700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**WIDESIDE72** · 03-17-2014, 08:07 AM

I have a 700r4 in my 72 stepside. The trans was rebuilt years ago then the truck it was in sat for a few years. When i swapped it into this truck i forgot to change the filter but checked the fluid several times. I had the tv cable adjusted correctly and it was operating correctly. A few weeks back i drove to a cruise night at the local Wendy's. when i went to leave it would not shift out of 1st. I checked the fluid again and it was about 2 qts low. I added fluid and it still wouldnt shift out of 1st. I changed the fluid and filter. There was some discoloration but no burnt smell. There was some grey in the pan (clutches) no metal. Iirc it had not been changed in 10k miles or so. I added a can of seafoam trans flush and drove the truck a few miles, drained the fluid only and refilled with fresh fluid. No change.

After i changed the fluid and filter the trans would shift up to third at hight rpm but no od. I checked the governor and it wasnt stuck and the gears werent stripped.

I am thinking the valve body is gummed up (?)

72freak · 03-17-2014, 09:02 AM

TV cable issues causing the loss of the gears?

**WIDESIDE72** · 03-17-2014, 09:52 AM

I installed a new tv cable when the trans was installed as the truck the tans was in previously was a diesel and used a shorter tv cable. When i had the pan off to change the filter i verified that it was still hooked up. I also verified that it had not slipped or otherwise got out of adjustment at the carburetor. I unhooked it at the carb and could feel resistance when i pulled on it at the carb end.

piecesparts · 03-17-2014, 10:32 AM

It sounds as if you are having issues with the valve body repositioning to shift properly. I would have them check that area. The 700 R4 trannies have an issue with the separator plate being a little soft and the shift balls will get stuck or dislocated to cause issues such as you are describing. There are hardened separator plates on the market.

**WIDESIDE72** · 03-17-2014, 01:38 PM

I had an issue with a 4l60e that was shifting hard into second. One of the balls was stuck in the plate. I took the plate and hammered it back from the other side. Worked fine from then on for as long as i had it.

myyamr7 · 03-17-2014, 03:28 PM

I just had a similar issue with my 200-4R after swapping from the small block to the big block in my truck. with the small block the trans always did shift later than it should, but my first test drive with the big block, it was shifting very late and no OD until about 65mph. After some investigating, the big block carb has a shorter throttle arm stroke, so with the TV cable hooked up and tight at full throttle, there was only about 1" of throw in the arm. The TV cable needs about 1.5" of throw to work properly. The tighter the cable is, the higher your shift points.
I made the correction to mine and gave it 1.5" of throw, tight at full throttle and it works better than ever.
If you didn't change anything recently, try backing off on the cable a little at a time and see if it makes a difference

davepl · 03-17-2014, 04:08 PM

How do you know the TV cable was "properly" adjusted? Are you certain the pivot point is exactly the same as whatever OEM setup it came off of? It's not as simple as cycling it with the button pushed, though that often gets you close.

Sounds to me like insufficient line pressure cooked the clutches.

72freak · 03-23-2014, 06:47 AM

Quote:

Originally Posted by davepl

How do you know the TV cable was "properly" adjusted? Are you certain the pivot point is exactly the same as whatever OEM setup it came off of? It's not as simple as cycling it with the button pushed, though that often gets you close.

Sounds to me like insufficient line pressure cooked the clutches.

Agreed 100%

Bigdav160 · 03-23-2014, 09:23 AM

Except second gear uses a band

Even if the TV is stuck the trans should upshift eventually. You might need the truck to obtain 30-40 mph to make it happen.

If it refuses to upshift I would look closely at the governor valve.

muckyp · 03-23-2014, 09:27 AM

I had a friend last week have what sounds like the same problem as you. I believe the trans shop replaced the modulator and all was well. My friend thought they said the modulator gear but I'm not sure what that is, so I am assuming it was the modulator. Either way it must have been simple and cheap cause they didn't charge him.

BustedCrank · 03-23-2014, 05:39 PM

Is it stuck in first, or does it seem like it just won't catch second? If the governor is stripped (just a little plastic gear), it will drop back to idle after you let off the throttle, instead of staying up in rpms like if you have the shifter in the first gear position.

I have had this happen, I could play with it a bit and get it to grab second gear, then it would drive normally until I came to a stop.

If you can get it going fast enough in first, and let off, and it catches third...then your 2/4 band isn't catching.

03-17-2014, 08:07 AM	#1
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,494	700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm I have a 700r4 in my 72 stepside. The trans was rebuilt years ago then the truck it was in sat for a few years. When i swapped it into this truck i forgot to change the filter but checked the fluid several times. I had the tv cable adjusted correctly and it was operating correctly. A few weeks back i drove to a cruise night at the local Wendy's. when i went to leave it would not shift out of 1st. I checked the fluid again and it was about 2 qts low. I added fluid and it still wouldnt shift out of 1st. I changed the fluid and filter. There was some discoloration but no burnt smell. There was some grey in the pan (clutches) no metal. Iirc it had not been changed in 10k miles or so. I added a can of seafoam trans flush and drove the truck a few miles, drained the fluid only and refilled with fresh fluid. No change. After i changed the fluid and filter the trans would shift up to third at hight rpm but no od. I checked the governor and it wasnt stuck and the gears werent stripped. I am thinking the valve body is gummed up (?)

