Exhaust heat and transmissions, tell me if this makes sense

[Science Abuse]

-4.0 DOHC straight 6

-Eaton M90 supercharger

-322hp, 378 lb ft

-2" OD exhaust?

 

The pair of 2" downtubes come together (by way of flux ugly weld) into a single 2 inch pipe, then back into a pair of 2" pipes. This 2" pipe runs within an inch of my transmission pan. This pipe would be getting very hot form all of the gasses cramming into it. Could the heat transfer from this pipe be enough to cause transmission overheating?

 

Thought, previous owner was a tool. Had an exhaust on it, but saved the old one. When he dumped the car on a dealership, he gave them the old exhaust to weld back on...poorly. Or they got a junker system, either way, I need to get rid of the pipe.

[Rally Pat]

what about wrapping it?

[Dr. Apex]

It's very possible as most transmissions have an operating temp like an engine, the Pathfinders like mine with the auto trannies are known for overheating when the fluid flow is slowed from something like a clogged cooler or pickup.

 

Try some heat wrap like mentioned or a heat shield between them. It also sounds like you have a choke point on your exhaust that could cause excessive heating which could be making things worse.

[Guest Removed]

fluid break down will cause extra heat. i take it the heat shields are missing?

 

and if its running too lean, that will give you more exhuast heat. too many factor's here too play with. is this the oe exhuast setup?

[Science Abuse]

What it has is a log manifold into 2 cat'ed 2" downpipes. These come together into a single 2" that runs past the tranny. It splits into two pipes and runs out the back like that. But going off the quality of the welds...or lack there of, I can't be sure that it is OE.

Everyone I've talked to about my transmission has said "I don't think you quite fathom the amount of abuse needed to kill a 4L80E". So I'm praying that super hot fluid is playing tricks on me. I drained the tranny last night (but not the TC) and filled it back up. After a short test drive I noticed the problems were still there, and the dip stick tip was too hot to touch, by allot.

 

Would overheated fluid cause hard shifts and a slipping feeling?

[Guest Removed]

Id say flush it ..the setup we use's sometimes fixx's hard shifts.

 

I think that you had a converter there at one time, with dual in's and out's.(if i remember correctly)

 

but that will cause way too much heat on the trans . cause if its close too the pan, (and the lines are over there to) it will over heat the trans fluid, and cause the fluid breakdown.

trans fluid does not like like too be over 175 degrees. and that trans take DEX VI fluid.

 

do not use dex III in it. you could be having a valve body issue.(they are known for it)

[Science Abuse]

do not use dex III in it. you could be having a valve body issue.(they are known for it)

Doh, I got info from alot of places saying that it takes Dex3, so that's what I put in last night. Also, I didn't drain the TC (I wasn't sure how I'd refill it).

[Mojoe]

That choke point sucks. Like many said, wrap it. I would also use a silicone spray on the wrap, and look into putting a heat shield between the exhaust and trans. All of this will run you about $30. All this with new fluid, should cover any relation of heat transfer.

[Science Abuse]

The plan is to replace and reroute the pipe, and make a heat sheild with ceramic or something from work (we have insulation that will stop molten aluminum from blistering paint 1/2" away..but I dunno if its waterproof)