ERA: How to R&R clutch from under car.

[speed220mph]

Rather than removing interior and tunnel from my ERA to repair a damaged ring gear, I decided to do the job from underneath. Problem is the driveshaft won't come out because of the c'member supporting the driveshaft hoop is welded into frame. This prevents the driveshaft from dropping down far enough to pull it out of the trans. No problem if you have a hacksaw. I cut out the center section of this small angle section, dropped rear of driveshaft, allowing trans. to slide back just far enough to clear bellhousing (after removing shifter wand). The bellhousing, clutch and flywheel was then accessible.

To restore strength to the c'member, I fabricated a 1-1/4x3/8 bar from 6061 T6 aluminum and drilled holes to match hoop bolts. After sliding everything back into place, I bolted my newly fabricated section into place and voila, done.

Only downside is material thickness doesn't allow full thread engagement with hoop bolts, so I'll replace bolts with longer ones. Another solution would be to use thinner material. To prevent galling aluminum, I used moly grease under nuts. Hard washers will be used with new hoop bolts.

Sorry about poor quality photo.

[RICK LAKE]

speed220mph Tom It's a nice way to get the trans out BUT you have weaken the chassic design. Alum is not as rigid as steel and bolts will not have the strenght of welds and solid channel. I'm sure for normal driving of a cobra it's OK but for the time you spent cutting the frame, 8 bolts and 10 screws and the tunnel is out. Cover the interior with a moving blankets so nothing stains or leaks on the interior. You can buy a plug for the back of the trans for 2.00$ at a swap meet or if you have a spare yoke to put in the tail housing. I would ask the engineer at ERA about this. My thoughts Tom Rick Lake

[speed220mph]

Rick: I know that you're saying, however considering this is a tension/compression-only member and I went up in section thickness by a minimum of five times, what I replaced the cut-out section with resulted in no loss of strength. Also, the area is at the crotch in the X in the frame, so the channel didn't do much more that support the driveshaft hoop. Good thinking, though. Dosen't hurt to question things.

Also, when you have unlimited access to lifts and trans jacks, it's a bunch easier to work from underneath . . . and it's faster.

By the way, I designed cars for a living, some of them race cars: Indy, IMSA, offroad, stock cars, ProStock, land-speed cars, even some production cars . . . too many to list. Even got close to the GT40. I have to admit, though. I've made mistakes, but please don't tell anyone. It's Ok if ERA uses my design.

[RACER X #99]

Tom,
Real nice idea.

While I don't have an ERA, my Contemporary used to have a solid 3" tube welded in for the trans mount. I got real tired of removing the engine to do trans work until I went the ERA route and made the tunnel removable. The later models from Contemporary started using a removable bolt in crossmember/trans mount and I was lucky unough to get one from Burtis just a day or two before he closed shop. I cut the old solid crossmember out and now trans removal is easy from under the car.I sure don't envy guys that have to pull the trans from inside the car.

Cranky

[RICK LAKE]

speed220mph Tom HI I am no engineer on stress and twisting of frames under load and G forces but knowing the ERA chassic design I would have thought that Bob P would have done this if it would not affect the car. Era cars are built like tanks. I was Stacy P hit on turn 13 of Mid Ohio at 120+ mph, the wall and tires, the car was destoried up to the cross member in the front. Rad and oil cooler gone Lift jack bent around but the chassic was still square and not twisted. The car was repaired and still races. I have both a 6 spd Nash and a G-Force 5 spd for racing, I can change the trans in 45 minutes by myself with few air tools. I did this for when I race at R&G. I have all the spare parts to repair the car except for a motor, this year that will be fixed too. I like the fact that I can pick the car up in 1 corner and the 2 tires lift the body doesn't crack. I don't do this often , don't get crazy Anyway it's a nice Idea. I'm going to pass. ERA updates there car all the time, they must have found something they didnot like about this. I know that the chassic is built in a jig. Maybe more work then they want to do. Cutting out the piece and beefing up the area. They are not worried about weight With an all Alum motor and 1/2 tank of gas, 2650 lbs is heavy, without me at 220lb. Have a good one Tom. Rick Lake

[a427sc]

I don't think there is any problem cutting the small cross piece that mounts the driveshaft hoop. As long as the replacement piece is strong enough to contain the flapping shaft, so be it. The driveshaft/trans were never designed to come out from the bottom, that's why it is solid and easier to build. I just pull the tunnel, it's easier. I found that the real problem in a clutch swap is not the transmission, it's the GD blowshield and all those bolts. I set up a pair of of long studs for the top trans mounting bolts and just slid it back, not pulling the throwout brg off the input shaft. I had modified the lower shield with a large removable plate to access the bolts. ZIP ZIP out and in, slide it forward and off you go. Underneith works too, if you have a lift.

D