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Porsche Transmission Rebuild


The most noticeable performance decline in manual Porsche transmissions is the ability to shift easily / quickly / cleanly from one gear to the next---up or down. Syncro wear is most often to blame. Given worn syncros, shifting puts gears and dog-teeth at increased risk of damage, particularly if a driver does not shift-compensate for syncro wear. Should you experience any noticeable oddity when shifting, I recommend inspecting this condition sooner than later. Reason being, it's more economical to replace just syncro rings as compared to also replacing ruined gears and/or dog teeth.

        '09 model Porsches and up have electronic PDK shifting.

        Transmission oil in most cases should be changed every 15,000 miles. Do this regularly and you will go a long way to preserving the integrity, performance, and value of your Porsche transmission.


Porsche Clutch & Flywheel


Clutches & flywheels have a factory prescribed wear limit. Once beyond that limit, driving performance declines. You can extend the life of your entire transmission by driving it correctly. Not sure how to do that... Find out right now with no obligation. 305-588-0874

Porsche 917 Long Tail line drawing shows top and side views of this race car's internal components

917 Long Tail

Click drawing to enlarge

miami porsche 3.0 litre engine with 2 broken studs marked with yellow
3.0 itre miami porsche engine rebuilt by gp autowerks with new ARP head studs

Top: Broken head studs are marked in yellow. What comes of this is the once precise flatness of head surfaces and cylinder faces being beat out of spec by combustion cycles. Bottom: ARP studs have replaced all old stock studs. An excellent upgrade as these will last indefinitely. They are expensive but worth it. It is always a customer's call regarding what parts a rebuild iinclues. GP Advice ahead of a rebuild is always available concerning part options.

Engine rebuilds typically begin with a leak-down test. This provides insight to what can be expected during rebuild in regards to valve and piston ring sealing integrity. Leak-down results seen above indicate cylinder #4 being best and #6 the worst. Differences seen here confirm this engine's lacking performance.

Leakdown test of miami porsche engine results show unacceptable delta between #4 and #6 cylinders
Anchor 1

One skilled person is capable of correctly & safely handling a Porsche engine during the entire rebuild process provided the equipment required is on hand. Here, a 3.2 engine rebuild has just been completed. GP is preparing to connect the engine and its' matching transmission prior to returning them as a unit to the Porsche on the lift.

Click photos to enlarge


Porsche Rebuild Parts - Aftermarket Parts


By default, genuine Porsche or OEM parts (when available) are used for repairs & rebuilds. If an owner prefers aftermarket, that's an option and accomplished when possible. If you have any question as to a comparison between a genuine Porsche part and the matching aftermarket part, ask. Discussion will reveal pros & cons so you can make an intelligent, informed decision. Or, leave it to GP to decide if you prefer. As a Master Porsche Mechanic, GP serves as a steward of your budget and guardian for optimal quality always. 

        Where classic Porsches are concerned, it's an increasing challenge to find certain parts. Good news is there are resources across the nation and abroad so tough-to-find parts... can be found. Experience knows where to look for you.


Porsche Records / Documentation


Keeping accurate Porsche service & repair records substantiates the care given a car. Such records also provide very valuable reference when planning an engine / transmission rebuild. Working on any area of your car for that matter. Benefit being the ability to potentially find documented answers to questions that may arise before or while work is in progress. In short, the recommendation is: be a Porsche service record keeper if you aren't already. 

Porsche Racing


GP / George Perdomo has GT and GTP class racing experience if you're interested. From the simplest of add-ons or refinements to your track Porsche, to extensive build outs for your class, you're in experienced, winning race hands here. 

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Following Porsche's Le Mans victory in 1970 and '71, the company redirected their racing efforts to North America and the CAN AM series. Teaming up with the Roger Penske organization, the 917/10 was created with magneseum tubular frame weighing just 100 lbs and a 5 liter turbocharged 12 cylinder engine producing 1,000 hp. In 1972, the 917 was the most powerful racing car in history. On the track, it brought McLaren's CAN AM leadership to a decissive end. The successor to the 917/10 was the 917/30 (the engine increased to 5.4 liters.) In August of 1975, Porsche took the 917/30 to the Talladega race track in an attempt to establish a closed course speed record. With Mark Donahue in the seat, they did so on August 9, 1975 with an average speed of 221.12 miles per hour---a record that endured for 15 years... eventually broken by an Indy car. 

