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Possible transmission trouble

23K views 145 replies 24 participants last post by  vincentm 
#1 ·
Since over 2 years I was looking for a good deal on a brand new PS Pump as it was a bit noisier than normal and you can feel a tad of play in the shaft (with the belt off). Actually Jake told me 2 years ago that my PS Pump is a bit is noisy, that’s how I noticed.
Well lately it was noisier and noisier (especially in the last 2-3 weeks). Took the belt off and span it by hand and I could feel other than the slight play, a bit of grabbing as it was spinning kind of like the shaft was splined.
So I got a new PS pump, spent the Saturday struggling with the PS Pump pulley (I did not have the proper puller and press). Eventually I got it in (all this because the new pump came with no bracket and in order to install the bracket you need to take the pulley off.

So Sunday went for a test drive/hardware store drive and I notice the whine is still there, well, is about 90% there. I was under the impression the whine happens as I pass over 2K RPN (when cold) and 3K RPM when hot. Well turns out the whine is during shifting, starts about 1 second before the shift and fades away about 1 second or so after the shift (total 2-3 seconds). The best description is a PS Pump whine (like steering held at full lock) maybe combined with a whispering hissing whistle.
Is clearly engine speed related as if I release slightly the gas pedal in the moment is going to shift (like you will do as you press the clutch in a manual transmission) the noise is gone instantly.
My first thought was “transmission fluid level”, and unfortunately is fine, but as I was wiping the dipstick to check the level it kind of seem to me the fluid is a bit odd in color.
Well I compared with the fluid from the 1q jug (extra jug after the fluid exchange I did 2 years ago or 45K Miles). Original fluid was red and I found absolutely ZERO derbies after 130K Miles. This is how the fluid looks now, I would say the fluid from transmission is more brown than red.

This is the fluid I used.


Now the noise is pretty noticeable with cold engine and transmission, fades away after the first 3-4 miles as the coolant temperature gets almost to normal operation value. The noise can be heard at any shift (up but not down) regardless of the gear. The transmission feels and behaves normal, but I think this is the calm before the storm. Is true, perhaps you need to be familiar with the car to hear it. The noise can not be pinpointed (not while driving) but you have the impression if coming from the right side. I would say that is because is coming trough the HVAC ducting and that’s about the place where is coming from.

The plan is to get to a transmission shop for a professional opinion as I know very little about automatic transmissions, just have the general idea of how is working but not enough to think of a possible cause. I am just thinking the fluid pressure goes up during shifting and that’s why I have the noise but is just a wild guess.
Unfortunately unless it sits for few good hours, is not going to make the noise, then I was planning to drop the pan and check for derbies and change the fluid. I know that changing the fluid won’t fix the mechanical failure, but I have to drop the pan anyway.

Maeng9981’s thread keeps ringing in my ear…bummer!
Any suggestions, opinions?
 
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#2 ·
I am starting to believe is not the transmission, maybe .
Today I was revving the engine in park to about 4500 RPM and in the instance I release the throttle I can hear a high pitch fairly loud winding sound. Definitely is located in the front right side of the engine bay (ok that would be front left side of the actual engine considering the transversal placement) – nowhere near where the transmission would be. This lasts for the first 1K RPMs from 4500 RPM down as the RPM drop. That would be accessories belt area (AC, Alternator, Idler pulley, maybe tensioner pulley, but that is fairly new). My first guess would be the 4 years old Delphi A/C compressor pulley/clutch. I do have the normal wobble on the ballancer (since always because of the rubber thing) but I am sure that won’t cause that kind of noise.
Yet why do I hear the noise even before the shift, just before the RPM is about to drop? Why does the whine is gone once it gets warm (yet the 4500PRM drop to idle whine is there even with engine warm).
I will definitely drop the pan over the weekend to check the magnets and filters.
I will start first with the accessories belt removed and the same 4500 RPM to idle in park RPM drop test.
 
#3 ·
This afternoon I dropped the transmission pan, I managed not to do much mess (started with a corner first). This was an exploratory surgery to see what’s what, my fluid was exactly 2 years and 1 month old or 45K miles.
Well this is what I found:

There are debris in the pan and in the bent screen, the straight screen was clean though. The debris in the filter were fine clutch material, while in the pan I had the bigger metallic and probably also some larger clutch material pieces, by large I mean kind of the stuff you get after filing something.
Here is a detail of the pan debris, notice the shiny metalic ones I highlighted blue and the rest is the brown stuff.

