Who can work on a GM 4L30E transmission with me?

[Irving]

Hello sirs,

My Amigo has the GM 4L30E auto transmission in it. I'm having some occasional symptoms that tell me that the Range Mode Sensor is dirty and needs cleaned. Apparently it is only an approximately 1 hour job, but I'm afraid to do it myself. I don't want to pay a shop to do it though. Anyone here have any experience with this transmission and be willing to walk me through this?

I could bring your beer or some cash. This is our ONLY vehicle, and I drive A LOT though, so you have to promise me that we won't screw anything up. I literally can not afford any down time.

If you know how to change the diff oil and drop the tranny pan and change that oil, I'd be down for that as well. I've worked on cars before, but never really owned an automatic transmission, or a 4WD before.

Please let me know. I'm available Wednesdays and Fridays between 10 am and 3:30pm and Saturdays until about 4 pm.

[Irving]

Bump for evening crew.

[tmleadr03]

What year?

What symptoms?

Are you basicly talking about dropping the valve body and trying to clean it up and put it back in?

[streetglideok]

range mode sensor, sounds like the sensor on the outside of the transmission where the shift linkage mounts. If thats it, not much to it, and Id just replace the thing, why mess with attempting to clean it. What kind of symptons are you having, and what led you to this diagnosis? Trannys were never my thing, I do more electrican and drivability stuff, but there is a few of us on here that may be able to help out with more info.

Hey tmleadr03, fancy seeing you here!lol

[Irving]

1999 Isuzu Amigo, 4wd.

Streetglideok is correct about the location of the sensor. I read the repair manual again, and the procedure seems a little easier than I thought the first time around.

I think it is like $85 to replace it, and everyone seems to have great results with just cleaning it out.

I was lead to this diagnosis by checking out an Isuzu forum and reading a ton of threads about the specific symptoms and the issue. Basically, when the transmission is cold, the shift from 2nd to 3rd, and 3rd to 2nd, is very rough. The accompanying symptom that lets me know I'm on the right track is that if I bring the car to a stop, and shift down through 3, 2, and L, the light on the dash does not correspond correctly with what gear I've actually shifted into.

Thank you for checking this thread.

[streetglideok]

The shift quality problem can be caused by an internal trans problem, fluid deterioration, as well as the shift position sensor as its sometimes called. With the complaint about the indicator, you may be on the right page with the sensor. I would check your records when the fluid was last changed, just an fyi. I havent paid much attention to the GMs lately, but there should be the connector, or a couple of connectors, some bolts that secure the sensor to the side of the transmission, and then a nut that locks the shift linkage to the shaft that passes thru the sensor. Shaft has flat sides on it as I recall. If I see a GM in friday, Ill try and pay attention to its design to verify. Its usually better to just replace that sensor, despite a little cost. Chances are, if its contaminated, cleaning it wont last, and you'll be back to the same problem or it may get worse. Plastic things dont do well with age, so from a professional, with no stake in this, make it easier on yourself, and try to swing a replacement part, but if moneys tight, no shame in trying to save yourself money to feed the family.

[Irving]

Thanks for the input, I appreciate that you'll try and look into that for me.

As far as the symptoms, I've never really had an auto before and don't know squat about them. However, I've spent about the last two weeks reading thread after thread about this issue, and my symptoms seem to line up exactly with other's experience. I'll have to look into how much the part actually costs. Is there a seal that I should be replacing to help keep the dirt out of there?

On a side note, I replaced 5 of the 6 spark plugs tonight and I'm glad I did. Already feels smoother, and I didn't think it felt rough in the first place. The last plug, is literally impossible to change with the tools I have available to me. Good thing I didn't start with that one, I would have just given up.

[tmleadr03]

I am with streetglideok on this one. If it is that sensor on the outside of the transmission you are probably better off replacing it. The part that is getting dirty and causing it to bind up there really isnt much of a seal on any (not this model but other vehicles that use the same style sensor) part that gets dirty. It is just a rotating gear and with the dirt it does not switch over.


It is buggering up in one of two places either at the connector to the left where the wiring comes in or the circle where the "insert" is. Make sure you take a look at the connector and do not have any burnt or bent pins.
http://i3.photobucket.com/albums/y69/tmleadr03/switch.jpg

Before you do this pull the trans dipstick and smell and look. Color should be red and a bit clear and smell should not be burnt.

[Irving]

I plan to change all the fluids I can. The transfer case and diffs seem easy enough. However, from what I understand, the transmission on this vehicle is a pain because it bathes you in fluid. I might just pay someone to drop the pan and change the fluid (no flush!) for me.

Thank you guys SO much for your help by the way.

If anyone is wondering why I'm asking questions on a gun forum, and not the Isuzu specific forum I mentioned earlier, it is because I've had trouble registering for said site. Once I finally tricked the confirmation email out of the site, it came with some message about how donating with Paypal was MANDATORY. F-that. I'll just come here and ask actual mechanics.

[tmleadr03]

I plan to change all the fluids I can. The transfer case and diffs seem easy enough. However, from what I understand, the transmission on this vehicle is a pain because it bathes you in fluid. I might just pay someone to drop the pan and change the fluid (no flush!) for me.

Thank you guys SO much for your help by the way.

If anyone is wondering why I'm asking questions on a gun forum, and not the Isuzu specific forum I mentioned earlier, it is because I've had trouble registering for said site. Once I finally tricked the confirmation email out of the site, it came with some message about how donating with Paypal was MANDATORY. F-that. I'll just come here and ask actual mechanics.

That would be all of them.

[Irving]

Haha, good to know.

[streetglideok]

Honestly, I cringe over those enthusiast auto sites. I could go on about the little bit of good info, and tons of bad info learned on there. You might find out about some common ailments from those sites, but guessing at the cause because it happens alot on a car is just another way for Murphys law to bite you. Ive seen some glorified parts installers use this approach with identifix. Sometimes you get lucky, sometimes you dont. Better off asking for automotive help on here, lol.

[GunsRBadMMMMKay]

If it has transmission cooler lines, you could try the poor mans method of flushing the trans. Get a couple lengths of hose, a couple buckets, and your oil. And a helper to turn the key on/off would probably help. Figure out which line is the out to cooler and which returns to trans. disconnect them, attach the lengths of hose, put the out to cooler line into an empty bucket and the in to trans into the other bucket and add the new oil. Run the engine and it should pull the new oil in while it spits the old oil out. Make sure you turn off the engine when the oil starts coming out clean or you run out of new oil in the bucket, and make sure you check the levels when your done. This is in theory but it worked on my car.

[THe Yetti]

To change the trans fluid: Get some cardboard or plywood and a large drain pan. Get a jack. Put the jack under the trans. pan and extend it until it touches the pan with just a bit of pressure to hold it. Then loosen all the bolts, remove all the bolts except those across the front of the pan, just leave them loose a few turns. Put the drain pan under the back of the trans. pan. Lower the jack and the fluid will dump into the drain pan. Some will splash out, which is what the cardboard is for. Then remove the front bolts. Clean the pan and change the filter. Put on a new gasket, no sealant. Reinstall the pan, torque the bolts evenly and not very tight. Then refill with fresh fluid.

[Irving]

Thanks for the step by step guys!