4+3 trans related

they make specific square plug transmission plug sockets ,
with slightly tapered sides that get tighter as they are pushed on deeper on the plugs

and generally if you use a propane torch to heat the plug a bit then soak the threads in a 50%/50% mix of MMO or trans fluid and acetone to rapidly cool it,
repeated several times they are much easier to remove
(don't set the car on fire residual acetone/oil mix you use to loosen threads, will light and burn so use sparingly)

I generally spray off area well with spray bottle of water and dawn dish soap between EACH,
mmo/acetone threaded plug bath and torch applications

got your fire extinguisher HANDY??

how many guys HAVE a CO2 extinguisher handy ? or for that matter ANY DECENT FIRE EXTINGUISHERS THAT ARE EASILY ACCESSED? an engine coughing back as you set timing or a bit of welding slag , a short circuit or defective battery connection, flammable solvents ,oily trash, sparks, all can be the...
garage.grumpysperformance.com

71ZahLAW7NL._AC_SL1500_.jpg
 
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Thanks, I will order that.
What’s a few more days anyway at this point.

Also, you just preempted my future question about the differential plug. One YouTuber said if was a 9mm internal hex, which it was not on my trial. My 5/8 Allen fit perfectly (Edit: It is my 3/8 Allen that fit perfectly. Maybe the the 7/16 would work but, to play it safe, I will have to get a different socket kit or purchase a 3/8 male hex socket to fit the Diff Plug). After just a hand tug with that, I stopped.
The kit you suggested has the right tool for that also.
 
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I guess that fill plug is square where the wrench goes on? You might have to use a pipe wrench on it, but I would get a new one to go back with. Or at least dress up the comers with a file after it's out.
I just saw Grumpy's post about the sockets. Obviously that would be the preferred way if you can get the socket on .

You might try heat on the trans case around the plug if you can even get in there. I torch head on a flexible hose works alot better than the typical torch head. They don't like it when the bottle is turned on it's side. Something like in the links below. I would also use MAP gas, it's in the Yellow bottles. Although it's not really MAP gas anymore, it something else that's not as good, but better that propane. They both use the same torch heads.



 
Indycars said:
I guess that fill plug is square where the wrench goes on? You might have to use a pipe wrench on it, but I would get a new one to go back with. Or at least dress up the comers with a file after it's out.
I just saw Grumpy's post about the sockets. Obviously that would be the preferred way if you can get the socket on .

You might try heat on the trans case around the plug if you can even get in there. I torch head on a flexible hose works alot better than the typical torch head. They don't like it when the bottle is turned on it's side. Something like in the links below. I would also use MAP gas, it's in the Yellow bottles. Although it's not really MAP gas anymore, it something else that's not as good, but better that propane. They both use the same torch heads.



Click to expand...
Do you think “new” new plugs are available from any source or is the salvage yard the only way to go for these old transmission parts. Would be nice if this is a common plug to many transmissions.

Also, I think this would be a good place for anti-seize when putting these plugs back in, or am I wrong?
 
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Also, I noticed some rust/corrosion on some of the manual shift linkages. I squirted Corrosion Block on them. Do I need to lubricant them with anything special or will a dab of Valvoline full synthetic gray moly- fortified NLGI #2 grease work, since I’m also squirting up the suspension grease points.
 
it won't hurt to lube the moving connections linkage or shifter levers ?connecting rod linkages ,
verify that the typical brass or steel bushings are well lubed on the shifter linkage if they exist
 
There are many different types of plugs, but the only difference is how you grab them so you can turn them. Like below is no different than what you have or internal hex that Grumpy posted above. Just have to make sure you have the right size.

They all use what's called "Pipe Thread", usually shown as NPT or "National Pipe Thread". It's a tapered thread so the further you screw the plug in the tighter it gets. Normally you don't need a sealer for a liquid, only when you are sealing a gas.

Most any local hardware store should have the plug you need. Best to take it with you, but if not the link below will help with measuring for size.

blog.sisupply.com

How to Measure National Pipe Threads (NPT) Correctly the First Time - Superior Industrial Supply | Blog | Hose, Accessories, Fasteners, Industrial Supplies in St. Louis Region

St. Louis based supplier Superior Industrial Supply offers advice on how to accurately measure national pipe threads (NPT). Call 314-638-6500 for more information.
blog.sisupply.com blog.sisupply.com

www.summitracing.com

Edelmann 209600 Edelmann Pipe Thread Plug Fittings | Summit Racing

Free Shipping - Edelmann Pipe Thread Plug Fittings with qualifying orders of $109. Shop Plug Fittings at Summit Racing.
www.summitracing.com www.summitracing.com
1696796025834.png
 
I can finally report some minor victories. I know you experienced wrenches may smirk but I got all the transmission and differential fill and drain plugs free with minimal extra hassle using the right tools suggested above. I had to dress the fill plugs on the OD unit and the 4 speed side with the help of a Dremel grinding bit and some hand files to enable the 9/16 square socket to seat well enough to allow a firm assist using a rubber mallet. The differential fill plug was able to be turned with the help of a recently purchased lower profile 3/8 hex socket and a swivel extension to get around the wall of the downward protruding storage box.

