Name the source of this smoke...

[cbbr]

'90 Suburban. 350/th400/241. Driving down the interstate with a heavy trailer. Smoke comes pouring out from underneath. Looks like a fluid leak. starts from just at the back of the engine. Looks to be coming from the drivers side only. Reddish in color (Trans Fluid?). Does not appear to be coming from the bottom of the trans, looks like its higher up. Hit the Y-pipe which caused the smoke.

 

[dyeager535]

Have a torque converter inspection plate in place or not? I had a vehicle that destroyed the front seal on the TH400, which leaked onto the converter, and without the inspection plate, threw it on the exhaust, causing it to smoke quite profusely.

On the drivers side though, if you've got oil cooling lines, theres that, and the oil filter surfaces that could leak oil as well.

Since you mention so far forward, doesn't sound like it woudl be something like the back of the trans or t-case.

 

[JEBSR]

sounds like the trans may be getting hot and pushing the fluid out of the vent tube. the vent tube is on top of the trans and I believe it runs off to the right side on that trans. If that is the case you probably need to change the fluid and filter and add a bigger cooler.

 

[HarryH3]

Slap a trans gauge on that rig! I've seen trans fluid bubble up and out of the dipstick tube when the trans is badly overheated. DON'T continue to drive it like that. Hot ATF hitting a hot exhaust manifold has caused many fires.

 

[1985_K5_Silverado]

Slap a trans gauge on that rig! I've seen trans fluid bubble up and out of the dipstick tube when the trans is badly overheated. DON'T continue to drive it like that. Hot ATF hitting a hot exhaust manifold has caused many fires.

That's the first thing I'd do, if I were pulling a heavy trailer - install a trans temp gauge. It'll let them know if they might need a bigger cooler, and that's a lot cheaper than a rebuilding a burned-up TH400.

 

[cbbr]

That actually makes sense. The trailer is a M105 (big military trailer) and is loaded. I only halued it about 10 miles, but the truck was straining. I have never hauled it as loaded as it was yesterday.

It does not appar to be a leak as it stopped as soon as I did and I could not find a leak with it sitting at idle running or even easing down the road afterwards.

The engine/trans is original (105,000 miles) so I don't think that there is an inspection plate missing and I don't have a trans temp gauge (yet) but do have the factory cooler.

I guess that I will change the fluid/filter and install a gauge ASAP. Thanks guys and any other suggestions are welcome.

 

[Blue85]

After my tranny puked on the manifold and started a fire, I found there was a recall on the tranny dipsticks, which replaced them with the locking-top type. It's good to make sure you have one of those, so that if it pukes, it has to be from the vent.

Spitting out fluid doesn't necessarily mean you are overheating. It could have been overfilled. Still, it's best to find out because the overheating will mean the end of that tranny.

 

[ryoken]

my money's on those ever-elusive hippy fairies nesting in his framerails.... troublesome critters, they are...

 

[yoshisv]

My 89 Blazer did this once turns out the oil pump in the transfercase was going out which caused the fluid to get hot and bubble out the vent tube. I noticed it smoking while i was driving down the interstate just like you stated.