My 95 Blazer has 240k on it. I've had rpm surging while cruising (1-200 rpm)
Sometimes skips 4th straight to OD. TC lockup with brake on or sometimes slips. Delayed /rough 1-2 shift sometimes. I was thinking of replacing the TC, TCC valve, all solenoids, and filter. But not knowing the service history on this trans (bought at 170k), would it be worth it to do a complete rebuild? master kit, solenoid kit, dvd, and TC, should be less than $500. I was a locksmith so I'm used to dealing with snap rings, springs, and other small parts. And with instructions I think I could do it in a weekend. Input?

 

Have you done any fluid/filter changes for the trans since you've had it? If so, when?

 

Are you seeing any codes?
If its shifing rough after it warms up the tranny temp could be getting high.
Should be a code for that.
If your TC slips it may be the clutch wearing out or the solenoid. Should be a code for it slipping as well. I'm not sure if the 95 had the PWM TCC or not but that is a known issue. I had to do the Sonnax fix in mine at about 85k. Had to do a rebuild at 144k when the rotor guide lost a couple fingers in the pump.

I rebuilt the 4l60e on my 99, all new seals, bushings, TC..etc for about $450. However I had to spend a few hundred on special tools as well. You'll need a
special compressor, bushing driver/removers etc.. or pay a tranny shop to replace the bushings.

 

I have not changed anything on this trans since I bought the truck. It was a one owner car, and everything else seems well maintained. I was worried about doing a flush on such a high mileage trans without knowing it's history. There is a ses that comes and goes (on & off a few times in a short trip). Pain to find anyone to read my codes b/c obd "1.5". Usually only shifts rough between 1/2 and only when I first start driving. Lately TC locks when I start the truck, put in gear, have to stomp the brakes to keep it still. Once it's hot it seems to do it less. doesn't want to downshift at hwy speed. A friend of mine owns a trans shop in town. Maybe I'll pay him a lil to come oversee assembly or take it to his shop after hours and do it. With the miles on it, I'd rather pay more and do it ALL. peace of mind is worth it

 

Stupid, but have you verified the fluid level is spot on when warm idling in neutral? Slightly low fluid level can cause everything you listed, especially on a cold tranny.

Your first step should be to do a pressure test as per specifications listed in the front of ATSG. If you don't have the ATSG manual yet, get one before you even think about rebuilding yourself. They're almost always available on amazon used&new.

At that high a mileage, you should look for a lower mileage junkyard unit on the cheap so you can use the vehicle while you dismantle/rebuild and not be pressured for time. I can pick up tested/working v6 4l60e's whenever I want for $125/ea at my u-pull-it, the s10 drivetrain is very common in junkyards. You can definitely SWAP tranny's over a weekend.

During a first time overhaul you ALWAYS need at least a few tools you don't have or parts that aren't in a "master rebuild kit," I really don't see you getting it rebuilt over a weekend regardless of aptitude. It simply won't happen if you don't do rebuilds for a living, and shops are typically busy and/or closed if you get stuck on something.

 

Sound like at the least you have a bad solenoid or a short. I had a Camero that wouldn't let go of lock up until you about stopped. I replaced the solenoid and it was fine again. However it never caused any problems starting out. I'd hate to think its never letting go.

Let us know what your tranny guy says, maybe you'll be lucky with a wire issue or solenoid.

 

Hard to get a good read on fluid level, filter probably clogged. The thing is, I wanna keep this truck, till gasoline is outlawed or god forbid I total it. Pretty set on doin' a rebuild. My buddy will cut me a deal if I bring it to his shop & help him do it. Plus he has all tools, right converter & filter. I'll see what he'll charge for that. I have an s10 I can drive if it takes 3 or 4 days. getting a decent refund, so for once I have money lol

 

Fluid level is like the #1 important thing. I can assure you you'll notice problems if you drive around with low tranny fluid.
I know a guy that bought a $3000 reman 4l80e a few months ago and he told me he never even checked the fluid level. The reman had the exact same problems a week later, fluid was low.

 

Of course it is. But it's hard to get the same reading twice on the stick, so I check 3 or 4 times and kinda average. I've heard that a clogged filter can push fluid up the tube tho.

 

got in this morning to go to work, shifted into reverse. Engaged very hard (idling high too) disconnect & check 1 at a time: map, iac, tps. Throttle still high (12-1300 rpm when usually 600-750). try to go down the road, it shifts hard and I think I only have 1&2. My cousin said TC has gone out. Gonna shop around for remans tomorrow.