a904 Front seal leak?

-
Slantsix64

Slantsix64

Well-Known Member
Joined
May 11, 2014
Messages
3,756
Reaction score
1,744
Location
Los Angeles
Hey guys so on the freeway last night started smelling some trans fluid. Sure enough it was leaking from the front seal. Now the car shifts perfect , oils not burnt or smells, it has a trans cooler, and a Shift kit.

It leaks when its parked and running its not leaking on start up but once i start driving when its parked i believe its all the trans oil left in the front case leaking through the trans shield.

First Question, can it just be the front seal? why i ask is because a long time i changed a front seal in my 71 darts 904 because it was pissing fluid. And it didnt fix the issue it had a internal pump problem.

Second question i had a shift kit installed in this transmission can i just swap it into another running one? thanks guys!
 
Might also have a crack in the convertor hub, common problem with mid year 904 convertors.
They will crack from the pump drive gear notches out past the seal area causing a leak.
 
Slantsix64 said:
Hey guys so on the freeway last night started smelling some trans fluid. Sure enough it was leaking from the front seal. Now the car shifts perfect , oils not burnt or smells, it has a trans cooler, and a Shift kit.

It leaks when its parked and running its not leaking on start up but once i start driving when its parked i believe its all the trans oil left in the front case leaking through the trans shield.

First Question, can it just be the front seal? why i ask is because a long time i changed a front seal in my 71 darts 904 because it was pissing fluid. And it didnt fix the issue it had a internal pump problem.

Second question i had a shift kit installed in this transmission can i just swap it into another running one? thanks guys!
Click to expand...
Might need a pump bushing and a new seal. If the bushing is badly worn, a new seal still may not seal.
 
lkopaska said:
Might also have a crack in the convertor hub, common problem with mid year 904 convertors.
They will crack from the pump drive gear notches out past the seal area causing a leak.
Click to expand...

Duane said:
Might need a pump bushing and a new seal. If the bushing is badly worn, a new seal still may not seal.
Click to expand...
Yup looks like its time to pull the trans, ill probably swap the valve body to another 904 i had a shift kit but in it. Is that possible? also i remember the output tail shaft had alot of play when i removed the drive shaft i could feel the play. or is that normal? I dont wanna rebuild a worn out a904 that has play in it
 
My money is on a cracked converter hub. I'm sorry.
 
Convertor hub crack and or front pump bushing. Same as the rear. Tail shaft bushing and or worn slip yoke. No sense replacing your trans if all else is good.
 
RustyRatRod said:
My money is on a cracked converter hub. I'm sorry.
Click to expand...

SGBARRACUDA said:
Convertor hub crack and or front pump bushing. Same as the rear. Tail shaft bushing and or worn slip yoke. No sense replacing your trans if all else is good.
Click to expand...

Thanks for the replies , i didnt know the rear tail shaft had a metal bushing that makes me feel better that it can get fixed. Maybe i can get this thing back on the road alot quicker than i thought
 
Slantsix64 said:
Thanks for the replies , i didnt know the rear tail shaft had a ales ametal bushing that makes me feel better that it can get fixed. Maybe i can get this thing back on the road alot quicker than i thought
Click to expand...
Yes but it takes a bushing puller. Maybe you can remove the tail housing and take it to a transmission shop to get them to replace it.
 
So pulled the trans i do feel some wear inside the converter these are some pictures

20211002_215637.jpg


20211002_215556.jpg


20211002_215559.jpg


20211002_215609.jpg
 
Converter. When i took off the dust shield there was a pool of trans fluid i had to wipe it down. Going to take it to my trans guys see what he says. Fluid was clean and no metal in pan.

20211002_215753.jpg
 
What is the condition of the hub where the bushing & seal rides? No pics of that.
 
Slantsix64 said:
Converter. When i took off the dust shield there was a pool of trans fluid i had to wipe it down. Going to take it to my trans guys see what he says. Fluid was clean and no metal in pan.

View attachment 1715800039
Click to expand...
How do you know that the front seal is leaking.
I once rebuilt my 904 and thought I had the pump in straight and bolts torqued. Only in the burnout on the track at high rpm would the oil leak out. I was stumped. Turns out I did not have the pump completely square in the bore. Removed reinstalled, retorqued, leak gone.
 
Is the converter scored right in front of the slots? Are there cracks going forward from the front corners of the slots?
 
Well looks like RRR was in the right direction, the torque converter was leaking from the welds where it inserts into the transmisson. When i removed the trans i took all the oil out except what was left in the converter. placed the trans on the floor put the converter back in next mourning say it was leaking. inspected the converter and found the issue.

Now trans guy is going to take a look inside and check the condition of the front bushing. Hope fully i can get this thing ready by the fall fling.

another thing can my shift kit of had caused this? its a transgo kit set on the hardest shift. Also does the spline on the input shaft look okay?
RustyRatRod said:
My money is on a cracked converter hub. I'm sorry.
Click to expand...

Bewy said:
What is the condition of the hub where the bushing & seal rides? No pics of that.
Click to expand...
 
A good tranny guy can tell if the bushing is worn by the way the converter fits. Taking the trans apart to check the bushing is a scam move. But if the converter is scuffed where it rides in the bushing (as previously mentioned) , there's a pretty good chance it's toast.
 
CudaFactHackJob said:
A good tranny guy can tell if the bushing is worn by the way the converter fits. Taking the trans apart to check the bushing is a scam move. But if the converter is scuffed where it rides in the bushing (as previously mentioned) , there's a pretty good chance it's toast.
Click to expand...

yeah scuffed and i couldnt even get it to go back in all the way well hes a good guy i use to deliver parts to him, hes just trying to figure out why it happened but i mean its been in the car for 2 years with 3.91s and transgo shift it pushed to the limit alot
 
Chrysler center pump gears just flop around in there and cause the converter to just stop cold. Look inside the pump and you might have to stick a skinny screwdriver in there to move the gear around for the converter to hit it in the middle.
 
You must log in or register to reply here.
-

Back
Top