| Author | Message | |||
     No_rice |
well i decided it was time to see if anyone on here knew the answer. i have a 1994 s-10 4x4 blazer with the 4L60 tranny in it. i lost second and overdrive out of it. it did drive fine, parked it. went in the house for maybe an hour and when i came back out and tried to leave it didnt work. seemed like it was slipping when i had it in overdrive taking off. i thought great it shelled out on me. but the more i pay attention i think it might just be a shift solenoid. i think one of them runs 2nd and overdrive? if that is right great. the problem is that no one i know is sure which one is the 2, 4 solenoid.... so if anyone happens to know the answer that would be much appreciated | |||
| Saintly |
Cant be a solenoid if you have no 2nd & OD. 4l60-e uses 2 solenoids for 4 gears, combo's are: Both on = 1st, "A" off & "B" on = 2nd , both off = 3rd, "A" on & "B" off = 4th so either solenoid "A" dies and you get 2nd & 3rd only OR solenoid "B" dies and you get 3rd & 4th only I would guess that you either broke or burned out the 2-4 band. That is real common on those units, especially in the 92 - 95 years (bad epc / line rise issues) The only other posibility is that you stipped the splines or sheared off the splined section of the sun gear shell, but when that happens you lose 2nd, 4th, & reverse. Since you didn't mention losing reverse(and that would be a very easy thing to notice), I would have to assume your band is toast. (tranny overhaul: my proffession for 17 yrs) | |||
| No_rice |
 that is really not what i was hoping to hear. but i do appreciate the response. yes i forgot to mention i still have reverse also. would that also explain the fact that if i put it in overdrive and try to leave a stop it starts out in high gear (third)? it will not shift. if i start out in first manually with the shifter it takes off fine, shift into second and no change, shift into third and it shifts, then shift into fourth and nothing. only way it uses first is if i manually put it there. otherwise it only uses third no matter the speed. reverse works great. | |||
| Saintly |
Yeah sort of, Its starting in 3rd because it is in default mode. It must have set a gear ratio error code when it was supposed to be in 2nd or 4th but wasnt. The ecm constantly moniters the commanded gear ratios with the actual by watching engine rpm and road speed. (rpm X commanded gear ratio = mph) if this computation yeilds results which are out of the ecm's acceptable parameters, it will set a gear ratio error and shut down the power to the tranny. Without power to the tranny, ALL solenoids go off, and as I mentioned in the 1st post: "both off = 3rd gear" So when you clear the code out of the ecm's memory the tranny will probably start in 1st, then remain in 1st thru the range where 2nd should be and then make a 1-3 shift at approximately the speed where a 2-3 should have occured. Then it will remain in 3rd and never upshift into 4th. Keep in mind that it will only do this once or twice, because it will once again set the G.R.E. code and power down leaving you with 3rd only again. You can only obtain 1st by pulling it into manual low with the shifter like you said. Wish I had better news for you, but the reality is that your tranny has to come out & be re-built or repaired. | |||
| No_rice |
well looks like i have another big project. have you ever heard of it blowing some fuses because of it also? at the same time the tranny acted up, i lost the fuse that runs the cruise control and a few other things are on that circuit that i cant remember. tried a bigger fuse and it pops just as soon as i hit the key . but it happened at the same time because i was using it right before i parked my blazer and came back out and everything quit on me. got me, im sure you know way more about tranny's then me and im not doubting you are right. i am just surprised that there were no signs of it acting up. just bam and done. this wont be the first transmission change for me, just the first time it went so fast that i didnt even see it coming. and i do really appreciate the help, honestly. i am currently unemployed as of recently, so taking it in and having someone trouble shoot it and then them pull it out and ect really isnt an option. way to much $ at the moment. | |||
| Saintly |
Ive never heard of that, but that doesn't mean it cant be related. The pcm powers up the tranny directly thru a pink wire at the main connector (round one on pass side of tranny). If a common fuse were to power up the ecm & the cruise controll, then I would suspect that none of the other ecm functions would operate (ie. fuel injection) and your engine would not run. Let me ask you this, does your "check engine" or "service engine soon" lamp stay on? does it come on during the bulb check when the key is first turned on? And did it ever shift from 1st to 3rd or was it in 3rd already when you first realized there was a problem? When I first read you post, and you said you lost 2nd and OD, I assumed you meant while you were in "OD" or "D" range. Also does the tranny seem to engage much firmer than usual when you first put it into Rev or Drive from park? If so, there may be an electrical problem that could be causing this. | |||
| No_rice |
well when it happened it had been working fine, parked it and shut it off. got back in about an hour later, put it in drive and it seemed like it was slipping when i tried to takoff. the change occured while it was parked. driving-fine, park and shut off and leave sit for hour, then get in start up and doesnt work. realised that it was seeming like it was slipping because even though i started it and put it in overdrive right away, the transmission just went into third instead and never even tried to use first. if it is in D or OD it will be in D no matter wether u r taking off or whatever. if u start out by shifting into first it will take off as though nothing is wrong, but shift to second and nothing. shift to drive and it finally shifts (a little hard, but assuming its because of the drastic gear ratio change from skipping a step). then shift into overdrive and no change. another odd thing is that if your are driving it at speed (say 55) and u let up on the gas the engine slows down but there is no compression braking. the blazer just coasts