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Old 12-17-2018, 03:50 PM   #1
jfoley
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7004r won't shift into 4th

1972 blazer 4x4. Since I have had my blazer the 700r4 won't shift into 4th. When I bought the truck before I drove it I swapped in a tilt column from 1971 blazer I had so I don't know where the problem lies... Park, neutral and reverse all match the indicators on the column. I thought maybe the selector was off but if I try to move it from "D" in the direction of "P" it just pops into neutral. I can't find anywhere that shows where the selector on the transmission should be for "OD". I adjusted the TV cable yesterday, shifts into 2nd at 10 mph, 3rd at 25 mph. TV cable is pretty hard to pull. Seems to shift fine, It wouldn't kick down before I adjusted the cable, and I haven't tried to see if it would now. Also the electrical connection on the drivers side is blocked off

Thanks for the help

Last edited by jfoley; 12-17-2018 at 04:12 PM.
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Old 12-17-2018, 07:29 PM   #2
tdangle
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Re: 7004r won't shift into 4th

I would make sure your shift linkage is actually putting the trans into 4th gear. Have someone move the shift lever to each position while you are under the truck (not running of course) and you can hear it click into each position. If it is going into the correct position for 4th, time to take it to a trans shop. Having the TV cable mis-adjusted could have possibly damaged the trans. And you are absolutely sure you have a 4 speed OD trans?
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Old 12-18-2018, 12:47 PM   #3
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Re: 7004r won't shift into 4th

Tried to make it kick down today and it wouldn't. I am going to try a new TV cable and adjustment. Doesn't seem like it should be that hard to pull but I don't have any experience with 700r4s.
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Old 12-19-2018, 12:05 AM   #4
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Re: 7004r won't shift into 4th

I would suggest doing some reading up on the 700R4's here on this forum. There are many, many threads. The more you drive this trans with the TV cable not adjusted correctly and the line pressures not checked and correct, you are doing serious damage to the trans. The TV cable does not control the kickdown, it controls the internal pressures of the trans.
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Old 12-20-2018, 01:26 PM   #5
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Re: 7004r won't shift into 4th

Thank you for your responses. I have read a bunch on the 700R4 on this website and others but was hoping someone would have a suggestion on things to check other than the TV cable. I know a lot of people confuse the TV cable with a kickdown cable which it is not. However, the TV cable does control line pressure, shift points, shift feel, part throttle downshifts, and detent (full throttle) downshifts. Since I adjusted the cable according to direction and my shift points are close but it won't downshift I though maybe something else was going on. I guess my next step would perform a pressure test to make sure the adjustment is correct.
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Old 12-21-2018, 11:11 AM   #6
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Re: 7004r won't shift into 4th

Thtas the best way to set them up .your tv valve may be hanging up allso
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Old 12-22-2018, 11:02 AM   #7
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Re: 7004r won't shift into 4th

For those who state the tv cable don’t control the kick down than how does a 700 r4 “kick down” from 4th to 3rd gear when you give the vehicle more throttle. The only controlling factor connected between the engine and transmission is the TV cable. What does the pressure regulator assembly do in the pump ? The TV pressure is increased with throttle response only, it raises line pressure for torque increase. TV pressure works against governor pressure for upshifts and down shifts. This is not main line pressure If the tv cable is adjusted/changed it impacts all upshifts and downshifts. That’s how it was designed to work. So if your transmission is shifting early into second at 10 mph than you do not have enough throttle pressure. Most likely shifting early may provide a shift into 4th early as well and you are not feeling it shift into 4th since it’s very soft and very early which slips the 3/4 clutches more than they were designed to take. Over a few of these soft type shifts it will burn up your 3/4 clutches.

I suggest to adjust your TV cable where your trans shifts from 1st to 2nd at around 20 mph. You will notice much firmer shifts. Maybe by chance you may feel it go into 4th. Just hoping at this point 😀. Maybe you will get it to kick down with more throttle pressure

Last edited by YoungPup1977; 12-22-2018 at 11:08 AM.
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Old 12-22-2018, 11:47 AM   #8
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Originally Posted by YoungPup1977 View Post
For those who state the tv cable don’t control the kick down than how does a 700 r4 “kick down” from 4th to 3rd gear when you give the vehicle more throttle. The only controlling factor connected between the engine and transmission is the TV cable. What does the pressure regulator assembly do in the pump ? The TV pressure is increased with throttle response only, it raises line pressure for torque increase. TV pressure works against governor pressure for upshifts and down shifts. This is not main line pressure If the tv cable is adjusted/changed it impacts all upshifts and downshifts. That’s how it was designed to work. So if your transmission is shifting early into second at 10 mph than you do not have enough throttle pressure. Most likely shifting early may provide a shift into 4th early as well and you are not feeling it shift into 4th since it’s very soft and very early which slips the 3/4 clutches more than they were designed to take. Over a few of these soft type shifts it will burn up your 3/4 clutches.

