32RH Shifting Issue

[RavenDork]

I have a 32RH in a 2001 4.0. I’ve had a recurring gremlin that I just can’t fix. The issue is essentially that it won’t stay in 3rd gear under certain conditions. It will shift into 3rd and coast in 3rd just fine. And it seems to be shifting just fine. But under any sort of throttle, even just a slight tap, it shifts into second and stays there until your foot is completely off the throttle. But it’s not all the time. It’s only if I’ve been going 45mph+ for 30 minutes or more.

I have adjusted and replaced the kickdown cable enough that while the issue might still be related, it’s not the cable or the clip on the throttle body, for sure. I also replaced the return spring on it, but it didn’t change anything, so I switched it back to the original.

There’s some additional information that might be relevant. The transmission leaks. I had it “rebuilt” 2 years ago, but I’m pretty confident that it wasn’t actually rebuilt.

I don’t 100% know this transmission, so I don’t know if I’ve been missing something this whole time. So I’m looking for any and all possible causes and things to check. I know with a lot of these posts, responses are kind of “most likely it’s this issue” and while I want that as well, if you’ve got any one off “oh this unexpected issue that was somewhere you’d never expect was actually causing the issue” I’d love to hear that as well.

I’ll try to respond and update as much as I can, and with each suggestion I’ll test and fix and update. I just want this fixed without going to a mechanic, cause I enjoy fixing it, and I don’t have the money for a mechanic to chase down and then fix the issue.

 

[hear]

Somebody is going to tag me on this thread eventually anyway, so I'll placehold while I'm thinking about what this could be.

So if you stay on the gas past like 60mph it stays in second gear? And then when you let off you get a nice rpm drop (more than like 150ish rpm)? I want to make sure we're not confusing a downshift for a torque converter lock/unlock.

Any chance you have a bluetooth code reader that could graph vehicle speed vs rpm? I have an OBDLinkCX and with their free app I can make some sweet graphs that can help diagnose stuff.

 

[RavenDork]

Somebody is going to tag me on this thread eventually anyway, so I'll placehold while I'm thinking about what this could be.

So if you stay on the gas past like 60mph it stays in second gear? And then when you let off you get a nice rpm drop (more than like 150ish rpm)? I want to make sure we're not confusing a downshift for a torque converter lock/unlock.

Any chance you have a bluetooth code reader that could graph vehicle speed vs rpm? I have an OBDLinkCX and with their free app I can make some sweet graphs that can help diagnose stuff.

Yes, it stays in second gear. And drops from like 4K-5k in secind to 1.5k-2k RPM in third gear. At least I presume.

And I believe it’s the gears because I found that if I disconnect the kickdown cable at the throttle body, then the transmission will act like a manual without clutch, letting me use 1, 2, and D as if they were 1st, 2nd, and 3rd respectively, which I did in order to get back home after a longish road trip.

I don’t have one but if you link me one I might buy one if it helps diagnose.

 

[hear]

Without the kickdown cable (actually, the throttle valve cable, but lets not split hairs), it should still shift like an automatic, just the shift points will be very early. Like you'll be in 3rd gear before you know it. It would helpful to know how your transmission acts while in D & the cable disconnected. You can always shift it manually like you describe. The cable just basically tells the transmission how much gas you're giving it, to know if it should hold the shift longer. But if you put it into 1, then 2, then D you can basically have an autostick, sort of.

Do you happen to know your rear end gear ratio & tire size? I want to do some quick math on expected RPMs.

As far as code readers, it's probably not going to help us troubleshoot all that much with what you just told me, but if you had the data it would be nice. Below is a graph I generated recently using that device & app.

This is what I use, everybody here has their favorite tool. I particularly like the OBDLink app, but I'm on iphone so that's a factor. I've used BlueDriver, and I didn't like it nearly as much, YMMV. If you own a TJ, I can't imagine not having something like this. I use mine regularly across all my vehicles.

https://www.amazon.com/dp/B08NFLL3NT?tag=wranglerorg-20

 

[RavenDork]

Without the kickdown cable (actually, the throttle valve cable, but lets not split hairs), it should still shift like an automatic, just the shift points will be very early. Like you'll be in 3rd gear before you know it. It would helpful to know how your transmission acts while in D & the cable disconnected. You can always shift it manually like you describe. The cable just basically tells the transmission how much gas you're giving it, to know if it should hold the shift longer. But if you put it into 1, then 2, then D you can basically have an autostick, sort of.

