Need Tranny Help - Can you identify these noises - The 1947 - Present Chevrolet & GMC Truck Message Board Network

8t5Silverado · 12-31-2004, 08:26 PM

I am hoping that it is not giving up on me. I will try to explain the noises, but it is hard to do with text. The fluid was a little low, but I topped it off today.

It sounds like it is coming from the flywheel or torque converter. In park, it is a racketty sound, like something is loose.

When I go through the gears, I get a different sound at each gear:

Reverse - Higher pitched "grinding"
Neutral - Not much noise
Overdrive - Not much noise
Drive - Not much noise
Second - High pitched "grinding" just like reverse, but a little louder
First - Not as loud as second, but still a little noise

When driving, it sometimes slips from a takeoff going into second. When going about 30, and stopping suddenly, it downshifts roughly, which I thought might have been the torque converter unlocking, but at that speed I wouldn't think so....

Whatcha think, time for a new tranny or is it something minor.

rolson1039 · 12-31-2004, 09:13 PM

my th 350 did that and within three days of working with it the whole tranny died... listening to it now i think its the torque converter but its too cold for me to fix now.. within a week i should have it brought to the high school for their guys to work on it

8t5Silverado · 01-01-2005, 05:44 PM

Thanks for the info.

I guess if I am going to bother replacing a torque converter, I should just rebuild the whole thing.

MylilBowTie · 01-02-2005, 10:28 AM

When the torque convertors go they will send a lot of debris threw the transmission. Don't forget to flush your radiator transmission cooler and lines really well to get all the debris out.

8t5Silverado · 01-06-2005, 02:06 PM

So does it sound like it is the torque converter?

The increased noise in second and reverse makes me think something else might be going on...

8t5Silverado · 02-03-2005, 02:44 PM

Ok, the "clunk" when braking hard from about 40 mph seems to be more pronounced now.

Can anyone else help identify the problem?

This may be related, but it "clunks" real hard when taking it out of park when parked on a slope (I assume this is the U-joints).

60-66 Nut · 02-03-2005, 03:31 PM

Just a guess, but did you check the torque convertor to flywheel bolts? That wouldn't account for the harsh shifting, but they can bring quite a racket if they come loose. A cracked flywheel can also make a weird noise. Good luck, let us know what you find.

60-66 Nut

8t5Silverado · 02-03-2005, 03:40 PM

I climbed under it real quick and couldn't see the bolts, but I plan on looking tonight (this time with a flashlight).

I should add, the tranny has plenty of fluid and it does not smell burnt.

If it were the bolts, I don't see why the noise would sound different in 2nd gear....

If it is that, does anyone know what size bolts (torque converter to flexplate) they should be?

60-66 Nut · 02-03-2005, 04:06 PM

You're right, does seem strange that the noise would be different in 2nd gear, but like I said I'm just guessing since you said it sounds like it's coming from that area. Hard to know without actually hearing the noise in person. If the convertor is taking a dump, seems like it should make little or no noise once it locks up, but again just guessing. The torque convertor bolts are usually 15mm, when you drop the cover to check them make sure to look closely at the flywheel where it bolts to the crank, if you can see it. I've seen them crack around the bolts.

60-66 Nut

8t5Silverado · 02-04-2005, 01:22 PM

Thanks. It's warm here today and tomorrow (50's) so I am gonna climb under it and look.

8t5Silverado · 02-05-2005, 02:59 PM

Well, I climbed under it. I don't know why I thought I couldn't see the bolts on the flexplate (maybe I was just looking from the rear).

It makes that "grinding" sound intermittently and kinda sounds like a big bug or katydid. (almost like the flexplate teet are rubbing the transmission case for just a second at a time, if that were the case, it would wear the teeth, which it isn't)

I don't see any wobble or anything at the flexplate when it is spinning. I have been told that it sounds like the flexplate is broken where it meets the crank, which sounds similar to what 60-66 Nut said.

CbHeEaVsYt · 02-07-2005, 06:59 AM

Is it a th700r?

MylilBowTie · 02-07-2005, 12:23 PM

Its a lockup torque convertor TH350.

8t5Silverado · 02-07-2005, 02:58 PM

No, it's a 700R4.

MylilBowTie · 02-08-2005, 02:29 AM

I thought it was a th350c must have been someone else's I was thinking of.

CbHeEaVsYt · 02-08-2005, 03:35 AM

700 r4 is wat i mean i had the same tranny in my truck and it started making those noises right before it blew on me it blew out 3 gear
from wat i read on here i geuss it cause i always drove in od in the city?!?!
hope i could help

12-31-2004, 08:26 PM	#1
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	Need Tranny Help - Can you identify these noises I am hoping that it is not giving up on me. I will try to explain the noises, but it is hard to do with text. The fluid was a little low, but I topped it off today. It sounds like it is coming from the flywheel or torque converter. In park, it is a racketty sound, like something is loose. When I go through the gears, I get a different sound at each gear: Reverse - Higher pitched "grinding" Neutral - Not much noise Overdrive - Not much noise Drive - Not much noise Second - High pitched "grinding" just like reverse, but a little louder First - Not as loud as second, but still a little noise When driving, it sometimes slips from a takeoff going into second. When going about 30, and stopping suddenly, it downshifts roughly, which I thought might have been the torque converter unlocking, but at that speed I wouldn't think so.... Whatcha think, time for a new tranny or is it something minor. __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

12-31-2004, 09:13 PM	#2
rolson1039 Registered User Join Date: Oct 2002 Location: NJ Posts: 404	my th 350 did that and within three days of working with it the whole tranny died... listening to it now i think its the torque converter but its too cold for me to fix now.. within a week i should have it brought to the high school for their guys to work on it __________________ so many trucks so little time!!!

