4l80e Overheating Issue
06-01-2017, 05:27 PM
#1
On The Tree
Thread Starter
4l80e Overheating Issue
To all,
Wondering if anyone has some insight into an overheating issue a friend of mine is having with a 4l80e trans. Builder unnamed and would rather keep out to prevent a pissing contest. Trans was installed by a professional shop and tuned by the same individual that did mine.
Trans is installed in a Silverado and is a close duplicate to my setup. Running a B&M trans cooler with electric fans on it. Around town (Florida BTW) trans temp will reach 230F which we will all agree is way too hot. Even after extended highway miles, trans temp does not want to drop. As a side experiment, started the truck in park from cold with a reading of 90F on the gauge. Let truck idle for 15min and trans temp reached 126F. That is with no driving. Seems like a quick rise to me.
Hoping within the next week to get with him and crack the return line from the cooler to ensure fluid is making the trip back from the cooler. Fans on cooler are working.
Any other suggestions/input is welcome and wanted. Thanks for the time.
Wondering if anyone has some insight into an overheating issue a friend of mine is having with a 4l80e trans. Builder unnamed and would rather keep out to prevent a pissing contest. Trans was installed by a professional shop and tuned by the same individual that did mine.
Trans is installed in a Silverado and is a close duplicate to my setup. Running a B&M trans cooler with electric fans on it. Around town (Florida BTW) trans temp will reach 230F which we will all agree is way too hot. Even after extended highway miles, trans temp does not want to drop. As a side experiment, started the truck in park from cold with a reading of 90F on the gauge. Let truck idle for 15min and trans temp reached 126F. That is with no driving. Seems like a quick rise to me.
Hoping within the next week to get with him and crack the return line from the cooler to ensure fluid is making the trip back from the cooler. Fans on cooler are working.
Any other suggestions/input is welcome and wanted. Thanks for the time.
06-01-2017, 05:27 PM
#2
On The Tree
Thread Starter
Forgot one other important detail which may lead to some better insight.
Trans company had to send someone to replace input shaft on site as torque converter would not slide all the way on splines. Was told there was a batch of input shafts that had a tolerance problem.
So I'm assuming transmission had to be at least partially disassembled to replace an input shaft.
To those with this knowledge, would there be a potential issue in this area that would cause this overheating issue due to a reassembly issue?
Thanks again.
Trans company had to send someone to replace input shaft on site as torque converter would not slide all the way on splines. Was told there was a batch of input shafts that had a tolerance problem.
So I'm assuming transmission had to be at least partially disassembled to replace an input shaft.
To those with this knowledge, would there be a potential issue in this area that would cause this overheating issue due to a reassembly issue?
Thanks again.
06-01-2017, 08:09 PM
#3
What year is the transmission? If the builder used the wrong size rear cooler line fitting it will overheat quickly. If the tranny is a '99 or newer you'll want to make sure the rear fitting is the longer style. Here is a link to show the difference
https://www.performancetrucks.net/forums/gm-drivetrain-suspension-22/4l60e-4l80e-transmission-cooler-lines-help-485402/
https://www.performancetrucks.net/forums/gm-drivetrain-suspension-22/4l60e-4l80e-transmission-cooler-lines-help-485402/
Last edited by darkirish63; 06-01-2017 at 08:17 PM.
06-01-2017, 08:49 PM
#4
When I had the issues with that fitting, I don't recall it overheating. It just chewed up some stuff.
For them to say the converter wasn't fitting, it makes me believe that they ended up damaging the O ring on the input shaft. Is the converter locking up? The easiest way to check this is by driving down the road with a steady throttle and use your left foot to lightly touch the brake pedal. You only need to touch it light enough to turn the brake light on. If it was in lock up, the RPM's will jump up as it disengages. If it is a stock converter it will only be a few hundred RPM's.
For them to say the converter wasn't fitting, it makes me believe that they ended up damaging the O ring on the input shaft. Is the converter locking up? The easiest way to check this is by driving down the road with a steady throttle and use your left foot to lightly touch the brake pedal. You only need to touch it light enough to turn the brake light on. If it was in lock up, the RPM's will jump up as it disengages. If it is a stock converter it will only be a few hundred RPM's.
06-02-2017, 04:05 AM
#5
Some aftermarket Billet input shafts are made larger to remove play, converters should always be test fitted in these cases. As for heat, a tight input shaft to converter clearance won't cause it but a tight converter to pump bushing can add some heat but shouldn't be crazy. Keep in mind that if it has a factory trans cooler in the rad that it's gonna warm up some even at idle from the rising coolant temp. 230 is too hot, and it should drop on the highway with a sufficient cooler. Mine never gets over 170 with a trucool 40k
And as mentioned above, a damaged input shaft oring will cause a no lockup condition.
And as mentioned above, a damaged input shaft oring will cause a no lockup condition.
Last edited by 03sierraslt; 06-02-2017 at 04:34 AM.
06-02-2017, 09:31 AM
#6
On The Tree
Thread Starter
Thank all. Installer ended up speaking with trans/converter builder who said problem will either be torque converter issue or trans problem. Friend is dropping truck back off for the installer to check for fluid flow through cooler. I believe stock radiator cooler part has been bypassed.
The disturbing part is the the fact that with the truck just idling in park, trans temp rises from 90F to 126F in a 15min span. I drive 2 miles to the gym in stop/go traffic and mine only reaches 126F. I'm bypassed with a trucool as well and never see over 160F.
As far as converter lockup, not sure now as I won't have the chance to check all this since he's dropping it back off.
I will report and follow everything up when we have a resolution.
The disturbing part is the the fact that with the truck just idling in park, trans temp rises from 90F to 126F in a 15min span. I drive 2 miles to the gym in stop/go traffic and mine only reaches 126F. I'm bypassed with a trucool as well and never see over 160F.
As far as converter lockup, not sure now as I won't have the chance to check all this since he's dropping it back off.
I will report and follow everything up when we have a resolution.
06-02-2017, 10:42 PM
#7
On The Tree
Thread Starter
Small update. Radiator was already bypassed. Rear fitting in trans is correct. There is fluid flow back from cooler. Another cooler was installed. Pressures in trans appear normal. Torque converter is locking up. Nothing has changed.
He drove it down here in the rain which should help remove heat and trans at highway speeds still ran 180F. During testing around shop, trans consistently gets up to 230F. Pretty much verified with IR temp gun shot at pan which reads 200/210F.
Trans/converter builder is being spoken with Monday to see if they will just send another converter. Problem is obviously trans or converter related at this point.
He drove it down here in the rain which should help remove heat and trans at highway speeds still ran 180F. During testing around shop, trans consistently gets up to 230F. Pretty much verified with IR temp gun shot at pan which reads 200/210F.
Trans/converter builder is being spoken with Monday to see if they will just send another converter. Problem is obviously trans or converter related at this point.
