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Discussion Starter · #1 ·
I bought a 90 model GMC 1500 with a 5.7l engine and 700r4 transmission a couple of months ago and the previous owner had a pair of vise grips holding the detent cable in place at the bracket next to the throttle body because the clips that normally hold it were broken. I of course purchase a new cable and for the most part all was well. I just thought the shift from 1st to 2nd had to much drag in it during moderate acceleration, so after about a week of this I decided to try and readjust the cable and while doing so the entire adjustment slider jumped out of the cable, the rigid edge was worn smooth. Exchanged the cable and used the same procedure adjusting it that I used on the first one, with slider pushed all the way in, pushed the "D" shaped button in and open the throttle to WOT. When I test drove the truck it acted o.k (not perfect, felt minimal slippage) until it got warmed up, then drive and overdrive quit working and the trans was pretty hot. Fluid level was good, so I readjusted the detent cable again, because I read that it may need this once everything got warmed up. No difference, got it home and made sure the wire didn't slip off the transmission end of the cable, and it had not. What Happened? I did everything I had done before with just that one shift issue. Did I burn up my trans?
 

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I cant stand those ratcheting cables, I used zip ties and tied my old one in place. The new one is holding for now but I will probably do the same thing to it.

Thats one of the things I hate about these transmissions, that and the lock up converter.

Mine still isn't right but its driving and shifting but it wont shift down to second gear, it will shift down to third. But its not slipping and I have all 4 gears.

Does yours try to shift into drive and slip or does it just not shift at all. You may have too much adjustment in the cable.
 

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700r4

You may have helped it on it's way,with the jerry-rig it had on there before it was on it's way to a death sentence.These overdrive transmissions have to have TV cables adjusted spot on or they will fry in a matter of minutes.Both the GM 700R4 and Ford AOD adjustments are critical, on your 700R4 it has probably fried the 3-4 clutch pack so a rebuild is in order.Your '87 core is a good rebuild candidate '86 and earlier left much to be desired.The cable on yours should be adjusted my means of a pressure gauge.
 

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Discussion Starter · #5 ·
700r4

Drake Dragon-While shifter is in drive or overdrive the trans stays in second at a much higher rpm than it should, it will eventually shift into drive and then its like I'm in neutral.

JeffB- I've been reading a lot on this transmission sense I've had it and never seen anything about adjusting the detent cable with a pressure gauge, how would this test be preformed?
 

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if the 700 trans acts like it goes into a neutral when it shifts to 3rd gear.... the 3-4 clutch pack is damaged.
 

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Steelersandchevy said:
Drake Dragon-While shifter is in drive or overdrive the trans stays in second at a much higher rpm than it should, it will eventually shift into drive and then its like I'm in neutral.

JeffB- I've been reading a lot on this transmission sense I've had it and never seen anything about adjusting the detent cable with a pressure gauge, how would this test be preformed?
Mine will shift through all of the gears at 3200 rpm. If I hold the gas down it will stay in drive until I lift or run out of road :) but I try not to take it over the speed limit so I don't know if it will eventually shift into over drive.
It wont down shift from 3(D) to 2 unless I move the select lever.
 

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Info

Steelersandchevy said:
Thanks for the info guys. Sounds like I have me a rebuild coming up.
Google 700R4 TV cable adjustment,when it comes up go down to the 4th site down,it should say:700R4 Info pg 1 from www. purplesagetrading post save this site on your favorites the info is extensive yet easy to comprehend so you will get it right.
 

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JeffB said:
Google 700R4 TV cable adjustment,when it comes up go down to the 4th site down,it should say:700R4 Info pg 1 from www. purplesagetrading post save this site on your favorites the info is extensive yet easy to comprehend so you will get it right.
Sumner ( owner of Purple Sage site in Utah) is a very good friend of mine.... I provided much of the 700r4 information for him and Sum is a very innovative fellow if you read through his site on the stuff he has built or modified

:thumbup:
 
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