700r4 locked up in gear.

[Dutch Rutter]

referencing this thread which may or may not be related. I do not know enough about automatic tranmissions to determine if its the cause of this new problem.

https://www.gmsquarebody.com/threads/temp-sensor-broke.30638/page-2

Copy and paste from the other thread:

Got home from work only able to use D because the trans would not shift to anything else. I figured it was the linkage, pulled the bar off tried shifting it with the fork on the trans itself and low and behold, nothing..

Drained, took the pan off i was able to bounce it into 3rd, 2nd, and 1st but now it will not go back into D or above. Nothing looks out of place to me. I was able to roll the truck as if it were in neutral but the internal linkage should have been in gear. Any ideas? Or at least how screwed am I.

You must be registered for see images attach

 

[Matt69olds]

I can’t think of any way the broken sender could have caused a no 3-4 shift.

without getting too technical, the way a 700 trans works is as follows 1st gear, forward clutch comes on. 2nd gear adds the band, applied by one of the pistons inside the servo cover. To get 3rd gear, the 3-4 clutch is applied. The same oil that applies the 3-4 clutch is also routed to another piston inside the servo cover to release the band. To get 4th gear, the band is applied again with another piston in the servo cover. Since you have 3rd, and 2nd her is there, the clutches/band needed for a 4th gear is good. That leaves a hydraulic issue.

Assuming you had a solid 2-3 and 3-4 shift before messing with the sender, I’m going to say maybe you stirred up some crap when all that fluid blew out the line pressure tap. Kinda like when you turn on a faucet in your house after having the water shut off for major repairs, the water looks kinda cloudy. You might get lucky just driving it and seeing if whatever is hanging up the shift valve works free.

 

[Matt69olds]

It just occurred to me, are you POSITIVE you adjusted the TV cable correctly once you reconnected it? If your flooring the gas pedal from inside the trick, make sure the floor mat isn’t preventing the throttle from opening all the way.

 

[Dutch Rutter]

The thing I am finding strange is that when it was stuck in drive this morning it shifted and acted normal except that I could only get D and N (manually shifting) if left to do its own thing in D, it hit all of the gears like it should. when screwing with the shifter and pulling the pan i somehow was able to get it down in 3rd, 2nd and 1st, manually shifting it by hand on the trans. Now it won't go back up to D. I even tried pulling back the (lack of knowledge) wheel piece that holds the lever in the selected gear.

The more I think about how its acting. The more I think it has to be something stuck in that manual valve or something along those lines. (I'll try and post up a video I took) fluid level was good and clean. TV cable seemed adjusted correctly (I did set it back after getting those bits out), shifts were good and firm but not teeth shattering, I did have a down shift when rolling on at 65mph on the way home today, and it did lockup at the usual point.

 

[Dutch Rutter]

Here's the video if it helps any (probably won't)

xc_hide_links_from_guests_guests_error_hide_media

I have a new gasket, and filter on the way. I could always toss in some fluid and run the **** out of it in hopes of dislodging whatever is hanging it up.

 

[Matt69olds]

I guess I misunderstood you. I thought you meant the trans wouldn’t shift out of third into overdrive. Your saying the shifter physically won’t shift into overdrive?

 

[84 M1008]

Here's the video if it helps any (probably won't)

xc_hide_links_from_guests_guests_error_hide_media

I have a new gasket, and filter on the way. I could always toss in some fluid and run the **** out of it in hopes of dislodging whatever is hanging it up.

Unless that is a built to the hilt, I would strongly suggest against running the **** out of it. Those transmissions in stock form didn't take likely to being beaten.

 

[Dutch Rutter]

I guess I misunderstood you. I thought you meant the trans wouldn’t shift out of third into overdrive. Your saying the shifter physically won’t shift into overdrive?

This is correct. Its a strange thing to experience much less for me to try and explain. Sorry about that.

Edit: it physically won't shift into D or anything above it. And before it wouldn't physically fit into anything but D and N. Seems I somehow how the valve passed the blockage or hang and now it wont go back up the gear selection.

I have an appointment at a shop for Tuesday. I dont believe it will turn into another rebuild as everything else was working well. Worst case replacement of valve body?

I did find this thread on a different forum. After reading through the broken English it seems pretty similar to my situation but I dont know how confident I feel about filing any internal transmission parts.

http://67-72chevytrucks.com/vboard/showthread.php?t=653973

 

[Matt69olds]

About the only thing I can think of is a piece of the temp sender dropped down the passage in the case, and is now stuck in a port for the manual valve. Make sure you tell them about the sender, I’d be willing to bet it can be fixed with valve body removal, cleaning, and reinstall.

I’d be tempted to remove the line pressure plug and start the truck again. Maybe you could work the piece out? All you would’ve outif it doesn’t work is sone trans fluid and time.

