Low milage Rodeo with trans problem

[Djb]

Is this the same hydrolic pressure that moves the transmission fluid through the lines and cooler? Only asking because there was plenty of pressure pumping fluid through the line to the cooler when I changed it out last weekend. I'll definitely give this test plug a try regardless. Thanks!

[Buster28]

Is this the same hydrolic pressure that moves the transmission fluid through the lines and cooler? Only asking because there was plenty of pressure pumping fluid through the line to the cooler when I changed it out last weekend. I'll definitely give this test plug a try regardless. Thanks!

This is the Line Pressure test port, it is connected to the output of the transmission Pressure Regulator Valve. You should see about 75psi. If the line pressure is good you know the pump is being rotated by the engine/Torque Converter shell. Additionally, as soon as there is line pressure the Overrun Clutch in the Overdrive section applies and the Torque Converter Turbine shaft is ready to provide torque to the 3 speed Transmission section at a 1:1 ratio.

[Djb]

OK, gotcha! Thank you sir! Glad I have one more thing to check before blindly towing it to the trans shop for who knows what.

[Buster28]

Found this chart, click on it to expand.

[Djb]

Fantastic!

[Djb]

Borrowed a trans pressure guage from a friend of a friend. I'll be testing it out this weekend. Keep you posted...

[Djb]

I was able to hook 2 different guages up to the trans output port. Used 2 different guages and ran 2 separate tests just to rule out faulty guage issues. They were both within 3psi of each other so I wrote down the averages of the results. Attached photo

[mudoilngears]

Looks like you’re within spec!

[Djb]

Agreed! So does this bring me back to potential torque converter issues or am I missing something else here? I've done all this work with the Rodeo parked in the street in front of my house. Level ground for the most part. I hate the idea of jacking this thing up enough to drop the trans/transfer on the side of the street. Plus, it's super towable right now. If I drop the trans and get in over my head with something and need to send it all to the shop, that's just gonna suck.
I'm happy to keep troubleshooting away, while praying the oncoming traffic doesn't take me out, but If it comes down to dropping the trans I think I'd rather just tow the thing to the shop. Soooo, any other ideas, guys? Thanks

[Buster28]

The test indicates there is adequate hydraulic pump pressure to operate the hydraulic components inside the transmission. The rear wheels will rotate with the transmission in gear on jack stands which indicates the transmission clutches are working. I think you can rule out the transfer case causing a mechanical bind because you can roll the truck around.

There is one last test to rule out the transmission. On the LH side of the transmission case by the shift linkage is a 7 pin (6 used) connector. If you disconnect the 7 pin connector it will disable the shift solenoids and set up a manual shift configuration.

With the 7 pin connector disconnected, when you place the selector is D, the Overrun clutch will release and the Overdrive clutch will apply and the Overdrive section will be forced into a 0.723 : 1 ratio (4th gear). If you have rear wheel torque in 4th gear there is a problem involving the Overrun clutch. The Overrun clutch is applied in Reverse, 1st, 2nd and 3rd gear.

[Djb]

Should this be tested on a jackstand with rear wheels off the ground? I imagine if there is torque in 4th gear it will be hard to tell with the vehicle sitting in the ground.

[Djb]

OK. I unplugged the 7 pin connector and the rodeo moved forward in 3rd and 2nd. In D I got a little torque, but only moved about an inch. In L it did not move at all. I went through all the gears a second time and no movement in any gear. There diffinitely felt like a slipping clutch issue. I'm understanding this to be the overrun clutch as the root of my problem?

[Buster28]

The 4L30e is actually a 3 speed transmission (plus Reverse) with an Overdrive section retrofitted to the front of the 3 speed transmission that provides a 4th gear capability. The Overdrive section contains two friction clutches (Overdrive and Overrun) , a mechanical clutch and a planetary gear set. When the vehicle is in 4th gear the Overdrive section is driving the transmission section at a 0.723 :1 ratio, when the vehicle is not in 4th gear (R123) the ratio is 1:1.

In 4th gear the Torque Converter (TC) turbine shaft rotates the Overdrive clutch which is applied, the Overrun clutch is released. In this clutch configuration the planetary gear set produces a 0.723 :1 ratio. The Overdrive clutch is only applied when the transmission section is in 3rd gear.

In R123 the (TC) turbine shaft rotates the Overrun clutch which is applied, the Overdrive clutch is released. In this clutch configuration the planetary gear set produces a 1 :1 ratio,

When the PCM commands 4th gear both shift solenoids are de-energized, this causes the Overrun Lockout Valve to operate causing the Overdrive clutch to apply and the Overrun clutch to release.
When you disconnected the 7 pin connector both shift solenoids are de-energized, placing the Overdrive section into the 4th gear configuration.

No torque to the rear wheels with Overdrive clutch driving the transmission (4th gear) and no torque to the rear wheels with Overrun clutch driving the transmission (R123) suggests the problem is not in the transmission or overdrive section, it seems unlikely that every friction clutch in the transmission is slipping. More likely the TC is not providing enough torque to get the vehicle moving. My guess is the TC needs replacing but I could be wrong.

[Djb]

I did get a small amount of "grab" in 2,3,D initially when the 7 pin connector was disconnected. It was after trying to accelerate and move for forward for a couple seconds that I lost that "grab" or traction and nothing wanted to move. Almost as if there was a slipping clutch issue but that was the last straw and so it finally failed. I'll start looking at the TC as my culprit now. To be continued....

