LS Swap Vibration at highway speeds - The 1947 - Present Chevrolet & GMC Truck Message Board Network

C10agent · 03-21-2020, 03:47 PM

Hey guys, I swapped a LS 5.3 gen 3 with 4L60 BP engine harness in my 72 c10. Here is my issue. When I drive the truck from when it was sitting so the trans isn’t completely warmed up, drives like a dream, no vibration at 70-80. But when I have been driving for a while and all is warmed up (trans 185 / motor 210) and I stop and turn it off and fire it back up, I get a vibration at 60+ it seems. Has anyone ever had this before? Does that make sense? Been dealing with it since I did the swap. Supposed to be a rebuilt 4L60 so I am stumped. Any info would be greatly appreciated. Thanks! Neil

**mongocanfly** · 03-21-2020, 04:24 PM

When it starts vibrating, can you try slipping it in neutral ..if its possible ,while its still rolling..and see if it still vibrates?
Does sound odd it only does it when warm and after a recrank.

C10agent · 03-21-2020, 04:35 PM

Thanks for the advice, will definitely try that. Thanks!

*dajn* · 03-21-2020, 11:13 PM

Could it be an engine misfire? I know its possible for an engine to run great and then develop a miss once warmed up. Maybe it's running on 7 once warmed up and creating a shake. Just a thought. Hopefully it's an easy fix.

*dajn* · 03-21-2020, 11:29 PM

One more thing. I have never had a vibration issue from the many 4l60e's I have owned but I did have shift solenoid issues in my s10 a few years ago. It was stuck in 3rd gear and I had to drop the pan to change the two shift solenoids. I realize that has nothing to do with your problem but maybe one of the other solenoids in the transmission is acting goofy. I have had hanger bearings cause a shake but that cant be it because those always happen at the same time and speeds.

C10agent · 03-22-2020, 12:03 AM

Quote:

Originally Posted by dajn

Could it be an engine misfire? I know its possible for an engine to run great and then develop a miss once warmed up. Maybe it's running on 7 once warmed up and creating a shake. Just a thought. Hopefully it's an easy fix.

I have been thinking about getting it retuned. I had not thought of that being the issue, I will check it out. Thanks!

prodjay10 · 03-23-2020, 09:28 PM

A bad torque converter can cause vibration.

*dajn* · 03-23-2020, 09:54 PM

Quote:

Originally Posted by prodjay10

A bad torque converter can cause vibration.

The problem is we are just throwing darts at the wall at this point. Hopefully its something simple.

prodjay10 · 03-23-2020, 10:35 PM

Did you ever clear the adaptive learning on the pcm for the transmission? I doubt it’ll fix this but I’m curious to know if it’s necessary or if it’ll cause any problems if you don’t.
Posted via Mobile Device

03-21-2020, 03:47 PM	#1
C10agent Registered User Join Date: Aug 2013 Location: Navasota, TX Posts: 708	LS Swap Vibration at highway speeds Hey guys, I swapped a LS 5.3 gen 3 with 4L60 BP engine harness in my 72 c10. Here is my issue. When I drive the truck from when it was sitting so the trans isn’t completely warmed up, drives like a dream, no vibration at 70-80. But when I have been driving for a while and all is warmed up (trans 185 / motor 210) and I stop and turn it off and fire it back up, I get a vibration at 60+ it seems. Has anyone ever had this before? Does that make sense? Been dealing with it since I did the swap. Supposed to be a rebuilt 4L60 so I am stumped. Any info would be greatly appreciated. Thanks! Neil __________________ Neil............... 1972 C10 SWB - Shop Truck in the Works 5.3 LS / Full Air Ride / Rear Notch 20" American Racing Daytonas IG - neilioustx - pictures of build/progress Born and Raised in the Promised Land.... TEXAS Y'ALL!!

03-21-2020, 04:24 PM	#2
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,597	Re: LS Swap Vibration at highway speeds When it starts vibrating, can you try slipping it in neutral ..if its possible ,while its still rolling..and see if it still vibrates? Does sound odd it only does it when warm and after a recrank. __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

03-21-2020, 04:35 PM	#3
C10agent Registered User Join Date: Aug 2013 Location: Navasota, TX Posts: 708	Re: LS Swap Vibration at highway speeds Thanks for the advice, will definitely try that. Thanks! __________________ Neil............... 1972 C10 SWB - Shop Truck in the Works 5.3 LS / Full Air Ride / Rear Notch 20" American Racing Daytonas IG - neilioustx - pictures of build/progress Born and Raised in the Promised Land.... TEXAS Y'ALL!!

03-21-2020, 11:13 PM	#4
dajn Account Suspended Join Date: Feb 2011 Location: Ogilvie Minnesota Posts: 461	Re: LS Swap Vibration at highway speeds Could it be an engine misfire? I know its possible for an engine to run great and then develop a miss once warmed up. Maybe it's running on 7 once warmed up and creating a shake. Just a thought. Hopefully it's an easy fix.

03-21-2020, 11:29 PM	#5
dajn Account Suspended Join Date: Feb 2011 Location: Ogilvie Minnesota Posts: 461	Re: LS Swap Vibration at highway speeds One more thing. I have never had a vibration issue from the many 4l60e's I have owned but I did have shift solenoid issues in my s10 a few years ago. It was stuck in 3rd gear and I had to drop the pan to change the two shift solenoids. I realize that has nothing to do with your problem but maybe one of the other solenoids in the transmission is acting goofy. I have had hanger bearings cause a shake but that cant be it because those always happen at the same time and speeds.

03-23-2020, 09:28 PM	#7
prodjay10 Registered User Join Date: Jun 2016 Location: Phoenix AZ Posts: 429	Re: LS Swap Vibration at highway speeds A bad torque converter can cause vibration.

03-23-2020, 10:35 PM	#9
prodjay10 Registered User Join Date: Jun 2016 Location: Phoenix AZ Posts: 429	Did you ever clear the adaptive learning on the pcm for the transmission? I doubt it’ll fix this but I’m curious to know if it’s necessary or if it’ll cause any problems if you don’t. Posted via Mobile Device



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