats on the band adjustment...The ongoing issue sounds torque converter related.  How much debris was there in the pan?  Metal?  If you're out of the woods with the transmission's condition, try the TCC, it's not a large investment.  Also consider a "flush" by a reputable outfit that will really flush through the system, including the torque converter.  Change the filter as part of the flush-and-fill.   

 

I think you may have a survivor in that 32RH if you can keep it from being abused by this irregular shift pattern...Also, if you feel like tackling it, consider the Sonnax upgrades to head off troubles.

 

Moses

[zidodcigalah]

There where no metal particles in the fluid.. However, I did some tests today.

First I removed the solenoid plug. I felt only two rpm drops (when 1-2 and 2-3) shifts occured so I guess that solenoid is not stuck, because I could not feel lock up.But, same thing happened again, 3-2 downshift would not occur on speeds more than 40 mph if I don't apply full throttle. On speeds less than that part throttle downshift does occur. When going uphill this bothers me because I feel lack of power when I overtake other cars ( I feel like its in 5th speed on manual transmission, and I cant get it to 4th without full throttle).

But I noticed something else that gives me the conclusion that this could be just normal behavior. 
I tried same thing with 2-1 downshift. On speeds more than 15-20 mph it would not occur on part throttle, but it will on full throttle. Is this normal behavior of this transmission? If it is, i guess that my problem is lack of power(engine trouble, but Im not sure because compression ratio is allmost perfect) or just the fact that this car is brick on wheels and aerodynamics play big role on 60mph+ speeds.

I suspected solenoid becaues I heard about TC shudder, and I do feel shuddering (like when ABS engages) but its constant and most noticeable on speeds from 40 to 50 mph so I guess it comes somewhere else from drivetrain. I have never driven cars with such archaic transmission like 32rh, but sure it's strong as hell. 

Petar
 

[Moses Ludel]

zidodcigalah...Ruling the solenoid out was worthwhile.  The shudder could be driveline or engine/transmission mounts related, or a combination of both.

 

From what you're describing, this could be a throttle cable ("kickdown") adjustment issue.  The throttle cable feeds information on throttle position to the throttle pressure valve in the transmission valve body.  The adjustment is quick and under the hood.  Here's the procedure: 

 

32RH Throttle Cable Adjust.pdf

 

Throttle pressure settings are crucial, and your transmission uses traditional linkage signals, which is a plus from a simplicity standpoint.  This is a simple adjustment.  Try it!

 

Moses