Transmission fluid overflow

#1

Every time I fill up the transmission fluid to the top, the next time I am at a track, the fluid splashes out of the breather hole and wets the driver side floor pan.

I thought about adding a catch-can but that will still allow fluid to spill out from the transmission and just get caught in a can.

I would need something to allow the fluid to flow back in later.

After a track weekend, the fluid is down enough to stop the overflow. I have been just running lower than full and not bothering to fill it back up.

Does anyone else have this problem? Is it just Mr. Junky?

#2

Attach a long breather tube to the top of the breather vent and run it all the way up into the engine bay. The tube is long enough that the fluid will not come of the end and will drain back into the tranny. The fluid that is coming out is not a whole lot anyway.

JP

#3

Am I the only one who thinks this shouldn’t be happening, period? When you say you are filling it, you mean to the point the fluid is even with the fill plug hole?

Are you certain it’s coming out the breather? There is a cover for some detent springs on the top that I’ve been told can warp over time and allow a leak. The replacement cover is made differently. It’s not expensive. I replaced mine when I had a different problem.

#4

I fill it until the fluid drips down from the fill hole.

I think it’s coming out of the breather hole. I will try the long tube method and see if that will help. The amount may not be much but it sure makes a mess and also sometimes it will splash on to the tires as well which I think is dangerous.

Thanks.

#5

While we’re on the subject… what size is the hex socket for the drain/fill plugs?

#6

17mm, I found a cheap one at Auto Zone?

If you can wait until RA I’ll have one with me.

#7

IIRC, 17mm.

#8

For me it’s usually the output seal or the shift selector seal that really blow the fluid. The telltale is the fluid spatters all over the rear bumper.

#9

While we’re on the subject of tranny leaks, if you happen to buy a used replacement tranny, before you install it, check the top of the rear edge of the case, near where the shift rod exits IIRC. The very early cars had a different shift linkage mechanism, and there is a threaded hole drilled all the way into the transmission. The later transmissions had the same boss, but it’s filled at the factory with a metal plug.

Anyway, if you don’t happen to notice this threaded, unused hole, and install the unit, the resulting oil leak will look exactly like the rear main seal is blown, 'cause that’s where it drips down. Solution is simple, put your favorite goop on a spare 13mm bolt and run it down tight.

#10

ctbimmer wrote:

[quote]While we’re on the subject of tranny leaks, if you happen to buy a used replacement tranny, before you install it, check the top of the rear edge of the case, near where the shift rod exits IIRC. The very early cars had a different shift linkage mechanism, and there is a threaded hole drilled all the way into the transmission. The later transmissions had the same boss, but it’s filled at the factory with a metal plug.

Anyway, if you don’t happen to notice this threaded, unused hole, and install the unit, the resulting oil leak will look exactly like the rear main seal is blown, 'cause that’s where it drips down. Solution is simple, put your favorite goop on a spare 13mm bolt and run it down tight.[/quote] Good advice. This I caught putting the trans from an 87 vert into an 89 car…Patton had this issue as well if I remember.

#11

ctbimmer wrote:

[quote]While we’re on the subject of tranny leaks, if you happen to buy a used replacement tranny, before you install it, check the top of the rear edge of the case, near where the shift rod exits IIRC. The very early cars had a different shift linkage mechanism, and there is a threaded hole drilled all the way into the transmission. The later transmissions had the same boss, but it’s filled at the factory with a metal plug.

Anyway, if you don’t happen to notice this threaded, unused hole, and install the unit, the resulting oil leak will look exactly like the rear main seal is blown, 'cause that’s where it drips down. Solution is simple, put your favorite goop on a spare 13mm bolt and run it down tight.[/quote]

Chuck,

Can you reach this hole from the bottom to put the bolt in or do you have to pull the transmission?

#12

csrow wrote:

[quote]
Chuck,

Can you reach this hole from the bottom to put the bolt in or do you have to pull the transmission?[/quote]Are you implying that was a first-person ask-me-how-I-know story?:wink:

Well, it was, and you can definitely reach it. It’s been a few years so I don’t recall the details, but I’m pretty sure we put the car on a lift, stuck our head up there near the guibo and ran in the bolt. No big deal.

#13

Could someone take a picture of a transmission from the top and show me where is this breather hole?

That would help me fumbling around from the bottom.

TIA

#14

If I’ve done it right, the picture attached to this post shows the breather hole as #3, #4, #5 in the diagram.

Steve D.

#15

Ahh… thank you very much.

Now time to get some Gates vacuum hose #27042 and get dirty fumbling around.

Do you remove just #4 and fit the hose on #3 or do you remove #3 and #4 and jam in #5?

I guess the last option is to remove #3, #4, and #5 and stick the hose in the hole itself.

Any suggestions?

#16

Remove 4, attach to 3.

#17

Generally when you remove the dust cap there is not enough left to secure a hose. Solution: Pack with heavy grease, drill for 1/4 pipe, tap for same, remove grease and shavings, and screw in 90 degree hose fitting. Attach hose and run to a catch tank behind the FR fender. Problem solved. Chuck

#18

cwbaader wrote:

Ummm, forgot one small step:

  1. Remove transmission

:wink:

#19

TheRedBaron wrote:

[quote]cwbaader wrote:

Ummm, forgot one small step:

  1. Remove transmission

;)[/quote]

Maybe:

  1. Ignore rules
  2. Remove transmission

:woohoo:

Steve D.

#20

Is a clamp needed?

This hose can be put on without any transmission lowering?