 

[Dutch Rutter]

@Matt69olds thanks for all the help through this.

I did exactly as you said when I dropped it off Wednesday. Today I ran them the new lubelocker and filter I had ordered for it. Chated with them a little. They said they'll need to pull the valve body to give me a full diagnosis (4 hours @$100 an hour) and I basically said do whatever we need to do.

I guess its possible that when I tightened the shift bracket back onto the shift shaft I might have over extended the manual valve. But I'm thinking your dead on the money with they'll pull out a shard of brass thats holding things up.

Buying a house at this same time makes things tight but if I can get out less then $2k (should be easily under that i think) I'll be happy enough.

 

[Dutch Rutter]

Got word today from the shop. Their exact words were "Man I dont know how to say this, but this thing is screwed. I have no idea what the shop that rebuilt this did to it. This part is NOT supposed to look like it does.... It needs either replaced or rebuilt."

They dont rebuild transmissions themselves but they are getting a price put together for a newly rebuilt and upgraded replacement to be installed.

I also contacted another local reputable transmission shop who does rebuilds and he told me that for a full rebuild and upgrade would be $2400 (I'm assuming that's the high end) and that is trailering it in and driving it home.

Would I be better off getting an entire different trans over rebuilding this one again? Assuming they both are pretty comperable.

 

[Matt69olds]

The transmission worked before you removed the sending unit? Then the only problem you had is the shift lever wouldn’t move? Now the shop tells you the trans is messed up because they don’t know what was done during the previous rebuild?

Is this their polite way of trying to tell you”we took this apart, and have no clue how to reassemble it?”

 

[Dutch Rutter]

Is this their polite way of trying to tell you”we took this apart, and have no clue how to reassemble it?”

Ooooooo that never even crossed my mind.. I'm going to have to pay them an unexpected visit tomorrow and look it over. It was strange that they told me they'd have it in Monday or Tuesday. And I had to call them today and asked about it before I got ANY information.

They were only supposed to take down the valve body. If I take it back from them how difficult is it to get that back together correctly and would I be able to see wtf is actually going on with it instead of "this doesent look right" when not actually saying any part in particular.

My gut is telling me to take it to the other actual transmission shop for any work, despite them being booked up till next month. Specifically since their "fix" is to remove and replace the entire thing. I dont like that. Kinda feels like pulling an engine because the cam has a wiped lobe.

Edit: The trans worked well before and a few days after the sending unit fiasco. Then yea, all of a sudden, after a drive to work at 20-70+mph it wouldnt physically shift out of drive. And they are saying its completely screwed.

 

[jjester6000]

Got word today from the shop. Their exact words were "Man I dont know how to say this, but this thing is screwed. I have no idea what the shop that rebuilt this did to it. This part is NOT supposed to look like it does.... It needs either replaced or rebuilt."

They dont rebuild transmissions themselves but they are getting a price put together for a newly rebuilt and upgraded replacement to be installed.

I also contacted another local reputable transmission shop who does rebuilds and he told me that for a full rebuild and upgrade would be $2400 (I'm assuming that's the high end) and that is trailering it in and driving it home.

Would I be better off getting an entire different trans over rebuilding this one again? Assuming they both are pretty comperable.

I got a feeling that they are taking you for a ride.

Pretty much every time me or anyone I know has had to deal with a transmission shop, they just say you need a rebuild.

No 3rd/4th? - Rebuild.

Leaking pan gasket? - Rebuild

Bad Transmission Mount? - Rebuild

Dirty Fluid? - Rebuild

Bad Outputshaft Bushing? - Rebuild

Hey can you check over my transmission? It shifts fine, but I just want to be sure that it is reliable - Rebuild.

If a Trans shop finds out that you need your clutch replaced, they will want to rebuild you god damn manual transmission.

I'm done with transmission shops (At least the places around here).

It really sucks since I have a 1951 Studebaker Automatic that needs a rebuild, and they want to charge me like $5600 to do so (Despite the fact that it is one of the simplest automatics ever made, and rebuild kits are still available).

I could buy a $500 parts car with a 3 on the tree and swap it into the Studebaker instead (Which is what I'm going to do).

 

[Dutch Rutter]

It is hard to find a decent person to do work for you anymore.

I'm tracking tho, and I agree. The place that has it currently is a general mechanic. And I'm thinking they know nothing of the inner workings of a transmission. Which explains why they dont rebuild them but want to sell me on buying a rebuilt unit (from someone else) so they can install it.

IF the other actual trans shop gets to look it over and says it in fact needs a rebuild. $2400 installed and driving away is about $1200 less then i paid for the same service on the same trans 2 years ago now.

I am also expecting the new rebuilt unit will cost me more then having mine rebuilt. At least thats what I'd expect.