915 rebuild.... starting to hate this car

[Geronimo]

Was hoping it was only going to be a 1/2 gear fix, well 3/4 gears were very worn. So get a call today and the case is warped and out of spec. Waiting on a quote for an 84 case they have on hand. They also suggest that I get the valves adjusted while the engine is out. Which I get is smart, but with my luck that will lead to head studs and an upper rebuild at least. So far the trans rebuild without the 3/4 gears was 4500.00 The new clutch and bits was 2500.00 which I thought was a bit high. Waiting on cost of the case replacement, though I feel like any labor should be nil as I would expect them to have checked the case as protocall in a rebuild, not sure I should pay for extras labor for them putting everything back into a bad case. Also waiting on valve adjustment quote. Pretty sure I’ll be in over 12k for this pile of crap car. Not a happy boy.

[Tylermelvin]

Lol your anger is relatable.

I just did about the same thing. Near full trans rebuild, new clutch and surfaced fly (mine was only 750), problem with my mechanic was he didn’t know to replace the speedo ring completely new and when put back together an old magnet apparently fell out and destroyed my rear diff. After all said and done with a LSD from kaaz, including main seals and gaskets, hoses, lines, and piping around the engine I was at 12k and it took him almost 2 months ffs. My 911 is now up for sale or trade for a 997 =)

[proporsche]

do you mean transmission case is out of specs??why? any details

Ivan
For clutch set and bit 2500???why?

Ivan

[Trackrash]

It will be interesting to hear what the experts have to say about a "warped" case?

What part of the case is warped?

Can you get an itemization on the clutch parts? Sounds kinda steep.

[cabmando]

I'd want a look at the gears myself. I helped my brother take down a high mileage 915 and the gears were fine. When people say they are grinding gears, it's actually the dog teeth that are grinding, not the gears.

[cabmando]

Originally Posted by Trackrash

It will be interesting to hear what the experts have to say about a "warped" case?

What part of the case is warped?

Can you get an itemization on the clutch parts? Sounds kinda steep.

I'm guessing it's the part of the case that hold the bearings. Don't remember what it's called but on certain year 915's it's known to wear. You don't know until you break down the transmission.

From my brother's thread on 915 rebuild: Mr. Zimmerman's excellent tutorial How-To: Porsche 915 Transmission Repair Tutorial Part 3 - Porsche Wiki notes that the 915/73 is much less likely to suffer rear pinion shaft bearing race wear issues, requiring machine shop repairs.

Geronimo,
You might want to look this thread over it has some really good info as well as pics that might help you evaluate your trans should you go look at it.
Gordo's 915 Transmission Rebuild

[Geronimo]

I did look at the gears, they were very rounded at the teeth.

[proporsche]

geronimo..the trany case if the bearings are loose in it can be done machine shop..there are plenty in LA...Even Marc Brixen can guide you to it..those quotes are very steep......take your time before you agree to the repairs...i have one case ...here for a long time if you end up needing one, it is yours free ,just shipping from Europe to USA will be up to you;-)

Ivan


need some tlc and oil otherwise all good

[Trackrash]

Originally Posted by cabmando

I'm guessing it's the part of the case that hold the bearings. Don't remember what it's called but on certain year 915's it's known to wear. You don't know until you break down the transmission.

Nick. Warped and worn are two different things. The worn bearing seat you are referring to can be machined. It is a common repair.

So my question, what part is warped to be in need of replacement?

[mepstein]

What’s warped and how did they determine it.

[Walt Fricke]

Geronimo
1) You should be getting the idea that there is a failure of communication here. Typically the gear pairs themselves are usually OK. Sometimes a tooth (or more) breaks off. If run without oil, bad things can happen and they turn blue. If somehow the oil (transmission fluid) is dirty, you might see pitting on the gear mating faces (especially the pinion gear). But the actual gears don't get rounded. The gear pairs are in constant mesh, so they don't clash when shifted (reverse is the exception).

Shifting is done by pulling a toothed slider away from one gear, and pushing it or another slider into another gear, along a lengthwise shaft. The slider's teeth engage the dog teeth on the side of the actual gear. These are the teeth which get rounded off with time or abuse or worn out synchros. They are what you might hear when shifting if very worn.

Actual gear sets (two gears, mated to each other by the manufacturer)are expensive new, though there are plenty of good ones available used.

Dog teeth, and the slider, and the synchro rings, are not cheap, but no where as expensive as actual gear sets.

Do a search for "915 gears" about anywhere. You should find a picture of some gears. Do one for "915 dog teeth" to see what those look like.

2) You don't say what year your car is. I'm guessing it is a 3.2 or 3.0, which means the transmission case is aluminum. Neither I, nor the others who have responded, have heard much about a warped case. The aluminum cases are pretty darn strong. The only thing I know can warp is the differential cover plate, and that's usually due to installing a 500 or more HP race motor, or maybe a broken ring/pinion gear tooth.

The responses address the alas all too common problem with these transmissions - one or more of the holes for the shaft bearings have gotten enlarged (ovaled), and no longer hold the bearing or bearings as they should. There is a fix for this - not cheap, but useful and probably cost effective long run.

These shop guys need to explain all this to you. Take a picture of the "rounded" gears. Take one of where the "warp" is, with maybe a straight edge lying on it to show the warp.



The

[rattlsnak]

^^ Yes, and how convenient they have a case to sell you..

[Matt Monson]

915 gear tips don’t contact. They never wear and get rounded. 915 gears wear when the heat treat gets worn thin at the base of the gear and they start to pit. Posts pics.

