Rocker arms/ Input Shaft leak ?

[GotaT]

Hey guys Im really ready to beging using my 71 targa. Its been awhile since I did an engine rebuild and still I havent been able to use it due to further oil leaks. Im sure some of your expertise will help me get it going.

1st
Its a 2.4 engine and 915 tranny. in a 71 car.

I have a horrible oil leak that is causing all sorts of smoke. Ive deduced the valve cover gaskets were definitly A culprit, but w/ further investigation I found that there is also some oil in the Valve covers (Shown in pics below -Yellow area on inner valve cover) This could only be caused to my knowledge by leaking Rocker arms shafts. However, I Did install New Rocker Arm Seals. My only guess is that the Rocker Arms were not positioned correctly where the seals were physically touching the housing. What is the proper method/guage for installing the Rocker Arms?
Does it matter which side the Allen Bolt is on when installing the Rocker Arms?


2nd
Once I pulled the engine to find my oil leak thinking it was the Oil Cooler (which checked out fine under pressure) I found that my 915 Tranny Input Shaft seal is leaking, Perfect time to fix it.
How do I get the Throw Out bearing Sleeve off? I pulled it and tried turning it but no luck and I dont want to Ruin it. Pic Attached Also

Thanks in Advance!

MITCH mas2868@yahoo.com

[MBEngineering]

HI not good that oil seal in the gearbox , as you will have to strip the box to fit a new one, from inside the diff housing, gasket set and a pinion nut to repair. the release bearing sleeve is in the box and is not removable?? like the later 915 box's

regards mike

[GotaT]

Originally posted by MBEngineering
HI not good that oil seal in the gearbox , as you will have to strip the box to fit a new one, from inside the diff housing, gasket set and a pinion nut to repair. the release bearing sleeve is in the box and is not removable?? like the later 915 box's

regards mike

"and a pinion nut to repair" ??? what do you mean.

Also, Who has the procedure/steps for replacement?

Thanks

[Jim Sims]

On the transmission pictured, the clutch release bearing guide tube is not removable. If I recall correctly certain 1972 and early 1973 915 transmissions must be partially disassembled to gain access to the input shaft seal from inside the differential housing. When one does this, the flanged pinion shaft nut is removed and the factory shop manual recommends replacing this nut each time it is removed (although some reuse it). As far as gaskets are concerned one could manage with just buying the paper gaskets between housings (around $1 each) and the input shaft seal - the whole gasket kit isn't needed if the transmission has been gone through recently. If not, this is a good time to replace all the gaskets and seals in the transmission so the whole kit may be useful. Other versions of the 915 with the fixed guide tube can have the seal replaced from the clutch side but this requires the use of a special seal extraction tool - looks something like an apple corer. There are numerous threads on rebuilding 915 transmissions and this seal replacement task would be a subset of an entire rebuild.

[Jim Sims]

Link to thread with picture of the seal removal tool that is useful for some of the fixed guide tube 915's:

How to change input seal in a 915?

[cstreit]

Be sure that oil in the valve cover is coming from the rocker shafts before you mess with them, and not just from the gasket leaking up into that area.

It's a long shot but worth the investigation.

[GotaT]

Jim, Im not familiar with these tranny's enough to know but How can I tell which Tranny I have as to the Guide tube you mention. I understand that you said my guide tube was not removable, and more difficult change the seal, but how can you tell, where is it?
I read the link article and was wondering if that tool would in fact work on my non removalble type tranny? If so, of course, Where can I get one? THANKS so much for your help! and all of your posts!

[Jim Sims]

What is the number on the bottom of the transmission?

[GotaT]

Originally posted by cstreit
Be sure that oil in the valve cover is coming from the rocker shafts before you mess with them, and not just from the gasket leaking up into that area.

It's a long shot but worth the investigation.

When I removed the covers of course there was oil in the spot I mentioned. I looked closer and noticed that Not all of them had the oil in that area and when I looked around the rocker shafts there was oil sitting there. Granted If there was oil anywhere in that large area I suppose that it could also sit near/on the rocker shaft bolt/nut possibly due to movement.
Do you know the Depth the Rocker shafts should be positioned???
Another note, when I examined the Gaskets they seemed to be very Snug to the valve covers and It didnt appear that oil would have slipped by. Ive also noticed that my valve covers are no longer good. They are warped and have hairline CRACKS in them on the edges. So they are getting replaced.
THANKS

[Scott Clarke]

Mitch-
The rocker shafts sit in bosses that are different lengths on each side of the rocker arm. The end of the shaft should be flush with the short boss. This should get the shaft close to centered on the arm, allowing the seals to be properly positioned within the bosses. The bolt should be placed so that the head is adjacent to the wider spaces within the cam towers and not the narrower ones. This enables easy removal and replacement of individual shafts. When tightening the bolts, rotate the head and hold the nut stationary. I think that the torque spec is 18 Nm, but you can go to 25 Nm if you have leaks. All of this is nicely described in Wayne's book, which I don't have with me. Please verify torque specs before proceeding!

The seals can be easily damaged during installation. I'd remove the effected shafts, clean them, install new seals, and inspect the bosses for scoring. It is really easy to score the rocker shaft bore during installation. Make sure you have the adjuster backed way out of the rocker arm, and that the cam is positioned so that the lobe is away from the arm before removing or installing the shafts.

-Scott

[jbrinkley]

Mitch, were you at the cajun dome for the autoX? I think I met someone that mentioned you, taking pictures. a relative or something?
I have an extra set of 930 lower covers. I also have some extra rockers and shafts and bolts and stuff from when I had a shaft walk out on the freeway.
PM me I'll give you my number if you want,

[GotaT]

Scott, That makes Perfect Sense on postioning! Thanks for your Input. Do you think it necessary to Completely remove the shafts, or could I get away with loosening and sliding them in the correct spot?
Thanks again!

Jerry you have a PM

[Scott Clarke]

Mitch-
I'd take them completely out in order to see what is going on, and in order to install new seals.
-Scott

[GotaT]

Anyone know where I can get the "how To/Steps" on tearing down the Transmission to replace the Input Shaft Seal. I've not taken one apart before and want to make sure I follow the "book" or someones experience thats worked.
Thanks for all the Posts!

[Jim Sims]

Factory shop manuals, Haynes 911 manual or threads on this website in descending order of expense.

What is the transmission number on the bottom? Look on the bottom surface of the narrow rib, running side to side and projecting downward.

[Charlie V]

Most of my oil leaks on the engine were on the rocker shafts. Last winter as part of my engine clean up, I over torqued the shafts and put some high heat RTV sealant on the ends. Drove the car hard this summer and it hasn't leaked a drop.

[GotaT]

HMM. Charlie your idea of putting that RTV on the ends of the shafts definitely seems like it would work. Maybe not the "by the book" way to fix it, but If you say it worked I may do that to mine.

JIM Sims. My TRanny looks to be 331671 There may be a 1 in the front but I think that it is just a Scratch mark. Let me know!

THANKS

[Jim Sims]

The "1" is likely the remains of a "7" which makes your transmission number 7331671. This unfortunately means you have one of the models that requires replacement of the input shaft seal from the gearbox side. The transmission will have to come apart enough to do this. From number 7337375 on the seals were installed from the clutch side.

[GotaT]

I was afraid of that. Im reading now in my Haynes manual the Steps. Seems VERY complicated, Not looking forward to it. Is there any way around removing the inner gears?

[Charlie V]

I was shown this trick from a friend who has played with Porsches for many years.