th350 issue

[hinkv10]

I have a bit of a frankentruck... originally an 87 v10 with a 305. Now has a carbed 305 out of an 84, th350 and a np205. I think the axles are original...

I've been having a couple issues lately.... what seems to be happening is that if I fill up the fluid to where it should be hot it seems to be coming out the vent on the top dr side of the trans. I believe the th350 is probably out of a late 80's or 90s trans because it has sensors in it (not hooked up). I just replaced the trans pan gasket and it is dry as a bone. I let it drain for 2 days and recoverd 6 quarts of oil plus what ever spilled... I've put in 7 quarts and it still doesn't register on the dipstick but the truck drives fine... in fact what it has been doing is leaking fluid under the car (the vent always has a dab of red on the green tip) and seems to be registering at the bottom of the dipstick... I refill it and a couple days later it is in the same place.

Now my question; I've read that th350 and the 700r can have the same dipstick but will the filler tube from a 700r bolt onto the th350?? I'm wondering if the tube could be too long and therefore I'm overfilling the trans... here are a couple pics;

ps when I dropped the pan I found an "extra" bolt next to the magnet. I looked on the valve body and there are several identical bolts but nothing was missing?? Some of the heads had a different mark but everything looked like it was where it was supposed to be...

http://s1158.photobucket.com/user/hinckley001Hinckley001/slideshow/tube

 

[HotRodPC]

As I was reading, I'm thinking you've got the wrong dipstick for the tube you have so you're overfilling the transmission. With being overfilled, the fluid will foam and it will come out the vent tube. Looking at the pics, that is a LONG tube so you've probably got a short dipstick. That bolt goes to the separator plate by the looks in the pic. If you're not missing one, then I'm not sure how it would get in there. If you want take a pic of the bottom of your transmisssion with the pan off. The whole area with the pan off. I'll see if I can recognize where a bolt is missing.

That plug in your talking about is for the Lock up on the torque converter. So you have a Th350C

 

[74 Shortbed]

That tube is sticking up way high, does the dipstick stick out the bottom of the tube??, if it don't you have the wrong stick for the tube and you'll be overfilled I'm betting on that, if you're overfilled fluid gets up into the rotating mass and gets aerated and will puke out the vent, also if the fluid is aerated you have air in the system and you won't have full apply pressure to the clutches which in turn causes them to slip and eventually fry them up..

 

[HotRodPC]

That tube is sticking up way high, does the dipstick stick out the bottom of the tube??, if it don't you have the wrong stick for the tube and you'll be overfilled I'm betting on that, if you're overfilled fluid gets up into the rotating mass and gets aerated and will puke out the vent, also if the fluid is aerated you have air in the system and you won't have full apply pressure to the clutches which in turn causes them to slip and eventually fry them up..

Exactly right !!! I too agree, he's got the wrong tube with a short dipstick and he's over filling it. I'm surprised it hasn't started puking out other seals yet.

BTW, the tube being to tall is no issue at all whatsoever, it's just that you're not getting an accurate measurment. So either get the right tube for your dipstick, or the right dipstick for your tube and you'll be good. You could even buy one those cheap china chrome dipstick tubes with the dipstick and replace the whole unit then YOU KNOW you have an accurate combo. You can use a tube from a 700r4, Th350, Th400, doesn't matter just so long as you have the correct seal for that particular tube. Either the grommet type or the O Ring type won't matter.

 

[hinkv10]

thanks guys. This truck is an adventure lol... I'm going to buy a tube and dipstick off of amazon and install it in a couple of days... I have a gasket kit that has 7+ gaskets in it so I should have the gasket I need in case the new tube doesn't come with one.

The pan is back on so I can't take a pic. I removed the filter and looked and could only find 1 hole that didn't have a bolt in it and it didn't have the right threads/ or any... so who knows... Also I reinstalled the dipstick with the pan off and you can't see the dipstick so its safe to say the dipstick is too short.

I love the truck and she is in very good shape and has a rugby dump kit so she is worth keeping and restoring. I'm just trying to avoid a new engine and trans till I move and get settled.

 

[74 Shortbed]

thanks guys. This truck is an adventure lol... I'm going to buy a tube and dipstick off of amazon and install it in a couple of days... I have a gasket kit that has 7+ gaskets in it so I should have the gasket I need in case the new tube doesn't come with one.

No gaskets on the tube, there's two style tubes one takes an O-ring the other takes a grommet, either one fits the case grommet is preferred.

O-ring style

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Grommet style

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[HotRodPC]

I too like the grommet model better. Typically, earlier model Th350 and Th400's used the O Ring type, the later Th350 and 700r4 use the grommet type. Here's the trick to the grommet type. People normally try to put the grommet and tube in at the same time. NO !!! Put the grommet in first by itself, then slide the tube into the grommet.

 

[hinkv10]

Thanks guys, I bought a long tube model chrome one off amazon for $15 and it looks exactly like the oring style. I took the dipstick and stuck it in my existing tube and it reads right in the middle lol. Done