Life expectancy of 4T60?

[wrightz28]

I've seen alot of older PAs with pretty high mileage around 200K here, so I'm just wondering how long the transaxle has held up.

Mine is a '87, 110K, and feels like about to blow.

I bought the car 6 years ago for $400, had blown heads on it with 72K. Since it was overheated numorous times and I was already there, I replaced the fluid (2 qts trickshift, the rest Dex III atf)and filter. Trans has held up fine until recently. Started slipping over the winter on all shifts when it was really cold. Little low on fluid, no biggie, add and be done. Well, about a month ago, from a standing stop, the car felt like I was standing on the brakes or trying to push another car, then all the sudden you'd get this shudder from the left front corner of the car and it would take off. Also when coming to a stop, a similar shudder would be felt, figured it was sloppy TCC disengagement. Finally got around to geting a look at thing recently, discovered the ECT sensor was off on it's readings. Replaced it and the shudder problems WERE resolved.

Why is were, capitolized? There not over. Since replacing the ECT, shifting problems are in abundance and strange. I resolved all the gear to gear shift feel issues by readjusting the TV cable. However, from a standing stop and VERY intermittently the trans will slip, horridly, then shift to 2nd, and all is well until the next time it decides to act up (maybe at the next stop, maybe not until tommorrow).

To top it all off, last night I had to accelerate from a stop quickly or else get T-boned by someone non-aware of the term right of way. Anyhow, the trans slipped, and then violently shuddered (like I hit a brick wall) followed by what practically sounded like the trans dragging on the ground. Before I could get clear to stop get out and verify if in fact the damn thing jumped out of the engine bay, all was 'normal'.???

Anyway, I'm going to change the fluid, probably almost all trick shift this time. R&R the vacuum modulator (have a funny feeling about it). I have no problem rebuilding it but there are thing I'd like to do with motor that I can't afford right now.

Any thoughts or ideas? TMAN, flatrater?

BTW, fluid is ok, no friction material on the stick atleast, and engine is fine (CTS resolved quite a few issues), no smoke from tailpipe to indicate that fluid is being sucked into the engine, but something tells me it's the modualtor if not the converter.

[wrightz28]

hmm, noone has had any trans issues?

[HotZ28]

Sounds like you have a line pressure problem. It could be the pump or if you are lucky, the filter. Usually the trans will last about 120K to 180K depending on the service and abuse. I have a lesabre that had to be rebuilt at 136K and my Park Ave Ultra has 170K and has just started to give some of the signs of needing overhaul. Do not use B&M Trick shift in in leiu of Dextron fluid. It is syenthetic and GM does not recommend that for older 4T60's. Also, if the tranny has not been serviced regularly it is not recommended to change the fluid. New fluid tends to sofften the clutches and cause them to break apart after they have hardened with use of old fluid. Complete rebuild usually runs about $1200 with new converter.

[wrightz28]

Well, you were close, twas a pressure problem caused by a completely failed vacuum modualtor, don't even know how the thing ever moved. After replacement all is pretty well resolved with just a little hestiation remaining form a stop when at operating temp. So, fluid and filter to repleninsh things and hopefully all is well.

Oh, $1200, eh eh, $140 for internal rebuild kit and around 90 for TC and a long day of cussing and moaning when I find more problems underneath it.