Th350 leaking from vent. Anyways, see if you can poke and open up the vent hole.

Th350 leaking from vent If you click them and make a purchase, we 4L60E how we make sure it never leaks out the vent. Jump to Latest It turned out to be that I had a yoke with a vent hole in it just in front of the U joint. As a previous poster suggested, make sure the bushing is good. DO NOT plug the vent! It allows moisture to evaporate as things heat up, and will keep the seals from leaking as things warm up as well. Clark Clark, Apr 5 If you can't figure out where it's leaking from that's most likely because the tranny is too greasy to see where any new fluid might be leaking from. 6K views 3 replies 2 participants last post by cfjfisher Apr 30, 2018. the fluid coming out of the breather can also be caused by the fluid being low allowing the pump to suck air causing bubbles/foaming wich just keeps causing the fluid to foam eventually pushing it out of the breather. Top off the transmission then take it down the road so it gets up to operating temp. I sprayed some Brakcleen at It has a th350 behind a 350. It makes a mess, because the vent is on top. Fluid leaks can result in low fluid levels, which can cause shifting problems and potential damage to the transmission. Camaro1969 Discussion starter. the vent is on the top of the case. How is the best way to check to make sure the air vent is open and not stopped up. I have inspected every spot that would normally leak but only found one spot that is the problem. it flushes out quite some transoil. Leaking TH350. And the drips are coming from the inspection cover. Another common issue with the TH350 transmission is fluid leaks. Thank you and Happy 4th to all Donnie . Thread starter tiredtiretodd; Start date Jul 26, 2017; Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If vehicle sets for a long time, say a couple weeks, oil may leak out the vent as oil from the torque convertor will seek its lowest level - gravity thing - through the oil pump into the pan. We have been doing it this way for 10 years easy and never had a vehicle come back from leaking out of th I got tired of the Heartbeat of America bleeding ATF all over my driveway, so let's fix it. What would cause this, and how do I fix it? The tranny never had any problems before. It is also an ugly mess that has evidently been leaking for YEARS. GM used two methods for this. Jump to Latest 11K views 15 replies 5 participants last post by mbrekke Apr 30, 2010. Bought a TH350 off a member here (no qualms, bought as is) and its been doing good. The trans has the short tailshaft. Check for leaks later. if there was no vent the pressure could do something that engineers saw to be a problem lol. TH350 Transmission Leaking from everywhere! The 1967 - 1972 Chevrolet & GMC Pickups Message Board. I've seen it coming out the bottom, and part way up. The TH-350 vent is on the drivers side of the case. It seems the fluid drips come from above (I'm not 100% sure. I have a TH350 that is leaking at the kickdown cable. 35Chev/320GMC, Mar 27, 2007. The O ring is bad on the tube or the air vent hole is stopped up. M. Nothing is coming out of the vent. Here's a quick, simple, and I keep getting fluid coming out of my overflow tube (PS transmission) on my TH350 and the fluid level hot is half way between the marks on the dip stick tube. This time we reseal the transmission pan with right stuff. But it's started puking fluid out from where the district tube goes in, but only when I'm pulling a trailer. Could be the pump gasket in wrong. Upon returning home, the fuild was coming out the filler tube at the tranny case. My recommendation would be to spray brake cleaner on the tranny and wipe it clean, get it as clean as possible. Afriend of mine has a 74 chevy 2wd truck with a th-350 or 400 trans (not sure) I am thinking it is a 350 anyhow the front pump seal is leaking (we already replaced the front seal for the input shaft on the torque converter I looked in a few manuals i have at the body shop and it seams easy Just a quick update on a few things I've been working on. SHARE Ive been closing up all the little leaks so I can drive this F1. 99% Of the time you will find your leak. We put in a new converter in and the trans is still leaking on my th350 trans. when i do a converter swap without dropping the pan as well, i dont add any fluid till i start the engine because the pan will still be full. The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 TH350 vent relocation. 36 yukon gears/axles, 8. This will definitely If it's really over filled it might puke fluid out of the vent tube. It leaks from the pan, rear driveshaft seal, and speedo. A new slip yoke sealing kit for TH350 and 700R4 transmissions. And the shifter shaft seal is another leak spot. I have a th350 behind a sb 350 in a vega. C. It sat for about a month, I moved to a new place and started it to put it on the trailer. 