[scottrx7tt]

You are dealing with a 40 year old car. Unfortunately, if you don’t work on it yourself, it’s gonna cost you some $ to maintain. I went through my own transmission, replaced the 1-2, 3-4 sliders 1st and 2nd gear dog teeth, and synchros, along with 2nd gear that exploded. I had the case fixed by CMS, and added the 1 piece bearing retainer. Total spend was about $2500. when I put it back together, I replaced the clutch disc only, that’s under $200. A valve adjustment is easy to do with the right tools and should not take more than an hour and a half. Honestly though, every valve adjustment I have ever done was never out of spec in the first place.

Originally Posted by Geronimo

Was hoping it was only going to be a 1/2 gear fix, well 3/4 gears were very worn. So get a call today and the case is warped and out of spec. Waiting on a quote for an 84 case they have on hand.

They also suggest that I get the valves adjusted while the engine is out. Which I get is smart, but with my luck that will lead to head studs and an upper rebuild at least.

So far the trans rebuild without the 3/4 gears was 4500.00
The new clutch and bits was 2500.00 which I thought was a bit high.

Waiting on cost of the case replacement, though I feel like any labor should be nil as I would expect them to have checked the case as protocall in a rebuild, not sure I should pay for extras labor for them putting everything back into a bad case.

Also waiting on valve adjustment quote. Pretty sure I’ll be in over 12k for this pile of crap car. Not a happy boy.

[manbridge 74]

Warped? By how much?

[Peter Zimmermann]

I, personally, have never seen a "warped 915 case/housing," but have repaired a ton of diff housings by having my favorite machine shop (EMS in Inglewood, CA) install a steel sleeve for the outer pinion bearing race. They do the repair for about $800. On rare occasion I have also encountered loose bearing races in the center housing, and the same fix can be done.

BTW; what are you getting for $4500? All 6 new bearings + diff carrier bearings? 1st & 2nd synchro rings/dog teeth, and slider? Replacement 5th gear?

BTW 2; please itemize the $2500 clutch bill. It only takes an hour to replace a clutch and crank seal (at the flywheel) with the engine out. Are you going to get a new disc, pressure plate, TOB, pilot shaft bearing and crank seal? What about the flywheel? What about the throw-out bearing fork?

[ClickClickBoom]

This situation is popping up with more and more frequency. The last 915 was installed in the '80s. My bet is the Factory training for said transmission support was discontinued shortly thereafter. This leaves the real in-depth knowledge with guys like the Late Great Grady Clay and current SMEs like Peter Zimmermann and Matt Monson. Every year these guys retire/pass on or close up their shops. This means the reservoir of knowledge dries up a little more. Guys are loathe to make a crate and ship their trans to a current known expert shop, instead take their car to a shop that is local and probably last looked into a 915 a long time ago.
When I was working as a aircraft A&P I specialized in warbirds and out of production aircraft. I turned more work away than I took. I worked on everything from Cessna 120s to Hawker Seafury's and charged 3x the current mechanic rates. As a current Airline pilot, I make a good living, but if and when I fabricate, I charge 1.5 my hourly pilot rate. A couple times a month I get calls from previous airplane/fabrication customers asking if I am available.
This trend will unfortunately increase over time, and as shops close, the remaining shops will pick up a larger lions share of the business. The shop that figures a way to "franchise" their operation with independent shops and create a reuseable shipping container, and a reasonable shipping process, making the process less cumbersome will have more work than they can imagine.
Think if you went to a "franchise" shop with your transmission issue, they test drive and make an informed assessment, then call the main overhaul shop, who then ship the reusable container to the franchise. Overhaul is completed, then shipped back to the "franchise". Cheap, not by any stretch, but still less expensive than the experiences of the last couple of guys posting on this site.
My 915/68 is 35 years old and still works like it should, I replaced the trans and engine mounts, shift coupler and shifter, to insure that the selected gear is indeed selected. That being said I have a 915/67 in my shop waiting for refresh/overhaul. I expect that trans to last at least 30 years, or long after I am worm chow.

[proporsche]

click clik..very well said...and true...
Peter i think i had my trany fixed by EMS-was there older German mechanic ?? He was a friend of a friend maybe you knew him, Alfred from Specialists on Lincoln Blvd...He did a great job on fixing my loose bearings with the sleeve..
Ivan

[ClickClickBoom]

Originally Posted by proporsche

click clik..very well said...and true...
Peter i think i had my trany fixed by EMS-was there older German mechanic ?? He was a friend of a friend maybe you knew him, Alfred from Specialists on Lincoln Blvd...He did a great job on fixing my loose bearings with the sleeve..
Ivan

My knowledge of the Porsche maint. community is limited. But what I have learned is its always easier and less expensive to hire specialized talent than to develop it yourself. Even guys like Peter Z. know their limitations, machine shop set up is another SME level job.
Could I disassemble a transmission, sure, can I read tooth contact patterns, dog teeth, ect? Less and less likely. When you add all the unwritten info that experience provides, it becomes more and more difficult, not impossible, to effectively rebuild your own transmission. Can it be done, absolutely, but I will never discount the collective knowledge of the guys who do this for a living. I prefer to drive and do the stuff I can and already know how to do. I have been to a bunch of factory level schools for specific aircraft/components, they give you a manual and you spend 2 weeks disassembling engines and accessory cases under the tutelage of the guys who wrote the book. When I took the Pratt & Whitney PT-6 course, the instructor had been with Pratt for 35 years.
Given the costs of the internal cost of gears and such, screw up and the price tag gets big really fast. I am risk averse when the cash pile can is at risk. When you look at the experience levels of guys like Grady Clay or Bruce Anderson, those guys had forgot more Porsche info than any 10 "specialty shops" combined.

[Marc Bixen]

Click Click, Well written posts. Thank you for your support and insight into our end of the repair world.
I think I'll refer to you as 3X!