Problem 200r4

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1320chevy

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Jun 23, 2023
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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.
 
I'm curious if issue isn't converter driven as well.

You mention coming into pits, it shifts on command, yet under load it's shifts are inconsistent. This could be fluid coupling issue and that is the converter.
Might be something to look into. I could send the converter out and have it opened or I could put the factory "d" converter back in it just for laughs. Either way, not doing it "till after race season is over though. Enough to keep me busy without extra work. The only thing that tells me it may not be the case is that originally, that converter was a lockup and Extreme had it re-worked to eliminate the lock up clutches etc. It never shifted correctly from the day we got it, regardless of what else was done to it.
 
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Did they hand craft the main spool valve and did they set the governor? If this was just a regular trans I would be inclined to check governor for proper operation and in this case I think it should be locked. What power adder do you have? Are you running boost or nitrous, both? If 6500 is you shift point what is the HP there? What is the torque curve like at that point?

On the TH350 when you shift at (_______) where does your rpm drop? And how fast to recover to next shift point at (_______)?

The random shifting you experience is indicative of valve sticking in the valve body bore or accumulator piston sticking, cocked in the bore, or broken spring.

I'll dig into some of the books, because believe it or not..., I might be wrong. But every thing you mention tells me valve body issue. If loss is 2nd or 4th it's the band, but you mention no flare, so..., hmmmm.
It was sent back once because I couldn't move the shifter with the engine running. It felt like one I had in my shop in a firechicken that was actually making ground through the shift cable and welding it in place. Only difference was that if you disconnected the cable and tried to move the shift ear with pliers, it would not move, Extreme never told me what caused it. I don't have the shift rpm numbers but when I was working it out, the drop off wasn't a lot on any shift. If it was a pro mod car, I would have entertained using the overdrive and lockup but we'd need a lot more engine to take advantage of that. There was some difference between the 200 and the 350 but it was expected because of the different gear spread. I originally chose the 200 because the spread was good and the only drawback was the factory flaws (that were supposed to have been cured by their design changes) The unit has pretty much no metering internally. No governor or accumulators either. Even at low speeds shifting sounds and feels like a fifty pound slide hammer. As far as Mr Diers goes, I saw a video of him bragging about how much better the 400's are and that the 200 should never be used in racing. And I know for a fact he put a 400 in his own racemobile. So, he really believes in his product?
The way I do a build, I don't create a situation where the engine has to make massive power to compensate for the deficiencies in other areas. The only concession I make is putting a 9" rear with a locker in the back. A 12 bolt would pull less power but a locker outlasts them. My big mistake was sending a stupid amount of $ on what amounts to an experimental part. Extreme advertises "where winning is easy".... Maybe, if they let you out of the funny farm after trying to make their crap work. (Later, I'll tell you how I really feel about this)
 
Exactly. He could be moving the shift lever and the trans is shifting but the rpm’s don’t drop - big power, small tire guys send their converters back (or have bolt together) to get them to respond in that manner.

Like I mentioned, a couple trips down a drag strip with some info would identify it in a hurry.

Steve Morris posted a video last night of the last day out with his wagon- it hangs at 8000 rpm’s through 3 gears and keeps accelerating.
Morris builds some interesting stuff. If I had his $ I would too. Nothing like cubic dollars.
 
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I did some diving last night, until the phone died, found this.


Seems like you are not the only one. I'm not directly experienced with Extreme and I want to offer the benefit of the doubt, but something there isn't right. In this other case Lonnie offered to buy it back and that's honorable. Any good shop should do the same. I know if it were mine I would have offered the same, yet I would have also focused on finding the root cause and fixing it if possible.

My gut feeling, and this is only blue sky here, but I wonder if they didn't just add the TCI manual valve body (MVB)??

Transmissions can be kind of funky at times, and especially when changing from OEM to total custom work.

At the time 2004R rolled out it was at the beginning of our current EPA nightmare. You have to figure the 2004R would be in an Oldsmobile 98 4 Door Cabin Cruiser mated to a 307. Not anything that anyone would call "performance", but it increased MPG, and that's what the OEM needed, and that was why it was created.

