200 4R "whine" at slow speeds

[Ttype6]

and the builder confirmed that yes, their transmissions are built that way and will do that.

What he is saying is that if he notices that the trans doesn't clunk during a 3-2 shift,he will do whatever it takes to create a downshift clunk. Does that make sense? I can here him instructing his people by saying "Make sure each one of these transmissions has a real good downshift clunk before they are shipped or your fired."
Eliminating the cushion spring not only creates an annoying downshift clunk,it will elongate the hole in the band that rides on the anchor until it rips the hole open which will necessitate the removal and disassembly of the transmission.. It is completely unnecessary and wrong to do this. Get a cushion spring in there ASAP.

 

[72Chevelle]

Heh, no, he didn't say "I build them all specifically with the intent they clunk" - what he said was that the servo he uses causes that and it is to be expected in their builds. And from something they said it implied there is no cushion spring in there. And I'm definitely not throwing them under the bus, they are a good, respected outfit. Just now that it is out of warranty, I was looking for second opinions as sometimes fresh sets of eyes/ideas are good to have, and I appreciate them from y'all. Some builders have success one way, others another way, and maybe this setup just isn't exactly right for my car.

First I will identify the issue, and if it's the torque converter (which is looking more and more likely), the tranny is coming out. If I can find a good local builder, I may take it in for some adjustments and a checkup while it is out (such as the servo spring) to make it more amenable for my car. If not, then the next step is to sit back and figure out what to do with it, as I'm not all that comfortable messing with the innards of a transmission myself.

What he is saying is that if he notices that the trans doesn't clunk during a 3-2 shift,he will do whatever it takes to create a downshift clunk. Does that make sense? I can here him instructing his people by saying "Make sure each one of these transmissions has a real good downshift clunk before they are shipped or your fired."
Eliminating the cushion spring not only creates an annoying downshift clunk,it will elongate the hole in the band that rides on the anchor until it rips the hole open which will necessitate the removal and disassembly of the transmission.. It is completely unnecessary and wrong to do this. Get a cushion spring in there ASAP.

 

[72Chevelle]

Yeah, all of my research is aiming me in that direction. Hopefully this weekend I can diagnose it enough to get down to exactly what it is, and then figure out how I'm gonna get the tranny out if I have to without pulling the motor. Have all the tools (including a tranny jack), its always getting the car high enough is the issue. Borrowed a friends lift 2 years ago when I put it in, but he no longer has access to it (so neither do I.)

It sounds like a bad Torrington bearing in the converter. What you are experiencing is a common symptom.

 

[Ttype6]

And from something they said it implied there is no cushion spring in there.

Was there some unknown force stopping them from putting in a cushion spring?
Was it totally out of their control?
They build them purposefully without a spring. It is the choice they have made. Every 2004r will clunk and stress the band anchor hole if you do this. What they did to you always causes a clunk. Notice I didn't say what they did FOR you. Did they brag about how much it will clunk when they talked to you about their builds? It is wrong and will cause problems. Get a spring in there ASAP.

 

[BMR]

X2 on the converter causing the whine. I have had a couple of vehicles do this. Currently my daily beater baby blazer has started it. It going to run it till it dies then rebuild it since it has 155k on it.

 

[72Chevelle]

Nah, I don't think there was any maliciousness on their part. And of course, they didn't brag about it. I didn't even know it would happen until I drove it the first time and it did it, I called, they said normal for their builds, I asked around, it seemed many builders at the time knew exactly what and why and no one ever said it was anything more than a nuisance.

As to what to fix, yes, I heard you. I now have to find a builder to straighten it out. That's what I'm trying to do now, would prefer local of course as that would be preferable. No luck so far (just like last time I looked) and I went to a remote builder highly recommended by many, did my research, but since I was new to the 2004r I didn't think to google "2004r downshift clunk" and know enough to ask about it until I got one. . And no one I asked never even brought it up. I didn't see it when I googled common 2004r problems either.