01-01-2005, 05:44 PM	#3
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	Thanks for the info. I guess if I am going to bother replacing a torque converter, I should just rebuild the whole thing. __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

01-02-2005, 10:28 AM	#4
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	When the torque convertors go they will send a lot of debris threw the transmission. Don't forget to flush your radiator transmission cooler and lines really well to get all the debris out. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

01-06-2005, 02:06 PM	#5
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	So does it sound like it is the torque converter? The increased noise in second and reverse makes me think something else might be going on... __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

02-03-2005, 02:44 PM	#6
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	Ok, the "clunk" when braking hard from about 40 mph seems to be more pronounced now. Can anyone else help identify the problem? This may be related, but it "clunks" real hard when taking it out of park when parked on a slope (I assume this is the U-joints). __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

02-03-2005, 03:31 PM	#7
60-66 Nut Professional Beer Tester Join Date: Aug 2004 Location: Louisiana Posts: 453	Just a guess, but did you check the torque convertor to flywheel bolts? That wouldn't account for the harsh shifting, but they can bring quite a racket if they come loose. A cracked flywheel can also make a weird noise. Good luck, let us know what you find. 60-66 Nut __________________ 60 Ford F100 Custom Cab 61 Apache Short Fleetside 64 C10 Short Stepside 65 C80 409 V8 5spd(X-Firetruck) 83 GMC 350 Olds Diesel 85 GMC Short Bed 86 GMC Short Bed 90 GMC R3500 Crew Cab 92 GMC 1500

02-03-2005, 03:40 PM	#8
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	I climbed under it real quick and couldn't see the bolts, but I plan on looking tonight (this time with a flashlight). I should add, the tranny has plenty of fluid and it does not smell burnt. If it were the bolts, I don't see why the noise would sound different in 2nd gear.... If it is that, does anyone know what size bolts (torque converter to flexplate) they should be? __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

02-03-2005, 04:06 PM	#9
60-66 Nut Professional Beer Tester Join Date: Aug 2004 Location: Louisiana Posts: 453	You're right, does seem strange that the noise would be different in 2nd gear, but like I said I'm just guessing since you said it sounds like it's coming from that area. Hard to know without actually hearing the noise in person. If the convertor is taking a dump, seems like it should make little or no noise once it locks up, but again just guessing. The torque convertor bolts are usually 15mm, when you drop the cover to check them make sure to look closely at the flywheel where it bolts to the crank, if you can see it. I've seen them crack around the bolts. 60-66 Nut __________________ 60 Ford F100 Custom Cab 61 Apache Short Fleetside 64 C10 Short Stepside 65 C80 409 V8 5spd(X-Firetruck) 83 GMC 350 Olds Diesel 85 GMC Short Bed 86 GMC Short Bed 90 GMC R3500 Crew Cab 92 GMC 1500

02-04-2005, 01:22 PM	#10
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	Thanks. It's warm here today and tomorrow (50's) so I am gonna climb under it and look. __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

02-05-2005, 02:59 PM	#11
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	Well, I climbed under it. I don't know why I thought I couldn't see the bolts on the flexplate (maybe I was just looking from the rear). It makes that "grinding" sound intermittently and kinda sounds like a big bug or katydid. (almost like the flexplate teet are rubbing the transmission case for just a second at a time, if that were the case, it would wear the teeth, which it isn't) I don't see any wobble or anything at the flexplate when it is spinning. I have been told that it sounds like the flexplate is broken where it meets the crank, which sounds similar to what 60-66 Nut said. __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

02-07-2005, 06:59 AM	#12
CbHeEaVsYt Pick up man Join Date: Feb 2005 Location: trenton mi Posts: 135	Is it a th700r?

02-07-2005, 12:23 PM	#13
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	Its a lockup torque convertor TH350. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

02-07-2005, 02:58 PM	#14
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	No, it's a 700R4. __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

02-08-2005, 02:29 AM	#15
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	I thought it was a th350c must have been someone else's I was thinking of. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI



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02-08-2005, 03:35 AM	#16
CbHeEaVsYt Pick up man Join Date: Feb 2005 Location: trenton mi Posts: 135	700 r4 is wat i mean i had the same tranny in my truck and it started making those noises right before it blew on me it blew out 3 gear from wat i read on here i geuss it cause i always drove in od in the city?!?! hope i could help __________________ heres sum pics of my truck 82 silverado c10 heres my baby 1990 k1500 check out this 1957 chevrolet for sale

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