Now the transmission front seal is leaking

[mycommander]

It started with Carb, replaced that, then it would not shift right. Today changed the fluid and filter, and I reset the linkage and now it shifts perfect and runs great!! But now, the front trans seal is bad. It has always had a small leak, but for some reason it is pouring out now. When I drive it all you see is a trail of smoke. My goodness, will this ever end? Is there a fluid that may expand the seal? I heard of one by Lucas, but I am not for sure. I put 7 quarts in as the book said too, so it's not over full. With that plastic flippen dipstick I can barely see the oil level as it is because the oil wants to go into the dip stick due to its sensor on the end. Any advice would be nice, thanks.

[ibdilbert01]

The front seal on the 727 isn't too bad to replace, its more intimidating than anything because you'll need to drop the transmission.   Its just a lip seal with a spring ring inside.  Usually these types of seals get a tear in them, so fluids that are suppose to swell seals are not of much help.

A small leak normally doesn't cause smoke, it just drips out the bottom of the inspection plate on the bell.   I suppose if its bad enough it could get splashed around the inside of the bell and on the back of the engine block and maybe cause smoke between the bell and the engine, but I myself haven't had one that bad. 

[LJ-TJ]

Do not despair. I agree with Dilbert. I was stymied at the thought of changing out the front seal on mine and they were talking a couple hundred bucks to change mine in my 727 transmission. I haven't got that kind of money. So I had to do it my self. Holy cow that's it! D:oH! It really isn't that hard to do. Don't panic the guys here will walk you through it. 

[Froggy1936]

Anytime you change transmission fluid on any veh that has more than 50K miles on it or is more than 4 yrs old you can develope a serious leak at any or all transmission seals as the detergent in the fluid will wash away the sludge that was stopping the fluid from leaking this problem becomes more prevelant with ea passing year and mile todays fluids are even more likely to cause leaks than the older formulations Some stopleaks may help or cure the problem temporarily but replacement is the way to go Also wile the seal is out very carefully inspect the bushing behind the seal for wear A severly worn bushing will cause the new seal to leak Frank

[Madathlon]

For one person replacing the front seal is a pain in the bum, BUT for two people it is easy as pie. I have all the tools needed for this. So all we need to do is get togather and do it. Oh ya the seal cost $3.95 at NAPA.

[mycommander]

Thanks Madathlon, do you think the 7 quarts is too much? I read on the auto zone repair guide it took 3 quarts! So I thought of pulling some out and seen if that was the case. The bummer part of it is, is I need it to move with. Its all wired up, got the hitch ( thanks to you). I can't seem to get the right answer for the amount of fluid. I have done the seals numerous times, its just NOW is a really bad time. Not to mention my jack will not go that high. So I will take you up on it. Its 2 bucks for the seal, might as well do the rear too, and the u-joint. Man, talk about a money pit! Thanks all for the tech info. It just ticks me off.

[Madathlon]

From what I read earlier it was in need of the seal for some time. What many people complain about on old rigs is how much it cost to fix them. But what the real issues is past owners putting off repairs until it does cost a arm and leg. I have a pump that will pull the tranny oil out so we can save it. IF there was to much oil in it it would have been slipping like crazy. but you said it working good. You could also consider putting in a standard dipstick.

You do have the right idea on doing both the front and real main seals. This will avoid leakage once we pull the tranny. Once you fix these items you wont need to for some time. Dont panic over theses small repairs. We just need to get together when its not down pouring out and do the fix.

[DaveVA78Chieftain]

For reference, here is the 78-79 Dodge MH Service Manual description
Dave

Fluid and Filter Changes
Fluid and filter to be changed and bands adjusted every 16.000 miles.
NOTES:
(1) When the factory fluid is changed as recommended above, only fluids of the type labeled "DEXRON" Automatic Transmission Fluid should be used. A band adjustment and filter change should be made at the time of the oil change.
(2) If the transmission is disassembled for any reason, the fluid and filter should be changed, and the bands adjusted.

