• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

904 tranny - is this a drain plug ?

pearljam724

Well-Known Member
Local time
10:03 PM
Joined
Oct 14, 2018
Messages
1,260
Reaction score
555
Location
U.S.
Changed my fluid, filter and adjusted bands this evening. Crawled under when finished to check for leaks when I noticed this bolt for the first time. Driver side tail housing behind pan. In pic it’s at 10 o’clock to the left of those two empty holes. What is it, a drain plug ? If so, I did things the hard way, lol !

549E0D47-AA06-4698-91E7-F5863DA6BE89.jpeg
 
Unscrew it, it'll drain:D
Seriously though, no, the pan would still be full. That's the (governor pressure?) adjustment.
 
That is not any kind of an adjustment. But you are right it is to check the governor pressure.
 
What does the governor do ? Is there anything in the manual pertaining to it ? I assume it has a relation with pump pressure ? Just trying to learn here, lol !
 
Last edited:
Think of the governor as a fly weight. As the tail shaft spins the governor weights move,regulating the fluid flow and allows the up shifts. The governor also over rides the kick down valve.I can describe the relationship between the two as push/pull. The kick down delays the up shift until the governor rpm over rides the fluid pressure of the kick down valve. I know , clear as mud.
Most factory service manuals have good color diagrams of the fluid paths in the valve body/trans case.
 
Spray that mess down with ,SuperClean let it soak a few minutes COLD,not after driving and hose it off.Good stuff!
 
Spray that mess down with ,SuperClean let it soak a few minutes COLD,not after driving and hose it off.Good stuff!
I’ll give it a try. I have a small leak I have to fix. Not sure where it’s coming from as I looked a few times and it’s difficult to decipher exactly where. I believe it’s from the oil pan gasket that butts up against the tranny. I’m hoping
 
Last edited:
The seal on this shifter shaft may be leaking.
IMG_20190817_101658.jpg
 
The seal on this shifter shaft may be leaking.
View attachment 818706
I realize that, thank you. I checked, it’s not. It only leaks motor oil. I can see it drip down onto the bell housing once in a while. It’s either the rear of the oil pan or the engine main seal. It barely leaks at a stand still. But, once the engine is warm/running and the car is in motion it must leak pretty good. That’s why it’s hard to find. It’s spraying onto the tranny and the exhaust a little. Not related, I broke a bolt inside the timing cover putting a new steering pump on. When I decide to remove the timing cover to remove the broken bolt. I’ll replace the oil pan gasket. Hopefully that addresses the leak and it’s not the main seal. I know the oil pan gasket leaks, how much and only it leaking is hard to tell now until I address it. Sometimes it doesn’t leak a drop sitting, other times it barely dribbles.
 
Last edited:
This leak is familiar with mine, however. My sendor doesn’t leak. But, I get a small amount of oil once in a while around the distributor and I know for a fact the distributor is tightened down well. This would cause a leak down into my area I explained a paragraph before. I don’t think this is my only leak because my firewall is pretty clean. As well as the top of the engine. Does the distributor have a seal located under the clamp down plate that would cause oil to leak in this area ?
 
Last edited:
I realize that, thank you. I checked, it’s not. It only leaks motor oil. I can see it drip down onto the bell housing once in a while. It’s either the rear of the oil pan or the engine main seal. It barely leaks at a stand still. But, once the engine is warm/running and the car is in motion it must leak pretty good. That’s why it’s hard to find. It’s spraying onto the tranny and the exhaust a little. Not related, I broke a bolt inside the timing cover putting a new steering pump on. When I decide to remove the timing cover to remove the broken bolt. I’ll replace the oil pan gasket. Hopefully that addresses the leak and it’s not the main seal. I know the oil pan gasket leaks, how much and only it leaking is hard to tell now until I address it. Sometimes it doesn’t leak a drop sitting, other times it barely dribbles.
Pull the trans inspection cover and look up between the crank flange and block with a light. If your main seal leaks there will be a drip or wetness up on the crank where it exits the seal. It's a very small area, but if it's wet or dry, you'll see it. Oil inside the bellhousing can be an indicator, BUT oil can wick it's way in there from up top also, through the mating surface of the cover as it's not a sealed connection..good luck
 
