Advice on repairing transmission bands?

[Jayden Young]

Hello there, I am new to this site, so if this isn’t the correct way to post a question, please make sure and let me know. Thanks.

I have a 1995 Camaro Z28 with the 4l60e automatic transmission here, and I believe i have a broken band or electrical issue perhaps, but I’m not sure, as I am not very knowledgable when it comes to automatic transmissions.
The original symptoms are:

Delay in shift from first until the speed gets up to about 20mph, then it shifts into third and completely skips second. Continues and shifts into 4th like normal, then lockup occurs as it should.

Lately, what has been happening, is it has been starting to not shift from first until i floor it completely then let off, then it shifts to third, but to get it to shift again to 4th, i have to floor the throttle hard, then let off again, then it will shift to 4th, but lockup will not kick in. Speedometer is jumping around about 15 mph up and down while driving also, as well as the idle is higher than it should be, (around 1000 rpm)

I pulled the pan, there were no shavings or anything in the bottom, the fluid looks fine and is a healthy color and smell, i replaced the filter, then ohm tested the solenoids. They checked out fine electrically. I cannot scan for codes right now, as it is a strange in-between hybrid year for the computer, and a standard obd2 scanner will not work.

The car is at a good local transmission shop getting checked out now, but as a DIYer, I’m wanting to repair it myself if i can instead of paying for their labor. What are some potential causes of this issue, and could i possibly fix it myself, or would it be a better idea to let them do it?? i have a shop and a fairly good skill level, but I’ve mostly done work on engines and not transmissions. Thanks in advance.

Topic

[college man]

Your best bet is to have any codes pulled to further go ahead with
diagnostic.

http://www.ericthecarguy.com/faq/solving-transmission-problems

[Lorrin Barth]

Rebuilding the 4L60E would be great fun. However, automatic transmissions are their own skill set.

One of the problems for a DIYer is the mess. An automatic transmission bleeds like a large dying animal as you disassemble. For the home garage I’d recommend using a plastic fiber tarp with boards around the perimeter forming a shallow swimming pool like structure on the garage floor. Make it big, a 4L60E contains many parts. Then you need a parts washer and compressed air.

You will also need a set of bushing pushers for this transmission and some sort of means of compressing certain parts that contain springs in order to remove or replace snap rings. If you have and and can do all of that, and don’t mind the vehicle out of service while you wait on hard parts to arrive, then consider doing the job yourself.

There’s many videos on youtube where this and other transmissions are disassembled and repaired. Go take a look.

[John Hugon]

First thing is to correct all engine drivability issues by following what Eric’s has listed in his problem topic section including the speedometer issue. Then follow what college man suggested.

Fast recap how second gear functions:

Second gear when shifter is in OD position: 2-4 Band, Forward clutch and Forward sprag clutch are applied. If so happen the transmission was disassembled and the Foward sprag clutch was put in backwards you will not have second gear…I learned that the hard way one time.

If you have a good fourth gear and no debris in the pan most likely the 2-4 band is ok. The band is applied by a servo which is located externally on the Right front of the transmission case. You CAN have a leaking 2nd apply piston in the servo assembly and the 4th apply piston be fine resulting in a failed 2nd but a good functioning 4th.

Second gear is controlled by a 1-2 shift solenoid. The 1-2 solenoid is located internally on the transmission valve body. When testing it should read 19-24 ohms…this would be at the transmission electrical connector terminal A to E.

[EricTheCarGuy]

Automatic transmission repair is not for the novice. There is a special skill set as well as special tools that come with it. In human terms, it would be the equivalent of brain surgery. General practitioners don’t do it, specialists do it. That should give you some indication of the level of expertise required to be successful with automatic transmission repair. Not saying you’re not capable, but it would be better if you were working with someone with experience and tools to show you the ropes before you dive into something like that.

[Bill]

The issue with the speedometer is a good clue. If the transmission computer is not seeing an accurate speed the trans doesn’t know when and how to shift. It’s possible it only has a bad speed sensor and you could replace that yourself.
If could also have other issues caused by a bad speed sensor that you can’t repair.

[David Nichols]

[quote=”wysetech” post=95661]The issue with the speedometer is a good clue. If the transmission computer is not seeing an accurate speed the trans doesn’t know when and how to shift. It’s possible it only has a bad speed sensor and you could replace that yourself.
If could also have other issues caused by a bad speed sensor that you can’t repair.[/quote]

I was thinking about that through the comments. The transmission needs to see how fast the car is going to function right. I wondered what that entailed and I think you completed my thinking, thank you.

[David Nichols]

[quote=”barneyb” post=95428]
One of the problems for a DIYer is the mess. An automatic transmission bleeds like a large dying animal as you disassemble. [/quote]

Okay, I’m all about the serious learning because I simply love auto repair. Your truthful, yet incredibly funny comment was not only wonderful, but easily translated to my wife. We laughed thank you.

[Lorrin Barth]

[quote=”AutoBravado.com” post=95671][quote=”barneyb” post=95428]
One of the problems for a DIYer is the mess. An automatic transmission bleeds like a large dying animal as you disassemble. [/quote]

Okay, I’m all about the serious learning because I simply love auto repair. Your truthful, yet incredibly funny comment was not only wonderful, but easily translated to my wife. We laughed thank you.[/quote]

I was getting ready to do the THM350 in my wife’s Firebird. My wife asked, “Is there a lot of oil when you take one of those apart?” I said, “Yeah, it goes everywhere.” She said, “Couldn’t we get a new one?” I had just seen an ad for a performance B&M transmission so that is what we got. She was worried I’d drag the oil inside the house. She knew me too well.

wysetech’s comment about the speedometer is the post here that I like the most. I’d go there first.

If you wish to see what is in a 4L60E transmission watch this video.

[Author]

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