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All of my knowledge for the 928 clutches is just from what I've read around here. Seemed that aside from the install/adjusting, the dual disk is the better of the two from what I read. It's what came with all the stuff I bought for the swap anyway.
don't know the differences in use , but my "race" shop advised me (in 2008 ) to use the single disc clutch… so that is what i have now for the rally 928 build.
I did a test in mounting it and all went "easy"....
Originally Posted by captainOCD
All of my knowledge for the 928 clutches is just from what I've read around here. Seemed that aside from the install/adjusting, the dual disk is the better of the two from what I read. It's what came with all the stuff I bought for the swap anyway.
Sue and I have something like 230K miles street driving in our S4 and GT, with a variety of clutches: Stock single-disc in the S4 from new for 60K miles, then a dual-disc for another 30K. The GT had a single-disc with a heavier pressure-place when we bought it (140K), worked fine but was a knee-buster, swapped for a dual-disc and then Greg's Carbon clutch- now at 280K. And we have a GTS, a stock single-disc but with a heavier pressure plate than the S4.
Here's my take on all this:
The S4 single-disc is the best option up to stock S4 torque (300-ish ft-lbs), will be a firm pedal but a fairly short travel-- i.e. only need to push it halfway down for a clean shift.
But the stock single-plate will not reliably hold a mildly modified engine (e.g. headers, tuning) without a heavier pressure plate-- which was how our GT was set up when we acquired it from Louie (heavier single-plate, headers, tuned).
For more torque you either need a single-plate with a heavier PP, or a stock dual-disc. The trade-off is lighter pedal but more travel for the dual-disc, compared to single-disc. Some folks like shorter travel with more pressure, old folks like us tend to favor lighter pedals. And the dual-disc is certainly more "fiddly". And for more torque, a dual-disc with a heavier PP.
Beyond that you get into ratified atmosphere. I believe that Louie's 600hp monster is surviving on a stock single-place with a "Hulk" pressure-plate. Spec stage-3 racing clutches also work well but are an absolute bitch do drive on the street. Greg's carbon clutch worked well for us, but also bitchy-- very short travel and a heavy pedal, and didn't survive his build of our GT motor.
thanks Jim for telling your experience.
If this is common, one could mount a smaller bore master cilinder for a single-disc , lighter pedal but more travel…….
Tonight I got the new mounts on the vibration damper, and got it and the bearings in the torque tube.
The bearings were able to be tapped it with boards and a hammer which wasn't too bad. The vibration damper had to be pulled in with allthread though, because surprise, it damps vibrations from hammers. I didn't use ky jelly as many seem to use for lubricating the bearings, instead I used elmers water soluble stick glue that I already had on hand (used for adhering prints to 3d printer beds). Similar to the ky, while fresh it provides lubrication, but as it dries will help adhere the parts some (just a side effect as far as I'm concerned), and again like the ky, should dissolve in water in the future.
The tape lines mark where the bearing and damper are in the tube. Trans end is on left, engine on right. The bearing closest to the trans, the damper, and the center bearing lines are the leading edge of each from the trans end. The engine side bearing is from the engine side.
The new mounts from 928intl seemed really nice. Despite the crusty initial appearance of the damper, the old mounts came off pretty easy. The new ones took a lot of effort to get on, so I think they'll hold onto the damper well.
It was getting late and I was too worn out from knocking in bearings and spending well over an hour pulling the vibration damper in, so I didn't get the driveshaft in tonight. Hopefully friday I can get that in and maybe get it attached the the transmission.
I finally got around to cutting out the tunnel for the shifter to come through (leather was already scuffed like that).
Also got the driveshaft in the torque tube. Pulling that thing out before was a complete pain. Putting it in cleaned off, with new sleeves, and with some stick glue to lubricate, it slid right in by hand. It doesn't feel loose or notchy like it with the ruined bearings before.
Got the torque tube bolted to the trans. Didn't torque the driveshaft clamp yet, but it and the bolt are in place until it's all installed. The trans seems to shift fine into all gears and the reverse lockout seems to work fine too.
Sidenote, the torque tube to trans bolts are at least size smaller in diameter for the 5 speed than the auto ones.
Tomorrow the plan is to get all the old fluid out of the trans and get fresh stuff in, then get it hung in the car and get the suspension lifted up afterwards.
Between yesterday and today I have the manual trans installed, rear end all put back together (wheels on and everything), and the clutch bled and seemingly working. I still have to put the exhaust back on (was getting late and I wanted to go get new bolts for the manifold to downpipe connection) and a bit of wiring to figure out (speed sensor hooked up, probably some messing around with what used to connect to the neutral safety switch, unless it's as simple as replacing the reverse light relay with the jumper).
Drained all the old fluid (tilted it back to make sure all the old stuff came out too). The fluid that came out didn't look like it had any chunks of metal and didn't look like it was very shimmery at all. I was making sure I got every last drop out of those new bottles.
Trans rolled under the car.
And getting lifted into place. I decided it was easier to just do the trans separately from the crossmember. Less going on at once, and easier to maneuver into place.
Then got the crossmember up into place.
I did manage to get the coilovers back into place then used the floor jack under the control arms to compress them enough to get the top nut back on so I didn't have to mess with spring compressors.
Donor car didn't have the shift boot or ****, so I just have the rubber seal under the boot and a **** I printed to fit the shift lever for now. Not pretty, but it'll work for now.
With the clutch engaged (slave not even attached) I moved the intermediate plate H adjusters all the way back towards the pressure plate. After getting the clutch bled (power bleeder wouldn't do it, but pulling the slave off and depressing it fully, holding for 30 seconds or so, then releasing and repeating got it bled) I fitted the bellhousing with the (crude) hole in it to watch the clutch operate. I was expecting to have to do quite a bit of monkeying around with it based on what I saw others going through, but it seems to be disengaging both discs as normal without any further adjustment. With someone uptop working the pedal I got this video. I was able to turn the driveshaft (trans in neutral) with one finger while the clutch was disengaged, so it doesn't seem to be dragging.
I need to do some more digging to finalize the wiring to bypass the neutral safety switch, but the car lives. Drove it around the street and took it to the gas station to fill up. The spec clutch definitely engages more aggressively than I'm used to, but more throttle solves that. Car shifts nicely into all gears, no grinding. I do hear a very slight noise (not bad sounding, but still there) with the car sitting in neutral with the clutch engaged. Doesn't sound any louder than what I could hear under the car in the auto though, so I think it might just be normal.
The S4 single-disc is the best option up to stock S4 torque (300-ish ft-lbs), will be a firm pedal but a fairly short travel-- i.e. only need to push it halfway down for a clean shift.
But the stock single-plate will not reliably hold a mildly modified engine (e.g. headers, tuning) without a heavier pressure plate-- which was how our GT was set up when we acquired it from Louie (heavier single-plate, headers, tuned).
It has been my experience that the stock S4 clutch will hold just fine up to 500 rwhp.
However, once I installed Louie's x-pipe, its hp contribution was enough to push the clutch past its limit.
Also, Jean-Louis could not dyno past 550 rwhp due to the stock clutch slipping.
Both engines put out much more horsepower than a mildly modified NA engine, yet the stock S4 clutch held until 500+ rwhp, so it is more than capable for any stock displacement NA engine.
I usually don't have anything better to do with my spare time than work in the garage. I worked on it a little bit each night after work, but by far got most of the work done on the two weekends. The manual was on the ground saturday morning. It went in much smoother than getting the auto out did (apart from getting the clutch bled).
EDIT: this wiring only worked as long as the auto tach with the range indicator was present. With this removed for the 5 speed tach more wiring changes needed made at the back and the CE. https://rennlist.com/forums/928-foru...l#post16323562
To the wiring point, I don't know for sure without heavily scrutinizing the wiring diagram, but I suspect there might be some variance between the wiring in the CE for the reverse lights for the auto and manual. Putting the bridge in place of the reverse relay would immediately turn on the reverse lights. I ended up leaving the relay there and hooking the reverse light output from the manual to the wires from the connector to the auto, and it works as normal (including the R on the dash). The only modification I did at the CE panel was to pull the kickdown relay out.
For the speed sensor, I just depinned the connector from the auto and then manual, then put the manual speed sensor wires into the auto connector and plugged it into the car.
Getting the neutral safety switch bypassed was a bit of a pain to figure out though, mainly because I was convinced I was looking at something wrong when looking at the wiring diagram the first couple times. It shows the starter circuit being grounded through the kickdown solenoid wire on the auto (unless I really am lost there). Sure enough with that wire grounded it starts though.
The brown with yellow trace gets grounded, and the bottom two wires there go to the reverse switch.
I grounded the solenoid wire to the ground point at the trunk, and connected the reverse wires with spade terminals for now. I think I'm going to go back to the junkyard and see if I can get the connector that matches up to the manual's connector so I can transfer the pins back to it and have it look more factory.
Last edited by captainOCD; 12-31-2019 at 05:08 PM.
So the trans was in the car for a week before it came back out chasing a noise. I found a couple needle bearings between the input and mainshafts that were definitely in need of replacement, but apparently they weren't the source of the noise. Long story short the main input bearing seems to be making the noise, but it turns perfectly smoothly, there is not any slop in the input shaft when installed, and I needed the 928 out of the garage to get my Charger in for a trans job, so the 928 is back together with the input shaft bearing making a bit of noise. Can't hear it when driving anyway, so unless it starts changing I'm not worried too much about it for now. That thread: https://rennlist.com/forums/928-foru...is-normal.html
I did at least get a chance to replace the leaking input shaft seal and put all new gaskets and orings on the trans while it was out this time, so hopefully no more gear oil slicks left behind.
In the process of tracking that noise I did find that the torque tube bearings (which I just rebuilt with parts from garage9) were far too loose on the driveshaft to the point where there was even some slop in the driveshaft. There was also some evidence in the form of polished spots on the driveshaft, to suggest that the driveshaft was spinning in the sleeves. Some grease was also starting to escape the sealed bearings (that said made in china on them). With all of that in mind, I would strongly advise against buying those bearings and sleeves from garage9.
I ended up getting some new bearing assemblies from 928intl. They definitely seem much nicer than the original carriers (I managed to bend one of those old ones removing them this time).
This brass shuttle I made (while I was up in PA and had access to my lathe) worked much better for installing the new bearings than the piece of 2x4 I was using before.
So now the car is out and driving and the Charger is in the garage for its trans replacement (thanks to incompetence by the dealership when messing with it last year, but that's another rant). My wallet isn't having a good couple weeks.
08-27-2019, 11:09 PM