Do you happen to know your rear end gear ratio & tire size? I want to do some quick math on expected RPMs.

As far as code readers, it's probably not going to help us troubleshoot all that much with what you just told me, but if you had the data it would be nice. Below is a graph I generated recently using that device & app.

This is what I use, everybody here has their favorite tool. I particularly like the OBDLink app, but I'm on iphone so that's a factor. I've used BlueDriver, and I didn't like it nearly as much, YMMV. If you own a TJ, I can't imagine not having something like this. I use mine regularly across all my vehicles.

https://www.amazon.com/dp/B08NFLL3NT?tag=wranglerorg-20


View attachment 632438

yeah, that’s pretty much what it was doing. If I left it in drive it would shift twice real quick and stay in third. But I was essentially able to just use it as third by starting in 1st then shifting to 2nd, which also would shift into 1st I think, but it would be past that shift point when I shifted into it

And as far as ratios. I’m not sure because the lift was done before I owned it. I don’t know what all they did correct or incorrect. But I know that a few things were done wrong, like wrong size shocks, and a few were done right(ish), like dropping the skid plate an inch and a half. But I’m pretty sure it wasn’t regeared and pretty sure it didn’t have the rear drive shaft replaced. But I do know I have 35” tires. Something that’s in the works on getting fixed, either by correcting the mistakes on the lift, or sizing down to 33” tires.

 

[hear]

I realize you said you already did this, but if without the TV cable it shifts hella early, and with the TV cable it holds 2nd forever, then the TV cable is at least partially responsible. I would start by re-setting the cable to be as loose as possible, and ideally have it act the same as if the TV cable weren't even there. Then incrementally adjust it until you can tell that it's affecting the shift points. I know you've done some of that, but humor me, will you?

If it's not the TV cable, then it's possible it's an issue in the governor, or with the governor valve. Could just be you need a fluid flush & new filter.

Has this been happening since you got it rebuilt? Or did it predate that, or did it creep in some time well after the rebuild?

 

[RavenDork]

I realize you said you already did this, but if without the TV cable it shifts hella early, and with the TV cable it holds 2nd forever, then the TV cable is at least partially responsible. I would start by re-setting the cable to be as loose as possible, and ideally have it act the same as if the TV cable weren't even there. Then incrementally adjust it until you can tell that it's affecting the shift points. I know you've done some of that, but humor me, will you?

If it's not the TV cable, then it's possible it's an issue in the governor, or with the governor valve. Could just be you need a fluid flush & new filter.

Has this been happening since you got it rebuilt? Or did it predate that, or did it creep in some time well after the rebuild?

I’ll mess with the TV cable and let you know what I find. Itll take me a little longer cause the issue usually takes a while to show up, but we’ll see how it goes.

The issue I’m having is actually why I had it rebuilt in the first place

 

[RavenDork]

I realize you said you already did this, but if without the TV cable it shifts hella early, and with the TV cable it holds 2nd forever, then the TV cable is at least partially responsible. I would start by re-setting the cable to be as loose as possible, and ideally have it act the same as if the TV cable weren't even there. Then incrementally adjust it until you can tell that it's affecting the shift points. I know you've done some of that, but humor me, will you?

If it's not the TV cable, then it's possible it's an issue in the governor, or with the governor valve. Could just be you need a fluid flush & new filter.

Has this been happening since you got it rebuilt? Or did it predate that, or did it creep in some time well after the rebuild?

So I drove the Jeep in two different TV cable configurations. One where I made the cable as tight as possible on the right side of the bracket where the cable clips into the throttle body’s bracket. Basically the cable between the rubber cone and the connection on the throttle, was as taut as possible. The other configuration was the opposite. I pulled the cable through until I couldn’t, and the put the white clip on and the cable on.



