Fronkenstein

For what its worth I thought I would share some empirical words of wisdom. These notes are taken from a much larger thread found at:

https://rennlist.com/forums/.../Project 928 started this week...

I want to outline the experience rebuilding an early 928 G3 5 speed transaxle. Sorry for the lack of pictorial chronicling but I don't own a GoPro Hero and using an ipad or phone is just a royal pain. So here goes with a written version.

AXIOM: NO FEAR - ITS JUST A PUZZLE

It's just a transmission and like a simple clock disassembly and re-assembly isn't that difficult. I have read a lot of hoopla on this site of how difficult it is and how you need to be a genius to rebuild one of these. If you have a reasonably equipped shop; have some extra cash to buy some tools which all of us love to have for the wife; and take heed of the following observations and advice I don't see why anyone cannot do this at home in there two stall garage.

PREPARATION: IMPORTANT STEP

• MENTALLY PREPARE YOURSELF: Follow the axiom and be patient as there is no cheating the process.
• CLEANLINESS IS CLOSE TO...: Clean everything. The case inside and out right down to raw aluminum (I start with Home Depot ZEP Orange Clean or Hardware store acquired SUPER CLEAN I also use caustic soda and phoshoric acid to prepare for clear ceramic rattle can painting)
• PAINT IT: Use a high quality Clear Ceramic Enamel from a rattle can. Use two cans and spray the inside as well as the outside
• Have the correct Porsche manual and PET to cover the transaxle you are rebuilding. There are serial number cutoffs for various parts like 4th and 5th gear synchros that are the same up until a certain serial number.
• SHOP AROUND: Good prices on parts can be found including with your local Porsche dealer. Also make sure the stated price on the website is the real price quoted price to avoid surprises like the one I got with Einmalig. I didn't catch the telephone quote price versus the website which was a $65 difference. Also make sure they actually have the parts. I ran into a considerable delay due to the fact the vendor didn't have the parts on the shelf so I had to go elsewhere. Expect to spend $650 to cover parts for a synchro rebuild. This doesn't include broken or severly chipped gears, bad sliders, or dog gear rings which are NLA.
• INSPECT EVERYTHING: Inspect everything at every possible angle and under a magnifying glass. The gears are served up abuse by persons who are eithe inept with a stick or think the can drive this like their GM or Ford product. These transaxles, while strong, don't have synchros that can handle abuse unless you're really good at double clutching and even then it should only be on occasion.
• MARK THINGS. Get yourself a paint marker, one in white and one in yellow. I use a metal stamp for some items. It is important to mark items such as the differntial carrier / axle joint hubs. These are shimmed diffently for each side and reversing them will have adverse effects on the ring and pinon.
• BE RESOURCEFUL. The Porsche manual will have you believe you need all kinds of special tools. This simply isn't the case. The alternative tools are blocks of wood; very large crescent wrench; a big vise; a of quality gear pullers; and good assortment pry bars both flat and hooked and big ti-wraps.
• A CLEAN BENCH: You need a place to lay your puzzle out in order of assembly. You will want to stage your assembly after everthing is clean.
• CHEMICALS: Have plenty of "red can" and "green can" of CRC Brakleen on hand. The red can is pure carbon tetrachloride which isn't very flameable but its fumes when hittng a torch creat phostine gas which is poisionous and at the least an irritant to your lungs. The red can evaporates slowly and very effective a heavy grease. The grean can is highly flameable but is very effective on light oils, gasket materials, tar, varnish and other similar grime. It is also a great drying agent since it evaporates very fast.
• REPLACE ALL SMALL PARTS, SEALS and GASKETS: No poinit on saving on roll pins, synchros, carrier bearings, rear case bearing, bushings, needle bearings, seals or gaskets unless they are truly NLA like the front carrier bearing unless you want to pay the various vendors $600 for a NOS one. Unless you really need one, don't bother. One source for inexpensive o-rings and seals is MSP Seals. I saved $150 by doing this.
• BE PATIENT: There is no cheating the process of disassembly and reassembly. This is pretty much true for any manual gear box.
• STICKY GREASE IS YOUR FRIEND. When assembling parts that tend to fall out of their assigned position, such as synchro energizers, sticky grease will keep them in line.
• DO NOT FORCE THINGS: If something isn't going together with the force appropriate to the process STOP AND INSPECT before pounding with a dead blow or brass hammer. What I mean by appropriate to the process is the difference between tapping a shifter shaft into place with a small brass hammer and driving a rollpin home with a steel punch and 24 ounce steel hammer. You will save yourself a lot of heartache by following this in general for all machanical work. There is a time and place for the use of force.
• IF IN DOUBT READ THE MANUAL: While I hate reading the manual AND the Porsche manuals, like CATerpillar, SUCK lemons, they do have some useful information.
• IF FRUSTRATED - GO HOME: No point is getting miffed, breaking something and then really getting ticked off.
• REMEMBER THIS IS A 928: Nothing is as it seems and nothing about these cars is simple and nothing can be taken for granted. When I purchased my first Porsche a couple of years ago I learned this lesson the hard way after replacing a T-belt. Fortunately I didn't lose the valve train but I did trash the T-belt. The 928 is no exception and I have never had a car that had so so many issues at every possible task and turn. Rebuilding the engine was cake in comparison with the rest of the car. In fact improvising the CIS system to run on my LH engine was also cake in comparison. EXPECT problems, there are an ample amount of gremlins and poor engineering in Porsche cars - all of them. Porsche is the only manufacturer I know of that can sell its customers on the "upgrade" idea when in fact its an ECO (Engineering Change Order) due to some engineering screw up. A classic example of poor engineering is no reverse lockout in these crash boxes.
• TOOLS: You will need good quality tools. Starrett or equivalent feeler gauges and metric dial caliper are a MUST HAVE. Sockets, ratchets, torque wrench or angle meter, extensions, wrenches, allen wrenches, screw drivers, pry bars, pliers, snap ring pliers, pick, razor blade and yes vise grips. And you will need to own or have access to an assortment of gear pullers and extension rods. And finally you will need a heat wrench (torch). This is needed at minimum to install the needle races which are part of the gear assemblies. You don't need a lot of heat but you need it. Something to keep in mind. Under most circumstances fast heating is far better than a slow rise to temperature. This means you need an adequate heat source. I prefer a MAP gas turbo torch (looks like propane). This is especially true if you need to remove a synchro slider ring gear from a donor gear like I did. This is a particularly scarey process because significant heat and pounding with a steel hammer and cold chisel are necessary when working on 1st, 2nd or 3rd gears.
• MAKE SURE YOU MEASURE: Make sure you follow the procedure to measure the end to end "X" play in the main gearset (1st thru 4th). Make sure that you measure the outside diameter of the synchros. Doing so will allow you to catch broken or worn slider gear rings and bad synchros. Again you will need a Starrett or equivalent quality metric dial caliper and same quality feeler gauges.
• RESiST THE URGE TO CHEAT OR RUSH: I guarantee the task you try to cheat or rush will bite you in the butt in either time redoing it; breaking something or having the epiphany after all is installed you forget a piece.

