A4 problems on a 93

[Injuneer]

Posting this for a friend.... I know NOTHING about auto trannies. Thought someone here might be able to help:

When I got this car (93 Z28 with 148K miles) the transmission was pretty toasted. Wide open throttle shifts were like throwing the car in to neutral.

I knew a guy parting out a thirdgen and it had a built ($1800) 700R4
in it that I picked up dirt cheap. This 93 had a 4L60 in it, which I
always thought was identical to a 700R4, but they aren't. The 4L60
has a 5 pin connector, and I noticed it had what appears to be
electric governors in it. The 700R4 has a 4 pin connector and does
not have the electric governors.

At first we just eliminated the other pin and plugged it in to the
700. The converter would lock/unlock constantly, not good. So then I
was driving the car with the tranny unplugged, basically no converter
lock up control, and that's when all these problems started. I did
get the TCI kit to control the converter lock up in 4th gear and
unlock it when you hit the brake (kit made for non-ecm cars) but I
haven't installed it yet.

I did install a new (no name brand, Allstar) 12" lock up converter
(around 2800 stall) when I did the trans. swap.

Any ideas? Need to change something in the ECM?

[Joe 1320]

Fred, other than the mismatch of the connector, I don't get what the problem is. The post is obviously an excerpt from a longer thread, but the symptoms appear missing? It also says the converter locks and unlocks consistantly which is bad?

[Injuneer]

I guess the first question would be "are the 700R4 and the 4L60 interchangeable?" - from the posts I've seen, they should be. Why does the 4L60 have the electronic interface - what functions does it provide? Is that normal? Why are the 4L60 and 700R4 interfaces different?

Like I said, I know NOTHING about the A4's (or any other automatic trans).

What I posted is what I got..... nothing was excerpted. I've been helping this individual (via e-mail) with a low power problem, and we've made good progress on that. Then he brought up the 700R4 problem and I didn't know where to start.

I'll try to get mre input.

[Disifer]

The torque converter lockup is the only part of the transmission controlled by the ecm in a thirdgen 700r4. If the ecm in a thirdgen and a 93 are different then the wiring pattern for the hookup of the torque converter lockup could possibly be different.
The lockup conditions can be changed with a burned chip in a thirdgen. That extra wire could be for some other way to measure when the torqe converter should lockup.


(sorry for my insomniac ramblings)

[94Z/28]

I dont know a lot about auto trans, but I am going to be running a 700R4 in my carbed 4th gen project. You are right the 4L60E and 700R4 are the exact same size the 700 will work with stock crossmember and mount. The way my trans is built is that it wont lock up in 1st 2nd or 3rd and I wired a switch to one of the pins on the conector to manually lock and unlock in 4th gear. Also another thing to consider is the geometry of the kickdown cable I had to get a bracket from TCI to make the cable work on a holley carb, may not apply to your application. Hope this helps

[fastTa]

First thing I would do is determine whether or not the TCC solenoid is good. Test the resistance across the TCC solenoid. It should measure between 24.5 and 26.5 ohms. If it appears to be OK electrically you can also test the mechanical function of the solenoid by manually grounding the TCC solenoid and having someone listen to see if it is actuating. This can be done by directly applying 12V to the soleniod or you can jump Terminal A and F on the ALDL connector. With no power applied, you should be able to blow air through the end of the solenoid. With 12V applied to the TCC solenoid's coil, it should force the checkball onto its seat preventing air from going through the solenoid. It is also not uncommon for the rubber 0-ring on the end of the solenoid to go bad. It needs to provide a good seal inside the bore where it is housed to allow for proper TCC engagement.

The 700-R4 uses no modulator and does not require a vaccuum source to shift properly, so also make sure the TV cable is adjusted properly.

I wouldn't imagine anything would need to be done with the ECM.

I believe GM Parts Direct sells a conversion kit that is specifically for converting from the 700R4 4 pin case connector to the 5 pin case connector of the 4L60.

[Injuneer]

Thanks for the help. The guy with the car bought a 93 Helms manual. He indicates that.....

Also, I got my Helm's manual. If you ever need any 93 specific
information let me know. Example on the 4L60 I was asking about. The
93 cars came with one of FOUR different 4L60's. Some had 2 wire, some
3, some 4, some 5! Now that I have the wiring diagram I think I can
send this TCI kit back and let the ECM lock it in 4th. That Helm's
was the best $105.00 I spent so far.