700R4 automatic transmission slips when shifting from 2nd to 3rd gear
Asked by Quinton Dec 21, 2012 at 07:12 PM about the 1985 Chevrolet C/K 10
Question type: Maintenance & Repair
My transmission began slipping when it switches from 2nd gear to 3rd gear. The truck isnt driven often as I go to college in
another state and use another truck as a daily driver. It does have transmission fluid. Also it leaks transmission fluid when driven
for a while so I have a blown seal somewhere. Any idea what could be making it slip?
13 Answers
The transmission fluid MUST be at the proper level. If the fluid is low the tranny could slip & go bad.
It's the third gear band that engages for third and fourth, soon you will only have first and second. The exact same thing happened to my 700r4 and I had to drive around in second for a while.
Time for a rebuild. Your bands or pump may be going. That is if you do have fluid in the trans.
I have a 93 k5 that sat for 10 years when it ran well for a mounth. I replace the carb and now it slips when shifting into third gear only at higher rpm at low rpm it shifts fine. I have ajusted the tv cable and did a trany servis. Sounds like ur problem did u ever find ur problem
tucken, what did you do to fix the problem, and after adjusting the TV cable, do you get all the channels? A good transmission service will include a completer flush to remove any old fluid or varnish build-up. The bands if not used on occasion will dry our and not work properly. I'm not that all familiar with auto trans, but is there an additive to add to prruce up the tired bands, seals or pumps?
Flush is terrible, auto trans fluid is high in detergents, old fluid is actually one of the best things to wash heavy grease off your hands with. If it's skipping then it's done, mine lasted a year and a half slipping into third before it finally quit shifting into third and fourth all together, you may find an additive to "fix" slipping but all it will do is suppress the symptom and it will still fail. That k5 had a 700r4 just like my truck.
My trany service was just drop the pan and replace filter . I also don't belive in flushing the trany. The sliping happen all at once one day runing great the next day is was slipping at highter rpms it shifts fine lf you take off at a lower rpm. It sounds like this is common in the 700s. I have only had 400s
Like I said, I'm not versed in autos, but I was told a simple lube and tune shop transmission change is not going to do any good because of all the junk and stuff still in the lines and pumps. A complete flush out on a dirty fluid transmission is best at removing the sludge. Anything less than that is a waste of money. Auto transmission are as finicky as a high school cheer leader as a girl friend. I have to go now, my cheer leader wife is calling.
All the junk sits in the bottom of the pan and on the filter, if it gets in the lines then your filter isn't doing it's job. drop the pan, change the filter, clean the bottom of the pan, new fluid. Repeat as recommended by the manufacturer.
You can completely destroy the internals of the trans, blow sun gears, burn the bands and clutches. Drain the fluid and everything will still look new inside the trans aside from the filter and bottom of the pan. As I said before there are more detergents in tabs fluid than any household cleaner.
Thanks for the info. I guess the originator of this post is toast.
Doing the "flush" with the machine is horrible because it back flushes the trans, instead of sucking from the filter it blows into the filter which unsettles everything the filter caught and dives it back into the trans.
My son's van had a problem where it would only go into 1st & 2nd. After replacing the governor it still did the same. Adjusted the tv cable...no change. Took the pan off the trans. I lay under the trans and watched the tv cable work. My son adjusted the tv cable tension so that the elbow in the trans almost touched the shift plunger. He adjusted and I directed. Shifts fine now. If we have a problem in the future will replace cable as it is is at it max adjustment now.