The above detail shows about 70% of the debris I found.
The magnet was pretty clean, at least there were NO metal debris on it, this makes me believe the metallic debris are aluminum (or the magnet is no longer a magnet), it only had fine clutch material on it like the screen.

At least the fluid was quite red, definitely more on the red side than brown (nothing like what the paper towel test looked like).
Well to be honest I have never seen an open tranny with debris in it, last time I did my fluid was bright red and I had absolutely ZERO debris. On the other had last time I did the job, I dropped the pan pretty quick so if there were debris, most were washed away with the fluid. So I have mixed results, not sure what to tell, I don’t like what I found but I am not an expert. I keep seeing being mentioned that is normal to find debris in the pan and magnet, and some could clog the passages. I mean, that must be some huge amount of crap flowing around to do so.

This is how the pan and filters looked like before installing.

I did the proper torque and in the proper sequence. I took the car for a test drive and first few shifts were super quiet. I started getting on it and I can still hear some whine (I have to really, really pay attention). I haven’t done the no accessories belt test drive yet. That would be tomorrow.

Anybody expert, or at least knowledgeable in transmissions?
Please feel free to express your opinion, for me this was not conclusive.
 
#5 ·
Please feel free to express your opinion, for me this was not conclusive.
Check the alternator - bad bearings make a whine - louder at certain rpm's than others.

Although it's only a possibility, my (no longer owned) 95 sts was misdiagnosed by 2 supposedly smart people.
A repair shop said "it sounds like it's coming from the trans", so I went to a trans shop.
And a Trans shop said "We can't tell - we will have to remove the transmission to find out"

I ran away from both of them as soon as I could, and found the noise with an old fashioned method of placing a very long screwdriver against different parts in the engine bay and putting the other end against my ear.

The alternator bearing whine (bad diagnosis of trans issue) coupled with oil getting into the radiator (bad diagnosis of blown a headgasket!!) caused me to park the car for a year until I got a chance to sort it out myself.

A new alternator fixed the trans and a new radiator fixed the oil in the water :)
 
#4 ·
I'm no tranny expert but I heard the same that fine shavings are not to worry about and chunks of metal/clutch then may be a cause for concern.I wish someone with more knowledge would chime in as much as you help others.are you positive the wine is coming from the tranny?
 
#6 ·
Unfortunately it only does the whine while driving (when shifting gears, or better said when there is a RPM/engine load change).
So the screwdriver thing doesn't help.
I was planning yesterday to remove the accessories belt and drive it around the block to see if is that or not, however yesterday I left early in the morning for a 2h thing (family related) and turned out that I got home past 10 PM. So the whole day was gone.
Today is work (since 5:00 AM they wake me up). I can't do anything until Friday my 9 to 5 is the whole day...
 
#7 ·
This sounds quite different than what I've experienced. I believe that's accepted amount of debris also. Significantly less than what I've found in my transmission.

Driving without accessory belt will tell, if it still happens, then it's ... the transmission.

Mine had debris and silicone fluid goo around the oil pump inlet/outlet and inside of the oil pump which I believe caused the whine.
 
#8 ·
Just drove it around the block with the accessories belt removed and yeah, the sound is still there so is the transmission.
It does it in the first 5 minutes until the engine up to temperature, after that no more noise.

As a side note, I did felt the engine running "happier" with no accessories drag, is like after a tune-up.
 
#10 ·
The noise inside the car with windows closed sounds like an electrical motor/power steering pump whine (like when you have the steering full lock but not too loud)/cymbals (after you hit it as is dying down). Mix these 3 sounds and that’s what I hear from the cabin right in between the shifts (1 second before and 1-2 seconds after). And is clearly on the right side (like in the glove compartment), because it propagates trough the HVAC ducts). It does have to be quiet around to hear it (like if there is traffic around I don’t hear it).
Windows open, again quiet around the car, the sound I hear is power steering pump whine (but is not that).
This only happens when in the first 5-10 minutes until the engine gets warm, after that not one single sound, the car has to seat at least 5-6 hours to hear it again.

