New one on me!

Tree Trimmer · Aug 6, 2011

it could be the bypass, as the possible reason the bypass opened is still on the old truck. putting the trans on the new truck w/o the cooler probably made it so the bypass didnt need to be open, therefore allowing cooling. and the fact that the new trans is also getting hot. imo, something is making the bypass open, or something creating those symptoms.

TARM · Aug 6, 2011

Yep I agree. And given that we are down to only the cooler and the lines to and from it and the trans. Everything else will have been eliminated by the move unless we are talking about an entirely different cause all together which I doubt.

cowboy_dan · Aug 6, 2011

Tree Trimmer said:
it could be the bypass, as the possible reason the bypass opened is still on the old truck. putting the trans on the new truck w/o the cooler probably made it so the bypass didnt need to be open, therefore allowing cooling. and the fact that the new trans is also getting hot. imo, something is making the bypass open, or something creating those symptoms.

Are you thinking about the 4r100 bypass? The truck in question is an OBS, so unless it was added later, it shouldn't have that bypass.
I was thinking more along the lines of a bypass internal to the transmission, if it exists.

Derek@Vision Diesel · Aug 6, 2011

No external bypass on these transmissions, these are e40d's that we are talking about. I put his sending unit on my truck and its reading extremely hot. I started my truck this morning and it was reading 130* then i drove 20 minutes and it was 205*

Tree Trimmer · Aug 7, 2011

well, apparantly i missed the obs part, and spaced on reading the sig, though he did say it was his buddies truck. though, i suppose he did say it right in the first line of the first post.

my bad, carry on, laughing at me now.

Derek@Vision Diesel · Aug 7, 2011

Today we blew the hard lines out, connected the rubber lines together so we have the OTW and OTA coolers both deleted, just running the oil through the lines and back to the transmission. About 10 minutes of normal driving and it was around 200* both on the AE (in volts, converted to *) and then on his banks gauge. In fact the volts read a little bit higher!
In my experience even without a cooler, it should not heat that quickly that easily. And im sure if we kept going could have easily gotten it hotter

Arisley · Aug 8, 2011

Open the lines, extend them down into buckets. Start the truck and see if fluid dribbles out or is getting pumped out.

Derek@Vision Diesel · Aug 8, 2011

Good idea! We will do that on Tuesday right before we install the new cooler

cowboy_dan · Aug 15, 2011

Well?

Derek@Vision Diesel · Aug 15, 2011

Cooler made the difference. Thanks guys!

It runs amazing with the new cooler. The oddest part though, my truck has the same transmission and the same stock cooler and it runs plenty cool, his ran REALLY hot

907DAVE · Aug 15, 2011

Didn't read through the whole thread but is his converter locking in okay?

Derek@Vision Diesel · Aug 15, 2011

907DAVE said:
Didn't read through the whole thread but is his converter locking in okay?

Seems to lock up real well, its running much cooler now!

cowboy_dan · Aug 16, 2011

Well good.
I still think the cooler is just masking a problem (just not sure where that problem is). But if he's happy, let him drive.

Derek@Vision Diesel · Aug 16, 2011

cowboy_dan said:
Well good.
I still think the cooler is just masking a problem (just not sure where that problem is). But if he's happy, let him drive.

What problem could that be.

He now has a new cooler, new trans lines, and a new transmission. It wont go over 160 just sitting in the drive way in drive for 15 minutes, and it runs 145 on the freeway.
Shifts, locks up, down shifts, all of this stuff is great. Maybe even better than my BTS!

TARM · Aug 16, 2011

OK but did you find or look for what was the cause. I think that is what is being pointed out. Did you run the fluid out the old hoses and see if it flowed well? Did you find anything wrong with the hoses? My guess is replacing the hoses is what fixed the issue and of course a larger cooler on top of that dropped things way down.

Derek@Vision Diesel · Aug 16, 2011

Tarm we did check flow, we flushed the lines good, we did pretty much everything. The only thing that actually solved it was the new cooler.

We havent pulled the front end of the truck apart to get the old cooler out and see what the problem was with it, but we will soon