[Djb]

Finally found someone to swap out my torque converter this weekend. Fingers crossed that was the only problem all along...

[Djb]

Brand new Heavy Duty torque converter installed today..... nothing works....still. Im told there are individual clutches for each gear (I’ve never worked on an auto trans orior to this) and they must be bad. So, trans is worthless at this point I think. Well, just spent $1300 for a throw away trans i think. Such a bummer.

[Buster28]

The 4L30e has 5 friction clutches, 2 mechanical clutches and a friction band:
OverRun clutch
Reverse clutch
2nd clutch
3rd clutch
4th (OverDrive) clutch
Roller mechanical clutch
Sprag mechanical clutch
Reaction Drum Brake Band

In Reverse, the OverRun clutch, the Roller clutch and the Sprag clutch are used
In L (Manual 1st) the OverRun clutch, the Roller clutch, the 3rd clutch and Brake Band are used
In D1 (Auto 1st) the OverRun clutch, the Roller clutch, the Sprag clutch and Brake Band are used
In D2 (Auto 2nd) the OverRun clutch, the Roller clutch, the 2nd clutch and Brake Band are used
In D3 (Auto 3rd) the OverRun clutch, the Roller clutch, the 2nd clutch and 3d clutch are used
In Winter Mode the OverRun clutch, the Roller clutch, the 2nd clutch and 3d clutch are used.
In D4 (Auto 4th) the 4th (OverDrive) clutch, the 2nd clutch and 3d clutch are used.

Click on chart to expand.

[Djb]

Thanks Buster28. My fault i didnt understand the inner workings of the auto trans. Never worked on one before. I thought the clutches were in the torque converter only. I figured that was were the “wearable” clutch material was coming from when i dropped the pan. Since there wasn’t any chucks if metal, just fine particles i thought the main inner workings of the trans was OK. Lesson learned. Knowing now that very burnt smelling, dirty trans fluid with a lot of fine particles on the pan magnet more than likely means trans is toast and prob not worth messing with. Hopefully someone else is helped by following this thread. Im about $1800 into the vehicle at this point, Rodeo, parts, and labor. Looking to find a rebuilt trans for around $2200 - $2500 now hopefully and swap it myself

[Buster28]

If you go for a replacement transmission be aware the electrical connectors on 90-99 are not the same as 00-03 and that a 2WD transmission cannot interchange with a 4WD version. Additionally, you cannot use a Trooper or Axiom transmission, you need one from a 00-02 Rodeo/Passport or 00 Amigo or 01-03 Rodeo Sport.

[Djb]

Thank you! Good to know! At this point Im going with a rebuilt one. Cant afford to spend any more on “unknowns” even it was pulled from a low mileage vehicle, there is no guarantee. Id rather pay a little more up front and have that warranty. Having the trans out yesterday, i was able to look over the engine real good and only found minor oil leaks around valve covers. Rear main was all dry. I still haven’t found anything wrong with this little rig other than the trans. It appears to be gently used and well cared for (minus the neglect to the trans). It even has all the records of oil change services. I assume the “no check stick” on the trans played a key part in its neglect...

[Djb]

If I find another 4L30e trans out of another vehicle( ex.. bmw)... would it be a direct replacement fit? Or does it have to be out of one of the vehicles you specifically mentioned?
I priced a rebuilt trans and its $4k. Sooo, looking for a used trans now. Man, this while project has not gone well at all. Being on an island with limited resources doesnt help. If I cant find used, my only 2 options are ditching an otherwise good rig, or rebuilding the trans myself. Neither is a good option in my opinion, but if you folks have any ideas I’d love to hear em! Thanks again

[Buster28]

You can only use a 4WD 00-02 Rodeo/Honda Passport, 00 Amigo and 01-03 Rodeo Sport 4L30e for a plug and play replacement. You can recognize a 4WD version at the junkyard by the tail shaft, a 2WD tail shaft is threaded so the yoke can be attached and the 4WD is not threaded. Additionally, a 00-03 4L30e has 4 Pin Overdrive Section connector and a 7 Pin (6 used) main case connector. The 90-99 has a 5 Pin Overdrive Section connector and a 4 Pin Main case.

This is what you have to deal with if you plan to rebuild your own 4L30e. This is a BMW version but very similar to an Isuzu 4L30e
https://www.youtube.com/watch?v=p-5p6mJyfds

[Djb]

I found a trans but unclear if will work... Anyone know how to decifer the trans tags? Here's my existing bad trans info:

GM FT
P.N. 96018555
S.N. 5914669



Potential new trans info:

R DOT
96041649
6103060
(no notation as to which is serial or part#)

This trans is brand new, but not sure how to cross reference the numbers. I have several pics of it and it looks like my trans on the outside, but I hate to commit to buying and shipping it to HI if it's wrong. Buster28, any specifics I should look for to verify it? It doesn't come with TC. Or maybe you have some knowledge on the number tagging system and how to cross reference?

[Buster28]

ID TAG# 96018555 is Isuzu Part# 8-96018-555-0 and is applicable to Rodeo/Amigo/Rodeo Sport/Passport 2000/2001/2002 4WD
This tag is mounted to the LH side of the transmission case by the shift linkage, your tag should look like this one.

ID TAG# 96041649 is used Opal vehicles. It is likely identical to 96018555 but I don't know for sure.

[Djb]

Yes it does. However the tag on the other trans is supposed to be for a 2000 rodeo 4x4 3.2 as well and the tag is different. Is it compatible?