I'm not driving the car right now, the only thing I'm going to do is try to diagnose the whine a little further, then take corrective action on finding someone and straightening this transmission out.

Again, thanks for the advice.

Was there some unknown force stopping them from putting in a cushion spring?
Was it totally out of their control?
They build them purposefully without a spring. It is the choice they have made. Every 2004r will clunk and stress the band anchor hole if you do this. What they did to you always causes a clunk. Notice I didn't say what they did FOR you. Did they brag about how much it will clunk when they talked to you about their builds? It is wrong and will cause problems. Get a spring in there ASAP.

 

[72Chevelle]

Hi again. I've been researching the servo replacements and such, and discovered that all of the servo kits I've found say to retain your existing cushion spring and collar when you go to do the replacement. Since I don't have any of the original parts, I have nothing to retain.

So, I was calling around trying to see if I could locate any of these parts so that if I do pull the servo I'll have 'em ready to replace. One person I talked to asked a bunch of information, including what the pressures are, and then told me that the cushion spring probably won't help anyway (and that it might even already be in there.)

His reasoning is that this tranny was built with high constant 1st and 2nd gear pressures (see above - 275 in 1st and 2nd pressure) and that due to that, when it drops down from 3-2, the pressure in 2nd is that it is most likely causing the clunk, not the cushion spring.

Now, as I said before, the builder never said it didn't have a cushion spring, it was implied based on his statements that combination of the pressures, servo and return spring (note he only mentioned a return spring, nothing about a cushion spring) would do that, and all I've read about these trannys is that leaving out the cushion spring would cause the clunk, so I was under the impression it wasn't there. But, it may very well be a cushion spring in there and it is still clunking due to the pressures?

Now, it does this clunk with the tranny in either 4th or 3rd, in which case the pressures are only 110 when stopped, it only has those high pressures with the selector in 2nd or 1st, so I'm not sure I buy this theory.

Any thoughts on this theory?

Also, I still haven't located the cushion spring and related parts so that I could swap them out, so I'm still looking (granted, only called 3 places so far. )

Was there some unknown force stopping them from putting in a cushion spring?
Was it totally out of their control?
They build them purposefully without a spring. It is the choice they have made. Every 2004r will clunk and stress the band anchor hole if you do this. What they did to you always causes a clunk. Notice I didn't say what they did FOR you. Did they brag about how much it will clunk when they talked to you about their builds? It is wrong and will cause problems. Get a spring in there ASAP.

 

[Ttype6]

Any thoughts on this theory?

You're correct. The pressure is low with the selector in drive or overdrive.

 

[72Chevelle]

Thanks. I'm having a heck of a time finding all the necessary parts to re-install the cushion spring, since I don't have any of the factory parts (I received this tranny as-is.) But, I shall keep looking.

And I will update this thread as I make progress (even if that includes just getting a whole new tranny built and using this as a spare, as I'm starting to get very frustrated at this one and ready to drop it in the ocean...)

You're correct. The pressure is low with the selector in drive or overdrive.

 

[Ttype6]

Thanks. I'm having a heck of a time finding all the necessary parts to re-install the cushion spring, since I don't have any of the factory parts (I received this tranny as-is.) But, I shall keep looking.

And I will update this thread as I make progress (even if that includes just getting a whole new tranny built and using this as a spare, as I'm starting to get very frustrated at this one and ready to drop it in the ocean...)

Which servo do you have?

 

[72Chevelle]

Couldn't tell you - it's an unmarked billet one, builder says it is a custom unit.

Exactly why I don't want to get into the internals of this thing myself.

Which servo do you have?

 

[RmvBfrFlght]

I'm not sure why builders think the 3/2 down shift clunk is OK. It is caused by the trans being in two gears at the same time. This locks up the output shaft for a short period of time. With my car it was so bad it rang the gear set in the rear.

I used to slip the trans into neutral before the 3/2 shift occurred. Then back into drive before coming to a stop.

