classic1

Hey guys I need some help. I am getting a squeal from my transmission when warm. It does not squeal when cold. It also goes away when I am on the throttle. When I let off, it comes back and it does it in all gears if I am not on the throttle. It is even their when in park and neutral. I have a video of it here:

http://www.youtube.com/watch?v=zPUrBBgSmhY

My set up is 1992 Silverado lm7 5.3 Swap, TR220 cam, Circle D 3200stall, Speed Density tune, Schoenfeld LT's, LS1 efans, transgo hd-2 60e, custom CAI

Let me know what you guys think it is. I am almost 100% sure it is in the trans because I have used a stethoscope to track it to there. It is in the torque converter area. The trans is good on fluid.

classic1

Any ideas?

myk

iTrader: (4)

Honestly that's the first I've ever heard of it. I google'd squealing transmissions and came back with some ideas like the pump being bad, or a bearing inside of the transmission itself being bad and the usual "it's not the transmission it's something else" responses. Unless someone has an idea I'd start looking into taking it in somewhere...

jam01

i cant tell where it is coming from from your video, but if is near the tranny maybe the flexplate is rubbing the cover. try pulling it off and looking there for rub marks or loose bolts.

classic1

Yeah I have done that same search and came up with those ideas. I even emailed Chris at Circle D but he had no ideas except the ones you listed. I guess I will have to just drop the trans and look for signs of rubbing.

Thanks

I thought the same thing at first but i don't think it would come with temperature and engine. I'll check it out though.

Thanks

85C10GENIII

This is crazy because I have close to the same setup as classic1, 4.8l 4l60e with a cam and a circle d converter and I have literally the same symptom you have with the squeal and cant figure if its the tranny or the torque converter. The guy that rebuilt my tranny says it is the TC, spun bearing most likely, but then I have another mechanic that says the same thing but also says to check the tranny filter to make sure its not pinched or sealed right cause it could be that as well. Please let us know what you find out, I will be taking my tranny out today hopefully and I will keep you posted. Sucks since it is a brand new TC!!

classic1

Oh wow. Well let me know what you find, I will be dropping the trans soon to figure it out. I did not think about the filter because it is a an AC Delco filter. i suppose it could be pinched.

Thanks for letting me know you are also having problems. I will keep you posted as well.

85C10GENIII

How long have you been driving your ride with the swap setup and when did you start hearing the noise? I have my setup in a 85 c10 and I literally put it together and started it for the first time last month and mine showed up couple days into driving it. It is exactly what you have but I am wondering if yours didnt show up for a while or if it showed up right after you put the TC in it?? I have my tranny out and opened it up and filter is locked in and good so I just hope its the TC. I have Chric at Circle D sending me a new one as we speak. Let me know.

classic1

I have had the Circle D converter since the day I did the swap and it started on the first few days as well. I am going to give Chris a call.

Thanks for your response and keep me updated as well.

Circle-D

iTrader: (21)

Does not sound like a converter problem, but sending another one to make sure. Definitely strange.....

Chris

classic1

Thanks for your support Chris!

classic1

Update on this: I put a gauge on the truck for the trans and the squeal starts at 116 degrees. So the trans is not overheating. 85c10geniii do you have a gauge? If so what temp does yours start to squeal?

Thanks

Jays_SSZ28

iTrader: (2)

Sounds like the IAC vacuum as it changes position.
Or the throttle blade.

classic1

Good thought. i thought it was vaccuum at first as well. I have a DBW throttle body though. I know it is in the transmission though. Right near the converter. Whether it is a bearing in the converter or transmission or even the pump I don't know yet.

85C10GENIII

i dont have a gauge so unfortunately I cant check that but mine does start when it is warmed up. My trans guy that rebuilt mine swears it is a TC problem. I opened up the bottom pan and checked the filter and everything is ok by the look of it and I cant open up the TC to check that so I hope it is the TC. Also was thinking that the trans fluid I put in wasnt good enough which could casue something to go wrong. I put DEX III but I checked and it actually calls for DEXVI which is synthetic. That is what I will be using when I put it back together. 6 plus a quart!! What did you use classic1.

Jays_SSZ28

iTrader: (2)

What did you do with the Canister Purge Solenoid Valve hose that went to the donor vehicle tank?

I'm betting on a vacuum noise still. DBW without the stock filter set up can let noise through, especially with a non stock idle.

I don't know of anything transmission related that will cause a noise like this and not show up on a pressure gauge or metal in the pan.

I've played with hp tuners and trans line pressure at idle and was able to make the pump regulator buzz, but not whistle like that video. I had a pressure gauge connected though so I could see the pressure go up as the noise got louder.

Also if it was not a trans pressure problem it could be a mechanical problem which usually creates metal dust. I'd take the pan off and break the filter open long before sending the converter back.
And still if it was a mechanical problem, I seriously do not see what would make it do it only at a certain temperature. It's usually all the time.

I still say vacuum problem/leak.

classic1

I plugged the hose that comes from the purge solenoid. I was sure that the squeak. was also a vaccuum leak as well until i used a stethoscope and poked it into the bellhousing and heard the whistle clearly right near the TC. I'm almost positive it is in the trans but just not sure where. i don't have a pressure gauge on it right now just a temp gauge. I'm going to adjust line pressure at idle and see if i can get the whistle to change tone or something.

Thanks for the tips

Jays_SSZ28

iTrader: (2)

Here is a video of me trying to duplicate the sound as you describe it.
This is the breather tube that goes from the valve cover to TB.
There are vacuum fittings above the bellhousing.

http://www.youtube.com/watch?v=n3CNwEY4N6A

classic1

That is very close to the sound. I'm going to check all of the vaccuum lines again. I'm almost certain it is in the trans because I can lay under and watch the converter move consistent with the squeal when I shut off the motor. Their is a compression kickback right before the engine stops and the converter moves at the same time. I'm not ruling out vaccuum leak, I just don't think it is by where and when I am hearing it. Mine is more of a screech than a whistle I would say. Thats why I think converter bearing or even the bushing that the converter seats against.

Thanks for your effort in helping me find it.

85C10GENIII

classic1, have you changed out the converter yet? And if yes whats the result?