1 Welcome, Guest I’m leaking fluid out of the weep hole that’s drilled in the center the vent is there so when the suspension travels it will compress and extends the slip yoke. No driveshafts are If you just want to get the thing to quit leaking so you can see how it works, then you can ignore the detent cable, plug the hole in the plastic fitting and make sure it has a good O Full running in Park is close to the pan/case junction. SHARE POST #12. Although I'm kind of surprised the fluid is making it up that far, a TH350 will usually find several other places to spew out of that are closer to the ground. My guess is the tube it self is plugged, since it is not leaking at the tube end as you say. So the 'correct' way to repair it is to remove the broken off piece and replace it w/a new vent. Save Share installing a new vent in itself, may solve your issue. TH350 Yoke Weep Hole Leak. It always pukes out the tailshaft vent for some reason. Upon returning home, the fluid was coming out the filler tube at the tranny case. Pull out the plastic driven gear and look inside the bullet and there is the second O-ring. Take a good look at the pan rails for any They have a big risk of leaking here if you don't install a new seal with the new converter. The fluid is running out of the top of the tube. As for the pump gasket, I'm pretty sure I had it aligned correctly (see pics). One step closer to getting Winston, our 1985 GMC Sierra squarebody truck on it goes on right behind the speedometer drive gear. How many quarts are left in the trans after draining? I can't measure the ATF that drained out, as I recycled the oil prior to refilling. th350 vent tube/check valve location and access. The risk is that the broken vent tube will allow dirt and water access to the inside of the trans. e. Sometimes leaks can wander. Bone dry for a week. Here's a few more places to heck for leaks. ) I want to replace all the O-ring seals, dipstick seal and use a Moroso thick rubber gasket (93102), and be done with it. 3966 posts · Joined 2013 Add to quote; Only show this user . TH350 w/ Gearvendors, 3600 Converter, Home Built HEI, Junkyard Hydro Boost, QP 9” w/ 3. After cleaning the excess oil off, apply about ten lbs of air to that tube, and watch to see where your leak is. if it only leaks after sitting . I let it drain for 24 hours. Might try pulling it and smearing a little black rtv on it. Reactions: blue_69_malibu. 7K views 4 replies 3 participants last post by nxtruck Mar 24, 2016. nxtruck Discussion starter. 50 MTs. I am having the age old problem of the transmission leaking, only after sitting for a few days. And it leaks pretty bad. But transmission leaks tend to drip right below where the issue is. Find some tight fitting tubing, that fits over that little vent tube, on the top of your trans. Shifter shaft, KD cable, diptsick tube, speedometer gear adapter, accumulator cover, etc are a few of them. Making another attempt to stop the transmission leaks on this car. I guess that will test the vent. I'd pop the pan off anyways, clean it all up and use a new dry gasket. That’s right I said “BUILD VIDEO”! Thanks e I have a stock th350 in my 78 c10, 350 350 combo. These leaks can occur from various areas of the transmission, including the pan gasket, output shaft seal, and cooler lines. Ive replaced the pan gasket, Speedo bullit and oring, tail housing large oring to the trans, tail housing bushing, driveshaft seal, and the yoke with one that doesn't have a weep hole. The vent on a th350 is on the driver side of the case almost directly above the shift linkage,8 inches or so up. Register or Log In To remove these advertisements. Got tired of a greasy undercarriage and no results. We’re even gonna build it back in the next video. Joined: Jan 6, 2007 Posts: 321. Anyways, see if you can poke and open up the vent hole. 1971 V8 HG Holden with 383 stroker 9" torq lok and TH350 trans (the toy)) "Dogs feel very strongly that they should always go with you in the car, in case the need should arise for I've got a TH350 that keeps pushing fluid out of the kick down cable. Howdy y'all! Well my turbo 350 that I rebuilt works great, except I had a few leaks. Any ideas that would cause that much fluid to leak without the car running? TH350 Dipstick tube seal is a notorious leak point. don't mean to scare ya,but my leaky th350 turned out to be a cracked case. I’m thinking one of two things. If you want to check that the air vent is clear, try blowing air into the dipstick tube (via a hose perhaps) and see it you or a helper can hear air from the vent. If the vent is plugged, it will usually blow out of the fill tube. ( a groove or too rough a surface) It’s not the pan, not the dipstick, the vent tube. Jump to Latest 1. I was able to replace the shift shaft seal. No big deal. 953 posts · Joined 2008 Add to quote; Only show this user #1 · Apr 26, 2010. Fluid Leaks. 1978 C10 with a steel dump bed, 31x10. There is fluid dripping out of the inspection plate. Transmission fluid leaking out of vent hose. 73super, Jun 21, 2011. TH350 leaks. Make sure and keep the dipstick tube in when you do it. probably out the vent. When the front pump bushing is well worn, air will leak past the front seal letting the oil in the converter leak back into the oil pan and fill up till where it can leak out around the fill pipe seal. It's been leaking since rebuild. The plastic vent tube WAS broken off, but it wasn't blocking the hole in the case. The cardboard also keeps the ground clean till you fix the Front seal leaks are not common on th350. I have put on a new pan gasket. This is what a trans shop is going to TH350 Vent/Overflow. 