If I mimic shifting a manual transmission slowly releasing the gas during the shift, the noise is gone instantly, if I go on gas in the first second after the shift I still hear it (like the last part of it dying down).
I see in the future that tranny going down, I guess I need that motivation to do the bottom end gaskets.
 
#12 ·
I am no transmission expert, just two my cents.... Not very likely, but do you have ruled out the possibility of a bad hub bearing? A few months ago there was a whining noise from front right corner and the noise level was proportional to engine RPM. It was a bad hub bearing!
 
#13 ·
Sounds like a noisey trans to me, I'd let it warm up a bit before driving and see if it still does it. If it drops in noise then not a hub more than likely. You could switch to a different brand or even syn trans fluid to see if it quiets it down even.
That pan looks very good for an auto BTW. Chunks and alot of material if what you don't want to see.
 
#14 ·
N* you know ive seen a few bad tranny's up here. My 97 totaly went at 370,000 km. Ive got 2 others that are on their way out. My white 99 is still perfect, very hard 1-2 shift when in 2. And thats how i test them. Stick it in 2 and let her rip, full throttle max RPM shift 1-2. You may know then if its bad or not, or it may explode into peices :)

Also, i still have that 98 trans with 120,000 km on it.

On another note, i think you should give me a call soon. I got a package delivered on Friday.

Auto part
 
#15 ·
I had the car over the weekend at the transmission shop (highly rated).
I had to drop the car Friday night and have it tested Saturday morning as it only does the noise while cold. If I would drive it to the shop for the test, by the time I get there is all is fine.
The transmission guy said is not transmission related.
Honestly I don't care how much experience it has on it, I know better that is indeed the transmission.
He said is for sure some pump starvation noise (and that I agree, is hydraulic noise not grinding/rubbing), yet he insisted is the PS.
I mentioned I had new pump installed weeks ago, the system was bled, I ran the car with no accessories belt and the noise is still there.
Well hi did not charged anything for the test and at least to be polite I purchase from the shop 1q of "super good" Rotella PS fluid that "for sure will fix my PS noise issue". I have fresh AcDelco fluid and I know better is NOT PS, no point wasting time changing brand new PS fluid.
I did noticed one thing, the noise is not only when shifting, the noise is also heard in park if I rev the engine >2000 RPM and I let it settle down to idle (while the RPM are dropping) and ONLY if I do it within the first 2 minutes or so after I start the engine (I don’t rev the engine cold so this why took so long to notice). Also if I rev the engine once will do the noise, second time almost no more (or if I REV it to 3000 RPM) and third time won't do it at all. Yet even in these conditions will still make the noise during shifting until gets warm. While shifting if I release/ease off the gas pedal the noise is gone, also if I do the opposite the noise will last a bit longer (and is a bit louder). Clearly is engine speed related. If it was a manual car I would say it does it as long as you have the clutch down to shift, is exactly like that.
I can tell the noise it gets louder and it takes longer drive to disappear, definitely I will be at the shop soon.
It surely sounds like is coming from the right (front) side of the engine (accessories belt area) yet again it does it with the belt removed.

I was thinking at the chains or chain tensioners, but why only when shifting, it is affected by the engine speed but not in a pattern I would expect something mechanical directly coupled to the engine would do it.

I am frustrated on my lack of knowledge in this field.
 