On TH350 that is running good, did you change the TQ Converter?
New converter with the 350. Didn't think the one from the 200 would have fit and even if it did, I don't like doing a job twice. They did sorta offer to buy it back but I really wanted to make it work. The decision to use a 200 wasn't a casual one. The "buy back" would have cost us money because they wanted us to pay all shipping charges etc. They offered a 400 as a possible swap but shipping, changing the crossmember and shortening or replacing the new driveshaft seemed like a deal breaker. I asked for a wholesale price on a different converter but they shot the idea down.
 
Yep I hear you. Sounds like you're on the right track. I'm surprised they shot down helping with getting you a new converter..., seems too easy. The Th350 is a gear pump and 2004r is vane, but the billet new stuff is 32 spline large diameter stuff so should interchange. TH350 (old school) running 27 spline narrow diameter would had shredded by now. I'll have to verify, but I believe the billet stator support and corresponding input shaft should both be the same.
 
This design has no tv cable. Everything is fully manual.
i'm not a transmission expert by means BUT no tv? again all i know is power goes in -----> all kinds of magical stuff happens and power goes out------> turns rear wheels... this way over my head but if this a drag car why not something else aside from a 200 4r (and i like the 200 4r)? i'm guessing something in the valve body. feel free to not reply cuz i dont know anything.
 
Yep I hear you. Sounds like you're on the right track. I'm surprised they shot down helping with getting you a new converter..., seems too easy. The Th350 is a gear pump and 2004r is vane, but the billet new stuff is 32 spline large diameter stuff so should interchange. TH350 (old school) running 27 spline narrow diameter would had shredded by now. I'll have to verify, but I believe the billet stator support and corresponding input shaft should both be the same.
Well, now being next to, instead of in the middle of this problem, I'm starting to think that part of the actual problem is not Extreme, but lies with Chris (builder for extreme). I don't think that Lonnie has any idea how many times I have been on the phone with Chris, attempting to talk out the problem. Thinking about it, I got no real solutions from him and many times he contradicted himself but not to be combative, I said nothing. Once telling me that since he can't figure it out, it's "impossible" that it does what we claim, and to "run the crap out of it and maybe it will break" so he can finally fix it...... Even the negotiation about a return, swap, or other remedy was by him supposedly after talking to Lonnie, felt like a sleazy deal.
I don't think Lonnie even actually knows how many times the trans was back at his shop. Even after having the unit "refreshed" (on our dime) they still couldn't tell me anything, and actually LOST the transmission (but I found it) (should have left it lost).
I think it may be a converter problem but don't play off of what I think, that could be my lack of trans knowledge sending me in the wrong direction. And yeah, If we had gotten a better converter, I might not be sitting here writing about what a piece of crap we have. Simple solution that may have actually worked. The up side to all of this is that I'm now great at R&R ing 200r4 transmissions!!
 
Mechanically (my opinion) I think you have a bad converter with possible valve body issue.

I think on the other, talk to Lonnie.
It's amazing that I've gotten more substantive ideas and answers in a few days than I did in a few years from Extreme. I think we will keep our eyes open for a decent converter and maybe put it back in the car next season.
Thanks to everyone who replied.
As far as dealing with extreme in the future, NO..... NEVER HAPPEN. We paid them good money and what we got was a very long headache!!!
 
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Did they hand craft the main spool valve and did they set the governor? If this was just a regular trans I would be inclined to check governor for proper operation and in this case I think it should be locked. What power adder do you have? Are you running boost or nitrous, both? If 6500 is you shift point what is the HP there? What is the torque curve like at that point?

On the TH350 when you shift at (_______) where does your rpm drop? And how fast to recover to next shift point at (_______)?

The random shifting you experience is indicative of valve sticking in the valve body bore or accumulator piston sticking, cocked in the bore, or broken spring.

I'll dig into some of the books, because believe it or not..., I might be wrong. But every thing you mention tells me valve body issue. If loss is 2nd or 4th it's the band, but you mention no flare, so..., hmmmm.
Engine is a 383 long rod with aluminium heads, Lunati Voodo cam and a performer air gap manifold, Bottom end is all forged parts and a good number of modifications to literally everything in the build. Diff id a 4:30 detroit locker It's an NA design with no adders. Making a guess, probably around high 400's hp based on trap numbers etc. One thing i"m still working out is that the acceleration curve seems to be like a rocket, then flattens out and in high gear runs like a pro stocker. Trying to un flatten mid range.
 
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