700R4 Not Shifting
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
700R4 Not Shifting
Working on a 700R4. The TV cable is and was adjusted per GM. It shifts all 4 gears perfect when it's cold. As soon as it gets hot (not just warm- hot) it won't shift 2-3 or 3-4. If I rev the engine 6000rpm+ it does a soft shift 2-3 and/or 3-4. Whatever it is, it's temp related. What should I look at first?
Racer
Joined: Mar 2012
Posts: 476
Likes: 37
From: Lynnwood WA
I had a problem with my 700R4 not shifting, that I traced to the governor. The piston inside it was hanging up. I pulled it out and used some gun cleaning stuff (patches and oil) on it and it worked for a few weeks, until I replaced it. No sure if that is your problem or not, but it is easy and free to check. Mine was also a tip that the trans had other problems in the past. It smelled like it had been in a house fire! 
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
The GM service manual suggests a seal failure as well, but does not address the temperature as a contributing factor. It's the temperature that is throwing me off. I also suspected the governor but have a hard tme seeing how the governor can work fine when cold and then not work when it gets hot. The governor is a pretty simple mechanical device. It has no temp controlled features. The trans does have the TCC system (Transmission Converter Clutch) and there is a TCC solenoid on the valve body. There is also a 3rd clutch switch and a 4th clutch switch on the valve body but I can't see these failing at the same time and again, the temperature influence doesn't make sense. I'll pull the governor and take a look at it. The first suggestion (internal seal) I suppose is possible... a seal failing as it gets hot. That means a pull/rebuild. The service manual also suggests a failed TC but again, no reference to temp related failure.
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
The governor is mainly WOT shift points , if you getting a 6k shift it appears o be working. You can drop the pan and test each pressure switch to make sure there not leaking , and also when you have it off you will see an accumulation of minute particles if this is excessive or a paste like dark grey sludge that would suggest some worn clutches.
A temp sensitive issue is not uncommon to a transmission matter of fact it is pretty common across the wide variety of car manufactures.
A temp sensitive issue is not uncommon to a transmission matter of fact it is pretty common across the wide variety of car manufactures.
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
The governor is mainly WOT shift points , if you getting a 6k shift it appears o be working. You can drop the pan and test each pressure switch to make sure there not leaking , and also when you have it off you will see an accumulation of minute particles if this is excessive or a paste like dark grey sludge that would suggest some worn clutches.
A temp sensitive issue is not uncommon to a transmission matter of fact it is pretty common across the wide variety of car manufactures.
A temp sensitive issue is not uncommon to a transmission matter of fact it is pretty common across the wide variety of car manufactures.
Racer
Joined: Mar 2003
Posts: 448
Likes: 21
From: Klein Texas
If the trans will shift, but at extremely high RPM, then you have a TV valve sticking in the valve body. If the trans just flat refuses to shift then the problem is the governor.
And yes, these metal parts expand with temperature
And yes, these metal parts expand with temperature
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Instructor
Joined: Nov 2011
Posts: 183
Likes: 0
probley in the clutch drum fluid gets thinner the hotter it gets and seals loose there tension also so id have to say its in the clutch drum built many 700r4s if it was the governer it wouldnt shift at all and the tv valve makes it shift high or low if stuck
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
Yes... temp related problems are common. I just can't figure out which component in this 700R4 is failing under high temp. It affects 2-3 and 3-4 shifts. The TCC (lockup) switch is in series with a temp switch and a 4th gear switch. When the trans is hot and in 4th gear, a ground is provided to the TCC switch which causes TC lockup. So this temp switch cannot be the culprit. I.E.- the problem is also 2-3 shift related. I could be wrong, but I don't see a wiring connection between the 3rd gear clutch switch and the temp switch.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
No matter what you do to fix the issue at hand, you need a LARGE, no, HUMONGOUS trans cooler in that thing.....how about another a/c condenser from a junkyard, mounted between the a/c cond and the radiator.....largest one your can hammer in there.....
IF I could run all my transmissions at 30f, I would.....
anything over 180f pan temp is BAD.....
IF I could run all my transmissions at 30f, I would.....
anything over 180f pan temp is BAD.....
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
you have to find what is common between 3rd and 4th gears. according to this chart the forward clutch and 3-4 clutch are both common. my guess is the 3-4 apply piston seal is leaking, causing the thinner hot fluid to leak by when it's hot. I would replace the 3-4 clutches also, if there's a pressure leak, they're most likely wearing faster then they should be.
According to the chart:
A 2-3 shift occurs when the 2-4 band is released and the 3-4 clutch is applied.
A 3-4 shift occurs when the 2-4 band is applied and the forward sprag clutch assembly is released, with the 3-4 clutch holding.
When I take it to redline when hot, it shifts from 2-3 and then I have to take it to redline again to get a 3-4 shift.
The common denominator does seem to be the 3-4 clutch.
I am assuming the bands are okay since it shifts and drives fine when cold. I'll pull the pan today to see what it looks like. I have to dig up the gaskets for the valve body. Off to my local Transtar.
Thanks for the chart.
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
No matter what you do to fix the issue at hand, you need a LARGE, no, HUMONGOUS trans cooler in that thing.....how about another a/c condenser from a junkyard, mounted between the a/c cond and the radiator.....largest one your can hammer in there.....
IF I could run all my transmissions at 30f, I would.....
anything over 180f pan temp is BAD.....
IF I could run all my transmissions at 30f, I would.....
anything over 180f pan temp is BAD.....