#18 ·
Well the weather is getting cold and the issue is slowly progressing (I guess as things are wearing out).
So now it is easier to hear the noise when the car is cold, as in before it was only doing it only in the morning after sitting for 8h now it does it consistently after sitting few hours (like I said, I suspect combination or cold weather and wearing out), it also do it for longer.
Also about the time I posted my last post, one very late evening when leaving from my parking spot at work (I had to reverse out) it kind of seem to me it slipped a bit. By that I mean the RPMs seem 200-400 more than normally (like leaving from a slight inclined spot, while the spot was dead flat).
I started paying attention to it and the best I can describe, first time when leaving from stand still (fluids cold) it does not seem to me as eager to leave as when it gets warmer. Don't get me wrong, is not an engine hesitation (or power) it seem like it has a slight slip.
Last night was the first time when I could definitely tell yes, definitely something is wrong. I started the car put it in reverse, parking brake popped up and nothing (mind you RPM on idle with cold engine is ~1000RPM) so I actually checked the parking brake light making sure is not on (it wasn't). I just slightly touched the gas pedal (maybe added 100 RPM) and it started moving. But you can definitely tell is not like stuck (rusted) breaks when is making a small pop and then moves, this time was progressive. Plus yesterday it was no rain earlier so no reason to get rust on the rotors while I was at work.
I could tell something is not 100% since I drive the car for many years, you can feel something is up.
Anyway after backing out, I put it in "D" and it did seem a bit sluggish, but not as in "R", I stopped and put it back in "R" (just to test) and it seem to be exactly like in "D", a bit sluggish but not like first time, this time with no brake no gas was moving (but again not like normally).
It made the noise shifting from 1-st to second then 2-nd to 3rd and then 3-rd to 4-th. It seems as long as there is a positive RPM sleep in the torque converter (above a certain value) it does it. But it does not seem to be that exactly, it does seem to behave a bit strange. Now when cold (like last night) continued to make the noise almost all the time while in 2-nd and half way to 3-rd. If I release the gas (not necessarily all the way) it stops, if I go back quickly on gas, sometimes (if cold) I can hear the noise again for a short while.
To be honest from the way I see it, it seem there is something that engages about 1 second before a shift and stays engages for a few seconds after the shift (longer if the engine RPM is higher).
I have an 8 miles drive from office to my house, it involves about a dozen traffic lights (including a 1/2 mile HWY - 6.5 to 7-th mile into the drive). The noise is dying down after the first 5 miles (use to be after the first 2-3) and by the time I get home is no more (unless I really, really hammer it during a shift, when I can hear a bit of remanent noise, kind of like cymbals). It does sound to me awfully like being hydraulic not mechanical.
Over the weekend I notice with the engine cold if I rev it past 2000 RPM I hear aproximarively the same whine while in P or N as long as I keep it there. It use to do it after revving past 2000 RPM while it was decelerating (which was hard to diagnose as it was doing once or twice at most and for ~2 seconds or so).
For some reason at the time it did it I was unable to open the hood (I was moving the car out of the garage to do some work inside). Later, once I finished I got the car back in the garage and I was planing to snoop around but this time it didn’t do it. I tried the car in “D” and RPM up to 1400 for 1-2 seconds (as the FSM says) and NOPE no noise, and that is really when the torque converter has positive slip (1400 RPM) and nope it does no noise. This is why I say it seem to be when there is a certain slip in the torque converter but not all the time (I kind off feel is something else).

One thing is for sure; time WILL tell what is wrong.
 
#20 ·
Sorry to hear that. As much as I love Northstar engines, I hate 4T80Es. Not engaging in gears sound awfully close to what I've experienced when my 4T80E was on its last legs. After that I started losing gears except second. But at this time period I was also losing trans fluid through the vent tube, even when there's nothing showing up on the dipstick, that might have been the issue.
 
#21 ·
Well today is the day when the engine and transmission are coming out after 15.5 years and a bit 175500 Miles.
The transmission whine is getting louder and consistent with every shift, it also seems to be there even after it gets hot (a bit less though).
It still shifts and drives fine in spite the whine, the tranny shop is shaking the head, they told is something they never heard in these transmissions since they do transmissions (old shop). I had even second and third opinions and all shook their head. I was protecting it as much as I could avoiding accelerating even moderately, lifting the foot off the gas while shifting and driving strategically to avoid slowing down thus give a reason to up shift again.
Jake is the man for the job (the only man I would trust), he will be dropping the subframe, separate the transmission and send it to the tranny shop.
While the tranny is being rebuilt Jake will be doing all the bottom end seals (and replace the slightly wobbly harmonic balancer).
Unfortunately I will be away in a business trip for the whole week but is great to have a friend that can help me with this.
This car has to be in tip-top condition after next week, next summer is going again around US.
 
