700-R4 problem

[alec78]

Last week the K5 started shifting funny. That is to say in normal easy accelleration in the city it would shift out of 1st somewhere between 15 and almost 30 mph. It usually shifted at 15, every time. She used to shift out of 2nd about 25 mph and now its anywhere from 35 to 45 mph. /forums/images/graemlins/eek.gif !!! OD is hit and miss...but if it does shift into OD its at or above 55 mph. Oh and the seats almost break when it does shift.

I figured the Throttle Valve cable was hosed so I tested and replaced it. It tested kinda ok, sluggish if anything but after removing it I noticed that a few strands in the cable were broke.

Well now it shifts at the "same" speeds but it going out of 1st at 25 mph /forums/images/graemlins/blush.gif! and I have not got out of 2nd yet (still in neighborhood).

Anyone have any thoughts?

 

[sickquad]

Well, there are some really good posts on this board as to adjusting that cable.

If a tranny is shifting late it is a pressure issue I think. So is there enough fluid? Should you adjust that TV cable a little tighter? Is it running too cold for some reason, added a cooler lately?

I would start with adjusting the cable again though.

 

[Thunder]

if your TV cable is adjusted right and you still have problems. You might want to check your governor. the plastic gear might be stripped.

 

[alec78]

I did a search before the origional post and didn't find anything... but then again, I'm working nights this week and my brain is about two steps to becoming silly puddy...

I did find a web site that gave a good step by step so I'll adjust the cable when I get home in the morning.

Fluid level is fine, I've been rather critical of it since this started. Also I have yet to add a cooler (should but am holding out for the NV4500 swap).

I'll check the Governor this weekend, just not enough energy to do that right now.

Bit-o-update:
I drove it in to work tonight and it shifted out of 1st at almost 30 (HARD shift); 2nd at 40ish (bit softer than first but still harder than normal); into OD at 55 (normal). That was getting to the Highway, about 10 miles from home. Funny thing is when I got back on the regular streets (about 10ish miles later) it was shifting completely normal!!! /forums/images/graemlins/dunno.gif

I should get more sleep before I try to finish fixing this...

 

[sickquad]

I remember a GM mechanic telling me once that he recommends overfilling the 700R4 a little bit. Said it couldn't hurt the tranny and if there was too much fluid in it it would just come out the vent. He said close to a quart overfull.

-Chris

 

[cootersk5]

im in transmissions class right now in college and im rebuilding a 700-r4. My teacher informed me that that most of the sungear shells are crack after a time but i would check your govener(or how ever it is spelled) cause it sounds like its not over riding your tv pressure in your valve body to cause and upshift.

 

[MA87K5]

When you leave for work is the tranny warm already? My tranny does the things you described when it is cold. After it warms up it shifts normal.

 

[big83chevy4x4]

sounds like the TV is not adjusted correctly. if the cable had a few broken strands, then it will alow it to strech and the loose one can cause it to become sticky.

to adjust it, push the button and push the end all the way in, then cycle the throttle out to full throttle (engine off) and you will hear clicking. this should be adjusted correctly. take it for a drive, you may have to fine tune it. just push the button and push the end in or out 1 click at a time till its right. pushing it in will raise shift points and pulling it out will lower shift points.

if that doesn't change it, then your governer valve may be sticking, you need to pull the governer and check the valve inside. you will be to check the gear also.

 

[alec78]

Hmmm.../forums/images/graemlins/thinking.gif Seems like that much over would get into the valve body...If I get the pan off I'll measure and post it.

I think the governor is ok (haven't checked) but it easy to so I will this weekend.

Tranny is not warm when I leave but after a few miles (about 5ish) it shifts fine. I was noticing this just yesterday. Any thoughts?

 

[hd-10]

i had the same promblem with mine and after pulling the tranny to put a new one on, the flex plate where it bolts to the engine was craked and broke so the tourque converter was shifting around. don't know if that was the promblem but it was the only thing i seen wrong. to check you should be able to unbolt you're torque converter and feel up in there to see if the flex plate is borken around the bolts? don't know if thats it but i wish i would have found and tried it before i got a new tranny.

 

[MA87K5]

I don't have a prob with my tranny shifting that way. It isn't slipping, overheating or leaking. I would leave it alone or flush the tranny 100%.