jet911

A question to those who have torn down and rebuilt a 915 5 speed.

I am looking at a exploded diagram that shows only two sliders (shifting sleeves). One located on the pinion shaft between the 1st and 2nd gear dog teeth (synchro hubs) and one located on the main shaft between the 3rd and 4th gear dog teeth (synchro hubs). Am I reading this correctly? If so, my assumption is that if you replace 1st and 2nd gear dog teeth, then you need only one slider (shifting sleeve) and one guide sleeve.

Still struggling with this rebuild. After 500 miles, the small Axial needle bearing that sits behind 5th gear went out. My mechanic is replacing and has the tranny apart again. This time (with free labor), I'm replacing nearly everything and want to make sure I'm not over looking. He told me to buy all the parts that I wanted replaced and he would install - no charge. The original rebuild 500 miles ago included new syncros in 1st & 2nd, new dog teeth in 1st and 2nd, and 5 needle bearings (new clutch kit as well). Now to complete, I've ordered all new bearings ($1,200 - ouch!), one new slider for 1st and 2nd, a guild sleever guide and syncro's for 3rd, 4th and 5th. The dog teeth for 3rd and 4th look fine. Am I missing anything else? I want to make sure I got it all this time.

Am I correct on the sliders?

Thanks for any help!

Jim
'86 911

Chris Bennet

I probably shouldn't say this, but I think replacing all the bearings is overkill. I'm surprised that the 5th gear one went. I just replace the sliders, dog teeth and syncros and sometimes the brake bands, energizer blocks etc. Hopefully your mechanic can get you parts at reasonable prices.
-Chris

Howard

Jim,

You are correct, there is only one shifter sleeve for the input shaft and one for the pinion shaft. Also, I agree with Chris, unless you've found excessive wear there would be no need to replace all bearings. I rebuilt my 915 and with 130k miles and the bearings were in great shape. I replaced the 1st/2nd synchro and 3rd/4th synchros.The dog teeth were worn so 1st and 2nd were replaced. Initially shifting was rather balky but after 5 or 600 miles it shifts very well now. BTW, you can get the complete rebuild kit from Pelican for the 915 for around $950, fyi.

Jeff Curtis

I concur on the bearing issue Jim, overkill. But what peace of mind you'll have!

As far as the sliders, yes, two of them, one for 1st/2nd, the other for 3rd/4th. The needle bearings for 5th/rev. went out likely due to trash in the transmission or improper/careless assembly...after all the bearing cages are fragile and those long needle bearings can't take much abuse.

Look forward to hearing that you have all your issues taken care of upon start-up.

...refill with Swepco!

Chris Bennet

Are you using the transmission with a 3.6 or something hotter than a stock motor? If so, check the fit of the bearings in the case. They tend to pound the case out so the outer bearing race is loose in the case. (New bearings won't fix this.)
-Chris

jet911

Everyone - thanks for the input. I questioned and re-questioned the need for replacement of all the bearings. I also thought it was overkill, but since the tranny was apart again, I decided to go with what the mechanic was suggesting. My hope now is that the I will have a strong tranny.(note: I will not use this guy again for anything - it has truely been a nightmare! During the last two months, it has been in his shop for 7 weeks.)

I'm looking now at ordering a set of factory shop manuals, and from here on in, I'll do the work on my P-car. I've been doing my own work on my other cars for years and now it's time to dive into my 911 for more than routine maint.

Chris, I'm running my stock 3.2. Thanks for the pointer.

Swepco 201 is going in - yep!

Thanks again all, and I'll update as the project is competed!

This board is great!

Regards,
Jim
'86 911

jet911

Well low and behold my p-car's back in the shop again... It seemed to have been shifting better particularly upshifting in all gears and down shifting from 3rd to 2nd and 2nd to 1st. Well on my way home tonight, I was on the freeway approaching my exit when I when to down shift from 5th to 4th. It was stuck in 5th. I double clutched and it still would not disengage. I pushed in the clutch once more and pushed the shifter forward then back and it disengaged, however when I attempted to put it in 4th, I had a horrible grind. My heart sank. I pushed it back to 5th and tried again with the same results, but it did engage in 4th. Tried it a couple more times and had to almost force it into 4th. What's strange is that it upshifts well most of the time. Have 900 miles on the rebuild. Went straight to the shop, threw the keys on the desk, told the wrench to drive the car home and tomorrow. Got this horrible feeling that the tranny needs to come out again....3rd time in three months. I'm very disappointed and frustrated. Can't wait to hear what he has to say tomorrow. I'm nearly to the point of asking for my money back on the labor and going to the dealer. I don't drive the car hard at all. Never redline, never power or speed shift and usually shift around 4K rpms. The sad thing is that the car shifted fine before this entire nightmare started except down shifting into 1st due to the blow dog teeth. Thoughts? Has anyone else had this much problem with a rebuild? Have I found myself an idiot for a mechanic? At least I was getting ready to winter the car, so if there is a bright side at least it may be that...

Regards,
Jim
'86 911

jet911

Confirmed, out she comes for the 3rd time in as many months............

Regards,
Jim
'86 911

druck

Jet,
Now I remember, you are the guy that thought I was a smuck for questioning why you didn't change the rest of the synchros and bearings. I couldn't understand why you wouldn't replace these items since you already had the box apart. A few other listers also chimed in suggesting I was being negative by suggesting this. This is why I felt so strongly about what I was trying to convey to you.
I'm sorry you had to find out the hard way.
Get rid of that mechanic.
Hope it works out,
d.

druck

Jet,
Don't listen to these guys. Change all the bearings. All you need is one to go bad and you're tearing down the box, AGAIN, for a fourth time.
Yes, it's expensive, bite the bullet, do it right.
If this is over your mechnics head send the box to Steve Weiner or Gary Fairbanks. Steve is an amazing wrench and it will be done right!
d.

jet911

druck,
Thanks! All bearings have now been replaced as well as all syncros, dog teeth for 1st & 2nd, 1st and 2nd slider and the shift guide sleeve. I believe I will take your advice and send the trany back east! I'm speaking to the mechanic on Monday about this solution. I'll be requesting that it will be at his expense or asking for a total refund.

Regards,
Jim
'86 911

druck

Execellent Jet. Don't let him wiggle out. Try to get some kind of written aggrement. Gary has quick turn around. Don't forget Steve Weiner.
It'll work out. Sorry about the expense.
d.