#22 ·
Some plans changed today. I had the tranny shop doing one last test (they got their specialist to do the test drive) and they said is nothing they ever hear in a transmission ever and are not sure is the transmission (especially since it works fine). They said if it was a bearing it would make noise all the time not just when cold (not really, because metal expands - I would comment). If it was a pump cavitaion, from August until now the tranny will have been toasted. I did explained that I did not drive the car like some housewife I actually paid attention and ease off gas when shifting, so the time period means nothing...
Regardless they said that in the stage it is now if they open the tranny even if something is wrong it may not be visible. So they recommended having Jake take one long look over the situation and have his opinion.
We did the test drive today and sure enough the whine is there, but after driving over 100 miles to his place, the car was warm enough so the noise is only very low.
He also (like everybody else) said that is not something heard before, and he also doubts is the transmission, yet he is not sure is what he suspected first (and I was suspecting too some point): lower chain tensioner.
The big argument against is: if it were the tensioner the noise would be as long as the engine is spinning, but is not (yet is engine speed dependent). Ok let’s say it is only at a certain tension on the chain and this is given by the variation of the engine speed/load. Then we go to the next scenario.
If it was something in the engine that is dependent with the load (say when is shifting the engine load is shortly changed), well it will do it during shifting and a bit after while there is some slippage.
However (and this is why I say is in transmission) the whine starts just a bit before shifting, and that could only be in the transmission. Also the way the noise dies down is a bit non-natural (as you would expect in a assembly that slowly engages), sometimes it dies down slowly sometimes almost abruptly, is like something is starting to spin just before shifting and then it sleeps during shifting and is slowed down after shifting but in a controlled matter (not natural). Also could be line pressure evolution and something makes the whine in accordance with the line pressure. The line pressure is regulated by solenoids and something could be leaky.
Regardless, tomorrow with a cold engine Jake will do the test and hear at it’s worst when cold (same noise just allot louder).
Definitely the whine is coming from the front (right) side of the engine, somehow down towards the firewall. That’s where the chain drive assembly is or also the transmission.

I am just so helpless, I am not able to diagnose it at all, I still believe is in the tranny, after months of living with it, I eliminated everything else.

Recap:
1. Engine RPM related whine during shifting (but seems to be starting just before shifting)
2. The whine is much louder when cold.
3. Is not in the belt drive assembly (noise still there whit the accessories belt off).
4. It does it on upshifts or (as Jake discovered today) it also does it on heavy engine brake.
5. General area of noise (to the best of my ability) seems to be front (driver’s side) of the engine maybe towards the firewall.
6. The whine is present when engine is cold, shifter in park while reving over 2000 RPM (or while decelerating from over 2000 RPM) sometimes one sometimes the other, sometimes both….
7. Sounds exactly like power steering pump (but maybe a bit louder at it’s worst).

I hope Jake’s hunch is right, and is indeed the lower chain tensioner, and maybe I can’t feel the starting of the shift soon enough. At the beginning is enough engine load/rpm variation to change the tension on the chain (thus the pressure/angle of the chain against the tensioner) significantly to make noise but maybe not significant enough for me to feel it, so I perceive that the noise starts before the shift.
 
#24 ·
In my case it was the inadequate viscous torque converter, which somehow failed and leaked its viscous clutch fluid into the transmission. Upon teardown, I could find the clear sticky fluid basically everywhere inside the transmission. Servos, oil pumps, valve bodies, side case, solenoids, everywhere. I also found that the fluid pressure control solenoid was gummed up with metal shavings and the clear fluid. The oil pumps did not have any metal shaving in them, but was packed with the clear fluid.

I just want to say that be very cautious with this as you are doing right now, since it can be very frustrating at times like this, and be ready for the possible worse case scenario but don't be afraid of it. The good news is that everything can be repaired.
 
#25 ·
Hey the car is with Jake now, if that's not reassuring then what is?

The plan was he drops the engine and tranny to send the tranny to the shop and while they do the tranny Jake does the bottom end reseal (as the engine is out anyway).
By that I mean, case halves gaskets, new oil manifold plate, oil pan gasket, oil filter adapter gasket, replace the harmonic ballancer, if the 2 steel lines running along the right (rear) bank are rusted have them replaced. Replace the 2 exhaust pipes between the exhaust manifolds and the cat (polish the inside if the “Y” pipe where the pipes are welded together).
To do so you need to get to the chains and replace the tensioners anyway so that would be the perfect issue to have. I would save the couple of thousands dollars for the tranny, how sweet will that be!
 
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