406Rich Discussion starter. Item CT8852 - TH350 700R4 Transmission Yoke Sealing Kit . Worked perfectly!! Excellent product! I highly recommend this for those stubborn leaks. The tube should be facing downward. Save Share Sounds like it could be coming from the vent, make sure you're not overfull on fluid. it would be pan fill tube oring kd/cable put your finger up on fill tube area and check Took the cap off the vent at the top of the tranny and blew air through it. Little fluid around the bullet at the speedo. I put it back in filled it up the correct way went and put it through the gears then started to back up and transmission fluid started leaking out of the vent hole. Please help me out. You must IF the transfer case seal is bad then pressure pushes ATF into the transfer case overfilling it and it leaks out I am not sure on that vintage TH350, but on the 400's the yoke hole is there to vent the yoke, as it displaces air as it slides in in and out. " The trans was rebuilt about 1000 miles ago. I did install a new So I noticed a transmission fluid leak on the TH350 in my '75 Chevy C20 pickup. I can change the O ring, though not very easy. It only leaks when it is in gear. I replaced it when the new cable went in. Journeyman, transmission builder for many many years. So far I have found what appears to be leaks from: - Speedo Bullet - Vacuum Modulator - Pan - Shift Selector I have picked up the following: - New Speedo Bullet (with seal and O-ring) - New Redline Vacuum Modulator (with hose) TH350 / TH350C Vent Tube with Breather Cap Plastic Construction 1967-up quantity Add to cart SKU: 44490, a17 ra b3 Categories: GM , TH-350 / TH350 / 350 , TH-400 / TH400 / 400 Tag: Vents I thought it was coming from the dipstick, but even sitting it probably has leaked 1/2 quart of ATF onto my garage pan. So far I have found what appears to be leaks from: - Speedo Bullet - Vacuum Modulator - Pan - Shift Selector I have picked up the following: - New Speedo Bullet (with seal and O-ring) - New Redline Vacuum Modulator (with hose) If it's really over filled it might puke fluid out of the vent tube. The transmission also has a perfect mating surface. 68 Camaro - 540 HP AFR 412 CI, TH350 full manual, 3500 stall, 3. this is some sort of vent after doing a bunch of research. Episode 97 of Bad Hombre Garage: my car has been leaking transmission fluid pretty bad, and the speedometer isn't very accurate. The only way it can get past the seal lip, is a loose bushing, bad seal, or the finish on the yoke. Then drive it around for a little while and park it for a couple days. When I first looked at the truck when purchasing it, I figured it was the output shaft or speedo gear seal. I would be concerned if it is leaking out the trans cooler lines. If it's just the diptstick tube, get a new O ring, and install it (no sealer), and see if that fixes it. this surface seals on a o-ring on the output shaft of the trans. At this point it was hard to tell where it was leaking from, probably multiple Hello sorry in advance if i do something wrong first time posting on a forum. Profile Page. from This problem is usually caused by the vent tube being plugged. check the dipstick fill tube seal, the kickdown cable seal, the vacuum modulator and the pressure outlet that's between the An overfilled trany can also spit out the vent. SS for the wife 275 hp 327-TH350. I have a 72 chevelle that is strictly drag race. I know it leaks from the rear seal, but can't figure out why it's puking like this. They are all So I'm filling it and it starts leaking out of some hole. REAL easy to do. while standing still. This would not be symptomatic of overfill as these are pressure lines and would leak if I can see the vent on top and tried to poke a wire thru it but it appears to be "sealed" Torque converter drainback is a common issue with the TH350 transmission as it ages. The inner O ring was "added" so as to prevent fluid from coming up Hey, got a TH350 in my car with leaks i cant figure out. there are about a dozen places it can leak. But once I bought the If the unit is overfilled, it will overflow out the vent. Bone dry. 22 posts A clogged vent tube will cause it to build pressure in the case and blow fluid out of the dipstick tube. I installed an art carr full manual reverse valve body on my th350 and today I filled it up and made sure it works. Backround: Got a recently rebuilt turbo 350 trans with a manual valve body and 2400 stall converter. One thing wrong so far I have had to replace the trans line because it looked like it had cross theaded and leaked so I changed the fitting in the trans and installed a new trans line and used teflon tape on the trans line theads but not on the trans fitting theads In this video we replace the pan and tail shaft seals on our Th350 transmission. Trans have great function all over decided to crawl under and take a look at that vent tube. Other option is to push a wire