Rebuilt miami Porsche six cylinder engine is mounted to engine stand with cylinder heads, valve covers, chain tensioner covers, and cam oil feed lines installed
Two Porsche engine valve covers showing difference between degreased surface and degreased plus media blasting

Air cooled Porsche engine thermal performance depends in large part on how clean the engine's exterior surface is. The cleaner the better as this allows heat to more readily escape the engine. It's up to my customer to decide what investment is made in "clean." Engine above has been degreased then media blasted. The alternative is to degrease only. Look at the difference below. (Click photo to enlarge.)


The quintesential Porsche race car of the early 1970's was the 917 series. So dominating was the 917 that racing rules were specifically altered to put an end to Porsche's unrelenting track dominance.

Porsche Engine Rebuild



Rebuilding serves to extract maximum power from your Porsche engine. Rebuilding exactly as Porsche's engineers requires great precision together with an intricate knowledge of: correct disassembly, cleaning, inspection, measuring, determining what can be machined and intelligently recycled and what must be replaced with new, pure assembly, and final run-in. Combined and done accurately, this all sets the stage for your engine's new, powerful, and long life ahead. All this is provided you with the smart investment made in a GP Porsche engine rebuild. Explore what 30+ years of street & track Porsche engine rebuilding means to you. Speak with GP about the goals you have in mind for your engine & car. And the budget you have to work with. 305-588-0874.

Comparrison of miami Porsche 3.3 litre engine before and after rebuild with restoration done by GP AutoWerks

Porsche arrived at shop with engine running with a noticeable knock. Diagnosis quickly determines an internal issue. After progressive dismantling with inspections done along the way, the problem is found: Whomever had previously worked on this engine failed to install #4 rocker shaft correctly. This led to the rocker binding... then that rocker's piston and valve making contact. The crankcase is open here to make an internal inspection. While the problem is the rocker shaft, since there was piston-to-valve contact, everything that may have been damaged must be inspected so any & all issues are found and accurate repairs are made in one session---there is no exception to comprehensively inspecting for any & all possible collateral damage. In this case, the damaged parts---valve, guide, rocker, rocker shaft, and piston---were replaced for #4 cylinder. Below, the engine has been reassembled and is about to be reinstalled. 

miami porsche crankshaft is being inspected while it sits in engine case at gp autowerks

Click photos to enlarge

PROFILE OF A PORSCHE ENGINE REBUILD - After removing the engine from its chassis, inspections are done before cleaning. This allows any potentially valuable engine issue evidence to be found prior to it being erased forever by cleaning. Compression and leak down tests may be performed. As disassembly proceeds, inspection of parts both visually and with measuring tools is made. Notes are made for future reference. Any anomalies found along the way are photo-recorded and sent to the owner immediately. Parts cleaning follows. More inspections are made and more measurements taken. Next comes an evaluation of what parts need replacing and what parts can be machined for reuse. The owner is involved in this phase as various decisions need making---decisions relative to: OEM or aftermarket parts use; what additional attention may be applied the engine given accessibility; and possible performance modifications if not already discussed. New parts and machined parts that arrive are inspected for correctness to the order, then for dimensions and quality. Unless agreed to otherwise at the outset, rebuild measurements are according to precise Porsche factory specifications. Likewise, the rebuild process is also done according to Porsche factory standards (unless agreed to otherwise.) Timing of inter-related parts is a critical Master Mechanic function. Attending this properly results in an engine performing to its' engineered optimal/maximum level. Upon the engine's completion, it's then reinstalled. A specific break in procedure  follows. Various inspections. Oil & filter change. Then tuning if needed, testing, perhaps a final tuning and testing. There are NO short cuts to precision engine rebuilds. No distractions are tolerated during critical stages. If your looking for Power + Durability, GP precision is what you what. 

       Looking for more than factory stock in your engine? GP can provide the expertise to make your engine rebuild better than what factory specs call for. Exactly what this entails depends on the goals you have in mind. In this regard, GP can help you understand & evaluate your options. Ultimately, you'll have a clear picture of what can be done to your engine during a rebuild, what the added investment is, and what the added performance outcome will be. Consultations are comp.




