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Chevrolet Blazer GMC Jimmy Transmission Problems



  • 20blazer0020blazer00 Posts: 28
    Ok I took it to the dealer today, and they decided to be nice and fix it on them. After waiting for 5 hours, the manager told me, that It was a mess I had. Turns out, that they found out, atfer they relaced the switch, that actually I have a bad electrical problem in the differential.That they would be keeping it over night, and Ill get it back tomorrow.
    As we were talking I just asked, what if they just unplug the 4wd option and just let it be a 2wd. He being honest, said that that was a last ditch option, but it was an option.I mean I wouldnt ever us the 4wd anyway. Because I dont live anywhere I would have the chance to use it, and by
    the way it has street tires on it anyway.
  • repairdogrepairdog Posts: 948
    Think you meant in the transfer case or possibly the front diff. There is an encoder motor in the transfer that shifts the case and these can rust or fail. Then vac swirches and on the front diff an actuator pulls a cable that couples and uncouples the pass side axle. All controlled by the TCCM or 4wd computer in the cab pass side kick panel.

    If its in 2Hi then you could pull the 2 fuses for the 4wd and that should keep you in 2wd forever.
  • 20blazer0020blazer00 Posts: 28
    Well, the dealership has had the blazer for 4 days now.
    I called them yesterday, to check on it, because the manager told me that it should be ready then. Its not!!!
    Then he dejectivly told me quote" We have no idea, whats causeing this problem, and probally wont know". That doesnt sound good at all. So, what to do? Would it hurt it to "unplg" the 4wd on it and let it stay in 2wd? As I need this truck, for daily trans. If that wont hurt it, then, I guess thats my only option. Untill I can take it some where else to give another shop a shot. Anyone have any ideas?
  • repairdogrepairdog Posts: 948
    You have a 2000 LS model so assume 3 buttons on teh dash and NO auto function button - if so this is the np233 case part time so that dealer is not very good- this is the easy case. If a 4 button autotrac case np236 its more involved.

    I can't recall if you ever stated the actual problem that started all this. Its either the TCCM (4wd computer - pull the battery cable for 30 min and reboot it)and these also have had moisture in the connector and they do fail, the encoder motor on the transfer case that steps in to engage the front diveshaft and also 4lo if selected, the 3 port vac switch, a bad vac line, the sensor on the transfer case, the sensor on the fornt coupler, the front coupler, the front actuator, or the switch. Also 2 fuses to check.
  • 20blazer0020blazer00 Posts: 28
    Ok I got it back!!!!
    The dealer said two things had shortend out, one being the encoder, and another thing(cant remember what it was). But that they couldnt figure out what or where made them short out,so, I got them to pull the fuses for the 4x4 part so it will only run in 2wd.( just hope that by pulling the fuses, that it doesnt screw up the truck).
    Thank you for your help with this.
  • bmorabmora Posts: 1
    Note: New Fluid/Filter changed about 2 weeks ago. Computer has been reset since then. 4X4

    Went for a drive yesterday. Got on the interstate. Very soon after reaching the cruising speed of 60-65. A very unhealthy sounding and loud noise began coming from in or around the transmission. The sound is a little hard to describe but I'll give it a shot. It was kind of a grinding metal gear noise. Kind of what I would think it would sound like if you put a vehicle into park at 60 mph. This "Noise" did not effect the speed of the vehicle or make it bog down. When it started I just took my foot off of the gas and coasted over to the emergency lane while lightly applying the brakes. Once I got down to about 10 miles an hour the sound stopped completely. I got out and saw some tranny fluid coming out from near the Torque converter Dust Cover. It dripped for maybe 30 seconds then stopped (vehicle still running). Got back in and drove 2 exits to see if It would do it again and it did. So getting off at this exit once I came almost to a stop the sound stopped. Continued to head toward my house and was going about 50-55 up a medium incline and the sound started again. So I again stopped and the Fluid did the same thing. Leaked for under a minute then stopped. I made it home the rest of the 8 miles with no problem. Only other time I noticed Fluid leaking was. Once I drove a little to far down the driveway and went over the edge of it so i put it in reverse and had to give it a lot of gas to come back up over the edge. Keep in mind that this edge is only about maybe 1 inch high and its a slight downgrade. Once I got out I noticed Fluid leaking.

    I am fairly experienced with the 4L60-E. My S-10 has the same tranny in which I rebuilt myself about 7 months/15,000 ago. Reverse went out then shortly after it would not shift on its own.