Instructor
Joined: Nov 2011
Posts: 183
Likes: 0
yes most 700r4 when they go bad you will find 3-4 burnt band worn bad reverse input drum scored up if you are planning to rebuild it your self use a master kit for a 98-02 4l60e they replaced the lip seals with molded pistons only thing you need to change in the drum is the return spring retainer that sets on the piston this will make your life easier when u rebuild this drum plus the pistons seal better order new realease springs for the 3-4 clutch pack
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Update... I did as much as I can with the tranny in the car... after putting it all back together and running diag on it, it appears that the torque converter is bad. It's a "RECON" from Transtar and had a history of "shudder" since installed. Unfortunately, the melt down caused collateral damage so I am just going to pull it and rebuild it. I''ll use a "new" (not rebuilt) TCI torque converter from Summit, along with "The Beast" reactor sun shell. Already picked up the "kit" but expect to have to replace other parts as needed (standard procedure on these).
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
The T/C has nothing to do with the shifting . The shudder you mention could easily be to early of an engagement of the T/C clutch ( To low a speed ) or in proper fuel metering because a carb can not deliver fuel correctly in a very high load low rpm situation , that is why you always find O/D units connected to fuel injected cars that have the needed sensors to automatically adjust fuel delivery.
Anyway I do agree you need to pull and go through the tranny , BUT when you put it back make sure your lock up system delays until you have a sufficient RPM to sustain the lock up.
Also if your running a rear gear lower the 3.55 on a carb motor the T/C lock up system needs to be set to never engage below 45 mph and even at that speed you may feel the surging or lugging or even the on and off of it as you slowly move up and down in speed.
Anyway I do agree you need to pull and go through the tranny , BUT when you put it back make sure your lock up system delays until you have a sufficient RPM to sustain the lock up.
Also if your running a rear gear lower the 3.55 on a carb motor the T/C lock up system needs to be set to never engage below 45 mph and even at that speed you may feel the surging or lugging or even the on and off of it as you slowly move up and down in speed.
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Thanks for the tips.
This unit has the wiring and controls for "TCC" and the GM Service Manual lists "bad torque converter" for a cause of failure to shift... so that is one of the things I considered. I am also skeptical of my diagnosis of the TC but with everything else in supposed working order and the GM shop manual pointing to the TC, I took a stab at it. I'll do a more thorough examination of the valve body when I get it on the bench. I had it on the bench 5 years ago and I remember checking all of the valves for smooth operation. A few of them were sticky but I thought I fixed those. The shudder is between 1800 & 4000rpm and was worse when cold. When it warmed up, the shudder reduced. The stall speed was supposed to be 1600-1800 but the RECON # of the one they gave me crosses to 1400-1600. I wanted the 1400-1600 so I didn't complain.
This is a small rectangular magnet (not the correct donut) in the pan..
I'm not going to fool around with this.. it's getting an overhaul and a new TC.
I expect to find a number of other worn out parts that I'll have to order. The last one I did needed a forward sprague, internal reaction gear support, and a new pump.
This unit has the wiring and controls for "TCC" and the GM Service Manual lists "bad torque converter" for a cause of failure to shift... so that is one of the things I considered. I am also skeptical of my diagnosis of the TC but with everything else in supposed working order and the GM shop manual pointing to the TC, I took a stab at it. I'll do a more thorough examination of the valve body when I get it on the bench. I had it on the bench 5 years ago and I remember checking all of the valves for smooth operation. A few of them were sticky but I thought I fixed those. The shudder is between 1800 & 4000rpm and was worse when cold. When it warmed up, the shudder reduced. The stall speed was supposed to be 1600-1800 but the RECON # of the one they gave me crosses to 1400-1600. I wanted the 1400-1600 so I didn't complain.
This is a small rectangular magnet (not the correct donut) in the pan..
I'm not going to fool around with this.. it's getting an overhaul and a new TC.
I expect to find a number of other worn out parts that I'll have to order. The last one I did needed a forward sprague, internal reaction gear support, and a new pump.
Last edited by Tom454; Apr 10, 2013 at 09:54 AM. Reason: typos
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Unless the pump body is scored, just upgrade yours to a 10 or 13 vane with hardened rings. Use a Trans-Go shift kit. Don't forget the little screens in the case for the governor and the TCC.
Look at the rear planetary set- the outer shell parking lugs should have the corners rounded and an oil slinger on the back of the inner to help keep it in the oil.
Look at the rear planetary set- the outer shell parking lugs should have the corners rounded and an oil slinger on the back of the inner to help keep it in the oil.
Thread Starter
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Unless the pump body is scored, just upgrade yours to a 10 or 13 vane with hardened rings. Use a Trans-Go shift kit. Don't forget the little screens in the case for the governor and the TCC.
Look at the rear planetary set- the outer shell parking lugs should have the corners rounded and an oil slinger on the back of the inner to help keep it in the oil.
Look at the rear planetary set- the outer shell parking lugs should have the corners rounded and an oil slinger on the back of the inner to help keep it in the oil.
I was going to do that 13 vane upgrade (#A74531CK) the last time around but the pump was toast. I didn't want to tear apart a fresh rebuilt pump so I let it ride. I suspect this will also be the case with this one.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
The BEAST shell housing comes in two varieties....one takes the stock thrust bearing, the one you WANT however is naturally a bit more expensive but comes with a TORRINGTON thrust bearing...roller bearing....that's what is in my motor home.....8000 GVW....
Last edited by mrvette; Apr 10, 2013 at 02:18 PM.