Endurance of your Porsche engine & transmission requires both areas receiving proper lubrication. This means:

  • Maintaining correct levels

  • Changing lubricants including filters on a scheduled basis

  • Using the correct lubricants for your particular engine & transmission

  • Adding oil radiator(s) for high performance driving

  • Maintaining clean oil radiators

  • Preventing / repairing oil leaks

The more frequently engine and transmission oil (and filter) is changed, the longer your engine and transmission will endure prior to needing major attention. 


Engine Tuning


Earlier model Porsches require manual tuning adjustments on occasion. Later model Porsches are computer controlled. GP is scanner savvy. In a nutshell, you're covered from nuts & bolts to digital bits & bytes when it comes to engine tuning. 


Click photos to enlarge

Inside of miami porsche transmission looking at syncros, dog teeth, and gears

Above: Gears, dog teeth, shift rods, forks, sleeves and bearings are being inspected in this transmission rebuild. If any anomaly is found, it's photo-recorded and immediately text-sent to the owner. Comments on what is found is always provided an owner unless that owner has a standing order for GP to progress with repairs as found status calls for.

Right: New flywheel is installed with pilot bearing and new bolts---new bolts are standard procedure as old bolts, once removed, are stretched from the initial torquing and so will not correctly stretch again. Old "doughnut-style clutch disk compared to new spring-style. Doughnuts tended to explode making a mess of components in a transmission's bell housing. 

george perdomo attending porsche transmission in his miami porsche shop
George Perdomo pulling Porsche engine on its stand inside his miami porsche shop
George Perdomo, founder & owner of GP AutoWerks, next to miami Porsche traga on car lift with car's engine in foreground

Transmission rebuild completed, the trans is connected to the engine with proper torque settings applied to fasteners. New oil is installed. Flanges on the drive couplings are cleaned and ready to receive the drive shafts/CVs with new gaskets.

New Porsche flywheel, flywheel bolts, and pilot bearing just installed on miami porsche
"Doughnut" clutch disk compared to spring clutch disk in miami porsche shop of gp autowerks


Profile of 1982 miami Porsche 3.0 Litre engine after gp autowerks rebuild
Back end of gp autowerks rebuilt 1982 miami Posche engine
porsche engine showing half blasted clean and half dirty in miami porsche shop of gp autowerks
comparison of dirty and clean porsche engine heads in miami porsche shop of gp autowerks
Clean Porsche crankshaft standing on end with connecting rods attached in miami porsche shop of gp autowerks
Clean Porsche connecting rod assembly laid out in pieces includng rod top, bottom cap, two nuts and rod bolts, and bearings in miami porsche shop of gp autowerks
clean porsche engine pistons sit on table next to their matching cylinders in miami porsche shop of gp autowerks

Mating surface on a Porsche engine/transmission rebuild must be very clean and flat. If not, the gasket applied is given the opportunity to leak. Eventually, it will.

miami porsche engine left side chain tensioner housing with chain, tensioner, and chain ramps installed
miami porsche engine right side chain tensioner housing with chain, tensioner, and chain ramps installed



With GP AutoWerks, your engine's rebuild, start-to-finish, is in the hands of one highly experienced Porsche technician. Whatever information you want, there's NO middleman to deal with here. A simple call and you're speaking with the person who genuinely knows your engine inside & out... "GP."

Standards & Beyond


Porsche factory specs, tolerances, torques, and OEM parts are meticulously applied to your engine rebuild as standard procedure. Should you be interested in going beyond factory engineered standards, or want more economy from aftermarket parts, consider what you'd like to accomplish. With any Porsche engine, more in any direction is possible. More operating simplicity from upgrades. More power from adding cc's, turbos or supercharging. More durability from going to extreme balancing of components. Bear in mind as engine performance increases, handling capability should as well. With years of GT & GTP racing experience, GP offers you the qualifications to intelligently guide you through the maze of options elaborating on the outcomes you can anticipate. This, regarding a consolidated engine-chassis performance mod for street and/or competition.

Same engine before and after GP AutoWerks rebuild. With most surfaces blasted and refinished with appropriate engine-area coatings (or left bare to match Porsche stock finishing) this engine rebuild is "with restoration"---an owner's option made at the outset of a rebuild. According to customer's goal in this case, work was accomplished to match a stock engine (for the period) as close as possible. While impressive from the outsides, when installed, this engine will offer the owner the same performance as when the engine was new.


