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(Update: TCC issue) The great 700r4 debacle of 2016.
See last post; I'm now troubleshooting a TCC lockup issue.
TL;DR: Slipping in 4th locked up; do the 3-4 steels in the picture below look normal?
I am still having trouble with my 700r4. What I thought was just a bad torque converter might be a bigger issue. I was experiencing slipping in 4th gear at low rpm high load (i.e. on a hill) when locked up with my old torque converter. Now have a Vigilante converter, and it's slipping pretty bad when it's supposedly locked up. It will go into lockup (rpm drop), but a small increase in throttle will raise the rpm and letting off will drop back down. I'm not sure if it's the lock-up or the 3-4 pack going. I put a new TCC solenoid in, sonnax TCC valve with the seal, and the input shaft o-ring is still there. I wish I would have replaced it when I had the TC off, since it's seen 3 different torque converts now, but it's not cut and was replaced when I rebuilt the trans.
Today when I was entering the highway I had a pretty bad lack of acceleration. The RPMs were pretty high but not much was happening. Unfortunately I couldn't tell what gear I was in, and I wasn't datalogging at the time so I can't say for sure it wasn't just thinking there was knock and pulling timing.
When I was replacing the 2-4 band, I checked the 3-4 clutch pack. Is it normal for the steels to be black like in the attached picture? The 3rd gear shift has always been pretty hard after the rebuild, in case that's important. It kind of sucks when you get done pulling and replacing it for the 4th time only to find it still isn't working right.
Last edited by someone972; 07-30-2016 at 01:32 PM.
Oh boy. So that probably means my 3-4 is toast. Replacing it won't be too hard, but now I need to figure out why this happened because if I do the same thing again I'll just end up with toasted clutches again. What would cause the 3-4's to toast? Maybe I got the clearance wrong, I did have a bit of trouble getting a good reading on the 3-4 clearance.
When I get around to rebuilding the 3-4 pack, I should probably check the 3rd accumulator check valve that goes into the servo bore for leakage. It's been a while since I rebuilt it but I may have neglected to do that step last time . I guess I should also check the input drum for leakage around the input shaft where it's pressed in and double check the 3-4 apply piston is holding pressure. Anything else?
The TV cable has always been adjusted properly, it has at least not been loose. When I installed it I verified that full pedal depression equaled full depression of the TV valve.
I installed the street strip kit from Pro-Built https://www.700r4l60e.com/store/prod...&cat=19&page=1. Here's the parts list for the 3-4 pack:
8 3-4 clutches (Hi-Energy), Borg-Warner .080
3 3-4 steels Kolene .060
5 3-4 steels Kolene .080
1 3-4 top pressure plate .128
1 3-4 bottom pressure plate .128
1 3-4 snap ring .062
When I installed it I ended up using my old 3-4 snap ring to get the clearance in the range suggested. I can't remember if it was thicker or thinner than the one Dana supplies, I think probably thicker? The only other mods I've done to the transmission are a sonnax super 4th servo and sonnax TCC valve with the seal on the end.
If anyone has any ideas on why the torque converter clutch applies, but applies weakly (slips under very moderate acceleration), let me know. I'll be poking around this weekend trying to figure it out. I've been driving it with the TCC disabled and it otherwise seems to work fine, so 3-4 pack is most likely OK.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
An update: I hooked directly up to the transmission to engage/disengage the TCC. Measured 25 ohm across the wires, and 0.47 A current when engaged. Directly controlling it did not help the issue. It takes about 3 seconds from flipping the switch until it locks up, but unlocking is instant. Once you feel it lock up it slips very easily. Any ideas?
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
Alright, dropped the pan, the solenoid holds 25 psi of pressure (max my little pump goes to) when engaged, and starts building pressure as soon as the switch is flipped. It releases when disengaged, will hold a residual 5 psi or so but releases any pressure above that. The o-ring on the solenoid looks fine and fits tight in the bore. I took a punch and pushed the TCC valve in and out and it seemed to move just fine. Current suspicions are either the o-ring on the input shaft has been damaged or is undersized from the other torque converters I've had on here. Next weekend I'll be pulling the trans to replace the o-ring, and if that doesn't fix it pulling it again to put the old torque converter back on. If it works with that one I can only suspect that I got a bad converter somehow, unless someone has any other ideas.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
Yet another update: Pulled the transmission, replaced the input shaft o-ring and the checkball capsule just to be safe. Old o-ring looked fine, and probably was, cause I put the trans back into the car and still has a very weak lockup. Unfortunately I forgot to hook the TV valve back up at the throttle body for the first time, hopefully I did not do any lasting damage. Interestingly, I noticed an issue I've seen before with this converter in the car even before my debacle with the TV valve. It seems like something is slipping under WOT, it will feel like it's accelerating then it sort of falls flat but the RPM increases. I noticed today that it also seems to be accompanied by a sort of ticking noise. It's certainly not TC to flexplate bolts being loose or broken flexplate because I just tightened those and inspected it. I'm going to pull the trans again, install one of my old torque converters, and see if the lockup and acceleration issue are any better. If so I think I can assume faulty torque converter, otherwise I have no idea what's wrong internally with the transmission. We're getting real good at ripping and replacing the transmission now though .