After going through what I would consider to be a mildly complex rebuild process due to an NLA gear that needed to be refit with a donor ring, I am pretty confident I could do the entire rebuild in two days. If you have never rebuilt a manual gear box - two weeks.

The great thing about doing the rebuild is you have the knowledge of everything that was done in that box and you saved yourself $2,400. And more importantly you can proudly say that you did the job. Buying a garage queen is nice for investment but having a daily driver you know intimately is so much more rewarding.

Fronkenstein

GregBBRD

Have you driven it yet?

How do those synchros now work?

There's some "hidden" things inside these gearboxes that virtually no one figures out....and these transmission are famous for grinding, even after they are "rebuilt".

I "redo" as many of these transmissions as I do originally!

James Bailey

on his long "project 928 " thread he posted that it is not in the car yet....but is back together ! So he is more successful than most .

GregBBRD

Hmm.

I suggest we wait to break out the beer until it is actually in the car and tested.

As you especially are aware (Jim helped me rebuild his transmission), the list of tricks and the things that get "missed" inside these gearboxes is pretty lengthy.

There's more to the story that installing a couple of new synchros....

We removed a "recently rebuilt" transmission this week. The owner spent $2500 on it. It is waiting for me to disassemble. It shifted and ground so badly that the car was virtually undriveable. Upshifting was possible if the rpms were matched. Downshifting in any of the gears was.....virtually impossible.

There definitely is some "magic" to making these things work correctly.

AO

Hey Greg, next time I need to change a light bulb, should I consult you first? Oh wait... WTF was I thinking? Sorry... my bad.

Fronkenstein

Greg,

In the spirit of this posting perhaps you'd care to elaborate on the "hidden things" and what you have had to "redo". Sharing is what makes rennlist valuable.

To answer your question as to whether the synchros work my answer without putting under power is a resounding yes. But that doesn't mean a thing until I put 330 HP into it.

Fronkenstein

GregBBRD

The troll ^^^^^ just eliminated that as a possibility.

I've got a new personal rule....since I gain nothing from helping people or passing on what I know....one troll and I'm done with that thread.

There's zero upside and zero need for me to deal with crap...since it makes zero difference to me, if anything anyone else ever fixes ever works again.

