727 Puking oil from dipstick

Danny Phillips

Danny Phillips

Member
Happy holidays everyone. I just reinstalled the 727 in my 74 Scout II after resealing it. When I fired it up after refilling it doesn't want to go into gear and when I shut it down it pukes oil out the dipstick tube. I put a new seal in the pump for the torque converter and new gasket and o ring on the pump. I filled the torque converter half full and then reinstalled it on the pump and verified it was engaged to the pump tabs. I had to slide it forward about 1/2" - 5/8" to bolt it to the flex plate. I also did the vent relocation and adjusted the bands. Anybody have any ideas before I have to remove it again? Thanks, Danny
 
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Did you verify correct fluid level while hot idling in neutral? What atf did you use? If it was just the puke and no issues with motion, I'd be leaning towards a failed vent relocation. But since you've got no motion, I'm thinking your converter is shot.

Edit...I really think you need to review and perhaps redo your vent before you go with a different converter. You might get lucky.
 
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Thanks for the reply trevor. I did the vent relocation with the pump out of the trans. I can blow through the vent real easy. Is there any way I could have reassembled the pump wrong. I did change the tc bushing and seal, drilled and tapped the original vent on the pump and installed a 1/8" pipe plug. I'm using valvoline dex/merc. I did get the Scout to move under it's own power but it took a lot of revs to move. When I turn the drive shaft by hand, it turns about a half of turn then gets hard to turn. Even if the transfer case is bound up I wouldn't think it should puke the oil out. I think I will disconnect 1 component at a time and double check the torque on both output shafts on the transfer case. I don't really want to pull the trans out if I don't have to. At least everything is clean under there. Thanks trevor, Danny
 
Not really, the mounting holes only line up one way. Did you install a new square cut perimeter seal around the pump and slather it with transemble or door ease? How about a new pump gasket? You still need to double check your fluid level the correct way, as I mentioned above. It could be that the fluid level is too low, allowing excess air to be sucked in, which aerated the fluid. Once shut off, that agitated fluid found the path of least resistance...your dipstick tube.
 
Hey trevor, I found the left rear brake hanging up was why it was hard to move. Unfortunately after letting the trans warm up to check fluid level the front pump / torque converter seal is leaking worse than before I sealed it. I did install a new bushing, seal, gasket and o ring and lubed everything up with a 50/50 mix of atf and stp per local trans shop. So out comes the trans again. Thanks for the good info trevor. Danny
 
Hey Danny

happy holidays to you.
Sorry to hear about the leaky troubles. I have been kinda following this, due to the fact that I'm about to completely go through the one in my 72 for a complete rebuild. As trever mentioned, airated oil does leaky strange things. Along with filling the converter, I also add oil into the tranny until at least hitting the dip stick, before I start the motor. When I actually do get to rebuilding my own tranny, I will also be doing the vent relocation. Just like the motor, the transmission needs to breath.
Hope yours is an easy fix. Be safe for the new years.

Btw
ron is doing ok. The motor is running good. His baby Scout is back into my care at the moment for a complete re-wire, among a few other things not related to the motor.
 
An overfull condition can create similar issues as well, although I've seen a 727 that was 2 qts overfull with stock vent hole not puke a drop from any orifice. If not corrected, I imagine it would have eventually developed a gusher. Being within the safe range is pretty critical for these units. As an aside, I've never added fluid to any converter prior to install. I count the qts I've added and once I have 7 in, that's when I fire up for warm up. Once warm I check the level, then I add 1 qt at a time, cycle gears, and re-check. I repeat until I reach the safe range. Then I go for a short test drive, come back and recheck the level. If it needs another pint or so, I add it. Probably 6 of one, half-dozen of another, but this has always worked fine for me. Once the level is registering on the stick, you're dealing with pints, not quarts to enter the safe range.
 
It appears to be leaking from the torque converter hub/seal. 4 more bolts and I'll have it on the floor. I read in one of the trans books that you should fill the torque converter half full, install it and then add fluid thru the dipstick. It was leaking almost as fast as I was pouring the fluid in. I hope I find a crack in the tc hub because I'm going to go ahead and put in a new tc. I'll try to take a picture of my homemade transmission jack. I drilled a hole in between the transmission mount attach slots in the cross member and used the bolt that holds the jack plate on the floor jack. I jack up the cross member to the transmission and use 2 ratchet straps to tie the transmission down. This works pretty slick. Thanks for the info trevor and kimball. I should know where the leak is for sure. By the way, I blew air into the relocated vent and there is no obstruction.
 
