Success, a scare, and a big THANK YOU!

[Josh D]

Some of you may have seen my thread regarding my transmission noise that turned out to be a bad pinion shaft 4 point bearing, a worn out bearing retainer, and spun pinion bearing outer race Found my noise!

No major projects are without some trials and tribulations. I was delayed a couple weeks waiting for the shift fork jig to arrive to complete the gearbox assembly. It arrived last Thursday, so I spent Thursday evening after work assembling the gearbox. Friday night was date night with the misses, no work happened then. Saturday I spent all day mating gearbox to engine, installing into car, repacking CV's with new boots (yuck), final hook up, prime and fire.

I expected issues getting it running again, as I had dissassemble most of the CIS to replace boots, seals, and gaskets. It fired up without any drama and idled very smooth, but a little high. Turned out I needed to re-adjust throttle linkage since replacing the non-existant throtttle crank bushings.

So now, everything is go for a test drive! Car is running fantastic! I nailed the clutch adjustment on the first try (new clutch disc installed). Gearbox is more quiet than it's ever been and shifting fantastically, and motor is smoother than its ever been as well. I couldn't be more pleased. That is until I got home and noticed all the smoke billowing out from underneath.

I grab a flashlight and look to find a stream of oil coming out from under the bellhousing area and the entire underneath of the gearbox and engine are wet with oil. WTF!?

So I get it up on stands and crawl underneath. Quickly determine its tranny oil. But from where? My first thoughts went to an overfill. I fill the gearbox while it was on the engine stand and put in almost 4 quarts (Iknow, I know) and it was coming out the vent at the top. So I pulled the fill plug, and a small amount trickled out. So maybe most of the overfill had already come out? Sounds good. It's getting late and I'm tired and dirty, I'm calling it a night.

So Sunday rolls around and my wife and I go on a great hike in some local desert mountains. I'm ready to take the car on another test run to see if problem is fixed. Well, it wasn't. This isn't a small leak, this is a gyser! So now I'm second guessing everything. Did I put the input shaft seal far enough? Did I somehow cut the seal with the input shaft splines? Did the pilot bearing fail? I'm seriously depressed and deflated knowing it all has to come out again.........In short, I'm bummed.

So at this point, I figure I'll do some research on Pelican to get more insight on mainshaft seal, which I determined at that point was the probable cause. I few pictures posted of the depth the seal should be into the guide tube had me believing that I had done it right. Also, this wasn't a small leak from a worn or torn seal, this leak was like there was no seal at all!

So then I come across a couple of posts on some random 915 threads by some noteable Pelicans (John Walker and RWebb) mentioning the orientation of the vent bolt on top of the gearbox and oil gushing. Hmmmmm. I did remove that vent when I cleaned the case. I knew it had been re-installed. What I didn't know was that it had a specific orientation. So I got the car back up on jackstands, got underneath and started feeling around. Hole in vent bolt was 170* from pointing forward. Could this be the smoking gun? Could turning the vent prevent me from having to pull everything apart again? Yes!

Talk about relief. A test drive after re-orientation of the vent bolt and problem solved. A huge thank you to JW and Rwebb for responses on somene elses thread that solved my problem. This forum is GREAT!

It was such a pleasure to drive my car in to work this morning.

[mnez]

NIce work! Glad you found it.
Now, for the rest of us, what is the correct orientation?

MIke

[Josh D]

Originally Posted by kodioneill

What does the orientation of the vent have to do with oil leaking out of the main shaft seal?

Nothing!

I was afraid that I hadn't pressed the input shaft seal far enough into the guide tube and that was the cause of the massive leak. Turns out, that wasn't the problem.

The vent tube/bolt has a hole on the side of it. The hole has to be facing the front of the car. The vent tube that extends into the case has a slant cut on it. If it isn't oriented correctly, it acts as a 'scoop' for the oil being flung by the ring gear. I had removed the vent tube/bolt when I cleaned up the case, not paying any attention to how it was oriented when I re-installed. Fortunately, it can be reached and turned with a 15mm wrench while in the car.

Finding that info on Pelican saved my bacon!!

[kodioneill]

I deleted my post because I searched and saw JW's Rwebb explanation. Nice going to solve your problem this forum is quite the resource.

[911Freak]

Josh, we're you able to determine the bearing retainer/race was toast or at least suspect with the R&P still sitting in place within the trans housing, with only the side cover off?
In other words, if I was to remove the side cover off the trans exposing the diff, could I see the damaged/spun bearing and/or bearing race, check axial play etc?

Thanks in advance. I'm trying to track down a clicking noise.

Btw I have a thread with pics of my R&P, diff housing and pinion shaft but because the teeth on the R&P look perfect I can only conclude any issues with the diff would be a spun bearing retainer etc. I'm hoping to verify this without tearing the trans completely down.

The trans is out of the car.

Many thanks.,

Jason

[zippy_gg]

Josh, just a sanity check here...
You said the tranny was leaking oil and you thought you over filled. So you removed some more oil and it still was gushing out, at least until you found and corrected the issue.
My sanity check question: have you re-checked the fluid level in the transmission afterward? I'd hate for your transmission to wear out or break down due to insufficient oil in it.

[Josh D]

Originally Posted by 911Freak

Josh, we're you able to determine the bearing retainer/race was toast or at least suspect with the R&P still sitting in place within the trans housing, with only the side cover off?
In other words, if I was to remove the side cover off the trans exposing the diff, could I see the damaged/spun bearing and/or bearing race, check axial play etc?

Thanks in advance. I'm trying to track down a clicking noise.

Btw I have a thread with pics of my R&P, diff housing and pinion shaft but because the teeth on the R&P look perfect I can only conclude any issues with the diff would be a spun bearing retainer etc. I'm hoping to verify this without tearing the trans completely down.

The trans is out of the car.

Many thanks.,

Jason

With the side cover off, your one bolt away from removing the diff and ring gear (flange bolt). With that out of the way, you should be able to test for axial play by trying to push/pull pinion gear in and out. Any movement here is unacceptable, and would mean the 4 point bearing or retainer or both are bad. To see either, gearbox has to come apart. Definetely would have to come apart to check for spun pinion roller bearing race in the intermediate housing.

With the trans out of the car, your really close to at least pulling the end cover, reverse & 5th gear, and the trans housing off to inspect the condition of the tranny. It's not difficult.

[Josh D]

Originally Posted by zippy_gg

Josh, just a sanity check here...
You said the tranny was leaking oil and you thought you over filled. So you removed some more oil and it still was gushing out, at least until you found and corrected the issue.
My sanity check question: have you re-checked the fluid level in the transmission afterward? I'd hate for your transmission to wear out or break down due to insufficient oil in it.

Yes, I do need to do this. Thanks for the reminder!