03-17-2014, 09:02 AM	#2
72freak Rottenwood Garage Member Join Date: May 2005 Location: Marietta, Georgia Posts: 4,321	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm TV cable issues causing the loss of the gears? __________________ 2004 Chevrolet Suburban C1500 2001 Chevrolet 2500HD Crew 6.0 1999 Harley Davidson Electra Glide 1972 Chevrolet C-20 Custom Camper "Dump Truck" 1972 Chevrolet C-20 Suburban "Big Green" 1969 Chevrolet C-50 Wedge Hauler "Leonidis" 1966 C-10 2x4 short fleet 327 4 speed "Race Truck" 1952 Plymouth Cranbrook "Rican" (my grandfathers) 1931 Ford Model A Coupe "Black Beauty" 1930 Ford Model A truck "Club Cab" 4x4 Rottenwood Garage and Speed Shop.....where everything must be racy! *It's not just a hobby..It's a LIFESTYLE!!!* Thanks for nothing Barrett-Jackson You cant fix stupid or teach accountability! Time wasters, looky Lous and tire kickers are everywhere!

03-17-2014, 09:52 AM	#3
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,494	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm I installed a new tv cable when the trans was installed as the truck the tans was in previously was a diesel and used a shorter tv cable. When i had the pan off to change the filter i verified that it was still hooked up. I also verified that it had not slipped or otherwise got out of adjustment at the carburetor. I unhooked it at the carb and could feel resistance when i pulled on it at the carb end.

03-17-2014, 10:32 AM	#4
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm It sounds as if you are having issues with the valve body repositioning to shift properly. I would have them check that area. The 700 R4 trannies have an issue with the separator plate being a little soft and the shift balls will get stuck or dislocated to cause issues such as you are describing. There are hardened separator plates on the market. __________________ Frank

03-17-2014, 01:38 PM	#5
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,494	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm I had an issue with a 4l60e that was shifting hard into second. One of the balls was stuck in the plate. I took the plate and hammered it back from the other side. Worked fine from then on for as long as i had it.

03-17-2014, 03:28 PM	#6
myyamr7 Registered User Join Date: Dec 2012 Location: Providence, RI Posts: 211	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm I just had a similar issue with my 200-4R after swapping from the small block to the big block in my truck. with the small block the trans always did shift later than it should, but my first test drive with the big block, it was shifting very late and no OD until about 65mph. After some investigating, the big block carb has a shorter throttle arm stroke, so with the TV cable hooked up and tight at full throttle, there was only about 1" of throw in the arm. The TV cable needs about 1.5" of throw to work properly. The tighter the cable is, the higher your shift points. I made the correction to mine and gave it 1.5" of throw, tight at full throttle and it works better than ever. If you didn't change anything recently, try backing off on the cable a little at a time and see if it makes a difference __________________ Mark 71 C10 Cheyenne 12 Aprilia RSV4

03-17-2014, 04:08 PM	#7
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm How do you know the TV cable was "properly" adjusted? Are you certain the pivot point is exactly the same as whatever OEM setup it came off of? It's not as simple as cycling it with the button pushed, though that often gets you close. Sounds to me like insufficient line pressure cooked the clutches. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

03-23-2014, 09:23 AM	#9
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm Except second gear uses a band Even if the TV is stuck the trans should upshift eventually. You might need the truck to obtain 30-40 mph to make it happen. If it refuses to upshift I would look closely at the governor valve. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

03-23-2014, 09:27 AM	#10
muckyp Registered User Join Date: Mar 2001 Location: Forney, Texas Posts: 290	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm I had a friend last week have what sounds like the same problem as you. I believe the trans shop replaced the modulator and all was well. My friend thought they said the modulator gear but I'm not sure what that is, so I am assuming it was the modulator. Either way it must have been simple and cheap cause they didn't charge him. __________________ 70 SWB 454/TH400

03-23-2014, 05:39 PM	#11
BustedCrank Registered User Join Date: Mar 2013 Location: In the rain Posts: 17	Re: 700r4 trNs trouble. Only has 1st and reverse shift s to others at high rpm Is it stuck in first, or does it seem like it just won't catch second? If the governor is stripped (just a little plastic gear), it will drop back to idle after you let off the throttle, instead of staying up in rpms like if you have the shifter in the first gear position. I have had this happen, I could play with it a bit and get it to grab second gear, then it would drive normally until I came to a stop. If you can get it going fast enough in first, and let off, and it catches third...then your 2/4 band isn't catching.



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