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Hi everyone. Been a while. I've been loving this trans since my last build 5 years ago. Especially with the new 3.70 gears and the 9" ford rear behind it. Crazy s**t though, the pump drive hub on the Edge converter sheered halfway off. I see one of the two pump rotor lugs in gone. I expect the OE pump rotor failed first and took the converter with it. Dana at Probuilt Automatics, who is my go to tranny guru, ordered this converter for me way back and it has been a great part of this brutus transmission.
But, now that I am faced with replacing it and of course the front pump, I want to ask for opinions on torque converter options for the 700R4. I've heard various opinions before on the Edge converters. I want to know if anyone has input and what unit you run, what you recommend. I'll be calling Edge today to see what they think about the failure and what they offer as an option. If it was, as I suspect the pump rotor that failed, maybe the same converter would be fine. I just need to build a better pump. I'm looking at the TCI pump with billet rotor. Any thoughts?
Give Dana a call and have him rebuild the pump (if salvageable) or build a replacement pump.
These pumps need to be blue-printed in order to last with some power.
Billet steel pump rotors are generally never needed if the pump was blue-printed and the torque-converter spacing was correct.
If all this is done and the rotor fails... the torque-converter is usually to blame.
There are two dozen great companies who make great torque-converters...
I would see what Dana has available... parts have been scarce and difficult to obtain for the last year.
If you are going with an engine over 750 HP, tell Dana this... he will usually consult me for the transmission build since I build these up to 1,200 HP.
I will only use a Yank converter. I am sure Dana will approve. I've been recommending them to any car I tune and they have never let me down.
Installation is critical, you can't just bolt it on and go. The distance between the flexplate and converter needs to be measured and set "converter pullout" Is a very specific number to engage the pump deeply but not too deep.
You must fill with fluid before installation as well... don't forget this.
Its also easy (apparently) to install incorrectly to the splines... or something.... I forgot exactly what it is people are doing from time to time but I guess some folks don't engage the converter properly during initial install and that also creates big problems.
So pay attention and follow instructions no matter what converter you use, common sense
Just make sure you check every converter before installing.
Put the bottom 2 links together on FB. Some language warning. https://www.facebook.com/
biltriteconverters/videos/495342814795168
Ideally, a new Torque-Converter should be obtained while rebuilding the transmission.
This is so that the Turbine-Shaft (alone) can be inserted into the new Torque-Converter; ensuring fitment and rotation without issues.
The Stator-Support Tube or Rear Pump half should also be inserted into the Torque-Converter; ensuring proper fitment.
Lastly the Transmission Pump Rotor should also be installed on the Hub of the Torque-Converter; ensuring proper fitment.
For the THM700-R4:
-Target a 1/8" (0.125") gap between the Flex-Plate and Torque-Converter.
-Use drill-bits to insert into the gap (a dial caliper is usually too large to fit in this space).
-Use washers if needed to establish proper spacing between the Flex-Plate and Torque-Converter.
-1/16" to 3/16" is considered to be the acceptable range for this application.
-Obtain drill-bits in those sizes to try and establish spacing within the acceptable range.
If using a large amount of Nitrous-Oxide or have an engine producing over 750 HP...
I would recommend different spacing specifications.
So ask, if you need to.
In regard to what Kingtal0n said about Flex-Plate to Torque-Converter spacing and failure to properly install the Torque-Converter fully.
Should the Torque-Converter not be installed deeply enough...
The Pump Rotor may only be partially engaged or NOT engaged; causing damage/ or failure.
Also, yes... Always prefill the torque-converter with ATF.
You have to be patient as the fill process goes very slowly.
Torque-Converter size will determine how much ATF will go inside (try and get as close to a quart as possible... smaller unit will not take that much).
Thanks for the great feedback guys. I know that TCI isn't always the best. But, they do offer parts that few others do. Like the speedo drive gear and housing that I got from them when I installed the 3.70 rear gears, and a billet rotor pump. I measure and check everything before I assemble, including the pump. If there was any issue with TCI's part, I would find it before it went in my trans. As it is, TCI is backordered til 7/1, at least through Summit. That leaves me looking at other options. I will contact Dana about the pump. I will go with a billet rotor this time regardless. It's for the same reason we run a chrome moly crankshaft. The nodular may be fine, but the chrome moly is virtually bullet proof.
