Posted: Monday, January 09, 2012 8:32 AM  

Posted: Monday, January 09, 2012 9:19 AM  

It is my understanding that the plugs are different. Housing are the same and some of the internals are different. I would get ahold of a good transmission shop and ask if it is possible. Let me know. My transmission I think is going out in my 99 c3500 and I have a fully built 700R4 that I was wanting to put in it.

Posted: Monday, January 09, 2012 10:07 AM  

It will bolt in, but that's it. The ECU will not control a 700r-4, and honestly, the 700r-4 is an inherently weaker trans. Also, you'll have to find some way to rig up the TV cable so it shifts properly, otherwise you'll burn it up in the first 50 miles. All in all, it's a bad idea. Find a good rebuilder and stick with the 4l60..

Posted: Monday, January 09, 2012 11:38 AM  

Won't a 700R4 work on a carburetored engine without any ECU?

Posted: Monday, January 09, 2012 12:21 PM  

Yeah, you need to wire up the lock-up for the torque converter, and properly set the TV cable...

Posted: Monday, January 09, 2012 12:25 PM  

Could not agree more that this is a really bad idea. A 4L60 (and E) and 4L65E transmissions are next generation 700R4's. They are beefier and solve some of the issues that the 700R4 suffered from.

For the amount you would spend on on getting your 700R4 into your Tahoe, you could pick up a good used one from Craigslist or have the bad one rebuilt.

http://www.hotrodders.com/forum/700r4-vs-4l60e-171778.html - see the first to last post. Good information.

Alec Whittington
Street Source

Posted: Monday, January 09, 2012 12:32 PM  

Teh 700R4 is out of a 91 1500. I think that that model tranny runs off of a TP sensor only and wiring the lockup for the torque converter will need to be done also.

I don't agree that it'll cost anywhere near what a tranny will cost to put this one in the Tahoe.

For some reason, Chevy went crazy that year with the 4L's and from what I have been reading, only a 4L from that same year (99) will work, so I am extremely limited in my Craigslist search.

Posted: Monday, January 09, 2012 12:35 PM  

I just noticed the link above.

Nothing in that forum sounds promising.

I might have a newly rebuilt 700R4 for sale.

Posted: Tuesday, January 10, 2012 7:00 AM  

If anyone is interested, I talked to a transmission shop and he didn't advise this. He said the 4L60E sends too much information back to the engine. It is in my best interest to rebuild what I have.

Thanks for the link above.

Posted: Tuesday, January 10, 2012 10:28 AM  

The only thing the engine gets from the trans is speed from the vehicle speed sensor. The trans gets more info from the engine. It reads the Throttle Position Sensor and engine RPM so it knows engine speed and load.

You can use a 700r4, besides the TV cable, and wiring up a torque convertor lock up switch, you would need a VSS for the ECM and your speedo. I would stick with the 4L60E like others are saying though, if you can afford it. They are a little bit stronger. Plus it's a lot easier to tune shift points because it's all in the computer, you don't have to swap out springs.

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Posted: Tuesday, January 10, 2012 10:40 AM  

I was told that the transmission sends info back to the motor that affects fuel settings.

Posted: Tuesday, January 10, 2012 11:45 AM  

Edited: 1/10/2012 11:48:45 AM by DroptSdime
Edited: 1/10/2012 11:46:32 AM by DroptSdime
Yea, the vehicle speed sensor so the ECM can adjust the fuel based on speed and load.

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Posted: Tuesday, January 31, 2012 4:58 PM  

I went through 3 4L60e's myself and can tell you from experience your best bet is sell your 700r and find you a cheap 4L80e and never look back...the cost isn't much more to do the swap