700R4 issues

[brody.malsom.52]

Hey everyone, I'm new to the site but thought I would see if I could get some insight on some of the issues I'm having with my 85 K15 Silverado. I bought the truck for $750, it has a 305 out of a camaro. I just took it for a short drive today and after about 5 miles of driving I lost all forward gears. The truck acted like it was in neutral. So naturally I fiddled with the gearshift trying to get it to go in gear, the only gear it would move in was reverse, and it would only move for a couple hundred feet then it act like it was in neutral again. Sad to say I had to get the dodge and trailer it home. I know next to nothing about the 700R4 transmission so if anyone could steer me in the right direction as to what I should do, I would appreciate it.

[Captkaos]

Based on your description your trans is gone.

Chris Lucas
73-87chevytrucks.com
squarebody.biz

[78BIG-TEN]

If your lucky a plugged up filter,does it whine when it goes in to neutral

[jg1977c20]

Them 700r4s have weak sungears , and thats the expensive part without knowing your finances its hard to advise whichnroute to go but if your getting a rebuild go for a heavy duty rebuild with upgraded sungear not cheap but it will last you this way

[LTZ C20]

The 700R4 for the first few years was not the best transmission. Had some week parts and gave it self a bad wrap just a little while after it went into use. In the late 80s GM redesigned some parts on the 700 making it a much better transmission.  They remarketed this new design 700 as a 4L60 so that it wouldn't be looked down upon by public as still being a crappy transmission. The late 80s and very beginning 90s 700's are much better than their early - mid 80s older brother.

As 77c20 stated, upgrading the trans with a rebuild and heavier duty parts will make it more reliable. I have an 89 700R4 mated with my TBI 355 in my 73, both controlled by the ECM and the pair works great. A setup I am very happy with. It has no problem handling the 400+ ft lbs of torque my engine throws at it and is capable of with standing about 500 hp.

There is no need to worry about the reliability of the 700R4 if you get it rebuilt as long as you use some heavier duty parts, have it built by a reputable shop, take care of it, don't abuse it and service it at the proper intervals.

[78BIG-TEN]

X2 LTZ.87 on should have most if not all the critical updates.Depending on if and how you use the tcc lock up is the year I try to find.*7 -*9 should have the tcc valve in the valve body but from all I've seen by 90 the bore for the valve was eliminated making it electric only

[jg1977c20]

My 92 jimmy had the 4l60 it was not electric but line pressure was controlled by a tv cable connected at the throttle body and it was imperitave it be adjusted correctly , I got 465, 000 kilometeres out of the tranny before it died I guess thatbworks out to just around 250,000 miles .  The old turbo 350 and t400 ive seen go around the odometer without any repair .

[78BIG-TEN]

To the best of my knowledge all 7oo's\4l60's had a solenoid applied TCC.Depending on year model,some applied with a vacumn switch and later models by ECM