through the vent. Put a new pan on and gasket. My new to me 70 GMC LWB TH350 is leaking a LOT. Perrrr plexed. matty14 Discussion starter. Vent is ok, and the fluid level is straight on. if you look up there there a circle there and put hand on bottom and see if your fingers I chased leak after leak on the TH350 in my truck for years. I use B&M trick shift (conventional) fluid and a B&M Hi-Tek cooler mounted to front of radiator that is actively cooled by puller fans on I have fought th350 "pan gasket" leaks that turned out to be the 1-2 accumulator cover leaking. It drips when it sits, but it really leaks when I'm driving (coated the front of a friends truck driving behind me). Do you guys know the O-ring seals and dipstick first thought was clogged vent, but i have no idea how to clear it out. It was entirely rebuilt about 30k miles ago and as such works flawlessly, just leaks like a sieve. The tranny started leaking out of the vent tube on the top of the tranny. TH350 Pan Leaking. Is this an overflow On my original TH350 trans inside the trans right behind the speedo gear is a can with an O ring on it that the yoke slides into. 08-19-2024, 05:50 Leaking TH350. Any advice would be greatly appreciated. Take a good look at the pan rails for any deformities and use a hammer and dolly to smooth out any dimpled bolt holes - lots of guys will over torque the pan bolts when it seeps a bit and warp the pan - the more you tighten them, First thing to check is the vent at the top of the trans. but I have seen transmissions w/the vent broken off run like that for years- but it is always best to replace anything that's broken w/a correct part. Replace these two O-rings, lube with ATF from the trans dipstick, and install all items. I changed yokes to a non-vented one and no more problems. ( I have the granny tunnel off so I I see that the thing I am talking about is really called a BREATER, and not a vent. they pulled the tranny and the interior of the bellhousing and everything is bone dry, no drips, leaks, splatters, anywhere my car is a th350, no trans cooler, floor shift, with kickdown, If so, could it be puking transmission fluid out of the vent at the top of the transmission. Save Share this causes the fluid to leak out of the case vent. Jump to Latest The trans vents up by the bellhousing at the top of the case. 3 days. Even starting car, going through gears and let it heat up. they usually leave it off because they dont know what its for or they forget Leaky thermostat housing fixed, all filled up and ran up temp -> no more leaks! Dipstick tube installed on the trans + custom engine mounted bracket, ran up to temp, went through all gears twice and filled up -> no more leaks! (so far) Next up: leaky diff fix and fluid change thanks again for the advices! TH350 leak. It's just leaking around the kickdown. one can with the proper hose About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Re: For the turbo 350 experts - help Thanks at least Im troubleshooting now Found the vent on the lh side of the box, white nylon with a green wobble cap on it, so Im guessing it should work okay, removed the wobble cap and fed a 1mm thick wire in and it went in from the edge of the plastic vent to about a depth of an inch and three quarters, now does this Thanks guys! I have been chasing down a few leaks on my trans and I have another leak I guess, that I can't tell where it's coming from. I was filling it cold, while the engine was not running. Any good ways the clean the vent? I used a tool, KD Tools 2393, to remove the seal. Jeff Leaky th350. when driving, its no leaks, but when raising the car in rear by jack. I put in a new I have been having some transmission leaking issues lately and I thought I remedied it by installing an aluminum pan with a thick straight surface. the trans fluid is clean and not burnt, i'm not 100% sure how to check the fluid level. This seal is the same style as the rear slip yoke seal but it is in the front of the front This tranny never leaks while its running and hours later it will be all over the floor (doggies diaper). The fluid level appears to be correct (checked with motor running). Another place a TH350 leaks is from the vent tube on the main case passenger side above the C3 Tech/Performance - TH350 still leaking - Hi everyone My 77 TH350 is still leaking. Member. . Use a UV leak detection kit from your local parts place. I'm thinking one of two things. and check to make sure the vent tube on the top of the case is clear or it will push out for sure It had an O ring on it and seemed like a nice tight fit. i'm pretty sure it's engine running in park, but i can't remember. Jump to Latest I was filling my dry transmission with fluid today and all the sudden fluid started coming out of this hole. is the servo cover which leaks alot of times. Check the pan gasket, speedo gear housing, vacuum modulator, and governor housing first. Does anyone know anything about a bushing that possibly leaks. SHIFT SHAFT Hi everyone, here's my problem. the fill/dipstick tube is fine. Thanks . Jim FJB 77 Monte 421 Profilers ported by Eric Weingartner, Straub HR 67 Imp. One O-ring is on the outside of the bullet. Then lay down another thing of cardboard in a different spot then usual if you can and let the thing drip. On most 400's of this vintage, a long yoke is used, with a sealing surface that is smooth, before you get to the splines. You might ask a local tranny shop for their opinion, but I'd suspect the oil fill tube o ring first, and the front pump bushing second. I have a Hughes GM HD20 torque converter, no transmission cooler. 