@@ Help .. 915 trans problems ..need expert !@@

Hello everyone ..

I just developed a probelm with my 915 trans
1976 , took it out of rqa ride today ,
and it got stuck in first gear , fo a minute
or so , had to jiggle around the shifter, to get it out of first , now first gear is unusable , the shifter works for all other gears , but when you try first gear it goes in , feeling normat , but all you get is a light whining noise in the trans , and its quite hard gettign it out of ( what use to be ) first gear ..

I have read before that this might be a fork
alignment problem in the trans ??

If some one , would be kind enough to help me out explaing on how to check and adjust the 915 shifter forks , i'll send them a family size pizza with all the fixings


Thanks in advance ..

- Joe -

Joe,

You are confusing a guide fork bolted to a cover plate with the three shift forks inside which shift gears. The pertinent info and diagrams are referenced in the following thread:

http://www.pelicanparts.com/ultimate/Forum3/HTML/005322.html

There is no adjusting of shift forks from outside the transaxle! And, the guide fork is either fastened down securerly on three studs, or not ... if not, you clean the threads, apply blue Loctite, and torque the nuts to spec. Reinstall cover ... end of fix!
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Warren Hall
1973 911S Targa

[This message has been edited by Early_S_Man (edited 04-07-2001).]

I had a very sloppy shifter.

I drained the transmission oil and then removed the cover plate under the transmission. Sure enough all three bolts that hold the shift fork down on the cover plate where loose. I tightened them up and put her back together. Shifting is no longer sloppy.

Tony
'78 911SC

Hello ,

Well i jcked up the car , drained and removed inspection cover.The shift guide plate was bolted securely.I watched the movement of the rod that selects between 1-2 and 3-4 and the rod appears to move correctly

So does that mean the trans has to come out ?

Also has anybody else lost just first gear in a 915 trans ?.Where it feels like its going fine into first gear but all you get is a light gear whining noise , and when you shift back out of 1st into second it has a good deal of resistance pulling it out of first , the rest of the trans shifts and works fine .. HELP !!

Thanks .. - Joe-

Povi,
Did you find any metal(chunks) in the oil when you drained it? It sounds like to me that your first gear syncro came apart and won't let it engage the gear. I reread your post, and you said its hard to get out of first gear, on your syncro hub there are three tabs if one or more of those bent or broke (on the first gear side) that would explain the force to get it out of first gear I would fish around in the trans with a bendable magnet (thru the drain and filler holes and inspection plate) looking for pieces

good luck
Tim in Sac

[This message has been edited by feelyx (edited 04-08-2001).]

if the syncro totally popped out of the few remaining dog teeth, it would be impossible to get it into the gear slot. you could barely go past the neutral position. if there are any teeth in the drain plug, that would help explain it. there may be just a few still holding the syncro in place. if so, don't drive it or serious damage may result if the syncro and brake band get wrapped around the gears, and chewed into pieces.

Hello,

When I drained the oil and checked the inspection plate , there was no sign of metal
not even a hint.I am pulling the engine and trans this friday.Does anyone have a hint on taking the front nose and cover off the 915 trans and how to check out the engagement forks..as in what am i looking for in there ??.

What could cause the trans to make a whining noise in first gear, seems like only one gear is spining in there, like the second half isnt engageing ??

I can build a mean 911 motor , but i have zero exsperience working on gear boxes..LOL

Also , i have had no problems with the trans up to this point whan it failed.And i wasnt beating on it just took it for a drive around the block .

Thanks to everyone who has helped me out so far .. your a great bunch !

Just a stupid thought:
Have you checked your ball cup under the shifter?
Normally, if it is torn down, you cannot shift anything any more, but who knows...

Jens

Hi ,

Yes the ball cup is fine.The trans will
shift fine in all gears except 1st, and all gear syncro's etc . work fine. The shifter
feels like its going into first as normal, and when you release the clutch car doesnt move and you can just hear a whirling sound in the trans .. not a bad sound , just like the gear is spinning around but not hooking up if you know what i mean.Then when trying to go from 1st into second its kind-of hard
to move the shifter , it doesnt mater if the engine is runing or not.but once the car is in second , you can shift all gears fine , including reverse , and all sycros feel fine
as well.

So the BIG question is what inside the 915 trans could cause the above symptom ??

Any 915 trans experts care to give a detailed explanation of what happens in the trans when you shift from neutral into first
and then from first into second ??..

Im stripping trans this friday , and will keep the board notified on the progress , incase this ever hapens to anyone else !


