68 Dart, 340, 727. The front seal is leaking badly so I'm thinking of replacing it myself. Are there any videos or tutorials on this subject? Would it be better to remove the engine/transmission as an unit and then repair the tranny? Are special tools required? Am I likely to find bad bearings or something that caused the leak in the first place? Sorry for all the questions...............this will be a totally new experience for me.
Replacing Front Seal on a 727
- Thread starter mokid
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Mad Dart
Nothing to see Here!
It is very easy to do. Pull the front pump cover after the trans is out. You will need a new seal and a pump housing gasket. Piece of cake. While it is out I would freshen the whole trans. That too is easy as pie. There is a youtube tutorial on the complete subject. It is easy, easy, easy.
fishy68
Tyr Fryr's Inc.
If it were just me I'd just pull the trans. No need pulling the engine too IMO. No special tools required. They make a fancy seal puller but a large flat tip screwdriver inserted at an angle will work just fine. It's always possible you'll find the front pump bushing and possibly even the torque converter snout in bad shape on a 45 year old car. Those can be remedied easy. YouTube is full of video's showing work done on 727's. If I were you I'd scan through them and find the ones that are most pertinent and watch them.
BTW: Louis's tip on refreshing the whole trans. is not a bad idea especially if it's original because most likely all the seals are hard as a rock. There's a whole series of rebuild video's on YouTube from start to finish
BTW: Louis's tip on refreshing the whole trans. is not a bad idea especially if it's original because most likely all the seals are hard as a rock. There's a whole series of rebuild video's on YouTube from start to finish
Mad Dart
Nothing to see Here!
Your right Tracy you can do it without pulling the pump. I figured and I should have explained....I would do the seal and pump gasket just to make sure the front of the Trans is all sealed up.
I wonder if it could be puking out the vent and the seal and pump gasket are not leaking at all? Thinking out loud.
I wonder if it could be puking out the vent and the seal and pump gasket are not leaking at all? Thinking out loud.
you have to wonder why its leaking in the first place, thats why pulling the pump and replacing the bushing and seal is a good idea. How bad is the leak? Does it drip or pour out when the engine is running or in gear?
unless yoou want to do engine work, just pull the tranny. drop the pan first to get most of the oil out of the way. when you have the tranny out, pull the convertor out quickly. you may then be able to see where it was leaking(sometimes). then stand the tranny on end in a bucket and secure it to your bench somehow. adjust the front band scew all the way in tight. remve the pump bolts. there are two bolt holes that are threaded 5/16. use a slide hammer with the aproppiate tip and out comes the pump. i like to reseal the whole assembly. so that means a front seal, bushing, gasket and o-ring. buy your parts from a tranny place. napa and those stores sell crap. look at how the bushing sits in its bore and press in the new one. use some vaseline to hold the spring in the seal in place and put some locktite on the outer periminer of the seal and carefully tap it in place. you could test fit the pump body on your convertor to make sure it will fit. reassemble the pump and place it on your convertor again to make sure it turns. find a longish 5/16 bolt and cut the head off. now loosen the band adjuster. place the gasket in place and put the cut off bolt in one of the pump bolt holes. this will be our dowl, so put it in a handy place so you can align the pump to it. lube the o-ring with something slippery. put the pump over the input shaft, align with the dowl and let the pump slide down to the case. now give it a strait hard push and it should just "pop" in and bottom out. put some locktite on the pump bolt washers and screw them in. put some vicegrips on the input shaft and pull up and down to check for endplay and make sure it turns. ajust the band to two turns, change the filter and pan gasket and your done. easy stuff.
Point and counterpoint...
I know from experience that pulling the trans isn't easy without a vehicle lift. You would need some very tall jack stands and a trans lift and so on. I also know from experience that if you own a cherry picker you can snatch the engine out and use the K member as a seat while servicing the front of the trans.
If the one seal has failed they are all subject to failure ( all the same age after all ). The selector shaft seal is the booger. If you don't pull the trans and replace that seal too, odds are you future post will read, " Where to add a hole in the floor pan for selector shaft seal replace? "
So tell us what tools you have and don't have available. We'll get'er done one way or the other.
I know from experience that pulling the trans isn't easy without a vehicle lift. You would need some very tall jack stands and a trans lift and so on. I also know from experience that if you own a cherry picker you can snatch the engine out and use the K member as a seat while servicing the front of the trans.
If the one seal has failed they are all subject to failure ( all the same age after all ). The selector shaft seal is the booger. If you don't pull the trans and replace that seal too, odds are you future post will read, " Where to add a hole in the floor pan for selector shaft seal replace? "
So tell us what tools you have and don't have available. We'll get'er done one way or the other.
I have a hydraulic engine hoist, jack stands, an extra yoke to keep the tranny from puking fluid when turned at a sharp angle. The reason I mentioned pulling the engine/tranny as a unit is I helped my son replace a 904 on a 318 a few years ago and it was a real pain dealing with the torque converter and bell housing bolts. I have no experience with 727's. The replies so far are very helpful. Thanks
Oklacarcollecto
Life is an experiment
If they haven't already been replaced, I would replace the freeze/core plugs with brass ones on the rear the block while the tranny is out.
Difference in 727 and 904 is the size and weight.
Unless you pull both at once,
Either way you go about it, you'll need to remove bell housing and torque converter bolts to separate the engine and trans.
transman
Well-Known Member
Don't forget to look at the hub of the converter also. If it's not mirror smooth like a crank journel, all your work to replace the seal and pump bushing will have been wasted. as a rough or worn hub will wear them out again.
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