Course conditions:

Temp: 90°F

Weather: Sunny

Distance: ~2 miles

Consists of curves and hills.



I drove the length of the course from a stopped position, and then driving at 50% gas pedal depressed, not changing my foot’s position to the beats of my ability.



The first test(taut cable) results were as follows



Shift to second time: 10 seconds

Shift to second speed: 25mph

Shift to second rpm: 3000 rpm

Shift to third: N/A

Top Speed: 70mph

Highest RPM: 4000rpm in second



The second run(loose) results:



Shift to second Time: 8 seconds

Shift to second Speed: 30 mph

Shift to second rpm: 3000 rpm

Shift to third: N/a

Highest RPM: 4000rpm in second

Top speed: 70mph

In both tests, when coming to my stop, the transmission didn’t go back into 3rd gear until my foot was at about 5% gas pedal depression


I didn’t continue testing since the results were almost identical.

 

[hear]

Generally you'll know in about 200 yards if it's made any meaningful change.

You might be the first case I've run across where you actually really do need to perform the pressure test outlined in the FSM. And now I'm kinda mad at myself for being lazy...I have a side project where I want to have an ESP32 & a fan of several pressure transducers that you can plug into the pressure taps on the trans and it will log all the data. But I'm not there yet, so I can't give it to you!

Since the 1-2 shift happens more or less at the right place, we can focus on what gives the 2-3 shift which is the 2-3 shift valve and the governor, along with the TV valve. The 2-3 requires more pressure than the 1-2 so it's possible the stuff that those shifts share in common are just on the edge of being ok/bad.

I didn't ask because the other shifts are apparently fine, but you did verify your fluid level, with the jeep running and in N (must be in N!)?

yeah, that’s pretty much what it was doing. If I left it in drive it would shift twice real quick and stay in third. But I was essentially able to just use it as third by starting in 1st then shifting to 2nd, which also would shift into 1st I think, but it would be past that shift point when I shifted into it

And as far as ratios. I’m not sure because the lift was done before I owned it. I don’t know what all they did correct or incorrect. But I know that a few things were done wrong, like wrong size shocks, and a few were done right(ish), like dropping the skid plate an inch and a half. But I’m pretty sure it wasn’t regeared and pretty sure it didn’t have the rear drive shaft replaced. But I do know I have 35” tires. Something that’s in the works on getting fixed, either by correcting the mistakes on the lift, or sizing down to 33” tires.

catching up on other replies... If you have it in manual 1, it will start in 1 but won't upshift. If you have it in M2, it will start in 1 and then shift to 2 when its ready. So what you describe is expected. The gear ratio is found easily enough by jacking up the rear & spinning the driveshaft and counting tire rotations. Your driveshaft not being changed is irrelevant (for this specific conversation, lol). 35's without a regear is something we'll talk about eventually.

 

[CMBD]

Here is your 32RH bible.

Im with @hear on the pressure test.

Your issue isn't in the diagnose by symptom section. Going to the two extremes didnt do much on the TV, what about in the middle?. Sounds like a control issue.

If the rear clutch was complete garbage you would have issues in all forward gears.

How is reverse? Reverse and 3rd have the front clutch in common.

 

[hear]

How is reverse? Reverse and 3rd have the front clutch in common.

It shifts into 3rd and even holds 3rd, so I don't expect the problem to be in that drum, and since M1 works the L/R band isn't the problem. Luckily there is lots to read on these topics. The 32RH is essentially an A-904, and also shares tons with the 727. So anything that applies to them very likely applies to us.

I'm pretty confident its in one (or more) of these 3 areas:

* governor
* 2-3 shift valve
* throttle valve

None of those require dropping the transmission to investigate; although you do have to remove the t-case and tail adapter to get to the governor. The valves are super tricky to diagnose (which is to say unless its obviously damaged I have no idea how to tell if something is wrong). It could be all 3 things failing to moderate degrees.