I could use a hand on explaining on how to take the front of the trans off.I have the factory service manuals but if anyone has
a few words to help me out .. I will be so happy I might kiss you ( applies only to female mechanics ..LOL )

Try checking the "pinch" clamp holding the shifter rod to the shift rod coupler.I had a problem where the transmission would not shift into 2nd and 4th.The loose pinch in combination with severly worn bushings made for some very weird transmission "problems".I also opened the access cover underneath and checked the "pivot fork", mine was not loose either.With the cover off I would shift the transmission into all four gears(using a pry bar to act as the "pivot fork").If you can shift the trans through the access cover the problem is with your LINKAGE!
The bottom line is: BEFORE YOU TAKE THE TRANS OUT check to see that the linkage(pinch) is tight and correctly adjusted! It sounds like the pair of gears which make up first gear are are not being pulled/pushed far enough into one another hence the "wherring" sound.

Povi,

Maybe you should take another look inside ... after making sure the coupler is tightly clamped in place. The 1st-2nd 'slider' (operaing sleeve) and dog teeth are visible forward toward the front of the car form that access opening. Missing dog teeth or a loose retainer might be visible, too! A Maglite 'AA' flashlight might be helpful to illuminate the inner workings while you look around.

------------------
Warren Hall
1973 911S Targa

Thanks early s man ,

I'll check it out , and if I cant see anything , i'll pull the trans friday
, I dont mind as I was going to clean up the engine compartment anyways

Any hints on opening up the trans once its
on the ground ?

Thanks

- Joe -

Joe,

Take the 915 to a wand car wash and spray it off really well before trying to take it apart! The Automotion/Performance Products 'T-Handle' is really handy to position the shift rod and go through the gears with the trans out of the car.

------------------
Warren Hall
1973 911S Targa

An update to my trans problem ..

In looking through the inspection cover
when a friend shifts the shift lever
the internal guide moves fine between
1st and second , so it does look like
the problem is in the trans , and not
with the shift coupler etc ..

Does any one know the 915 trans well enough to give me some ideas why the trans will seem like it goes into first but wont engage
both sets of gears just makes a whirling sound like one but not both gears in the set are spinning, and there is no grinding noise goinf into 1st gear or while its 'there', but when trying to go from 1st to 2nd its hard to get it out of what was 1st gear. however if your in neutral and go into 2nd its nice and smooth , all other gears are fine ??

Thanks to all that have helped me along so far .. I will be dropping trans on friday, so any info will be greatly appriciated !!

- Joe -

Hello all ..

Well i managed to get the trans apart , and check it out.I found a couple small hunks of metal about 1/4" square , when i pulled the nose off .I then pulled the outer gears off , reverse and 5th , .then pulled the main housing off, In examining the gear sets it looks like the syncro hub ( the triangle shaped deal with 3 points) , is bad ..the pieces of metal I found were the tabs off the syncro hub.It looks like they broke off on the 1st gear side of the sycro hub , the other half of the 3 metal tabs are still there on the 2nd gear side of the hub.And in playing with engaging 1st gear , the engagement slider doesnt move all the way into 1st gear because the remains of the broken tabs are slightly mushroomed out so it wont let the engagement teeth mate up. I examined both sides of the engagement teeth on the 1st gear and the slider hub ( the thing that the half moon shift mech moves ) and they appear to be fine.And prior to me loosing first gear i had no problems with sycros, shifting etc.. So it looks like I just need the sycro hub and I'll be all set !! , Unless anyone has some other info / ideas for me while im in there ?

Question ... how do I get it off ??, as i havent taken any gears off yet inside the main housing ..HELP !

In looking at the factory manuals , it looks like you put a gear puller on 1st gear and pull off the gear with the bearing
mounted in the front of it at the same time, then I should be able to slide off the sycro hub , replace it , and then put first gear back on then find a pipe or something and tap the bearing back on the shaft ..

Is the above correct ??

Thanks in advance ...

- Joe -

Question ... how do I get it off ??, as i havent taken any gears off yet inside the main housing ..HELP !

In looking at the factory manuals , it looks like you put a gear puller on 1st gear and pull off the gear with the bearing
mounted in the front of it at the same time, then I should be able to slide off the sycro hub , replace it , and then put first gear back on then find a pipe or something and tap the bearing back on the shaft ..

Is the above correct ??

sounds right to me.

While you are in there you might want to change your bearings, brake band groups, and any other wear parts. Also in 77 they beefed up the syncro hub (where yours broke). You might see of it is useable in you trans.

good luck
Tim in Sac

if you just want to fix the hub, and leave the rest, after the 2 housings are off, pull the roller bearing off the end of the mainshaft,remove 1st gear from the pinion shaft, take out the 1st/2nd shift fork bolt, and pull off the operating sleeve and brass fork together. if you have a long arm puller, use it, but they will come off reasonably easy with a couple of large screwdrivers and care. the 3 arm hub then slides off. reassemble in reverse order and center the operating sleeve between 1st and 2nd by way of the fork bolt. i would recommend a complete teardown and replace all syncros and 1-2 and 3-4 op. sleeves, as well as update 1st press on teeth, new style 1st and 2nd brake bands and dogs, and any other press on teeth that are worn down. have a good look at all the bearings too. were there any grinding gear problems or bearing noises previously? good time to fix them.