I know my assembly and install were solid. This trans has been bulletproof for 6 years now. I have 1/8" clearance between the TC and flexplate. The Edge street strip converter is a 9.5". It holds 1.5qt before you end up with fluid pouring out when you stuff it. I'm quite confident that the converter had nothing to do with the failure. The rotor broke because of many trips to the 7K RPM rev limiter. The broken rotor took out the converter hub. I've long held that the MSD soft rev bounce is hard on trans parts. I try not to hit it but I do it way too much.
Dana hooked me up with the Edge converter and it's been a good part. If I installed the same one again, with a billet rotor that wont come apart, I'm sure it would do fine. My question for Edge, or anyone else is whether their street strip unit is enough for my future plans. I will be installing a 400cid in a few years close to 600hp. I don't want to have to buy another converter. I can have the one I buy now re-stalled if needed.
I will talk to Yank as well and see what they have to offer.
I opened up the pump today. The rotor is in 4 pieces. The wear surfaces are scarred pretty good. It may be machinable but would have to remove too much material. Oh, I did find the missing piece of the converter hub. Wonder if some superglue....... Good news is absolutely nothing came out of the pump. Not one spec of shrapnel. The fluid is like brand new, the pan is clean. Even the magnet hardly has any metal dust on it. For one thing that's a testament to going full roller, replacing all thrust washers with Torringtons. While it's not convenient timing, at least this breakdown gives me an opportunity to correct the almost imperceptible bind on my 2-3 shift. Just one tiny bit bigger on hole G should do it.
I hope to speak with Dana tonight about a new pump. I spoke with Edge and they will rebuild their converter back to new condition for $190 with a one week turn around. I'm shipping it out them after work today.
I hope to speak with Dana tonight about a new pump. I spoke with Edge and they will rebuild their converter back to new condition for $190 with a one week turn around. I'm shipping it out them after work today.
Dana would be your best choice!
He has been blue-printing these pumps for a very long time.
If you plan on the HP being around 650 or higher... tell him to give me a call about line-pressure and TV-pressure that I set for higher HP builds.
I never did this on my last rebuild, but that was for my truck using stock application parts.
So to make sure I fully understand, this method basically bottoms the torque converter snout into the pump half.
this area shown here in yellow.
You set up for ~0.120 clearance, so that when you tighten it down to the flex plate using washers (as shown in this example) the converter snout pulls away from the pump half and leaves ~0.120" clearance? This ensures it doesn't rub the pump housing and also full engages the pump rotor?
Setting the space between the Flex-Plate and the Torque-Converter is to ensure that the Hub of the Torque-Converter remains properly engaged to the Transmission Pump Rotor.
The Flex-Plate actually Flexes... It is designed to do so... it is the purpose of the Flex-Plate verses a Fly-Wheel.
As the Flex-Plate flexes, the Torque-Converter hub will move back and forth very little inside the Pump Rotor.
The spacing is set to prevent the Pump Rotor from getting crushed and breaking...
As well as maintaining contact of the Torque-Converter Hub to the two Drive-Tangs of the Pump Rotor.
Inspecting the broken rotor from my pump, I can see that it could have used more drive hub engagement. I'll try to post some photos, maybe this weekend, but the rotor tangs are chewed off about 2/3 down, meaning I had about 3/16" of clearance. I'm replacing my flexplate and when I go to install the trans, I'll make sure I end up with .120" clearance. Everything is on its way. Dana is backlogged on pumps and can't help me right now. I have two cores that I'll have machined and rebuild to keep as replacements. Meantime, I have a pump coming from Monster. I'll go through it and make sure it's good to go before I install it.
I pulled the VB this weekend and increased hole G from .125 to .140(the next drill size, 1/64" larger). I hope the up size will clean up my 2-3 shift. It's been a little tight ever since I switched from the Superior servo to the Sonnax. I suppose it's the cushion springs that make the difference. If it ends up being too slow a shift, I have an extra separator plate I can set up and try again.
I'm redesigning my TCC control with this install. My TCC wasn't working for a minute before the pump failure. I tested my 4th gear pressure switch and found it's not closing. I've had issues with these switches in the past when their used to switch the TCC solenoid directly. I had mine switching the ground side of the solenoid and it didn't last very long. I have ACCEL DFI which uses a relay to power the TCC solenoid. Unfortunately, on the Gen 6, ACCEL never did implement TCC control into the programming. The ECM simply turns the relay on when the key is on. ACCEL's instructions direct the installer to simply use the relay output like ign. on power and wire TCC control as if the ECM control didn't exist. What I'm doing with the redesign is using the 4th gear pressure switch to operate the relay, vs. the solenoid. The relay will place less load on the switch and it should hold up better. I'll also add a switch to enable/disable TCC control.
