The Stovebolt Site Forums The Shop Area Driveline Transmission leak

1954 3100 235 3 speed manual

Tried search function with no luck but here goes.
New owner here and have been going through truck fixing things here and there.
I have the shop manual but is not clear enough for me to understand the connection between transmission and driveshaft. Went to change tranny oil and found it very low, noticed small drops after filling and continues to seep slowly while in garage so wondering if any videos out there about the shims and seal on where to start.

For some more background after a 50 minute drive I picked up a nail that was unnoticed until next day when came out to flat tire, axle seemed to leak decent amount with the truck tilted that direction and axle vent was clogged so cleaned that out and hasn’t leak there since, also checked diff levels couple times after driving with new tranny fluid so I THINK it is not leaking past to overfill diff and maybe that occurrence was freak series of events but I am no expert......but the collar slow leak remains

Other things on list for another day is oil leaks enough on flywheel to see line of throwing vaporized oil if parked idling, drips what I assume is normal-ish for these trucks leaning towards heavier side but after maybe 100-200 miles haven’t had to add oil yet

Also need to find flywheel cover! Maybe that helps leak a tad bit less spray?

Anytime you post be sure to include year, make and model along with engine size and transmission type. Read through all the forums to determine which one is appropriate for your question. Welcome

Is the leakage coming from the ball collar to transmission joint or the rear where it slides in the torque tube?

If the differential fill hole is not overflowing with gear oil (coming from trans.), the bushing and seal at the front of the torque tube is probably good. There is a gasket kit available if your leaks are around that ball collar. Unfortunately, if that is the case, the engine and trans would have to be pulled forward, or I believe, someone may have moved the rear axle enough to separate the drive shaft from the yoke.

Hold your horses! If the source of the leak is from the gaskets in the universal joint ball collar, the gaskets can be replaced by lowering the torque tube. Unfortunately it’s not as easy as it sounds, but is doable. Let the OP respond as to the source of the leak first before we get into that procedure.

Thanks, Phil

I made some enhancements to the OP's picture.
Oil on the crossmember.
Front half of transmission looks wet.
To me, the area at the ball and the tube connections don't look all that wet.
A little dripping directly below on the concrete but this oil could be coming from upstream.

Nice job on the photo enhancement! The OP did mention several leaks including one from the rear of the universal ball collar to the torque tube and another from flywheel area. Let’s get Mako1975 to weigh in and provide more info!

Wow amazed with all the quick responses and even people improving my photos, encouraged that I walked into a helpful community that I plan to bother with questions for awhile

I purposely moved the oil catch pan to let tranny leak show up separate from
Engine oil leak on crossmember flywheel, more concerned for tranny leak right now as oil seems mostly to be annoyance over the normal amount they seem to always leak since haven’t had to add oil since I bought it.

Forgive if I use wrong terms but the “collar” between rear of tranny and driveshaft definitely is leaking the new gear oil easy to see and smell. Always a drip right on that ribbed collar

Hopefully this picture is better. Didn’t want to overload with too many questions about different issues oil/tranny leak in one post so tranny first

The first thing I would try to do is tighten the collar. There are two washers sandwiching a seal (either felt/cork/neoprene) that gets compressed when you tighten the collar. As the collar seal wears you can tighten to get it to stop. If your lucky the packing material isn’t rock hard as many of this age are.

I installed a new neoprene seal and tightened it pretty good and it still leaked. I tighten twice more and finally got it to stop. Trust me, it was really tight, much more than I thought it should have been but it stopped.

Use a strap wrench to tighten. Good luck!

I will definitely try that. Didn’t want to just start cranking on things without asking people who have done it. How hard was that seal to replace when you did it?

By the way that leak drips on the concrete equal about 5 days of sitting in garage not moving

In not hard but is quite involved. If we get to that point, I have some detailed instructions on how it’s done. Basically the front on the torque tube needs to be lowered enough to enable sliding the universal joint ball collar forward to remove. That involves raising the rear tires off the ground and dropping the rear transmission mount among other things.

Any advantage to loosing and checking washer/seal/cleaning?

I'd like to apologize in advance for high jacking, the thread.
But I have the same problem, except the for the mentioned washers. They are missing.
Would anyone have the dimension for these. ID, OD, and thickness. For I will be replacing the internal U-joint, in the near future, and would like to install them at this point.
Thanks in advance.

They shouldn't be too hard to find, and you're going to want an entire set if you're replace the U-joint.

Here's a link to the gasket set at Chev's of the 40s - Torque Tube Seal Kit

The only thing I think would help, is backing off the collar nut and cleaning the threads. I don’t think you would be able to get the washers and seal out without damaging them.

Personally I would just try to tighten and if it doesn’t budge then try the loosen and clean.

