Bought an "exotic build" 200r4 transmission for our G body (85 montecarlo). Unit has all the bells and whistles offered. Special pump, special clutches, all thrust washers replaced with rollers, many hard parts custom made from billet or heavily modified. Valve body is of this companies own design and is supposed to be based upon the best oem but with many "secret" modifications. Converter was supplied by the same company and is supposed to be around 3000 stall with no lockup feature. OK, the problem is that the unit has never worked properly but being patient, we kept sending it back in hopes that they would make it work. (unit has been in and out of the car over seven times and NEVER has worked right. SO, WHAT'S THE PROBLEM? Well, it has finally sunken in that the shop that created it, is in way over their heads and simply don't have the knowledge base to draw from to make it work. The main problem is, this is a race car. During competition, the driver makes a shift at lets say, 6500rpm. The transmission does not respond. It does not slip and the rpms do not flair but keep going up as if the next gear had never been selected. Then, at random, it will shift. This is unpredictable with regard to rpm but always happens. You simply cannot depend upon it for any kind of consistency.. Yes, fluid is full and is not ever burned. The shop contends that this is impossible and that we are just wrong. We took this unit out of service and replaced it with a th350 and the problem is gone. so, it's not us or the car. This unit has cost us over $4,000 and I'd really like to have it working.
Problem 200r4
- Thread starter 1320chevy
- Start date
This is kind of what I was thinking at first. At first I was inclined to think, broken spring, intermittent stuck valve in bore or jammed up accumulator. The governor should be bypassed, there is no accumulator or should be locked out. No need for check balls, so as you rule these things out, plus red fluid and nothing burnt??? Over running clutch fractured or shattered, but no signs or symptoms of that...
Should have the billet servo, but that's an issue with 2nd and 4th and no symptoms of that.
Shifts fine when coming back to pits, but erratic under acceleration. About only things left are issue with front pump or converter.
Because it basically acts like a manual with the clutch going out, the only thing left is fluid coupling which provides Crank RPM to the input shaft and then to the gear sets and on to the wheels... About only thing left is bad converter.
Should have the billet servo, but that's an issue with 2nd and 4th and no symptoms of that.
Shifts fine when coming back to pits, but erratic under acceleration. About only things left are issue with front pump or converter.
Because it basically acts like a manual with the clutch going out, the only thing left is fluid coupling which provides Crank RPM to the input shaft and then to the gear sets and on to the wheels... About only thing left is bad converter.
Doubt that it's the pump because that's the second pump. First one exploded.,.Actually third pump because after replacing it it leaked and I found that the back side of one of the pump housing bolts had broken through the outside. But all that aside, the problem existed before the pump change and after that was done.
my answer would either have been "how much?" or "fuel line or fuel injection line?" . even those that ask for it don't always know the difference.
regardless, don't know what's going on supply-wise but we've had a hard time getting ANY fuel line stocked in the store lately.
Yes agree, if it was the pump it wouldn't shift normally coming into the pits like you mention. Still a SWAG for what it really is, but for what you describe, it more likely sounds like converter issue.
I agree with ^^^ except the use of the term ‘bad’ haha. I’ll use the phrase ‘incorrectly spec’s’ haha.
I’ve mentioned previously, the OP is needing the converter to function extremely different than most ‘racing’ converter applications - he’s attempting to use the converter as a standard transmission type clutch imo. He meds a low stall clutch that cam handle a fair amount of power. Most low stall converters are considered ‘stock’ and/or non performance.
I could be wrong with this, but I BELIEVE this what is getting him.
Using a stock type converter would not be beneficial at all. Starting line staging would be very difficult because the converter would try and "push" the car over the line when the rpms were increased. High rpm on start, puts the engine into it's power band and ensures a good solid reaction time. and 60 foot time. Stock type converters are generally large, and that, in itself is a problem. (too much rotating mass). You could use a trans brake but with a large low rpm stall unit, it would quickly destroy itself either from heat or just plain not designed for that.
What common consensus is , is that the conveter stator sprag id likely not holding but not entirely slipping, giving it a very late and random engagement. I've researched the problem perhaps more than I ever wanted to but that's the same conclusion I've reached.
I agree. I wasn’t implying you need a stick converter, but rather a converter that reacts like a stock converter at higher rpm, but a race converter below 3500-4000 (tight).
Pete Nichols , who used to work for Hughes Performance and now works for Circle D, would be my go to guy. But I’m confident that others might be able to get you something that will work. I have a couple of friends that swear by PTC.
If I were in your boat, I’d be contacting someone that builds custom converters. I recommend Pete N because he WILL respond to messages and phone calls. I can’t say he’s the best guy for your program, but he’s not a bullshitter. I’ve pointed this out in some of my build thread late last year - he’s not a salesman that will sell you something that won’t work.
I can't afford the converter I want. I want one of the ones that are bolt together so they can be serviced or modified without having someone else do the work. Presently, they are only used by pro-mod guys and stuff of that caliber though. Why? because I really want to try out the mechanical diode being used instead of the stator sprag.