like its in nuetral. if you want to keep going and u give it gas it has to speed the motor back up to about where it was before and then u can feel it start to pull again as the tranny starts doing something. like the motor free wheels until it catches back up with the transmission. i am also fairley sure that all my lights (bulb check)light up with the key turned on but i know the check engine light ect. does not stay lite up while driving. as for shifting from park it really doesnt seem any harder that usual. so say an electrical problem was the cause and neither solenoid was getting power or shorted or someting. would it be possiable for it to go into like a default mode or something where each solenoid is stuck in some combination leaving me 1st 3rd and reverse? i mean i am fairly mechanically inclined, but not really all that well on the overdrive trannys had more dealings with 350 400 th's. but this just has me stumped. i am was leaning towards something electrical in the tranny because of the INSTANT breakdown. got me its confusing me. things i would nomally think are not working out to be the problem | |||
| Saintly |
Ok, you may have an external electrical problem which is not in the tranny. The fact that it NEVER had first unless you pulled the shifter into low could mean that you lost power to the tranny. The odd sensation of no engine braking(compression braking as you call it) is normal for this transmission when driven in "OD" or "D" since it used a "coast clutch" for engine braking. The coast clutch is commanded on in manual "2" range or by the ecm(via a 3-2 downshift pulse width modulator). If your tranny has lost power all these things could occur. Here's what you need to do next, 1. if the engine has been run, wait 1 hr for it to cool off. 2. go under the passengers side of the truck, on the passengers side of the tranny you will see a heat shield held on by two 13mm bolts. remove them and the shield. (the shield keeps catalytic converter heat away from the tranny - hence step one.) 3. behind the shield and plugging in vertically onto the case you will see a round grey electrical connector. There are two "squeeze tabs" on the connector. One faces the front of the truck and one faces toward the rear. 4. simutaneously squeeze the two tabs and pull the connector up and off of the tranny. 5. there will be approx 11 or 12 wires in this connector. with a good light aimed at the connector you should be able to see that the pins/wires are labeled alphabetically starting with "a". 6. you are looking for pin "e" which has a pink wire connected to it. 7. when you find this pin, get a test light. clamp the alligator clip of your test light to the tranny case or any other good ground. Turn your key on (dont start the engine) just turn the key on. 8. probe pin "e" with the test light - it should light up. If the light does light up then your tranny has power and probably burned/broke the band. If it does not light up, you've got an external electrical problem. Also if you find that there is no power at that pink wire, you could splice a length of 16 gauge wire onto the pink wire and power it up at the battery(use a 15 amp fuse inline as a precaution) Then plug in the tranny and take it for a ride. If the tranny works when powered up then you could simply find a permanent fused power source for the tranny(make sure your new source is only hot with the key on or you'll drain your battery). In the meantime I'll try to get a picture of that connector and pin "e" location posted here for you. | |||
| Saintly |
looks like this:
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| No_rice |
u have no idea how much i am appreciating your help. i will have to try it out tomorrow and see what happens, since my other car is in the garage with the heater core torn out  ya great luck i have going. such is life. but i will try it out tomorrow and see what i find. i know the connector u are talking about though so it shouldnt be to hard to find out. THANKS again | |||
| No_rice |
THANK GOD! well i couldnt find any power going to it so i hot wired it and it seems to be working ok. drove it for awhile and its shifting good. i still have to redo it right once everything cools off again. but that wont be a big deal. i am so happy! i sincerely thank you so very much for all your help, you have no idea how much it is appreciated. | |||
| Fullpower |
rice you havedamn sure got lucky finding such a resource as saintly here. glad your trans is ok. imagine your average transmission shop would have bent you over pretty well with the symptoms you reported. all hail badweb. | |||
| No_rice |
yes i got VERY LUCKY that saintly was willing to take time out of his day to try and help me. just one more reason i love this place! ya most places i talked to seemed just as confused as me. only thing that sucks is it is kinda hard to buy somebody thats half way across the country a beer or 12  | |||
| Kinger |
Very interesting thread. What a great help Saintly was. I was reading very closely as my 95 S10 is going to roll 170,000 on the way home from work tonight. The truck still runs pretty good, but the tranny feels like it is slipping or not grabbing the best sometimes. I need to double check, I may be due for a fluid change. Thanks for the good read! | |||
| Saintly |
no_rice, Man that's great to hear! For once I'm glad that my initial impression was wrong. I'm glad I could give back to someone at this site, as I've certainly received a lot from here over the past few months, from some of the members. Hell, Dean(fullpower) is one of the guys most directly responsible for me getting my firebolt back up & running after being down for 2 months. His posting of pictures and part numbers made my chain conversion become a reality after I became quite distraught about breaking 2 drivebelts & getting stranded 3 times this past spring. If I've not said it before, THANKS DEAN! Anyway, happy trails riceman. | |||
| Johnnylunchbox |
Saintly - you impressed me more than enough with your home-engineered XB chain conversion, but now you have achieved stephen hawking status in my eyes. | |||
| Gentleman_jon |
Fritz, You're a regular Saint!  | |||
| No_rice |
well it seems to be holding together fine, and obviously getting WAY better gas mileage!  thanks again. later |
