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So I finally sorted my 993 hub and 964 ABS gear issues for the track car. Of course I found a thread on Pelican just after I was done that showed the same results.
The rings are pressed on. So I pressed off the 964 ring and the 993 ring and swapped the ring from the 964 to the 993 washer. The cast part number on the hub does not coincide with the PET. I am assuming it is a casting error as the part shows up as 96434106501 for all 993's vs the cast part number which reads 964341605 After doing this I decided I wasn't happy so I had a pair of perfectly good front axles from a 964 I decided to cut up. These come with the ring already in place and have the splines to lock everything in place and I am not sure but feel that I would get a better fit all around as the bolt to me seems a bit sloppy. The cut end is slightly heavier but not a concern as the weight is negligible and the fit precise.
Since nobody was willing to pay me $200 for the pair of perfect C4 front drive shafts I figured I would modify them to fit. Black ring is the 993 48 toothed ABS gear and the silver is the 964 45 toothed version. The 964 front shafts mate up the same as the 993's C2/C4 setup so it was easier than machining parts to fit the 964 bearing centered washer. This part # 20 is available from Porsche for about $450 per side.
So I have been keeping myself busy with small projects as the world seems to be opening up a little. Finished the front ABS gears and shafts cut from the C4 shafts. I should be able to install those this week depending on if I work on the C2 or track car. Slick top has been on hold this week.
The shafts were easy. The lathe wasn't working so I used a bandsaw to cut the parts. You can see the steel that holds the CV joint which is an extremely strong piece. Once the CV joint is removed and grease cleaned I cut the second unit. Coated the ends with a rust inhibiting paint.
So let's talk LSD's. I have been going back and forth about upgrading the track car LSD and moving the 993 LSD to the C2. I will be pulling that LSD next week to see what was done to it. AFAIK it should have GT plates in it although I don't know how many. The torque wrench showed over 45ft pounds before she broke free.
The 993 unit I believe is an OS Giken unit but not sure. The 993 unit is machined billet. The 964 unit is cast iron. Nowhere near as strong has only 2 friction plates one each for accel and decel and a 40/40 split. I will rebuild the unit either way but decided to open it up and see what condition it was in. So long as you don't damage the bearings or race there is no need to readjust the lash since it isn't messed with. At this time I am planning on keeping it but if not I will put it up for sale with so many other bits I no longer need.
So removal is quite easy and I don't think I need to go over it. There are threads already started for that. The unit as you can see is cast iron and. the shims are at just below the bearing but I will not need to mess with them. The large 12.9 bolts hold the ring from the ring and pinion to the LSD and are easily removed.
Once the ring is removed there are 2 bolts holding the LSD top pale to the housing. It is a bit of work separating the halves but not that difficult. There are 3 plates and a thrust washer one is a spring plate, a friction plate and end plate. Which I will be replacing. I then cleaned and inspected everything for cracks or damage.
The unit is in like new condition, really only the friction plate which is toast needs to be replaced but while I am in there I replace all wearable parts.
The rest is just cleaned and inspected. For those that don't know the ramps or in this case the 40% accel and 40% decel ramps are the V's in the parts shown. As the torque twists the assembly this rides up the rams pushing the parts one direction or another causing the spring plate to push against the friction plate locking the wheels. As rudimentary as I can get. If this were a turbo or CUP car LSD it would be a 20%/100% locking diff so the V grove would look far different.
^^ spring plate
Definitely put some heat into the friction plate and this unit has not been working since the car had 42k miles on it. So they don't last long but are a decent LSD for standard street driving just not very good for track use unless you don't mind rebuilding them every 20k miles or less but it isn't all that difficult to do.
BTW thought you GT3 muffler guys might be interested in seeing this. This is a GT3 Titanium muffler that blew apart. Seeing more and more of these.
I have no idea what any of this is that you are doing, but it sure is interesting to watch all these rings, and gears and teeth. You definitely have enviable skills!