Should be ready to reassemble and install weekend after next. I'll try to post some photos and update this thread when the job's done.
I would pass on Edge. I bought a 12” converter 2 years ago for the 700R4 in my truck. Trans was rebuilt by me 7 years ago with a different converter. Anyway, installed and had almost 1/4" clearance, pilot loose in back of crank. tried various shims and no shims had bad vibration even at a standstill in neutral. Pulled trans in early September and sent converter back down to Edge (from Canada, $110 CND). claimed it was perfect, balanced fine,etc. months go by,sometime in January and get back in contact.now the story is I can add 1/8" onto the pilot or give you a refund. I took the refund and went with Circle D. Waiting on exhaust so cant comment yet, but clearance was much closer, 0.060” shim got me into the 0.125" range.
I had an Edge 9.5 converter i bought over 12 years ago from Dana @ Probuilt. Was never really happy with it, though i was a lot younger then and have got full circle on what I want. Have read others over the years that said their Edge converter was slower than others, but after my most recent run in, never again.
are you using 1 terminal or 2 terminal 4th gear switch? GM ran 1 terminal 4th gear switch to complete ground on TCC solenoid from factory. My 2004R was setup like this as well as my current setup in my truck with 700R4. No issues. Are you sure there isn’t a problem on the + side of things? factory has a brake switch, vac switch and all the wiring between.
Hi Morgsie. I have verified power to pin A and ground on pin B of the 4 pin connector. I do use a 2 pin switch. I could just as easily use a 1 pin with the way I have the circuit wired now. I was using a switch on the ground side of the solenoid, connected to the 2 pin press switch, to enable/disable the TCC. Now, I'll be using the same switch to control activation of the relay. ACCEL DFI gen 6 is very similar ECM to the factory GM in 1987. One difference is they use a relay to control TCC solenoid.
Quick update: Talked to Edge today. Converter is finished and on it's way back to me. My pump should be finished and ready to go in by this weekend if the planets align in my favor. Hey morgsie, just now saw your comment on Edge Converters. Sorry to hear you had a bad experience. I went with Edge because of Dana's recommendation. I've been happy with the converter's stall rate. The alignment hub fits the crankshaft just fine, no vibration. I'll see where my clearance comes out, how much I have to shim the converter, with the new flexplate and rebuilt pump.
Hi again folks. Thanks to everyone who contributed to this thread. Particularly the discussion on setting torque converter hub clearance. I don't remember ever looking at that before. I certainly hadn't shimmed the Edge converter when I installed it originally. Got the transmission back together and installed this past weekend. Installed a new flexplate and set converter clearance to .120". Without shims it was .155". Added .035" shims to get.120". I went through the pump and installed a set of Transgo steel rings I've had laying around. Also installed a Sonnax heavy slide spring and my .296 int. and .500 main boost valves. Was pleased to find the builder had already removed the second land on the reg. valve, Transgo's cooler flow mod. With warm oil, I get 95 psi at idle and 250-270 at 3,500 hard throttle. I forgot to run a bay test at 1,000 and 2,000 base and full TV. The results I got on my road test tell me the pump is doing alright.
Andre changed up the stall in my converter just a little during his repair. It's got a nice little kick to 4,300 at hard throttle that wasn't there before. I think he might have increased the ratio just a bit too. I like the change. I plan to finish my tunnel ram EFI intake this summer. The slight raise in stall will fit that very nicely.
I'm still not sure what caused the rotor on my last pump to crack up. Dana says it's very rare and unusual. I know that a billet pump rotor isn't generally necessary but I still plan to build my two spare pumps with billet rotors. Anything to be sure that a repeat rotor failure never happens. These two pumps, one of them being the broken rotor victim, are in good shape. I'll have the pockets and faces refinished and have clearances machined to .002". For now, my IROC is back on the road for summer. I'd like to say I'll be easy on the new pump for a while, but I probably won't.
04-22-2021, 09:58 AM
Good news is absolutely nothing came out of the pump. Not one spec of shrapnel. The fluid is like brand new, the pan is clean. Even the magnet hardly has any metal dust on it. For one thing that's a testament to going full roller, replacing all thrust washers with Torringtons. While it's not convenient timing, at least this breakdown gives me an opportunity to correct the almost imperceptible bind on my 2-3 shift. Just one tiny bit bigger on hole G should do it.