Then one day I did a manual 3/2 shift at moderate speed and it was brutal. Thought the driveshaft exited the vehicle.

Installing the cushion spring and using a slightly stiffer return spring fixed the issue.

RemoveBeforeFlight

 

[Ttype6]

Exactly why I don't want to get into the internals of this thing myself.

I don't describe the servo as an internal part. It is what is behind the round cover on the passenger side of the transmission. Remove the retainer ring and everything can be removed. You could remove the servo,find out there's nothing you can do to modify it,take pictures of the parts and post them,and put it back together. Then we could proceed from there. I still use the stock GN servo with the stock 3rd accumulator piston seal at 700 hp and have never seen the need for a different one.

 

[72Chevelle]

Yup, understood. The only reason I mentioned it as internal is that I've been reading up on how to work on it, the removal procedure and then reinstall keeps stressing that you could dislocate the band, have to measure the clearance to the band, etc. which are internal.

I think I've got it figured out, but they also mention grinding down or welding the tip of the pin to make adjustments. So I'm still studying and reading.

But yes, I can pull the existing one apart, take pictures and post and do as you mention. But, in my case, I am pretty sure I have to pull the tranny out to get to it as it is so close to my floor pan. Since I'm thinking I have to pull it anyway for the torque converter, I'll do it all at once. Probably be pulling it in the next week or two, depending on how life decides to intervene. And then what I find, the tranny may just stay out until I get everything sorted to put back in.

Thanks for the suggestions, much appreciated.

I don't describe the servo as an internal part. It is what is behind the round cover on the passenger side of the transmission. Remove the retainer ring and everything can be removed. You could remove the servo,find out there's nothing you can do to modify it,take pictures of the parts and post them,and put it back together. Then we could proceed from there. I still use the stock GN servo with the stock 3rd accumulator piston seal at 700 hp and have never seen the need for a different one.

 

[Ttype6]

Yup, understood. The only reason I mentioned it as internal is that I've been reading up on how to work on it, the removal procedure and then reinstall keeps stressing that you could dislocate the band, have to measure the clearance to the band, etc. which are internal.

I think I've got it figured out, but they also mention grinding down or welding the tip of the pin to make adjustments. So I'm still studying and reading.

But yes, I can pull the existing one apart, take pictures and post and do as you mention. But, in my case, I am pretty sure I have to pull the tranny out to get to it as it is so close to my floor pan. Since I'm thinking I have to pull it anyway for the torque converter, I'll do it all at once. Probably be pulling it in the next week or two, depending on how life decides to intervene. And then what I find, the tranny may just stay out until I get everything sorted to put back in.

Thanks for the suggestions, much appreciated.

The Sonax servo comes with a pin that is purposefully too long so you can grind it down for the desired clearance. The measurement that is talked about is simply the distance that you can move the servo cover in after assembly. There's nothing to measure inside the trans. The only time I've had difficulty getting the pin to engage the band is with the trans upside down on the floor. With the trans in the car,gravity keeps the band where it needs to be and you simply slide the servo in without issue. The only time I ever needed to weld the tip of the longest GM pin (they come in four different lengths designated by the number of rings cast into the body of the pin 0-3 rings)was when I ended up with a defective band (too long). The factory servo length is easily modified with washers and pin selection. The most common pins I've seen have three rings cast into them.

 

[jthomas]

I've been following your post for a while as I had similar issues. Mine had the 3-2 downshift clunk so I came to this site for help. For me the servo cushion spring solved the problem:

I had the Superior servo in mine. I pulled tranny, removed servo, and found it had no cushion spring. I contacted Dave Husek and he provided a cushion spring and Sonnax Servo and walked me through the installation. If you go with the Sonnax Servo, the main thing is to grind only a little at a time off the pin and keep checking clearance till it's right. Plenty of threads on this site about best way to check the clearance. Don't use the Sonnax recommended travel of .110" as it is too much. David recommended .040 so that is what I went for. Downshift clunk is gone and band is living fine on recheck.