I suggest to adjust your TV cable where your trans shifts from 1st to 2nd at around 20 mph. You will notice much firmer shifts. Maybe by chance you may feel it go into 4th. Just hoping at this point 😀. Maybe you will get it to kick down with more throttle pressure
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Old 12-22-2018, 11:54 AM   #9
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Re: 7004r won't shift into 4th

I ordered a pressure gauge to test the pressure but it hasn’t arrived yet. I made the TV a little shorter and it shifted 1-2 at 25 mph. Still no 4th gear. I don’t think it going into 4th because it’s running about 2800 rpm at 65 mph. Not sure what the gear ratio is guessing 4:10s with 33 tires”
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Old 12-22-2018, 04:50 PM   #10
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Re: 7004r won't shift into 4th

Quote:
Originally Posted by jfoley View Post
I ordered a pressure gauge to test the pressure but it hasn’t arrived yet. I made the TV a little shorter and it shifted 1-2 at 25 mph. Still no 4th gear. I don’t think it going into 4th because it’s running about 2800 rpm at 65 mph. Not sure what the gear ratio is guessing 4:10s with 33 tires”
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So you really don’t know if it is actually shifting into 4th. The TCC is not locking up either than. Correct ? Plus no voltage is going to TCC solenoid since it’s not connected at the driver side of trans. Do you have a TCC shift valve ?
What happens with the rpms if you pull down on the shifter one click. Which should be 3rd at 60 MPH.
Does the rpm increase

Can you provide a pic of the bottom of the trans
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Old 12-22-2018, 06:42 PM   #11
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Originally Posted by YoungPup1977 View Post
So you really don’t know if it is actually shifting into 4th. The TCC is not locking up either than. Correct ? Plus no voltage is going to TCC solenoid since it’s not connected at the driver side of trans. Do you have a TCC shift valve ?
What happens with the rpms if you pull down on the shifter one click. Which should be 3rd at 60 MPH.
Does the rpm increase

Can you provide a pic of the bottom of the trans
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Old 12-23-2018, 02:47 PM   #12
jfoley
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So you really don’t know if it is actually shifting into 4th. The TCC is not locking up either than. Correct ? Plus no voltage is going to TCC solenoid since it’s not connected at the driver side of trans. Do you have a TCC shift valve ?
What happens with the rpms if you pull down on the shifter one click. Which should be 3rd at 60 MPH.
Does the rpm increase

Can you provide a pic of the bottom of the trans
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Old 12-23-2018, 03:14 PM   #13
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Re: 7004r won't shift into 4th

Based on the rpm it is not shifting into 4th. I shifted down one click and no rpm change at highway speeds so the selector must be in the correct position. If I shift up it goes into neutral. I adjusted the TV cable and it goes 1-2 at 15 and 2-3 at 30 mph. It is definitely a 700r4 based on the pan. I don’t know if I have a TCC shift valve. I thought you could run without locking up the converter and still use 4th. I wonder if they used the dipstick and tube from the TH 350 that was originally in the blazer? I ordered a new dipstick and tube for 700r4s but it’s a real pain to reach the bolt holding the tube on the bellhousing.
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Old 12-23-2018, 07:29 PM   #14
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Re: 7004r won't shift into 4th

What is applied in 4th
2/4 servo
3/4 clutch
Forward clutch

What could it be, 3/4 shift valve
Governor

Th350 fill tube will not work on a 700r4.

Now we really need a pic.

Last edited by YoungPup1977; 12-27-2018 at 06:46 PM.
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Old 01-01-2019, 08:57 PM   #15
jfoley
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Originally Posted by YoungPup1977 View Post
What is applied in 4th
2/4 servo
3/4 clutch
Forward clutch

What could it be, 3/4 shift valve
Governor

Th350 fill tube will not work on a 700r4.

Now we really need a pic.
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Old 01-01-2019, 09:13 PM   #16
jfoley
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Re: 7004r won't shift into 4th

My pressure garage arrived and everything is in spec at idle. Park and neutral 55psi, reverse 100 psi, overdrive and manual 55 psi, manual second and low 105 psi. I couldn’t accurately perform the full TV pressure test because the truck would creep forward and I would have to let off the gas but the pressure in overdrive would jump to more than 110 psi and I still had throttle left. No change in pressure if I disconnected the TV cable at idle. If I pulled the cable out approximately 1/4” with out throttle the pressure would rise. The only thing I did notice is the gauge would “blip” when shifted from one gear to the next except when shifted from 3 to 4. Gauge would “blip” when shifted from 4-3. I plan on trying a ordering a new TV cable but I heard there are lots of different lengths and I prefer not to order a universal one. I added a pic as well. Thank you
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Old 01-02-2019, 02:08 PM   #17
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Re: 7004r won't shift into 4th

If first second and third are fine there are only two things left - 3-4 valve line up in the valve body and the governor.

I seen several loose heads on governors that would prevent the upshift to fourth.
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Old 01-02-2019, 08:23 PM   #18
jfoley
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Re: 7004r won't shift into 4th

Ok, I’ll start by checking the governor. Thank you
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Old 01-07-2019, 12:19 PM   #19
jfoley
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Re: 7004r won't shift into 4th

I swapped in another governor and no change in shifting. Gear was a little warn in the old governor but it appeared to be free and functioning properly.
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Old 01-08-2019, 08:48 PM   #20
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Re: 7004r won't shift into 4th

Have you dropped the pan on this 700. If you did was there any thing in the pan.
Clutch material and or metal.

Other stuff to check
Check the 2/4 servo.
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Old 01-08-2019, 09:44 PM   #21
jfoley
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Have you dropped the pan on this 700. If you did was there any thing in the pan.
Clutch material and or metal.

Other stuff to check
Check the 2/4 servo.
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Old 01-08-2019, 09:51 PM   #22
jfoley
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Re: 7004r won't shift into 4th

I have not dropped the pan. I just ordered the ATSG rebuild manual. For 700R4s. I was going to read up a bit on disassembly and then decide if I want to try and take the valve body out in the truck or just drop the trans and transfer case so i don’t have to work on my back and mess with the balls going all over. The trans fluid isn’t great but also not terrible.
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