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
I have a street strip pro-built trans and 2400 vig stall. Mine does the same thing you have described. Although, I had this trans mated to my stock engine and never experienced this. It was only until I mated it to the new motor that this slipping/bucking at lower speeds/rpms happened. A tune was able to fix this issue, but we were data logging this weekend, changed some parameters, and now its back. I will have to compare the two bins and see what is different. But I don't have the equipment to do it at the moment. I'm convinced it has more to do with tcc lockup speed than anything else. The pro-built trans didn't do this on my stock 150K L98.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
For my issue I pulled the Vig and put the stock 12" back in and it immediately went back to firm lockups. I sent the Vig back for warranty and got a new one, but haven't been able to install it yet to verify if it is any better or not.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
I bought mine probably 11 years ago, even though it likely has less than 5k miles on it. I doubt I'd be able to get it replaced. But good to know you're having a positive outcome.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
In reference to your photos above of the 3-4 steels, assuming those are kolene steels, they are black from the manufacturer due to the kolene treatment. Linder steels are plain steel color, kolene are black. If you have a trans from Dana, it will have kolene steels in the 3-4 clutch. The lighter color towards the inside of the steel is wear. The important thing to check now would be the 3-4 frictions. Do they look worn or burned?
Does the trans hold well in 3rd? A hard 2-3 shift may be a sign of 2-3 shift timing not set up right. If 3rd gear holds strong at full throttle, the 3-4 clutch is not the problem.
How is your 4th servo set up? Is the pin travel correct? You may need to step up to something like the Sonnax 4th servo to increase band clamping force in 4th gear if you do alot of towing.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
Apologies for the late reply. They are indeed Kolene steels from Dana's kit. Frictions looked ok. It holds good in all gears since I swapped the torque converter back. I did install a sonnax 4th servo though while I was troubleshooting. It didn't help the issue but I like being able to actually feel 4th engage and I have no qualms about having more holding power. I've been meaning to install the warrantied converter to see if it is any better than the first one but haven't gotten around to it yet.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
Originally Posted by someone972
Apologies for the late reply. They are indeed Kolene steels from Dana's kit. Frictions looked ok. It holds good in all gears since I swapped the torque converter back. I did install a sonnax 4th servo though while I was troubleshooting. It didn't help the issue but I like being able to actually feel 4th engage and I have no qualms about having more holding power. I've been meaning to install the warrantied converter to see if it is any better than the first one but haven't gotten around to it yet.
Cool. One thing I've become more aware of is the 3rd accumulator check ball. We tend to ignore it because it looks to be a PITA to replace. I've got two on order from Summit Racing for when I go back into my 700. I'm just going to replace it to be sure.
If this guy's leaking, you'll have reduced 3-4 apply pressure and can also have a slow 2nd servo release on the 2-3 shift which will tear up the 3-4 clutches.
EDIT: One thing that is never a bad idea is to verify line pressure. If you had a TCC circuit that was dumping pressure in 4th gear, you could probably see it on a 400psi gauge tapped into the line pressure test port. There are also pressure test ports for 2nd, 3rd, and 4th apply circuits if you have an issue in any one of these gear ranges.
Re: (Update: TCC issue) The great 700r4 debacle of 2016.
I went through some headaches on my 700r4 before i got it perfect, and then right as i was getting ready to pull the pressure gauge i installed my pump rotor popped.
For your input housing pistons, even a slight roll of the lip seal will fk you over.
If you have not done so use the later stamped steel bonded pistons.
They are a direct drop in, however you may need the later style spring cages.
For the down shift issue you want to look real hard at your tv valve, get a really good idea on how it should look by checking the tv mendaze site (on my mobile hard to get a link).
Make a mental note on where the tv is at at the idle setting.
I had lots of issues with mine trying to follow the transgo instructions that came with the 700p shift kit.
In the end i ignored the washer instructions and watched where the valve was sitting vs what the tv mendaz site showed and i ended up with a very very nice OD shift.
07-26-2016, 12:18 AM
. I guess I should also check the input drum for leakage around the input shaft where it's pressed in and double check the 3-4 apply piston is holding pressure. Anything else? 
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