I did not check the diff fluid level yet until I clean up all the dirt around the plug, but it will probably be near full as the differential case is bone dry and there is no separate drain plug.

The oil started to come out as soon as the manual transmission plug was removed, so that was full.

However, the OD fluid was down to about the level of the pan bolts internally. I hope that finding will not doom the reliability of the OD going forward. I’m not surprised it was down as the external pan side looked wet. I’m not sure if there is a fluid pickup that sucks the fluid from the lower pan back into the transmission.
 
While I have asked about this before, something still does not make sense. That is, since no gasket was used by GM on the OD pan gasket, just RTV, it seems it would make more sense to put RTV on the underside of the gasket, place into the pan, flip it over on wax paper with a weight on it overnight, like valve cover gaskets, and then put RTV on the upper side of the gasket before bolting back to the OD unit. Then wait overnight to set, and the refill the OD.
 
you could certainly go that route, and not HAVE ANY LEAKS, on an oil pan gasket, if its the correct gasket for the application,
Ive done it that way occasionally with no issues

Fel-Pro Oil Pan Gaskets - JEGS

Fel-Pro offers quality gaskets to meet OE & aftermarket performance needs. Material Notes PermaDry gaskets feature molded rubber construction to provide an overall even clamping force. PermaDryPlus gaskets feature one-piece molded rubber construction with a rigid carrier design for easy...
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synthetic chevy oil pan gaskets - JEGS High Performance

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does synthetic oil cause leaky gaskets?

hey grumpyvette? as far as synthetic in old cars. does anyone actually have any proof that synthetic oil eats seals or is it one of those wives tale things. BTW I have on several occasions seen guys who complain about various oil leaks on valve covers and rear seals ETC. Used, engine...
garage.grumpysperformance.com

oil pan gaskets

now Im sure most of you guys have seen or used both types, (the old cork 4 piece sets and the newer synthetic one piece design oil pan gaskets) in my opinion the newer synthetic one piece style is FAR superior! if you read the instructions they say to not use a sealant, Ive found that use of...
garage.grumpysperformance.com

index.php
 
I've never used anti-seize on a pipe thread used on a filler or drain plug. If it leaks, THEN give it another 1/8 to 1/4 turn. Now if you are sealing a natural gas pipeline, then I use a sealer made for that purpose. Don't use a silicone sealer for natural gas.

But I guess it wouldn't hurt anything either ..... your choice.
.
 
I may be totally wrong, but Ive used a very thin coat of
81z7WD3y3uL._AC_SL1500_.jpg


on those threaded plugs , side plate gaskets etc, with no issues for decades
(apply to dry grease free threads)
it tends to prevent trans fluid leaks and differential gear lube leaks rather well.
s-l1600.jpg

 
Grumpy said:
I may be totally wrong, but Ive used a very thin coat of
81z7WD3y3uL._AC_SL1500_.jpg


on those threaded plugs , side plate gaskets etc, with no issues for decades
(apply to dry grease free threads)
it tends to prevent trans fluid leaks and differential gear lube leaks rather well.
s-l1600.jpg
Click to expand...
I was more worried about how difficult opening those plugs were in a vehicle that puts little mileage on between interval fluid changes but many years may go by. With the proper tools, it is probably an overthink and anti-seize may not be needed. But if I were to get leakage from the plugs, I will try your suggestion. As it is, I’ll be using some of that similar Permatex high tack 80060 on the OD pan bolts.
 
I have an observation about installing the filter with the grommet on the OD unit: This requires finesse as the grommet, when placed on the filter, and then pushed onto the feeder post, will continually dislocate into the filter without seating properly. The trick from a YouTuber about placing the filter with grommet into the freezer for about 20 minutes did not work for me even after 40 minutes. The idea, which was a good one, was to harden the grommet somewhat to make it more firm preventing it from flexing. However, after quite some frustration, I had to visually change my observation point under the car to the front looking backward, where no direct obstruction is present, and to directly observe the top of the grommet. By slowly finessing the filter and grommet upward and stopping when a threatened dislocation was present, success was finally obtained.
 
It’s been over 2 months since touching my C4. It is still on jack stands but noticed just to the drivers side and just to the left of midline a large area of seepage on the garage floor; it looks like the Royal purple Synchromax fluid just put into the overdrive unit. While I did not check the fill hole level on the OD, the amount on the floor could very well be consistent with the fluid remaining at or slightly above the pan gasket interface.

I do see a fluid drop hanging and ready to fall from a pan bolt, but cannot be sure where/or if other leakage is occurring, or even from the pan gasket interface itself. It should be noted that I never started the car to get a heat cycle or to get any mixing of fluid with any of the remaining fluid in the OD system. Maybe that was a mistake in retrospect to let it sit so long.

