Hi, I'm new here so a little advice and knowledge would be appreciated.

I did a search but only came up with inter year compatibility questions for 1995 to other years.......quite a few of the same problems with the 1995 transmissions I see.

My vehicle: 1994 Chevrolet Blazer (Full size) Automatic transmission. 4 X 4 drive train.

Here's my problem: I seem to have lost gear #2 all together. The tranny shifts from 1 to 3 when I let off the gas at about 2500 RPM or higher and not before. then she shifts normally all the way through the next gear and overdrive. So I have been told by Aamco and 2 other independent shops that I need a transmission rebuild. Aamco said there really aren't any codes present they would just go in and change out any problematic components(named a few parts that I can't recall) upgrade or replace key parts that make the transmission function correctly. Basically a guessing game as they work I guess.

So here is my question: The guy I bought it from has a transmission from a 1999, states it has a removable bell housing. Will this transmission from a 1999 Chevy Tahoe mate with my engine without incident?

Any assistance would be greatly appreciated. Maybe I'll get lucky and someone will point out a 'fix' that I have overlooked that will restore my 2nd gear without replacing the transmission.

What I've done so far: Changed disgusting, murky, filthy, burnt, useless ATF fluid. Changed clogged filter. Changed A-B(1-2) solenoid. That's about the extent of my troubleshooting knowledge thus far with respect to automatic transmissions.

Thanks in advance for your help fellow forum dwellers.

 

Everything in the ATSG manuals that I have states that the 93-94 4L60E's are very different from the 95's and 96+ versions. I know there was a rather large revision to the TCC apply solenoid, but I do not know if an older on/off control such as your 94 has would damage a PWM TCC solenoid or if it would just lock up like it's supposed to...

What engine did the '99 Tahoe have?

 

The 99 trans will not work. As swartlkk stated, starting in '93 they began the conversion from mechanical/hydraulic shifting (700R-4 that uses TV cable off throttle position) to the electronic shifting using solenoids. I noticed there are parts missing missing from the valve body in the '94 4L60E that are not in the '95 that I have in my Blazer( a few springs and a solenoid).

However, I just rebuilt a '94 with the same issue you have. Unfortunately you can change all the fluid and filters you want, but it will not do any good. I'm going to guess it has fairly high miles, maybe 150K+. What I think happened is the 1-2 Accumulator piston wore out causing the 2nd gear servo to not apply enough pressure to the 2-4 band. Lack of pressure caused the band to slip which burned and now you are in this predicament.

You cannot fix this without pulling the transmission. If you want to do it yourself, you can half-a$$ it for about $50(parts and manual). Will it work, yes. How long, I don't know since there is band material and steel filings everywhere in the trans, lines, and converter.

Hope that helps.

 

Thank you both for your input! You have to love online forums, transmission and mechanic shops need to begin to research integrity so they can win the trust back from the general public.

TZFBird- You are right on the money with your thoughts. I replaced the seals on the 2-4 servo assembly over the weekend and VOILA! I have 2nd gear now. Since buying the truck I have not had 2nd gear so it is REALLY nice to be able to not have to 'tap' the throttle for the car just to change from 1st to 3rd,lol.

Granted, the 2nd gear 'slips' in and 'slips' out which leads me to believe that I need to check what you've suggested 'TZFBird', the "1-2 accumulator piston" for wear. Seems like I am not getting enough pressure to engage the 2-4 servo. Or my 2-4 band is just so burnt that it is only capable of 'slightly' engaging....hmmmmm.
**TZFBird, is the forward accumulator piston (located next to the A-B solenoids on the valve body) the same as the 1-2 accumulator piston you have made reference to?**

This is my first time 'messing' around with an automatic transmission, I am an engine guy..........WHo am I fooling, I am just a 'tinkering', mechanically inclined businessman who happens to have a little common sense and is kinda good with his hands, lmbo.

****I am only documenting my travels as I go, not offering a fix to anybody's problem****-Reason I say this is I don't want anyone contacting me saying I offered a fix to their 'similar' problem and it didn't work so they are holding me liable for the few dollars ($10.00 in total that I spent for parts) they spent,lol.

Thanks 'TZFBird' and ' swartlkk' for your input and knowledge!

 

Forward accumulator is the horizontal piston in the tail end of the valve body. You should be able to check it by just dropping the pan. It will have a steel cap over it with one big spring for the piston and a smaller spring for a valve, so watch out for those. If you pull that out as well as the steel pin, the piston should be tight on it. If it's worn out, it will wobble on the pin. The 1-2 accumulator is inside the cap on the driver's side rear of the valve body(3 bolts holding it on). Same applies for the condition of that piston. There should be a big spring in there as well. Do some research because some of those pistons can be installed backwords which will prevent this problem from happening again in the future.


Don't let that slipping fool you, you may still end up needing to replace that band and possibly the forward input drum. But if you change all these parts, at least you'll know what is good later.

Also, make sure to do your homework before starting any of this. I've only learned all this by reading and rebuilding several of these. I never went to school for it or even talked to someone who does this for a profession, so I'm learning as I go.