Thanks Greg I have all of them already ordered them when I purchased the u-joint.
Just need the washers.

Bob

Place an ad in the “Truck Parts Forum” and you might just get lucky!

When I changed the gear oil in transmission it had lots of SWARF......unknown when last time it was changed but it had enough in it to hold a magnet through catch container no filings just tons of powder hoping it just wear and tear and very old oil

As for engine oil Here is main source of oil leak, the ultimate source I am not sure. It is manageable for now I believe in the “live with it” category since haven’t had to add oil yet. Just did an oil change and sent it in the black stone labs just to get it analyzed. Should i UV test to see if maybe just leak down from valve cover area etc? Not sure if I want to get into rear seal territory yet if not having to add oil

I've seen many (well used engines) with the cover left off. Sludge (clutch disc dust, coolant and oil) can plug up the cover weep hole. If the goop level gets high enough, it can get onto the surface of the clutch and ruin the disc and maybe the pressure plate. If the engine was rebuilt and not leaking, I would definitely put a cover on it to keep out the road debris. Where is the oil coming from? Possibilities:

Valve cover and gasket
Lifter galley cover and gasket
Rear main seal
Oil pan and gasket
Oil pan drain plug
2X small welch plugs (rear access plugs) inside the bell housing area
I'm sure I'm missing something but someone will pipe-in shortly.

I buy engine cleaner at my local FLAPS, put on my "get dirty" clothes, cover (plastic bag etc.) the distributor and air cleaner, spray the cleaner on a COLD engine (hot cast iron can crack) and wait. Then I get out my pressure washer (adjust to very low pressure) and clean up the oil mess. Sometimes it takes scrub brushes. I do this in a place (definitely not on the concrete driveway) that doesn't kill the green grass that I just planted. When it's cleaned up, let it dry out. Drive the truck a little distance and check for fresh oil leaks.

Fingers crossed the oil isn't coming from the rear main seal or the welch plugs.

Yeah that’s why I thought maybe use UV to find leak but always best to ask people who have dealt with it before. Took some pictures of other wet areas that seem possible to distribute right to flywheel and disperse everywhere from there.....what leaks would you say should be dealt with and which ones just live with it not needing to add oil frequently

One the tranny front I was able to crank 1/4 turn out of the collar and drove around with no leaks so far. Going to leave overnight night and hope it remains dry!

Good to hear, hopefully you got it fixed. If not, don’t be afraid to tighten it a bit more!

I agree with buoymaker, to clean the engine first then look for leaks. That leak you see at the bottom of the push rod cover could be from the valve cover. It appears in your second picture, that oil has been running down the side of the cover for some time. Clean it and then watch, you’ll find it.

The valve and pushrod covers are easy fixes, so those are the first ones I would go after.

The thin metal of the valve cover and galley cover can bend if you overtighten the screws. Once bent, the seal is compromised. Tightening the screws again just makes it worse. When the covers are bent, I take them off and straighten them to original shape on something like a flat bar. I put on a new cork gasket and don't overtighten. Some owners like to put sealant on the cover side of the gasket. You can also purchase load spreaders to apply more even pressure. The problem is that they are noticeable if you wish to maintain an original looking engine. To get cork to seal it needs to saturate with oil. It eventually will leak a very small amount of oil and turn black but this is normal.

Well after a couple drives it’s back to leaking. I’d like to tighten it more but even using sandpaper it’s hard to get a good grip with rubber strap wrench. I even broke the strap (semi old strap). I assume something more aggressive like a pipe wrench is not advised? I’ll get another strap wrench anyway since I need one and give another go

I would get another strap wrench, I use an ancient nylon one, sometimes a cut bicycle tube instead of sandpaper. Please avoid a pipe wrench you will likely regret using it.

In reading some older posts there is a comment that someone experienced that the collar (also called cap or torque tube retainer) can loosen by itself. The idea being that the deteriorated seal no longer provides backpressure against the collar. If that is true then the collar can be fixed (made not to move) but I fear that it only delays the need for seal replacement. Keep posting the forum.

The leak has slowed and I have it about as tight as I feel comfortable torquing on it. I think for now it is easier to live with it checking fluid levels... 1-3 drips on ground when sits for 24 hours

I have a drip pan under mine just in case. When your ready to replace the seal, I just replaced mine so I can help with the details.Good Luck!

Found a reproduction plastic cover for flywheel. Doesn’t seem to have a weep hole or is that another location. Thought might drill small hole
In bottom if needs it

Also need to find out what hardware fits in threads for original going to do some trial and error tomorrow with my assortment to see thread pattern to buy some new ones

For a 235 with manual transmission.

Should be same as valve cover screws

The clutch inspection cover bolts are 1/4”-20 x 1/2” long grade 5.

Thank you!