In my earlier post I discussed tackling the under-plenum updates. Here I cover the drivetrain updates which turned out to be more significant and challenging in unexpected ways. Early on Sunday we were back at Jim’s for the drive-train work. Again the WAZOO guys were in full attendance. Darrin was back too to help the transmission pull – this after working all night at his “day’ job.
Jobs for this day included:
- C-beam and Drive-shaft removal
- Transmission Removal
- Install Fidanza Lightweight Flywheel
- New Clutch/Pressure Plate and Throwout Bearing
- Rear Brake replacement
- C-Beam Plates install
- Hurst Short Shifter install
Darrin and Jim handled the transmission work. The ZF transmission is a heavy beast and removal was accompanied by much cursing. Darrin described it as being like a 3D jigsaw puzzle and the rotations needed to maneuver the trans through the various attachments and exhaust certainly lived up to that.
One thing we “discovered” is that my Borla exhaust system isn’t stock. Usually they are equipped with a resonator box similar to the stock exhaust, but mine had been customized with just a pair of straight through pipes. This also has the effect of removing the well-known Borla restriction at the end of the resonator. I’ve always liked the noise of the Dragon and now I knew why. It sounds very different from others you hear, throatier but not (in my opinion) excessively loud or uncomfortable to drive.
After installing the Fidanza and clutch it was time to put the transmission back and this was where we struck problems. The input shaft would simply not go back into the clutch and no amount of swearing would make it fit. After some lengthy discussion it was decided that the throwout bearing was likely the cause. The early transmissions have a thicker input shaft than later ones and this requires a different bearing.
So the transmission was removed again. The swearing got louder. I felt even more embarrassed at causing these helpful people so much work. We contacted the clutch supplier by email and he informed us that there was a plastic liner in the bearing that needed removing for installation on the early model years. Jim didn’t like the idea of trying this and, as he had an early bearing in his supplies (as you do!), we switched it for the right one.
While this was happening Darrin took the opportunity to explain his obsessive-compulsive disorder regarding shirts. He has three different sets of shirts, C4, C6 and general. When he drives his C4 he can only wear a C4 or a general shirt. When driving his C6 it must be a C6 or a general shirt. And yes, he has at times gone home, switched cars and shirts to be matching
After getting the transmission back in the car the drive-shaft was re-installed, along with the C-Beam and C-Beam plates. We also replaced the rear universal joint as the original one fell apart when we pulled the drive-shaft and again, magician Jim had a new one “in stock”. This becomes more significant as you’ll see later.
The brakes were next. After dis-assembly we found some corrosion and gunk build up on the pins that the two-sides float on. This explained how the rear rotor had worn out on the inside first – the caliper hadn’t been floating correctly. Cleaned up and reassembled (both cars and drivers), we were ready for another test drive.
The change was quite amazing. The Fidanza removes around 16lbs (7kg) of rotating mass, allowing the engine to wind up much quicker than the standard unit. Again the Dragon was singing, but with even more gusto! I also noticed a slight extra gear-type noise. The Fidanza unit is known to introduce more noise and it was so slight that it was a more than reasonable trade-off for the extra acceleration.
We were up early on Wednesday for the journey to Bowling Green. The plan was to meet up with a number of WAZOO guys and make our way over in time for the traditional Wednesday “cocktails” courtesy of the ZR-1 Registry. There were six of us traveling and it felt great. What do you call a group of ZR-1s motoring together? A flock? Herd? Pack? My best thought was a “growl” – and that’s what we sure had – a growl of ZR-1s heading west. Two hours into the drive, I heard a strange high-frequency buzz – nothing like anything I’d heard before.
I immediately started to slow down and pull over to the side of the road. As soon as I did a seeming explosion sounded, followed by a a deathly thunk-clunk-thunk-clunk as I pulled off the highway. Whatever the cause, I knew it was serious.
David and Garth pulled over with me and we tried to determine what was wrong. I had no drive at all, just the thunk-clunk. Looking under the car the best we could, it looked like the rear U-joint had given way. This wasn’t anything we could fix at the side of the road, that was for sure.
I’m not sure if I’ve felt lower than at that moment.
The others had carried on but Jim turned around and came back to help. After a long miserable wait (not too long really, it just felt it!) the car was towed to a local shop that the tow truck operator thought might be able to help. Unfortunately when we looked underneath, the entire drive shaft was torn up and unusable. The shop said they could get one, but it would take a couple of days.
The nearest place of immediate assistance was Jim’s emporium, back where we’d started. He volunteered to go back with me so we could get things fixed. On the way back he called up Darrin and a few of the other WAZOOs who hadn’t been headed to the Corvette Museum and they were waiting for us at his shop when we arrived.
Darrin and Jim have patience rivaling that of saints, as they raised the car to work on my driveline for the third time in the space of a few days. The aluminum straps that hold in the U-Joint were history and there was nothing for it but to install a new shaft (which Jim just happened to have in his supplies!).
Incredibly we were back on the road in around three hours! You couldn’t get that kind of service anywhere and quite honestly I was amazed. What’s more, when we did a test drive that extra “gear rattle” I had noticed earlier had gone. It’s hard to say exactly after the fact what happened as there wasn’t much left of the U-joint. I believe that it was faulty from new (a new part isn’t necessarily a good part).
I’m happy t say that the journey to Bowling Green this time was completely without incident; what’s more the extra “geary” noise was gone. The Dragon was singing as sweet as always and all was right with the world.