I'd take the short shift kit out. That can only mean a bit less life...

New tranny fluid won't hurt.

 

Yeah, but I just had the kit put in. I'm not terribly hard on my trans, no quick shifting. I just like the shorter throw.

 

Rick: The way that you describe your shifting indicates that your synchros might still have a lot of life left. Following cold starts, before selecting first or reverse always shift the transmission into a gear that you know (by practice) will work smoothly. For instance, my transmission likes to be put into third gear cold, so that's what I do - put the trans into third before selecting first or reverse, after every start. This usually completely eliminates the 915 struggle that some have. Trans fluid (never use synthetic gear oil in a 915!!!) will rarely help this condition, which can actually be considered kind of normal; if not normal, certainly typical.

When your mechanic said that your car is out of clutch adjustment, that's not a cable issue, it's a clutch disc wear issue. As the disc becomes thinner over time, two arms under the differential, on the clutch linkage, move closer together. As that happens, correct adjustment clearance, using those arms, can no longer be achieved. When you replace the clutch you should also do the cable, but be aware that there are after market cables out there, and they're JUNK! The easy way to tell a factory cable is to look at the bowden tube section of the cable, where it passes by the left side of the transmission. It should not have any writing on it, while the after market cable will say "Made in Western Germany" in white letters. Make sure that your mechanic knows that you know about this, you want a dealer o.e. cable no matter what.

Regarding your gate system, I don't know what that is, and I've never driven a car fitted with one. The short shift, if it's the stock '85 version (10% shorter than '84 and older cars), is very nice, but if you have an '86 Super Short Shifter version (20% shorter than '84) it becomes tempting to shift too fast, which can shorten synchro life. Short shifters are really a mixed bag, some people hate them, some love them. I have the '85 version in my car, and drive it exactly the same as an '84 or earlier car. I had an SS version in a different car, hated it and took it out after only 6 months (the SS version also has a heavier motion, which I also did not like).

Have the clutch done, refine your technique a little, and leave the trans alone, I'm not hearing any symptoms that say do the synchros now.

 

243 - shorter gear shift lever

This is one of the options on the car I'm buying. Anyone know the purpose of this option? I'm pretty sure it's not a short shifter.

 

Pete,
Is it not possible to perform a proper rebuild without the very large cost of special tools . I see over on the Pelican forums a great deal of threads on the topic , with what sounds like good results.
Are these repairs just not going to last ? I read the section in your book where you discuss but it just seems that some out there are able to make reasonable repairs.

 

Inniswhe: First, I think, we should define "repair" and "rebuild." A repair is usually performed on a low mileage transmission that has had a synchro failure. An adventurous DIYer can remove the transmission, somehow support it on a work bench or other clean surface, and remove the nose cover. At this point you will need the boomerang looking tool that holds the mainshaft so the M/S and P/S nuts can be removed. I'm not going to do a tutorial here, but after the 5th/R gears are off the center housing can be removed. Now you're confronted with choices; (1) Remove the entire gear cluster, or (2) Pull first gear off and fix any 1/2 synchro problems. You're also faced with; (1) Trusting that the shift fork for 1/2 was set properly and that you can measure it so it can be returned to the same position, or (2) Buy the shift fork jig to reset it per the manual. Now you must determine if your 1/2 dog teeth are damaged, and if they are you need to buy the puller to remove the old dog teeth, and have a gear press available to install the new one. From this point, if you bought the shift fork jig and manuals, you can probably go deeper and remove the gear cluster. Now you can address the 3/4 synchros, but you have to buy the special socket to remove the nut in the middle of the main shaft (you can take the nut off without the special socket, but you can't torque the new nut without it).

At this point you're getting pretty close to "rebuild" territory (that is, checking everything), and if the pinion bearing race is loose in the differential housing, the diff must be disassembled, and the housing sent to a highly qualified machine shop that can machine a steel spacer for the bearing race to be pressed into. Assembly will require that the pinion depth be checked (last time that I checked that tool was about $2500), the diff carrier bearing pre-load must be checked (inch-pound pressure type torque wrench + stub axle special tool + pullers should bearing removal/shim replacement be required), and the ring gear backlash checked/set (dial indicator + holder + stub axle tool + pinion shaft holder required). Now the trans must be assembled (3/8" drive and 1/2" drive torque wrenches required along with a variety of extensions & sockets), and hopefully there is a set of expert eyes nearby that are willing to lend a little assistance.

Transmissions are all about tools, and some of the posts that I've read about how "simple" they are, or that it only took "two hours to fix", or "I don't know what they're talking about, I didn't need any of those tools", are, quite frankly, pretty scary. They also make me concerned for the person who comes along, and buys the car with the assumption that the trans has been "rebuilt", along with the sellers explanation that they all "shift that way."

 

Just rebuilding the CV joints scared the crap out of me. One false move and it was frozen. You are talking about a rebuild way beyond that level. some jobs are just best left to the pros.

 

Thanks for the detailed reply, Pete, appreciated. The gate system on the car is basically a spring loaded system that centers the shifter (when in neutral) to the "default" position, which is b/t 3rd and 4th gear (google Seine Gate System). When downshifting from 5th gear, it eliminates any concern of potentially choosing the wrong gear ("the money shift" as others have called it) and blowing up the engine. I put it on there w/ the short shift kit (I bought the factory kit from pelican, not sure which one that is from the others you have mentioned) as sometimes short shifters can make a 915 a bit more ambiguous. I'm not worried about me doing it that much, but just in case I have others drive my car, I don't want to be concerned about them choosing wrong gears if they're not familiar w/ the car.

You do have to counter the springs weight though as you shift - or else you can prematurely wear out your synchros.

My wrench said that the synchros might need some work b/c 3rd gear is usually the first to go, and when shifting into third, it can be a bit notchy.

Thanks

 

I'd like to say after attending Jerry Woods class on tranny rebuilds, it does take some special tools, a good eye, patients, and resist trying to get away cheap by not replacing certain parts thinking it's okay.
Of course he made it look simple, but I know it's not...well at least not the first, second, or third time.
You need to be very organized and give all your attention to what you're doing...interruptions must not happen i.e. phone calls or the wife wanting you to pick up the kids.
However, with that said it's a nice challenge if you like turning the wrench.

The motor was even more of a challenge with measurements of air volume between the piston and the heads.

BTW - It was a very good class to take with volumes of information on 911s.

 

Excellent thread.

We better be nice to our 915's !!!!

 

"You need to be very organized and give all your attention to what you're doing...interruptions must not happen i.e. phone calls or the wife wanting you to pick up the kids."

Amen!

Rick K: Your mechanic's experience is very different from my own! Only about 5% of the 915s that I've repaired had issues with 3rd gear, I found that 1st was the big trouble gear, with 2nd gear running a close "second."

 

Thank you Pete for your PM. I'll be down there on monday. Today the ven blu met and I are going to deliver candy to customers in Temecula.

 

...and will you be making that delivery while wearing flowing white hair, a full beard, and a funny red costume?

 

+ front mounted cyclops 3rd brake light?

 

Pete, got the call back from Marc and we talked for a good half hour. It sound funny that I would drive by several other shops to buy 4 1/2 pints of oil from him , but he is the first guy to ask if I had LSD and that sealed the deal. Sounds like he was paying attention when he was working for the master. I am looking forward to seeing what goes on in a real shop without being asked for a credit card imprint and a $100 deposit for "conversation". Monday I'll fire up the ride and head down to Long Beach with a couple empty gallon jugs for the good stuff. My drive to Temecula was complete with a quick stab at XXX coming up the 215 out in Perris. Smoooooooth on the juice