Porsche® Revive the Passion -
Open heart Surgery

Video presentation courtesy of Porsche N.A. Permission on file.

GP AutoWerks:


7011 S.W. 46th Street

Miami, FL 33155


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Miami Porsche Service, Repair & Rebuild Shop

GP AutoWerks

Miami's Master Porsche Mechanic

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Disclaimer: Porsche, the Porsche crest, and Porsche car model numbers & names are under licensed use by Porsche Cars North America, Inc. (PCNA) from the owner Dr. Ing. h.c. F. Porsche Aktiengesellschaft, Porsche AG ("Porsche.") The PCA logo is the property of the "Porsche Club of America." The "Porsche Museum" name is the property of Porsche. No association or affiliation with Porsche, PCNA, The Porsche Museum, or PCA is intended or implied by GP AutoWerks, an independent Miami-based Porsche service, repair, rebuild & PPI shop that offers comprehensive Master Porsche mechanical care for classic & contemporary Porsche sports cars---356 through 991, 928, 944, Boxster, and Cayman. Editorial content is provided in this website including both text & photos. Editorial photos are presented with a box rule around them. Any use of the word "safe" or "safety" in this website holds a car's owner and/or driver ultimately responsible for all matters concerning the standing, driven, or otherwise in use vehicle. Credits: Videos are Porsche productions presented for educational & entertainment purposes only. Permission for presentation is on file. Outlined photos are editorial content. Photos of Miami Porsche service, repair, rebuilding and PPI depict the property of GP AutoWerks' customers. All such photos are used with the expressed permission of GP AutoWerks' customers whose permission is into perpetuity. Photography, unless credited otherwise, is © 2015-2020 Karl Hansen. All rights reserved. Photo captions are provided to reflect photo content and credits appear where due.

Website structure © 2015-2022 GP AutoWerks. All website content but for credited photos is © 2015-2022 Karl Hansen. All rights reserved.

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Miami Porsche Service, Repair, Rebuild  |  GP AutoWerks

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mobile device header photo for rebuild page: porsche engine during gp autowerks rebuild with pistons exposed


Power + durability.

Only from precision.

Master Porsche engine rebuilding. All work done to precise Porsche factory specs. Want more power, cc's, have a smoother and even more durable engine than stock specs call for? Discuss your rebuild options with GP. Have 30+ years of performance Porsche engine rebuilding experience on your side. Power + durability from precision---the lasting value had with a GP Porsche engine rebuild.


1979 miami porsche turbo engine gp rebuilt with restoration

To know more about the potential in your Porsche engine from a GP rebuild, please call. Or, look into the desktop site. There, you'll find much more rebuild info along with many captioned GP photos taken while work is in progress. Curious Porsche facts also await you. Visit:

PORSCHE Service / Repair / Rebuild / PPI


miami porsche engine on gp autowerks engine stand during engine rebuild
comparrison of new and old porsche transmission dog teeth for miami porsche 911
dial gauge showing precise porsche cam timing as set by gp autowerks in miami
miami porsche's connecting rods laid neatly on table
miami porsche transmission gears during rebuild
gp autowerks rebuilt 40-year old miami porsche engine now runs as if new
Porsche Logo on Porsche Service Repair P
Porsche Club of America Logo on Porsche

Porsche, the Porsche crest and Porsche model names are the property of Dr. Ing. h.c. F. Porsche Aktiengesellschaft, Porsche AG ("Porsche") and is under licensed use by Porsche Cars North America, PCNA. The PCA logo is the property of the Porsche Club of America. No affiliation with either Porsche or the Porsche Club of America is intended or implied by GP AutoWerks, an independent Porsche service, repair, rebuild & PPI shop located in Miami, FL., U.S.A. Any use of the word "safe" or "safety" in this mobile site holds a car's owner and/or driver ultimately responsible for all matters concerning the operational safety of the car being driven or otherwise used. Please see desktop website for full disclaimer and credits.


Website structure © 2015-2022 GP AutoWerks. Website content unless credited otherwise is © 2015-2022 Karl Hansen. All rights reserved.

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