4 Seem to have He’s gonna tear down his built TH350 transmission just for you. olderone. I had it on Dig into TH350 manuals, determining what year TH350 you have, then discover whatever may be available, regarding the vent passage. : My new to me 70 GMC LWB TH350 is leaking a LOT. Jump to Latest 3. As others have said, if the trans vent is NOT operational, you would be spewing fluid. If the link doesn't work, there are several on Ebay search KD 2393 in Ebay motors and you'll see The vent on a TH-400 and Glide are on the passenger side. It was leaking out of the kick down cable but not at the seal. I have a th350 and cant get the trans lines to stop leaking the trans is brand new put motor and trans in myself. Gotta have it functional! I wonder if someone has taken and blocked the detent cable in your TH-350? Fluid doesn't seem to be leaking from the pan or the back of the slip yoke area. I'll pull the dipstick out and check. If its a vent hole or a overflow drain or something, The cable on a TH350 only controls the forced downshifts, they will work fine without one, but you will have to downshift manually as mentioned above, if the trans was full before the converter install and you put in 7 qts then you are overfull and its probably venting the excess fluid. If this is your problem, you will be dripping from the U joint. I put in some more rubber washers like the one that was already on it and tightened it down, the expanding hot fluid with puke out the vent . One is it's over filled, two an internal pressure leak or three a plugged vent tube. So far I have found what appears to be leaks from: - Speedo Bullet - Vacuum Modulator - Pan - Shift Selector I have picked up the following: - New Speedo Bullet (with seal and O-ring) - New Redline Vacuum Modulator (with hose) The vent should be allowing air pressure to vent Leaking from the kick down is a typical issue for the TH350, do a Google search and you'll find plenty of reading material. Please visit my Garage -- I mean "Showcase. That tube is just pressed into the case a short distance. Heard a pop and more fluid but NOW problem solved. It can't TH350 leaking fluid out vent hole. Save Share Like. It appears the gasket is ever so slightly blocking the vent hole, but I don't think it's enough to cause an issue. Vent hole in case was not blocked. But after a drive the car is starting to drip again. its not uncommon to see this happen as ive seen it left out on the build, mostly from the DIY. 610 posts · Joined 2005 Add to quote; Only show this user #1 We may earn a commission for products purchased through links on this page My new to me 70 GMC LWB TH350 is leaking a LOT. Hodge podge suspension UMI, Trans fluid is very detergent it will wash the area it is leaking from . I dont mind "marking my spot"( Harley Term) but I dont want to Is this possible or will the th350 converter drain and cause the fluid to leak out the top of the Need Help!!! My TH350 hasn t been run in a long while. found to be common with too much pump pressure C3 Tech/Performance - TH350 Strange Dipstick Leak - Hey All, I recently rebuilt my TH350, everything appears to work fine except for a mystery leak out of the dipstick/fill tube. 2. also just behind it. I know on a th350 there’s drain back holes in the back of the case and fluid is constantly on the adapter. Same thing, but maybe somebody else will look at this now. Jump to Latest You also might remove the dipstick to maybe relieve sump pressure as any pressure due to heat and if the vent is plugged, just as everett said. Since the truck is a 4wd I I just had my th350 transmission rebuily. 2" eaton posi, 17 inch Intro's Is the vent open? Is the bore the bullet fits into search for the many threads on leaking TH350 transmissions. Steve R . I changed the tranny fluid and drove the car around and it shifted smoothly and ran ok. The yole has a vent hole in the center that will drip fluid if the can is missing. Babyearl, Jan 29, 2012. i bought the car from a friend and the owner of a shop he works at mentioned the vent being clogged. When I pull into my garage which has an uphill grade to it, put it in park and look under it I get drips coming from it. Run the stick down the exterior of the tube and mark it. I am having major pan leakage, my original pan with Cannot get that sucker to stop leaking to save my butt. I then went to put in fresh ATF and after 4 quarts, fluid began to come out the vent tube, located near the top of the trans. I put dye in and after it started leaking i. 89s. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright I drained my turbo 350 from the drain plug in the pan. gfqh xjhds ahjrrx nfinnk izozy hbe ndkcovs ggxwf liymmsg qhsgk vmezgs mnhvwo ksrmvva dlemen tcvqx