I have no idea what any of this is that you are doing, but it sure is interesting to watch all these rings, and gears and teeth. You definitely have enviable skills!
Thanks Vince,
It is actually not as complicated as most make it out to be. What is becoming complicated is designing the exhaust and fabricating it and the Intercooler which has its own set of issues. Now we are getting into fluid dynamics and having proper flow without creating turbulence is not all that easy. Ironically I had to learn about a lot of this from my foundry days. Designing a gating system to feed critical parts took a lot of skill and math to figure out how to get the molten metal into the mold without creating any turbulence which could make the difference between a defect free Class 1 Grade A 100% inspected part or a run of the mill Class 4 Grade D no inspection required part. I mostly made Class 1 Grade A or B parts requiring close examination and tight criteria. Hopefully we get this right. I just enjoy working with my hands on anything. I spent some time building cabinets for my man cave kitchen this past weekend so as long as I can keep myself busy working with my hands all is good.
I am hoping the top to the C2 comes off today. If so I will have some pictures later.
So nothing new to report. My slick top is on hold. Pino had to finish a gorgeous 914-6 GT he had been working on and my track car had to come off the lift to drop a 997TT engine with a lot of leaks. I hope to start finishing the front suspension changes on the track car today and begin the slick top again tomorrow but we will see. Meanwhile I thought I would share the gorgeous paint job Pino did on this 914. I could only find a single imperfection which is so minor and this fresh out of the paint booth so it hasn't been touched yet. I bet he spent more time preparing the hood on this than most shops do on the entire car.
Meanwhile Happy 4th everyone. This will be the saddest 4th in years I usually hold a huge party and we watch the Macy's and other local fireworks from my backyard but not this year.
I hope everyone had a great 4th. It was the first time I had people over for a small social distancing gathering. Great to actually talk to people face to face so to speak. The Macy's fireworks was a huge disappointment but clearly visible through the myriad of fireworks being set off by neighbors. Must have been a few hundred people in the distance setting off some impressive displays and the weather was just perfect and clear.
So I am still in limbo with the C2 but still working on the track car. I won't be making my track event at the Glen as I have surgery scheduled again on the 21st which just messes everything up. I do plan to have this thing finished in the next month or so.
Finished the right side evo upright but need to install the inner evo ball joint tie rod end. I also need to make the brackets to hold the ABS wires and fuel lines.
On the C2 front I rebuilt the LSD. The plates arrived from sunset on the 4th. How the world has changed. Couldn't get anything delivered on the 4th a year ago and now seems nothing is sacred.
Interestingly the new plates on the left including the friction plate measure nearly identical with roughly .002" wear but it is enough to make the difference. The 964 220 coded 40/40 LSD is a 2 friction plate design unlike the 20/100 which appears to be a 4 friction plate design. I will have to pull the one from my turbo one day to see if I am correct in my assumptions. I don't see the need to upgrade this at this time not a great unit but worth having operational. I honestly feel I could have saved some coin and just replaced the friction plate but it wasn't that expensive to replace everything.
I like to photograph all my work and look it over before closing things up. It is amazing what the camera can sometimes pick up the eye doesn't. I guess when I switched out the seal on the input shaft the spring came loose and just hung on the shaft but when I looked I did not see it. I am clearly getting older and going blind. I guess too many years looking for the 2T hole on all the x-ray film I shot for parts I inspected. Glad I double checked it could have been a costly mistake.
I used a paint pen ( I need a new one) to mark the date and cars miles on the LSD so when it is rebuilt again I know what life I got out of it or the next person will know. I also did not replace the uber expensive 12.9 bolts that hold the ring to the pinion in place. I read one of Matt from Guard transmissions posts that he reuses the bolts but for reassurance loctite's them in place. This is a street car so I see no reason to not reuse something like this. Each bolt was marked upon torquing down. Was a bit of work in 96 degree humid conditions.