Good luck with it. The guys that are helping you really know their stuff so follow their directions and you will get it figured out.

 

[72Chevelle]

Ok, so to follow up on the original issue I was discussing (the "whine") - I did some diagnosing today. Here's what I discovered.

Started the car up (hasn't been started in about 2 weeks) - no whining at all, at any time, in any gear, park or neutral. Let the engine warm up, still nothing. Trans temp was about 110-120 or so. (Side note, not sure if it matters - I have the trans cooling plumbed from the trans -> radiator -> external cooler -> return to trans. This way, in the colder weather, I do get a little heat into the trans.)

Took the car for a good long ride (it's about 80 degrees here right now), topped off the tank, etc. Seems to be driving fine. Trans temp slowly working it's way up to the 160-170 mark. At this point, I start to hear the little whine. Anyone who has ever heard a weedwhacker - it sounds like the strings swishing when you rev it up, just not nearly as loud.

Pulled into the driveway, had my wife hop in and start putting in in/out of gear, revving it a little in gear and out of gear, etc. while I crawled around underneath both sides of the car.

At a dead stop, in any gear position (reverse, 4th, 3rd, 2nd, 1st) and you rev it a little (from idle at ~900 or so to about ~1100 is all it takes) you hear the little whine. In Park or Neutral, can't detect any whine at all, and at least my wife says she couldn't hear it (and I suspect I couldn't either but I'm paranoid so I was hearing everything. )

Now, it's not all that loud, and as far as I can tell, only does it once the trans warms up, not cold.

Opinions on what's up? Torque converter? Normal, totally screwed, somewhere in between?

And thanks for all the advice so far (and thanks for future advice too), it's been great, I appreciate it.

 

[72Chevelle]

Well, I'm back.

So, the whirring (in gear only - nothing in park or neutral) was getting louder, and it started to make a chirpy sound right around 1000 rpm. Everyone said "torque converter, replace the torque converter."

Ok - so I had a new converter built and sent out, and replaced it. Got it fired up today, and it still whirs and has that chirpy/squealy sound right at 1000 rpm in any gear (but not park or neutral.) Definitely coming from the transmission. I had my wife in the car, rev it slowly to 1000 then vary it a little around it so I could video it.

Fluid that came out was perfect, barely any residue in the pan (remember this trans only has a few hundred miles on it since built 2.5 years ago), TV cable adjusted fine and checked pressures, all good, seems to shift and drive just fine (but I only took it for a quickie, easy throttle test drive for less than 1/2 mile.)

Now I'm thinking my original issue may not have been the torque converter... I was hoping it was a quick fix, not a pull and ship back across the country type fix (especially since it only had a 1 yr warranty.)

Any ideas? I've never heard anything like this (coming from a transmission anyway.) Maybe a second bad torque converter? Which would be just my luck...

Thanks.

 

[72Chevelle]

Just to follow up in case anyone stumbles on this.

Found (and fixed) the screechy/chirpy problem in the video. It was the depth of my shims on the converter pads. They were at the perfect depth that they caused the pilot on the crank and converter to be rubbing slightly as the converter would move slightly and the flex plate would flex and cause the chirp/screech. Changing the shims to a different depth (but still in spec) resolved that issue.

Now, my original slight whirring/whine in gear only still exists with either converter. So I'm convinced the converters are fine, and so I'm still looking for that slight whine. But fluid is perfect, it shifts fine, moves fine, etc. just has that whirring/whine. If I ever find it I'll post back again.

 

[mikestertwo]

Just to follow up in case anyone stumbles on this.

Found (and fixed) the screechy/chirpy problem in the video. It was the depth of my shims on the converter pads. They were at the perfect depth that they caused the pilot on the crank and converter to be rubbing slightly as the converter would move slightly and the flex plate would flex and cause the chirp/screech. Changing the shims to a different depth (but still in spec) resolved that issue..

Always put a little grease in the pilot hole in the crank shaft when installing a converter. They don't call the flywheel a "flex plate" for nothing.