    Any help will be greatly appreciated.
  • repairdogrepairdog Posts: 948
    I am not a trans expert but possible front pump seal leak - is the trans overheating (radiator good and side cooling section). Vent os on top so maybe coming out there.
  • gmcrichgmcrich Posts: 6
    I have a Jimmy W/140K miles and it started acting like it was slipping/jerking ONLY when I was in reverse and heavy on the throttle. I changed the filter and made things worse. Now it only seems to have 2nd gear (40mph)and still jerks when I am in reverse. Prior to changing the filter I didn't have any issues with forward gears. I had a hard time squeezing the pan in and out of the exhaust. Could I have damaged or unhooked something by rubbing the pan across it? If I can regain my forward gears I could get by for awhile. Any ideas on what could cause these problems? Any help?
  • gmcrichgmcrich Posts: 6
    I have a Jimmy W/140K miles and it started acting like it was slipping/jerking ONLY when I was in reverse and heavy on the throttle. I changed the filter and made things worse. Now it only seems to have 2nd gear (40mph)and still jerks when I am in reverse. Prior to changing the filter I didn't have any issues with forward gears. I had a hard time squeezing the pan in and out of the exhaust. Could I have damaged or unhooked something by rubbing the pan across it? If I can regain my forward gears I could get by for awhile. Any ideas on what could cause these problems? Any help?
  • repairdogrepairdog Posts: 948
    You probably hit the wiing running thru beneath the valve body and may have nicked it or disconnected a solenoid.
  • gmcrichgmcrich Posts: 6
    Is there a way of checking this through the computer codes? Does Autozone or Advanced Auto have a diagnostic machine for transmissions? How many solenoids are there and what do they look like? I just need to regain all of my forward gears and hope reverse lasts for awhile.
  • repairdogrepairdog Posts: 948
    Auto stores don't scan transmissions. Each gear shift has a solenoid. Most trans shops will hook up their scanner and give an estimate for free or low cost to get the business.
  • r8r_n8shnr8r_n8shn Posts: 1
    Hi all...I am a complete idiot when it comes to cars so PLEASE be easy on me. wife has a 2000 blazer. The tranny is shifting hard from 1st to second. It only does it when it is hot outside. My first thought was that the tranny is overheating. Is this possible and how would I go about fixing it. We had it in the dealership last year and the put in a new part that I can't remember what it I said...I am a car idiot. Any help would be greatly appreciated. Also she just told me that the light on her push button 4x4 switch also goes out and seems to do so at about the same time the tranny acts up. :mad:
  • repairdogrepairdog Posts: 948
    The part may have been the TCC in the trans as it effects the hard shift. Usually a new filter helps as any crap in the trans gets in the valve body and the computer adjusts the pressure to compensate. But if the 4wd is acting up the PCM/omputer adjusts shifts and pressures in 4wd so that would be a reason - see if the dash switch is fully connected or plugged in, and as you said you are not a car person so take it to the dealer to determine which other of the many sensors etc for 4wd is bad.
  • shantel1shantel1 Posts: 3
    Can someone tell me what code P1870 is for a 99 Jimmy? :confuse:
  • lauchonlauchon Posts: 1

    Hi, my blazer almost got burned twice, first time in summer in a long trip, oil came out of the transfer case, leak over the exhaust system and burned all the electrical wires. The mechanical said that a malfunction of a seal between the automatic transmission case and the transfer case, allow the oil from the transmission filled up the transfer case. The seal was replace.
    Two days ago, again oil came out from the automatic transmission and almost burn the car again, but I saw the smoke come out of my car and stop the engine on time. Now the mechanical can't figure out what happened, they said that a a little device call "Quick Down" present a failure that's making lose oil again. truly I don't believe them anymore...

    Any ideas (besides selling my car)?

    Thanks, just for reading my rusty english. :sick:
  • repairdogrepairdog Posts: 948
    That seal could have been bad and the transfer case will then fill up and overflow out the top at the 3 port vac switch for the 4wd. Transmission has a vent on top also so check the fluid level and make sure its not over full (when hot at idle in park check dipstick. Then is the cooling system OK as the trans fluid goes thru the pass side of teh radiator and if it overheats will expand - are you towing something in D which is really overdrive?
  • ddealddeal Posts: 1
    I have recently noticed a exciting new noise coming from down below. I believe it is coming from the right front and my wife said she could feel it in the floor of the passenger's side. Let me give you a history. In April it had the front end bushings and CV axles replaced. I took it to a reputable 4x4 shop, so I trust the work. Now, three months later this. If I had to describe it, it is kinda like someone is taking a hammer to the floor. Not constant. It's not too loud and doesn't seem to be linked to the tranny. 4WD works with no change in noise. Anyone's help would be greatly appreciated.
  • ldtdldtd Posts: 4
    this sounds like something I'm having issues with and could use some advice/help. My 4wd 98 Jimmy (just over 200k mi)has had 4 transmissions in it since July 2006 - I have a 2yr warrent. on it. Needless to say I'm a bit miffed at the shop for all this hassle. I never tow anything, but they seemed to the the tranny was overheating so with the last transmission they added a tranny cooler to it. Well that was this spring.
    This past week I noticed that when I was re-accelerating between 40 and 50mph, and typically when going uphill, the Jimmy seemed to hesitate almost like a couple before it settled down. So I took it to a shop I trust - they put it on a reader and got nothing, we drove it on the reader - it acted up just like always - but no reading. So he sent me to another transmission shop. They found the tranny stick 1 1/4 low, fill it, and then test drove it with me. No hesitation on this short drive. When we get back to the shop they check the dipstick again - and it's low. So he fills it again and schedules me for a better inspection the next day. I took it in the next day - they tell me I have a leak in the transfer case and that I should take it back to the tranny shop where I have a warranty. So when I take it back to the original transmission shop the mechanic takes me out while its up on the lift and shows me the gasket between the transfer case and the tranny - there's not a trace of oil..or anywhere else on the transmission. The only transmission oil is under the plug on the back of the transmission case where he tells me the previous shop let the extra transmission fluid out of the transfer case. He then tells me it's a seal on the inside of the transfer case that's allowing the transmission fluid to fillthe transfer case and that's not covered under a transmission warranty. He'd fix it for $175 - the first transmission shop said they'd fix it for $275. So finally I take it to Tuffys - and tell them the whole bloody story, they put it up on the rack, check the radiator fluid for foreign fluid, look at the underside, check the transmission fluid on the stick and in the transfer case - and find NOTHING WRONG! However, since the fluid had recently been topped off they suggested I drive it for 50 miles or so and bring it back for a 2nd look-see. I've been told by 2 shops that the fluid in the transfer case can come out the vent if it overfills and shoot onto the exhaust and start a fire. So now I'm confused, and frustrated and do not know where to turn.
    Does anyone have a similar story, or suggestions? PLEASE? I'm a girl who's just now learning about her car, so any information about this would be very very helpful. thnx
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