I will be able to mount the new LWF and clutch assembly and finish the engine and trans assembly now that this is out of the way.
I will close it up today. I also noticed how flat the seal had become and was beginning to weep a little. All these little bits add up.
Wow, nice to see the guts of these things. I was looking at my transmission to change the externally accessible seals and wondering what it must be like inside.
This is the simple side of the trans. It gets a bit more complicated as we get into the gears and guts. I have a full 6 speed trans in pieces and it is a bit daunting. One day I plan to put it back together but need a few expensive parts and currently have no need. It was more a spare for my track car in case I need one. I have a spare G50/03 and a G64 from my 90 C4. I remember Rob saying he wanted to do a transmission insanity thread one day. I might consider donating the G64 to the cause.
I removed the spring from the seal and replaced the shaft seals. It is far easier to do it with the guts removed. I saw your pipe removal tool approach which seemed to work nicely but opening the side isn't much work and apparently the expensive O ring for the cover plate was beginning to weep from shrinkage. It is a good time to do them all. You just need to be careful not to damage the bearings otherwise it is back to ground 0 and need to adjust the lash which is a PITA time consuming job.
Was hoping to get further but jumped in on helping my son do an air filter change on a 991.2. He is working at the shop I am doing my track build at. I am sorry but what an overly complicated car. The 964's are complicated enough but the work involved to access a simple air filter is just ridiculous. Makes all other water cooled Porsche's seem easy.
Anthony- what are the options for tie rods? evo vs 993rs= solid vs cushioned inners? Basically I see Tarrett OR 993rs options on the market- is that correct?
@Peteinjp The tarrett (not sure who actually makes them) RS/EVO style inner tie rods are the solid type copied from the factory RS/EVO design. The standard 993 inners are the larger rubber cushioned style. When I first built the car I had pinned the standard rubber style at 0 and 90 degrees. This helped stiffen the unit similar to the RS solid type. At the time the solid type were NLA from the factory and not yet made by Tarrett. Since I am switching the standard 993 aluminum uprights over to the C2 I decided to use all the bits and will be using the pinned rubber ones on the C2. The track car gets the solid ones. Very nicely made units hard to tell the ball end from the factory design. My only issue was that the threads that bolt into the steering rack were lathe cut and do not have the thinner shaft at the base of the tightening nut. I was planning on using the 964 spacers to prevent me from binding the steering against the inner wells at full lock and this is not a flush fit. Not a big deal the spacer will jam against the rack and it should be fine.
I purchased the 964 wide body version so I spent $70 I didn't need to. Initially I was going to use the 964 outer tie rod end so i would need them but I found my stock 993 outers which will do the same thing. So I will be putting those parts up for sale. I will try to take pictures of what I can and post later. They are installed already so I won't have side by side photos.
This is all I took but I thought I had taken more detailed photos. When these rotors are done I plan to add aluminum hats as well. Possibly spacer out the calipers and use a larger Dia rotor.
What is really scary is the parts here at just one corner represent more money than I spent on my first new car a 79 BMW 320i. I also spent the same as the BMW on the donor car this was built from. I wish I purchased a dozen more back then. 😂
The bolt above is just for holding the bearing together in case I needed to move the car. The picture below shows it replaced with the abs gear setup I made. Once the brakes are working I can use them to help me tighten the nut which I have to check but I believe it is 388 foot pounds or something like that.
Yeah- I hear ya- time vs cars.. My first car was BWM 2002 (weber side drafts- great first car!) That was and big expense up from the BMW r90 bike that was my first vehicle. Could never imagine the costs associated with hot rodding a 964 30 years later. But its probably best not to think about that too much- at least until my car is back together - Haha. I'm shooting for next spring cause I'm doing most of the work myself. Just had the body on the rack and it was straight as could be so that's a good start.