Thank you, my inspection cover is completely flat. Therefore, I don’t have to remove it to see up by the crank area you are referring to. There is about a 3/8 inch gap that allows me to see up in there. There’s definitely very little oil dripping every once in a while. But, the back of the oil pan seals in that same exact location. I don’t know how anyone could decipher one leak compared to the other by looking up in there ? The only way I see, is replacing the oil pan gasket. If it still leaks you know your main seal leaks. That or your oil pan gasket fix, is still leaking. Lol !
 
There is a distributor base O-ring seal.

IMG_20190817_115132.jpg


I've never had one of those with a profuse leak, but they are easy enough to replace.

The leaks that I have experienced in that area are the intake manifold gasket. I had a couple leak in the corners where the intake manifold, block, and head come together. Specifically, the gap between the spongy rubber intake manifold / engine block gasket and the gasket between the head and intake manifold.

I used RTV in the red areas when I installed the next new set.:D

IMG_20190817_121043.jpg
 
Last edited:
There is a distributor base O-ring seal.

View attachment 818776

I've never had one of those with a profuse leak, but they are easy enough to replace.

The leaks that I have experienced in that area are the intake manifold gasket. I had a couple leak in the corners where the intake manifold, block, and head come together. Specifically, the gap between the spongy rubber intake manifold / engine block gasket and the gasket between the head and intake manifold.

I used RTV in the red areas when I installed the next new set.:D

View attachment 818781
Thank you, kindly. It’s greatly appreciated. I guess a good start would be cleaning everything and closely monitoring it, which I have. Problem with that, once it’s clean and the car drives down the road 20 miles. As you know, a leak goes everywhere and it’s sometimes hard to tell. It’s definitely motor oil, definitely coming from rear of engine. The car sat all winter and hardly leaked on my garage floor. I’ve taken it out a couple dozen times this summer. In between those trips, it barely leaks at a stand still. Sometimes it doesn’t. It’s mainly leaking moving, then it leaks pretty well I believe.
 
You could try using a flashlight and a mirror to inspect those areas while someone you trust maintains the engine at around 1,500/2,000 rpm.
885911591423lg.jpg
 
I think I just now found a few little spots. I have minimal dripping from timing cover. Most seems to be coming from back engine, driver side valve cover that seems to be dripping down onto the starter. And one that seems to worry me most is passenger side. Where tranny and engine are bolted together. There’s some leakage there by the corner of the pan. It’s hard to see the interior of the bolt hole. But, it appears the threads in the hole are stripped. Therefore, who ever mated the engine to the tranny neglected to put a bolt in. I ll post a pic in 30 minutes or so. Im wondering if I can just run a bolt and buy through and snug it up a little ? Regardless of any leak it may be causing, I’m more worried about it missing that bolt. Unlike most people, very small drips don’t bother me. I understand all drips can be fixed. And any machinery 50 years old is likely to have drips here and there. But find it amusing that people would point out stuff like that on anything old. As if it’s ready to blow up, lol ! I’m talking about real life observers.
 
All 3 of these pics are of the same bolt missing. Just different angles. It’s directly behind the oil filter and by the tranny dipstick where the block mates to the tranny. The threads on the tranny are fine. But, I’m not sure if the engine block holes are supposed to have threads because the threads either look worn or it’s just markings from an old bolt. All other bolts that mate the two come in from the tranny side. Leaving me think, the block hole threads are nearly worn off. Or the bolt is supposed to be inserted from the block side into the tranny threads which are fine. Tell me what you guys think into importance of that bolt in relation to leaking or anything else. Disregard gunk on tranny dipstick tube, tube doesn’t leak and this car had another engine in it before.

222651D3-2CB9-48E0-90B0-8169B0215695.jpeg 64AF972C-AE2C-4881-981E-D86C7B0DCD2C.jpeg 7D1F0DD7-F608-4A31-870D-F2CDA2DD6F33.jpeg
 
Last edited:
Auto Transport Service
Back
Top