My 98 cadillac sts which has 101,000 miles with 4t80e tranny began hesitating at around 55mph on the freeway... the car felt like it was going out of gas and the rpms reved near the red line then back down then back up..back and forth as i accelerated.. There had been a lght whining sound when i accelerated in park and in neutral coming fromm the front of the engine. Anyway after i exited the freeway i stopped at a light and when the light turned green the car reved like it was in neutral and wouldnt budge.. i cut the car off then back on and thr tranny was able to engage for 5 seconds literally beforec craping out again. i let the car sit for 12 hours or so and tried to get some movement out of it and nothing hapened...none of the gears worked not even reverse..no 1,2,3 or d,,nothing budged...even when i shifted the gears with the shifter there was no usual resistance as i was shifting the gears like you are suppose to feel when engageing gears.. the shifter was just sliding freely and not engageing at all. I ended up haveing the car towed and now am lost as to what has happened with the tranny.. I did feel like the car was driving like a v6 instead of a v8 on the streets as i would get on it or try to accelerate or make a pass..it didnt seem like it dropped in a lower gearto accelerate it was like it stayed in whatever gear it was in and slownly accelerated..even with brand new spark plugs! could the transmission slow down the car if the tranny is on its way out? i also have a busted motor mount and when going fast the engine shakes horribly..maybe this is what lead to the tranny being blown..I have checked the tranny fluid level and seems very full and normal color and smell..I checked the linkage short arm under the hood to see if it was mmoving when i shifted the gears and it moves as it should. Best advice i got was the clutched in the tranny are bad.. how would i know this ?what are the signs? any help would be nice thanks


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It seems pressure control soleniod failed , check for codes, have trans serviced - pan full of trash - she's done.At a 100k she should be just getting broken in.

 

ok thanks for the reply... the preessure selenoid you mentioned would the failing of that be similiar to bad clutches? Because i have been told that the clutches are bad..but wouldnt some of my gears work.atleast one?.. im betting your right about the pressure control thing , assuming that if that is bad then all the gears would stop working right? My mechanic said that i should be able to get some movement if it were a selenoid, he thinks it may drive ****ty but it should still budge a little..but the car wont move just revs.. could you fill me in a little more about the pressure control selenoid and how the failure could be made apparent or some signs and syptoms or is the behavior of my car that im explaining all signs and an example of failed control selenoid? Basically is the "bad clutches diagnosis" out the window or are they closely related..thanks for the help again

 

o yea there are no codes related to the tranny just a catylalic converter code, bad egr code, and camshaft sensor circuit low .

 

codes you describe could cause lack of power, but should cause delayed engagement.

 

so the codes may cause a delay in acceleration and shifting but wont stop the tranny from engageing completely right?.. my question was .. would bad clutches cause none of the gears to engage? and are you saying that the pressure control selenoid will stop all engagement of gears if it is bad? is there one thing in the tranny that will cause all of the gears in the tranny to not engage? the reason im asking because i may just rebuild that part of my tranny instead of swapping it for another used one, but on the other hand i can get a used tranny here in sacramento,ca for 700 and get it installed for 500..so at this point i may as well just replace the tranny? This is my first caddy and i am learning that repairs are frequent and expensive but i dont want to spend more doe than i have to..so any advice would be great..

 

Trans problems are kind of unusal.there are some soleniod concerns. trans should engage even if it wont shift 8000 rpm @ 80 mph

 

"Trans problems are kind of unusal.there are some soleniod concerns. trans should engage even if it wont shift 8000 rpm @ 80 mph ", what didu mean by ...wont shift 8000 rpm 80 mph?

 

Trans has more electrical type failures, sensors and soleniod,than mechanical,clutches and hard parts.If caught early you can do a repair. however with mileage on car they will want to overhaul. Electrical failure should leave you with second only(8k@80mph) and reverse.Pulling trans pan should tell the story.Your used trans deal maybe your best way to go, but make sure it is right trans for your car.STS has 3.73 final drive,make sure there is no trash in either pan,I suggest while side cover is off for inspection replace filter and pressure control soleniod

 

so is it possible to replace the pressure control selenoid without takeing the tranny apart, is it just a cover to take off or does it require the tranny to be taken out and opened up completely...thanks for the help.. I wanted to know if a 96-99 deville transmission from a vin 9 donor will work flawlessly for my 98 cadillac sts..the vin 9 has the 3.71 gear ratio if im following correctly...if i were to get a vin y it would work but throw off my computer huh? Also would you purchase a tranny for ebay..found one for 400 bucks 60k miles on it with 6 month warranty and 7 day exchange guarantee money back...i did the research on the company which is called camarga transmissions located in kansas, they seem legit and have a website and phone number and are even listed in the yellow pages..my final question is would you buy the tranny from them or any online source for that matter or do you know anyone that buys car parts online, I just dont want to get taken but then again i'd be saveing a lot of money!