Anyway- I picked up a set of RS carriers last week for a great deal so- brakes, tierods etc all on the list ATM. I'm thinking of the lightest setup I can go with so 993 calipers with racing brake 304mm disks and 993 rear calipers/964 disks, 17" Fikse with 225/255 Advan a050. Not a full on track setup but good for a few open days at Suzuka every year. They have 45 minute slots.
Tarret is a bit more than new 993rs tierod/inners. On the fence there. Do the stock rubber inners really dampen feedback that much?
@Peteinjp
What is really scary is the parts here at just one corner represent more money than I spent on my first new car a 79 BMW 320i. I also spent the same as the BMW on the donor car this was built from. I wish I purchased a dozen more back then. 😂
Originally Posted by Peteinjp
Anyway- I picked up a set of RS carriers last week for a great deal so- brakes, tierods etc all on the list ATM. I'm thinking of the lightest setup I can go with so 993 calipers with racing brake 304mm disks and 993 rear calipers/964 disks, 17" Fikse with 225/255 Advan a050. Not a full on track setup but good for a few open days at Suzuka every year. They have 45 minute slots.
Tarret is a bit more than new 993rs tierod/inners. On the fence there. Do the stock rubber inners really dampen feedback that much?
It really is unbelievable the cost of redoing the front suspension on these! Nice work so far... it's looking well sorted. I've been piecing the parts together over the last year just due to the total cost of it all. I did end up spending the extra dollar on BBI uprights, but still... dang RS tie rods are maddening for something so simple. The tie rods and rotors are the last things I need. I picked up RSR inners thinking I could just buy 993 RS outers but of course it's not that simple since you have to buy both the inner and outer and end up spending close to a grand on tie rods, unbelievable! I eventually caved, ordered, and they came back out of stock. This was 3 months ago... and I still haven't recovered from the defeat!
I'm now thinking of bailing on the Porsche tie rods. I've been able to spec out some inners from a BMW 3 series and outers from a Nissan 300zx for $100-200. It's more of a this winter project though. I know it sounds like a sin, but anyone else look into alternatives?
^^ that is interesting. I like the BBI parts but picked up a new set of EVO/RS uprights from Porsche for under $1000 a year back when they were re-released. Kicking myself for not buying the stock out. I hear only one side is in stock and asking $1500 for it now. So typical Porsche.
I have come to the point on this build I want it to be the best of what is out there which makes sense without throwing money at it unnecessarily. Looking forward to the 3WC MCS suspension over the antiquated H&R Supercup I was using. This car should be as tight as any 964 but definitely not a street car.
One of the issues with going from cast iron to aluminum is aluminum transmits more vibration and will be felt. I am not concerned with it for the track and will see how tha standard 993 uprights do on my C2 for the street. As mentioned I had pinned the stock rubber units so I have no comparison and can't say how much pinning does compared to the RS/EVo units. I pinned them at 0 and 90 degrees staggered. You need to do it low on the unit as the inner metal vs rubber only extends up so far. You can see what I did. I also double roll pinned them one larger dia and a smaller dia inside that so as not to come loose. The entire metal area is full of rubber but far stiffer than the 964 design.
Here are the EVO/RS units installed.
The ABS ring gear setup I made installed. There is no bolt head so I will need to apply the brakes to torque these down.
Nothing new to add other than we are ready to finally cut the top off. A bit of delays getting there. Unfortunately I am on self quarantine til Tuesday and may be awhile before I am back up and running. Pino will work on it while I am through all of this. Finally got through to the carpet people. Headliner is on the way but they are telling me the carpet set won't be ready till September. Bummer. Also there may be some movement on the cobalt blue America Roadster. They ordered parts for the car and began the conversion back to stock which I am a bit upset about but we will see what they come back to me on price and if it works I will be starting yet another project. If it happens I am considering the narrow body rear trailing arms and my RSR speedlines on it with the spare set of big reds I have.
06-25-2020, 10:54 AM