Drain and Refill
(1) Raise vehicle on a hoist, Place a drain container with a large opening, under transmission oil pan.
(2) Loosen pan bolts and tap the pan at one corner to break it loose allowing fluid to drain, then remove the oil pan.
(3) Adjust both bands (see "Band Adjustiments`).
(4) Install a new filter on bottom of the valve body, and tighten retaining screws to 35 inch-pounds.
(5) Clean the oil pan and reinstall using a new gasket. Tighten oil pan bolts to 150 inch-pounds.
(6) Pour six quarts of "DEXRON" type Automatic Transmission Fluid through the filler tube.
(7) Start engine and allow to idle for at least two minutes. Then. with parking brake on, move selector lever momentarily to each position. ending in the neutral position.
(8) Add sufficient fluid to bring level to the "ADD ONE PINT" mark.

Recheck fiuid level after transmission is at normal operating temperature. The level should be between the "FULL" mark and "ADD ONE PINT" mark.
To prevent dirt from entering transmission, make certain that dip stick cap is fully seated onto the filler tube.

Dry fill capacity:  17 pints

[mycommander]

Thanks Madathlon, Its hard to panic right now. I have never seen a front seal leak like that where just about pours out! I think will use a standard dip stick the next time I go to pick-n-pull. Saving the oil is great too! that concerned me some. The stupid pan is leaking because it was over torqued by the old owner I guess, and I forgot to pound out the holes, so I will have to do that too. Thanks Madathlon, Just let me know when!

[mycommander]

Thanks Dave, I will cut and paste that to save it for the RV file. Its getting rather thick. I appreciate you taking the time to write that out for me.

[ibdilbert01]

When I removed my tranny, heres what I remember (It was dark, 2am, just me, and I only had a tiny flashlight, so If I miss a step, someone please chime in). Also my chassis is a 71, so I expect its not the same, maybe close.

1. Put the front of the RV on blocks to pick it up a bit and shore up the tranny with some jacks.
2. Pull off two Tranny lines, kickdown linkage, park neutral safety switch plug, selector cable and remove the dipstick, as it tends to get in the way.
3. Disconnect the drive shaft from the tail.
4. Take inspection plate off and remove the 4 flexplate bolts.
5. Remove bell housing bolts
6. Towards tail of tranny is a tranny mount, removed those bolts and removed park brake cable.
7. I have a 71 chassis, and there is a cross member attached to the frame rails that the tail shaft is mounted to, I ended up removing the 8 bolts holding this to the frame to get it out of the way in order to drop the tranny.  My exhaust is dual and didn't get in the way, so I didn't have to remove it. 
8. start gently prying the bell housing away from the engine, making sure everything stays shored up, once seperated, lower the jacks and muscle the tranny out for repair. 

Some tips:  If you have a digital camera, snaps some pictures.  Never hurts to have a reminder how things were, and then later you can upload them here and brag about the fun you had! A few post back someone said the tranny takes 17 quarts, thats 8.5 quarts, but keep in mind you might have an external tranny cooler, so you'll want to compensate.  You might want to make note of various sizes of bolts, so you can remember where they came from to put them back.  You don't want a rig like mine, where I'm sure all the bolts are all mixed up!    And its not a bad idea to put some tape around any adjustment rods, like the drop down linkage so when you put it back together, you might not have to readjust it.   If you know someone with a motorcycle jack, they tend to work well for lowering transmissions.

[GWINGER]

Since the fluid is pouring out you may need a pump bushing.
Be sure to check the condition of the torque converter snout.
A grooved snout will not seal up. A bad bushing causes wobble of the converter. If you have to pull the pump put in a new pump seal and gasket. The pump can be pulled without special tools. All that you need is a piece of chain, two bolts and two hammers.
J

[Froggy1936]

The previous comment was  17 Pints  wich is 8.5  Quarts   They state amts in pts for adding a pt at a time when near full  Frank

[mycommander]

Thanks for the help everyone.

[jkilbert]

also most tool rental places have tranny jacks to rent fairly inexpensively. or if you have a friend with a motorcyce/quad lift, they work well also