Longblue

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.

Longblue

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.

kingtal0n

iTrader: (1)

My 4l80e barely scratches 180*F after driving 50 minutes in noon, rush hour florida traffic. It hits 140*F pretty quick but seems to taper and slowly rise from that.

this is the cooler I used, with -6an
http://www.ebay.com/itm/External-alu...dX7xI3&vxp=mtr

The fan never turns on. It isn't even wired up yet. The longest trip I made so far is 30miles. car weight around 3200lbs (guess). 4.11 rear differential ratio.

Make sure the trans is locking up and fluid is flowing through the cooler. Also, I am using a 9.5" 2800 stall converter, which might be helping. No WOT or fast driving either.

Cole Train

iTrader: (30)

my 80e only hits the 180-190 when it's 90+ degrees and i'm sitting in traffic. As soon as i get move it drops

Longblue

Thanks guys. I have a 3200 stall in my heavy Silverado and see nowhere near the temps he does. We will be checking trans cooler flow to eliminate that. I'm still suspicious that the trans has internal issues as the temp would rise 36F just from a 15min idle in park.

wht/73

Is it bypassing the radiator ?
Where is the temp being taken from?
I would think it would almost be cooked by now.

Longblue

He just got the truck back and I haven't had a chance to look at that. I bypassed the radiator on mine. No need to heat the Trans fluid up down here. Temp is taken from stock temp sensor in Trans that displays through dash. Reads correctly at startup (i.e. reads roughly same as outside air temp) Is a thought that sensor may be getting off scale as it heats up and reads high. Don't think I've heard of this but it is a sensor and weird stuff can happen. Going to shoot the Trans pan (Hughes deep finned pan BTW) with an infared heat gun to attempt a rough measurement. I know the temps of the trans fluid will read differently depending on where the fluid is in the trans i.e. pan vs. converter so it will be a rough reading.

Just overall slightly worried that trans was taken apart to replace input shaft and if that could affect anything if assembly was incorrect?

clinebarger

Most likely not, Unless the pump gasket got messed up where the cooler feed hole is.

Is this a traditional lube or a center lube 4L80E?
Is the TCC operational?

Longblue

I'm not going to gave a chance now to inspect as friend is dropping truck back off with installer. Installer talked with trans/converter builder who said problem is either trans cooler related or torque converter issue. I would have liked to see if there was any slip when in lockup.

I will update when the problem is found.

Longblue

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.

Nathaninwa

Just a couple random thoughts here and may not be related at all

How is the cooler plumbed? It should feed the bottom and exit the top. This way all the air is purged from the cooler.

A water/trans cooler actually cools way more efficient, but no less than the cold side radiator tank which is cooler than engine temp. Running it through the radiator first takes the initial blunt of the heat out then the air/trans cooler can operate more efrectively

Longblue

Cooler is mounted at a 45 degree angle to horizontal. Both lines do come in from bottom. I have heard about air getting trapped inside and causing flow issues. I felt the in and out lines to the cooler and the out is slightly cooler so it seems the cooler is taking some temp out. It is mounted behind an opening in the valence so it does get airflow at speed and has 2 fans that are running on it.

I'm on the fence about running a cooler through the radiator down here in FL. I run a trucool 40k on my 3200 stalled truck and bypassed the radiator and never see more than 160/165F banging around town in the heat. The trucool is almost twice as big as what he runs. I don't run electric fans on my cooler and it is partially blocked by the intercooler.

Guess we're going to see if the converter/trans company is wiling to swap out the converter to eliminate that possibility.

Stay tuned.

LSrBest

iTrader: (1)

Was this ever figured out? Having some issues my self

Longblue

Not as of yet. Friend purchased a new PTC converter that has yet to be installed. Previous converter builder felt converter might be causing the heating issues. Friend decided to go with another company for the converter. Long story here.......

So I will let you all know how that works out.

wht/73

Did it feel that loose to make that much heat?

Longblue

Never personally drove it but was told it was pretty bad. It was sent back in to restall and was somewhat better, but still high trans temps. Bad sign is that temps still didn't want to come down even on the highway with the converter locked. Checked for slip by log file and no slippage when locked.

Guess we'll see. He's not back in town until August. Stay posted.

kingtal0n

iTrader: (1)

If the converter is locked and there is no slippage I Do not see how the converter could contribute much, if any to raising trans fluid temps.

Longblue

Nor would I. Converter builder believed it was a possibility though. Guess we'll see after the new PTC.

Longblue

So, small update. New PTC converter has reduced temperatures a bit. Topping out at 200F now after being hard on it. So that has helped lower it 20F. Driving around converter locked it sits at 165F. It apparently doesn't like to come down in temp after reaching 200F.

Odd ball thing about all this is I run the same everything (trans/converter) now minus the trans cooler. I still don't ever see over 165/170F.

So the search continues.....

wht/73

So normal driving it's 165*?
If it is, sounds about right I would guess.
Why did you get rid of your cooler?
Did ya give it to him? LOL!