I lay odds that if you carefully inspect the converter that the neck is cracked. The spit back of fluid usually indicates a bad stator in the converter (lack of motion too)
 
I thought it was the tc too, I taped up the converter snout and installed a fitting in the drain plug location and hit it with about 145 psi and soaked the hub, mounting pads and the pilot hub where it rides on the crankshaft spacer. No leaks. I took the tc to the local trans shop and the only thing they can figure out is that the snout where it rides in the bushing might be undersized. I ordered a rebuilt torque converter from them and they are going to look at my front pump (only pump)and check to see if it's cracked. I can't see one anywhere but that doesn't mean it doesn't have one. Trans guy said it wasn't very old and when I removed the front and rear clutch packs they looked brand new. Still had the part numbers on them as did the front band. I guess I'll know for sure when I get the new converter Wednesday.
 
Danny phillips said:
I thought it was the tc too, I taped up the converter snout and installed a fitting in the drain plug location and hit it with about 145 psi and soaked the hub, mounting pads and the pilot hub where it rides on the crankshaft spacer. No leaks. I took the tc to the local trans shop and the only thing they can figure out is that the snout where it rides in the bushing might be undersized. I ordered a rebuilt torque converter from them and they are going to look at my front pump (only pump)and check to see if it's cracked. I can't see one anywhere but that doesn't mean it doesn't have one. Trans guy said it wasn't very old and when I removed the front and rear clutch packs they looked brand new. Still had the part numbers on them as did the front band. I guess I'll know for sure when I get the new converter Wednesday.
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I recall one rig having the check ball in the wrong place in the valve body causing this issue too. That and a non-lockup converter in a lockup trans. Caused the splines to screw up.
 
One thing that needs clarification is how this transmission was functioning before you did anything. I know the main impetus for you pulling it the first time was to fix a leak and my assumption is that it was fully functional aside from that. Were there any other issues besides the leak? Did you open up the valve body for inspection and cleaning? The IH 727's are all non-lockup style, with non-lockup converters.
 
Thanks carnuk &trevor: the tranny was / is working perfectly except for the torque converter drain back issues. I took my torque converter to the local trans shop and judging by the color (light blue) he estimated it was only a couple of years old. Today I took the tranny to him per his request to inspect the pump, bushing and seal. So far no obvious reasons for the leakage. I still think the torque converter hub does not fit the bushing tight enough. Hopefully I'll find out what it was. When I resealed the pump everything went back together the same. The transmission leaked very bad before I removed it but it worked fine as long as it had enough fluid in it. When I got the tranny hooked up I filled the torque converter up half way and filled the tranny until it was starting up the dipstick. I double checked the vent relocation and verified the vent is in the proper place, about 1" left of center line and it is definitely in the wet part of the trans. I did not touch the valve body. This transmission worked perfectly except for the torque converter drain back and that only started mid part of last year. I also used new rubber coated washers under the pump bolts. From what I could see most of the wet in the bell housing was slung out from the out side of the torque converter. The sealant I used for the vent relocation was tfe paste from the local lumber yard. I've been using that for years on aircraft fluid fittings (pipe not flare). I'll let you all know what I find out tomorrow and thank all of you for your input. You guys remind me of where I used to work before I got hurt, a mooney factory service center. If we couldn't fix something, no one could. Danny
 
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Thanks for the update Danny. The outcome of this will add to the knowledge base. Fortunately for most, but unfortunately for you, this doesn't seem to be a very common occurrence. Can't offer you much beyond covering the basics, but it sounds like you're in good hands now.
 
Hey trever; I drained the torque converter and transmission last night and I'm going to refill today. I finally got enough twists in the chrysler dipstick to work in tube in the Scout. The stock chrysler dipstick tube would not work with the tube I got at pick n pull. I got them out of a 1981 plymouth duster or the dodge version. With the new dipstick tube is installed, the way the bend is hit hits the firewall right next to the back of the head. I measured the lengths of my original dipstick tube and the replacement and they are the same. So now I have an accurate measure of fluid. Thanks trever and I'll post up this evening how it works. Danny
 
It lives:thumbsup: no leaks, pops into every gear nice and solid. Definitely needed new torque converter, bushing & seal. Adjusted the bands, new fluid at the correct level. Ready for the bush. Thanks for all of your help trever, and others.:gringrin:
 
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