Trans smoke under accel. [Archive] - Chevelle Tech

: Trans smoke under accel.


onebadd66
Sep 3rd, 05, 9:47 AM
Was looking at a video of my car launching and right after 60ft or so,the car pours out grey smoke from under.Looked and say trans fluid on the pan,back on the x member down the pipes even the hint of it on the rear bumper.
Check the modulator,no sign of fluid there.All the bolts and drain plug are tight.I'mm assuming this is where the fluid is comming from but why?
Looking for some help so I don't toast the trans.
Around town,it's ok even when I jump on it from time to time,no hint of smoke.Just under hard and constant acceleration (track time) do I (we) notice it. Thanx in advance for any help,

Bob West
Sep 3rd, 05, 10:19 AM
Could also be coming out of the vent tube. Top left main part of transmission behind the bellhousing.

onebadd66
Sep 3rd, 05, 10:23 AM
Bob,Thanx But what I know about trannys you could put in a thimble:clonk:
Where is the vent tube located,and why would it be coming out there? From the psi in the trans? Again thanx :thumbsup:

onebadd66
Sep 3rd, 05, 11:31 AM
OK,see that. Now what would make the fluid come out there? too much fluid? too little? THanx

Bob West
Sep 3rd, 05, 12:06 PM
Since I'm not an expert, I'd think it would be too much fluid or too much internal pressure whether caused by a shift kit, valve body, or internal leak???

onebadd66
Sep 3rd, 05, 2:17 PM
Is there anyway to reduce the pressure? Fluid looks fine. The trans has a Transgo shift kit,but Iv'e never heard anything bad about them.Is this something that happens with certain shift kits?

BillK
Sep 3rd, 05, 6:28 PM
Steeve,
I am certainly not a trans expert but I do know that the vent tube has nothing to do with transmission line pressure. It relieves pressure inside the case, like an engine breather does. The only things I can think of that would cause it would possibly be overheating, or if there is an internal leak allowing air to get into the system and foaming up the fluid enough to come out of the vent. Are you certain it is coming out of the vent and not from a loose cooler line etc ?
By the way .... get it fixed before you make another pass ! I have had trans fluid under the slicks at 125 mph and believe me it is not a good feeling. Not to mention making the track very unsafe for the next guy in your lane :(

onebadd66
Sep 4th, 05, 9:20 AM
Bill,Thanx for the info.I'm not sure weather it's coming out the tube or not. Untill Bob mentioned it .I had no clue that there was a tube.That's why I post here and ask fellow members, to learn.
Over the week end at some point I plan on cleaning the trans with some grease cutter ,to see if maybe I can spot it.It does look like most of it is concetrated on the pan.however the lines do look dry,as do the dip stick,and the mod. checks out as well.

If there's any thing else you or anyone can think of please let me know.
BTW ,I'm also going to install a cooler with a fan as well.

Cameano
Sep 5th, 05, 3:17 PM
Make sure it's not coming out of your dipstick tube, running down. Had that happen on a rebuild once. Didn't check the vent tube, it was plugged up. :clonk: No vent=fluid out the dipstick tube when hot. Yours could possibly be partially plugged. Also check for cracks in your cooler lines and fittings, that might only be spraying under higher pressures, i.e. when you're on it. If you want to check the vent, if it's the older tube type, run a piece of wire up into it carefully, and see if it comes back out clean. I wouldn't really recommend shooting air through it if it's dirty, as the dirt will go into your trans. It'll only end up in the pan, which can be dropped and cleaned, but it's still extra work.

onebadd66
Sep 5th, 05, 6:13 PM
Darren, Good point.I'm glad I read this before I shoot air into the tube:eek:I don't see any signs of fluid on or around the dipstick.
So far I shot down the trans with degreaser,and cleaned it up clean.Tomorrow or so I plan on getting it to a station up on a lift so Ican inspect it further.as drips on rear seal,pan,in,out tubes stuff I can see alittle better standing under the car :D Thanx for the help so far.I'll chime in again when I find,(or think) Iv'e found the problem.