The procedure I used to prevent leaks was to use the Permatex ultra black RTV 82180 on the gasket on both the pan and transmission sides, allowing for 12-24 hours of setting. I also used some Permatex super high tack sealant 80060 on the lower threads near the head of the pan bolts, maybe inexpertly, and torqued the bolts by hand to what I perceived the correct torque by feel, as I did not have such a low reading torque wrench. After 24 hours, I then filled the OD with fluid.
Since the leakage may be similar to that which existed before I decided to change fluid and filter with a gasket, I could just accept that. However, I should top off the filler hole with new fluid and watch the level over time.
I’m thinking I’ll be alright if left alone since the pick up/filter of the OD unit is lower in the pan anyway where the fluid cannot escape the confines of the pan.

Other than that, what should be done?

Some additional thoughts:
I could remove any pan bolts that I think are leak sites, and completely cover the entire thread with the high tack 80060,then tighten and retorque. I could then wait and recheck for further leakage. But I would not be surprised if there would be an inability to set properly with fluid already in the pan.

Since there were no heat cycles, should I even consider capturing all the fluid, and removing the pan in the hope that I can reseal the gasket, without damage to it, and reseal the pan bolts using better technique, and use the same captured fluid, since it is entirely fresh, or just get new again. Do I really need a inch lb torque wrench?

PS: While I think I would have noticed the leak earlier, is it possible that the big cold spell recently from 16-34 F temps has provided the impetus for the leak. The fact that the leak is continuing tells me that the level of fluid in the OD must be higher than I thought.
 
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For stubborn pan/case leaks I've used Permatex "The Right Stuff". This stuff is significantly stronger than normal RTV. The only down side is it's also significantly harder to remove parts that have bonded. It comes in tubes, cheeze-whiz cans, and caulking tubes. I've used it on my 4+3 pan (back when I still ran the 4+3) with no gasket and zero drips. I would also smear a little on the pan bolt threads. 1706827164119.jpeg
 
Stick the Corners said:
It’s been over 2 months since touching my C4. It is still on jack stands but noticed just to the drivers side and just to the left of midline a large area of seepage on the garage floor; it looks like the Royal purple Synchromax fluid just put into the overdrive unit. While I did not check the fill hole level on the OD, the amount on the floor could very well be consistent with the fluid remaining at or slightly above the pan gasket interface.

I do see a fluid drop hanging and ready to fall from a pan bolt, but cannot be sure where/or if other leakage is occurring, or even from the pan gasket interface itself. It should be noted that I never started the car to get a heat cycle or to get any mixing of fluid with any of the remaining fluid in the OD system. Maybe that was a mistake in retrospect to let it sit so long.

The procedure I used to prevent leaks was to use the Permatex ultra black RTV 82180 on the gasket on both the pan and transmission sides, allowing for 12-24 hours of setting. I also used some Permatex super high tack sealant 80060 on the lower threads near the head of the pan bolts, maybe inexpertly, and torqued the bolts by hand to what I perceived the correct torque by feel, as I did not have such a low reading torque wrench. After 24 hours, I then filled the OD with fluid.
Since the leakage may be similar to that which existed before I decided to change fluid and filter with a gasket, I could just accept that. However, I should top off the filler hole with new fluid and watch the level over time.
I’m thinking I’ll be alright if left alone since the pick up/filter of the OD unit is lower in the pan anyway where the fluid cannot escape the confines of the pan.

Other than that, what should be done?

Some additional thoughts:
I could remove any pan bolts that I think are leak sites, and completely cover the entire thread with the high tack 80060,then tighten and retorque. I could then wait and recheck for further leakage. But I would not be surprised if there would be an inability to set properly with fluid already in the pan.

Since there were no heat cycles, should I even consider capturing all the fluid, and removing the pan in the hope that I can reseal the gasket, without damage to it, and reseal the pan bolts using better technique, and use the same captured fluid, since it is entirely fresh, or just get new again. Do I really need a inch lb torque wrench?

PS: While I think I would have noticed the leak earlier, is it possible that the big cold spell recently from 16-34 F temps has provided the impetus for the leak. The fact that the leak is continuing tells me that the level of fluid in the OD must be higher than I thought.
Click to expand...
Well, I’ve found that I made another rookie mistake that accounts for why my transmission pan gasket leaked so much. It turns out I had no idea how much/little torque was applied to those bolts without a torque wrench tool. After purchasing the $30 dollar HF battery powered torque cube, which had a low enough range, unlike my click torque wrench, it turned out they were blindly set to less than 1/3 the proper low range limit of 72 inch lbs. In retrospect, I knew I was spooked by the comments of not over tightening those bolts to avoid breaking them.

So now, in the days since, no drips yet although the gasket interface has some slight ooze. I can live with that slow a rate of likely drips as the opportunity to keep the gasket surface completely dry was lost after those poor technique loose bolts. Next time I’ll have the tool to do better.

I have one post fluid exchange observation that was also supplemented by greasing the linkage on the 4+3 transmission.it is how buttery smooth the transmission is now. Any slight clunkiness is gone. There is a lesson there about scrupulous lubrication at probably more frequent then standard published intervals for cars that are not driven actively and often.
 
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