Here's how this actually works: As you're on the gas, TV pressure is increased. As you speed up, governor pressure increases. As long as the TV pressure is > than the governor pressure, the TV pressure will keep the valve in place and the 2-3 upshift will not happen. Eventually you go fast enough that the governor pressure exceeds the TV pressure allowing the 2-3 valve to move, which makes the kickdown servo release (to un-apply 2nd) and direct pressure to the direct drum (so those clutches apply and you get 3rd). Governor pressure is essentially 1psi per mph, so 1-2 happens at lower governor pressures than 2-3.

That basically narrows it down to either
A) It's possible that the governor is sticking at a pressure > than what is required for the 1-2 shift.
B) there is excessive TV pressure. This is most easily pinned on the TV cable adjustment but....

Everything I've read points to the TV cable, Occam's Razor and all. But given that you can't adjust the cable at all to reduce this behavior, I'm wondering if your rebuilder messed with the throttle pressure screw. That's why I need to know what was the precipitating event that introduced this behavior. Did it ever shift right after your "rebuild?" Or did it shift ok, and then you touched the TV cable? No shame, I suffered with an out of adjustment tv cable for a long time until I finally got it right not all that long ago.

I really believe you need to do the TV pressure & governor pressure tests as prescribed in the FSM. The TV test will also show if there is any binding in the cable or stickiness in the valve.

 

[CMBD]

OPs post #8 is confusing. Doesn't get 3rd but talks about getting back in to 3rd. Does it really get 3rd?

I'm down with its a control issue.

 

[hear]

OPs post #8 is confusing. Doesn't get 3rd but talks about getting back in to 3rd. Does it really get 3rd?

Oh yeah, I didn’t catch that.

 

[CMBD]

Oh yeah, I didn’t catch that.

I was thinking all or nothing on the TV adjustment could do something weird and maybe something in the middle might be another shot for test purposes.

Pressure gauge doesnt lie. That is what it is.

OPs 1st paragraph in post #5 sounds like stuck governor with the quick 1-2

 

[RavenDork]

I’m back y’all, sorry for the silence, been a busy weekend both with work and home and haven’t had time to mess with the Jeep or even think about it.

First thing I want to address is there seems to be some confusion on whether it shifts into 3rd, and I can solidly say that it does. It never fails to shift into 3rd, with TV disconnected or connected. The issue is that it won’t stay in 3rd under throttle.

Also, feel that it’s worth mentioning that I did in fact check the fluid level on the transmission and it’s dead in the middle of the “OK” range. Though I’m concerned by the color, as it’s no longer red, but has kinda greyed out. Though I’m betting that’s from burning the clutch from the “manual” shifting, and all the different tests and stuff.

I was actually typing a big long paragraph about how it was actually quite random when my memory accidentally worked for a second.

I remember when this issue started, and it might be helpful. It was right after the Great Smokey Mountain Jeep Invasion 2 years ago. The road trip is quite mountainous and nearly all highway for me, and I remember that it would drop to second on some of the inclines on the interstate just from the struggle of driving a Jeep on the highway. But it wasn’t anything odd. Just a big clunky Jeep fighting gravity.

But two days later I drive from Lexington, Kentucky to Richmond, Kentucky, and that’s when it happened for the first time. Again, wasn’t doing anything weird or crazy.

But that trip to Jeep Invasion was certainly eventful. Radiator blew out and it had to get towed to our cabin where we replaced the radiator. Took it through some mud while I was down there.

And then a little while later after messing with the TV and checking fluids, to no change, I sent it to get rebuilt, and I don’t think the rebuild had any real effect on the issue, good or bad.

I’ll try and do a pressure test soon, just don’t know how. But once I do I’ll update with results.

Also don’t know if it helps much, but the issue does seem to be affected by heat, whether it’s outdoor temp or transmission temp, I’m not sure. So in the winter, I’ve not had it happen hardly ever. If at all. That’s when it’s like below freezing. And then spring comes around and it’ll happen after about an hour of driving. And now with this heat wave and it being 90+ most days, it only takes about 20 minutes to start happening.

I think I touched on everything, but in case I didn’t I’ll be responding pretty quickly again so feel free to point something out again.

 

[RavenDork]

edit: accidentally posted the same thing twice

 

[hear]

I'm bumping this so I can find it again when I have time to actually process it.