LM7 5.3 with 700R4 - can't get the transmission to shift right

Well after posting about this on several sites, the overall consensus was to swap out the 700r4 to a 4l60e or 4l80e. Also special thanks to nycutlass for speaking to me on the phone, I hope to meet with you in person soon.

I ended up finding what the seller described was a 105k mile 4L80e out of a 2010 van locally for $500. He swore up and down that the transmission works, but I have no way to prove that. I decided to gamble on it for $500. The 19180257 part # suggests its a GM reman piece. The fluid looks pink-ish brown-ish, and doesn't smell burnt. I will drop the pan and examine it further later. There doesn't appear to be any dipstick tube, I will have to get one.

I will have to splice / pin in a 4L80e transmission pigtail. The PSI harness I have does have the VSS pigtail, but no transmission harness and no input speed sensor harness; those I will attempt to pin in myself.

Given my limited knowledge and abilities, should I look to pull the motor/trans together through the top of the engine bay, or should I look to unbolt the existing trans from the motor and unbolt the yoke from the driveshaft and try to drop the trans alone from below the car and attempt to slide the 4L80e from below? I will have to get the car high enough to do this on jack stands and get comfortable working on my back.

How would you guys go about swapping this transmission if you never did this before? I would like to learn to do this myself.

Any other tip to follow prior to attempting an install? Yoke options, driveshaft length calculations, torque convertor spacing, etc?

The 4L80 I picked up which needs a good cleaning:

4l80e_01.jpg


4l80e_02.jpg


4l80e_03.jpg


4l80e_04.jpg
 
the install of this transmission is really up to your location and time and access to the tools needed to do it all weather its pulling it or crawling under the car. i would only get a yoke for the transmission for now when its all in i would measure the length of the drive shaft and move on from that point. as for the torque converter that depends on what cam you are using. so now's the time to pick for sure which cam you will use and buy that convertor now
 
take pictures of the pan when you remove it. I'm curious how it looks inside before you clean it
 
Cut the ‘ears’ off. They will be in the way and are unneeded. You really want a converter - the Jegs XD is great for the price and lower power levels.

If the trans works properly then it will last a long, long time at sub 600hp.
 

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor