Trans troubles (still)

[xxxdominion]

Hello Prime,

It has been a few months since I last posted. I finally got the rebuilt 5 speed back from the shop last week with a ring / bearing / syncro rebuild due to the transmission developing a leak after the clutch went out. Unfortunately, the transmission is still leaking from inside the clutch housing area. What I would like to know is, is there ANY POSSIBLE area fluid can escape form the case other than the input shaft seal.

Items that were replaced:
Input shaft seal (twice)
both left and right axle seals
main seal
speed sensor
reverse light sensor
clutch and flywheel

All the work (besides the trans rebuild) was performed by yours truly.

The only possible thing i can think of is a fracture somewhere that was missed by myself and the rebuilt technician. or am I missing something? This is now the third time the trans has been out of the car for this issue. When filling the trans, I filled it on a level surface until fluid began to pour form the fill hole, it it overfilled? or should I just but a new transmission case?

 

[ralph cerbone]

Hello Prime,

It has been a few months since I last posted. I finally got the rebuilt 5 speed back from the shop last week with a ring / bearing / syncro rebuild due to the transmission developing a leak after the clutch went out. Unfortunately, the transmission is still leaking from inside the clutch housing area. What I would like to know is, is there ANY POSSIBLE area fluid can escape form the case other than the input shaft seal.

Items that were replaced:
Input shaft seal (twice)
both left and right axle seals
main seal
speed sensor
reverse light sensor
clutch and flywheel

All the work (besides the trans rebuild) was performed by yours truly.

The only possible thing i can think of is a fracture somewhere that was missed by myself and the rebuilt technician. or am I missing something? This is now the third time the trans has been out of the car for this issue. When filling the trans, I filled it on a level surface until fluid began to pour form the fill hole, it it overfilled? or should I just but a new transmission case?

sounds like a vent problem , pressure builds in gear box and pushes out trany seal . seen this many times in trans &rear ends .
find the vent and make sure it is clear , being do these for over 40 years, just check it

 

[xxxdominion]

sounds like a vent problem , pressure builds in gear box and pushes out trany seal . seen this many times in trans &rear ends .
find the vent and make sure it is clear , being do these for over 40 years, just check it

SOunds plausible. It only begins to leak after a 12-15 minute warm up. Is the vent on the top of the trans?

 

[B2FiNiTY]

Check the case for cracks.

 

[ralph cerbone]

yea ,search trans case on any acura parts web site ,it is part #39 ,vacuum hose . could it be a crack ?of course but check simple things first .Assuming all seal were properly installed!

 

[OLDMNSX]

You might try this. Park the car on a level surface with access to the fill plug. Remove the fill plug and see if any fluid comes out. Let it sit with the plug out for 30 min.
Just a thought.
Brad

 

[Larry Bastanza]

The vent for the NSX transaxle is the small rubber hose, just below the air filter on top of the trans.

Also are you sure it is trans oil? I only ask since in that area(behind the flywheel is the crank seal) from the outside it would be the same leak location.


HTH,
LarryB

 

[xxxdominion]

The vent for the NSX transaxle is the small rubber hose, just below the air filter on top of the trans.

Also are you sure it is trans oil? I only ask since in that area(behind the flywheel is the crank seal) from the outside it would be the same leak location.


HTH,
LarryB

I'm as sure as the day I got married, so, 90% sure its trans fluid.

I kid...... But I use royal purple motor oil, changed the oil before the trans was filled with Honda OEM clear trans axle fluid. It also has that distinct gear oil smell that I unknowingly wore as cologne all day yesterday. Therefore, the fluid seeping from the underbelly of the beast is clear, and smells like crap.

 

[Larry Bastanza]

Ok, my next thought would be the mainshaft bearing, causing the mainshaft to wobble, not allowing the seal to work. Did the mainshaft bearing get changed during the rebuild?

 

[xxxdominion]

Ok, my next thought would be the mainshaft bearing, causing the mainshaft to wobble, not allowing the seal to work. Did the mainshaft bearing get changed during the rebuild?

Ring and bearing kit / syncros were all done.

I just let the car sit and run for about 20 mins untill operating temp was achieved. no leak. So it only happens when the trans gets warm. I wish there was an easy way to diagnose this.

*edit. well at least the shop said they were done....

*edit 2. Could a clogged screen cause this isuue?

- - - Updated - - -

sounds like a vent problem , pressure builds in gear box and pushes out trany seal . seen this many times in trans &rear ends .
find the vent and make sure it is clear , being do these for over 40 years, just check it

Pulled the little rubber hose off the vent fitting in the top of the trans. ran bake clean through it. The fluid passed through just fine. I could see down in to the trans through the small hole as well. I think the vent is clear.

- - - Updated - - -

You might try this. Park the car on a level surface with access to the fill plug. Remove the fill plug and see if any fluid comes out. Let it sit with the plug out for 30 min.
Just a thought.
Brad

I originally filled the car while it was on four jack stands. It took a little bit over 2-1/2 qt of Honda genuine trans fluid. I stopped when it began to drip from the fill hole.

- - - Updated - - -

Check the case for cracks.

I scoured the clutch housing carefully before I even took the trans to the shop. And usually on cast aluminum a fracture may be minor but quite evident. I didn't notice anything unusual during the inspection. It was also thoroughly cleaned with brake clean / degreaser.

 

[xxxdominion]

Sorry for the resurrection of an old thread but I'm BACK!

I't has been a year and only 150 unhappy miles put on the 91 but for the third time the trans has been removed, I found the problem which confirmed my suspicion all along.

There was a small gouge in the trans near the LSD side dowel behind the oil seal in the dowel hole. I don;t have pictures but the gouge form the OS Gilken clutch exploding made it through the housing just enough to create a 0.33mm hole in the case, allowing just enough fluid to seep through during mid to high RPM's. The hole was so damn tiny i missed it the second time the trans was removed.

The fix is easy enough: clean the area with a small die grinder and apply flux / JB weld to plug the hole. It is an un-pressurized system so this should last the life of the clutch case. The good news is the trans does not have to be re separated to replace the input shaft seal or the CV seals. While the trans is out I'll go ahead and do the pan gasket, replace some coolant hoses, and make sure everything is buttoned up to factory spec.

I can't tell you how exited I am regardless of R&Ring the trans three times. She will be back on the road just in time for SOWO and with the addition of a TL big brake kit for the front. and a full brake service with some Hawk pads. Looking forward to breaking the 100,000 mile mark!! Happy driving Primers!

 

[Larry Bastanza]

It is an un-pressurized system so this should last the life of the clutch case.

That, in fact, is not true for the NSX trans. It is one of the very few manual transmissions that actually has a pressurized oil system. Oil pump is driven by the DIF gear and it has a filter system and pumps oil throughout the trans.

My $.02

Regards,
LarryB

 

[xxxdominion]

It still doesn't create positive case pressure. But nonetheless 300 miles in a week and no leaks. All is well in the world again. 300 to go to 100k =D