You people want help, advice, or want me to pass on some of my 45 years of experience....you need to apply the required peer pressure to control these a$$holes..

As far as transmissions are concerned, I'm sure it's as easy as."changing a light bulb" for everyone but me....it took me years to figure out what needed to be replaced and why....bit I'm just a dumb old professional Porsche mechanic that's had hundreds and hundreds of these things apart and working perfectly.

And if not that easy, they can always ask AO how to do it!

I sincerely hope that yours works and shifts perfect. Don't worry about 330hp going through it. The early transmissions are pretty robust. The input ball bearing on 5th gear is relatively weak, but there's an easy fix for that....I'm sure anyone that can "change a light bulb" can figure out how to fix that!

Fronkenstein

Greg,

No issue with your rule. My rule for troll management is ignoring them. Anyway one question. Are you located in New England by any chance? Your self-description sounds like a long time Porsche guy not fast from me. If so then you should remember our discussion about a gray 1977 911SC Targa in Hampton NH that you did a purchase verification on within the past 6 months.

Fronkenstein

Fronkenstein

Greg,

One other thing about troll management is that unfortunately freedom of the press runs amok and there are no controls other than a verbal spanking which just leads to further tongue lashings and that begets more trolls from which point the two or three initial posts turn into 400 pages of drivel.

AO

So when YOU are the one "trollin'" what happens then? Does the universe end?

Here's a guy sharing his experience. He's not asking for anything in return. YOU come along with nothing to contribute but fear. Instead, wouldn't it have been better to have said, "Hey don't forget to check XYZ..." and actually be helpful?

Nope. YOU make it sound like a mystery, black art, magic, whatever. So who is the troll here? YOU are the troll.

I get it. YOU have a business to protect, and this could eat into that (probably not). So it probably was a wise move for YOU to jump into a thread right away and scare others off. This will either protect your business, your stature, and certainly your ego.

You are such a self-serving fear mongering prima donna. I'm surprised you haven't penned a book titled,

"Greg Brown's 9 Secrets to 928 Ownership"
Chapter titles to include:

• Headers? I got your effin' headers right here. Anything else is crap.
• My exhaust is a secret... oh wait... it's Magnaflow
• Fuel lines are magic. I have an elf that makes them, do you?
• Trannys... how to handle them (and not get diseases)
• 928 tensioners... why mess with perfection
• Oil vacuums. If you ain't got one, your engine will blow up
• Oil separators... actually you don't need a vacuum
• Oil baffles. Now I've got it & why it took me 7 years to see what others were already doing

And my personal favorite:

• I build stroker motors so well... they never need tuning. When they blow up... it's operator error.
  
• Bonus chapter How to: Trollin' with the best. How to make it look like you're the victim of your own attack when called out.

[self-imposed vacation]

Fronkenstein

Ahhhhh-huh. Guys I am fairly new to rennlist but I am a 30 year email, message board and Internet veteran that knows this isn't going to get any better.

Worse is any usefulness or hope of sharing info is either gone or will be after the next non-technical non-mechnical comment is made.

Please can we just keep this on point?

Thanks,

Fronkenstein

Rob O

Has a moderator read AO's post yet. If so, isn't that the type of post that should be deleted asap? Shouldn't AO be given some kind of warning about doing things like that? How does it contribute to the topic in any way? It's just instigating someone (Greg) that is just trying to help.

It's really aggravating to see topics and conversations like this get ruined by someone with an alternative agenda attacking people. I bet 99% of people reading this forum don't want to see this type of stuff. This is a technical car forum, not a soap opera. This stuff is getting really old.

Everybody has heard "if you don't have something nice to say, don't say anything". It's not the hard to do.

I personally think AO should apologize to the original poster and Greg as well as the rest of the readers here for his post. That's wishful thinking, but it would be the right thing to do.

AO, I bet your not actually a bad guy. But posts like you made above just aren't appropriate.

I really hope the original poster's transmission rebuild works out perfectly for him and hopefully this forum is here to help him in the future.

Rob

Fronkenstein

I think I am going to request deletion and repost. And the first sign of off topicness I will just close the thread.

Kinda sucks when all you are looking for is collaboration and this happens.

Fronkenstein

The Deputy

The saying was a bit different at our house...my mom use to say..."if you don't have anything intelligent to say, don't say anything at all."

Needless to say...you could hear a pin drop in that house...lol

Hopefully the trans works like a champ and we can put this whole topic behind us...and learn from its worth. I believe, and judging by previous and numerous post in the other topic, the OP will certainly post his results in a timely fashion and be forthcoming with any mistakes that may have taken place.

Brian.

Fronkenstein

Thanks Dep