opinions on 4L80E converted 6speed automatics (i.e. TCI 6X)
 

I've been contemplating a 6-speed automatic for quite some time now. But with the failure of my TH700R4 last week, I've been thrust into the position of having to make a decision now...

Wanted to get opinions on these 4L80E-based 6-speed automatics... (i.e., like TCI 6X).

So far the ones I know about are TCI and PATC. I like having the automatic (as opposed to swapping over to manual 6 speed), but the idea of having the 6 speeds available is very appealing.

I've been reading up online and many of the threads/posts are several years old, and they're a mixed bag of praise and complaints... everything from no problems whatsoever, to having to take the tranny out a few times and sending back to the manufacturer for a refund).

Wanted to see if there have been any more recent experiences with these and whether I should make the attempt.

Thanks.

Just to clarify, 4l80e is a 4-spd auto.

Have you looked at the 4l60e version? Supposedly it's the same size as your 700R4 (believe it's the same, other than electronically controlled).

Yes, 4L80E is a 4 speed. Sorry, I went back and edited my original post for clarification.

4L60E version? I was unaware of that. Who makes it and what are the opinions on that? My long term future plans may have a 500+ hp 427 sbc, so hp capability is a concern. What I do now needs to keep that in mind.

Rick,

Tci makes a 6 speed auto out of a 4l80E. They are expensive...

For the money, I would use a 4L80E and be done with it.

Understood it's expensive. I'm really just looking for real world experiences with it. The price is kind of a separate question.

Interesting development...

Over at Protouring.com, a company called Power trian control solutions came up in discussion.

they make a valve body that converts a 4L80E to a six speed using the overdrive gear as a gear splitter.

Talked to the guys at PTCS just now...

Take it for what it's worth...

I guess they developed the valve body for a military application that, according to the tech guy, was far more brutal on the trans than what I'd subject it to.

Since the car is only driven <5000 miles/year, if the long term durability of the transmission is even partially degraded (which they contend it isn't), seems like it would still last me a long time.

They're stuff to do the conversion is ~$2000 (controller, paddle shifters, valve body, and harness). So if I can get a low mileage used factory GM transmission for ~$1000 or less, could probably do this pretty cheaply. Probably would get the lower gear set too from TCI for $900.

My mistake. Thought he was just referring to the regular 4l80e, not the 4l80e-based TCI 6x.

If I were you, and dead set on a 6 speed auto, I'd go with GM 6l80e and be done with it. But then I heard the 6l80e is huge and may require cutting the trans tunnel.

Yeah from everything I've read, the 6L80 doesn't fit.

Well, everything fits with enough cutting. :superhack:

Been to your site several times, loved what you've done to the car.