Corvette project car

[280Z Turbo]

The old Borg Warner T10 is out. I need to check codes on this thing, but it has a cast iron housing with an aluminum tailshaft. I'm told the '63 corvettes were supposed to have all aluminum cases.

There was a lot of metal debris in the oil. The gears look fine, but I'm sure the slides are toast.



Broken spring on the clutch fork. Does this mean I have to replace the entire fork?

[280Z Turbo]

Well, the transmission was built in 1959 so it's from a 1960 Chevrolet passenger car or Corvette. What a mishmash.

[280Z Turbo]

Fancy new wheels all mounted:



Flywheel has some cracks and hot spots in it. Should I resurface this one or use the lighter aftermarket one from Autozone? The new one feels about 10 lbs lighter which might make it a PITA to drive in traffic. I'm not a big advocate of lighter flywheels on street cars.




The cast iron bellhousing is incorrect. The car is supposed to have an aluminum one.

If you will recall, the PO put washers between the flywheel and pressure plate which probably brought the fingers out more since the clamp force was less. We removed the washers and bolted the PP back up, but the throwout bearing flopped around without depressing the fingers.

The fork looks correct, the clutch linkage looks correct, the clutch pivot looks correct, throwout bearing is the same as the new one, etc. The only things we know are wrong for a '63 are the bellhousing and old pressure plate. Not sure if the bellhousing or clutch are different enough to cause the issue we were seeing though.

[280Z Turbo]

I found a picture of this bellhousing with the proper clutch fork. It looks different than the one we have. I noticed that the fork kind of got hung up at a certain point in the travel, like the bellhousing wouldn't allow full movement, so I think this may cure it. The fact that dumbass PO tried to cure the issue with washers between the flywheel and PP is a testament to his stupidity.

http://www.ebay.com/itm/1956-62-Corvette-CAST-IRON-Bellhousing-3733365-F187-X-4-speed-bell-58-2x4-FI-/131221165486?pt=Motors_Car_Truck_Parts_Accessories&hash=item1e8d6415ae&vxp=mtr

[280Z Turbo]

Well, pulled apart the trans and everything looks great. All parts are present, synchros look good, dog teeth are fine, slides are fine, gears are fine, all parts present. All I can figure is that the issue is a bad adjustment on the shifter.

[FlatBlackCaddy]

That's like the first thing you took apart that wasn't junk.

[280Z Turbo]

Started working on the rear suspension. It had "helper" springs installed because the PO didn't want to fix the sagging rear spring:



Got the rear spring loose. Spoiled the threads on the mounts by doing the ol' impact unscrew-thunk method. Shoulda used a jack to support the spring.



Got the shock loose by cutting the piston rod then cutting the upper mount bolt. The bolt was seized inside the bushing.



New and old bellhousing. The correct bellhousing is WAY lighter than the old cast iron one.



Cracked front cover for the trans. Thinking we should replace:

[280Z Turbo]

The only thing I can come up with for what's causing it to pop out of 2nd gear is the slider that connects the hub to the gear.

They have specially cut torque lock sliders that are supposed to prevent this. At $31 a piece, I might as well go for it.

[280Z Turbo]

Ordered the sliders and the bearing cover.

I hear a lot of talk about GL-4 vs GL-5 gear oil. Some people say new style GL-5 gear oils are corrosive to brass synchros in old transmissions. I always ran GL-4 (Redline MT-90) in the Z. I bought some of this for the Vette's old T-10:

http://www.summitracing.com/parts/bpo-023-7729/overview/

[FlatBlackCaddy]

I have a bunch of MT-90, for the very reason you stated. When in doubt I'd put the brass friendly stuff in anything.

[280Z Turbo]

Pulled out the differential. Turns out it's a 4.11 posi, which is pretty good

The reason why I pulled the diff out:


Old cover vs. new. New one is reinforced at the mounting area for the transverse leaf spring.


Crossmember cleaned up, but it's still rusty inside. I want to have it acid dipped. Anybody know where I could look for this service?

[hotrodalex]

I know of a place in Cincy but that won't help you much. Use teh googles.

And if 4.11 posi is "pretty good", what is " excellent"?

[280Z Turbo]

I know of a place in Cincy but that won't help you much. Use teh googles.

And if 4.11 posi is "pretty good", what is " excellent"?

Probably a 3.70. I'm glad it's not a 4.56, since that would be way too rowdy for highway use.

I calculated it out to be 3000 rpm at 58 mph and 3900 rpm at 75 mph. Would be at 105 mph at 5500 rpm. 105 is fast enough in a car shaped like an airplane wing.

[hotrodalex]

Yeah I'd need an overdrive to put 4.11s in. I like my 3000 rpm @ 70.

[280Z Turbo]

So would I, but other than NVH, what does it matter?

MPG and engine wear are a non issue.

[Soup DeVille]

There's a place called Rustbusters on ten mile east of John R in Madison Heights that acid dips parts like that. There's one on 8 Mile and Wyoming too, but I can't recall the name of it.

Don't know of any on the west side over there though, sorry.

[280Z Turbo]

There's a place called Rustbusters on ten mile east of John R in Madison Heights that acid dips parts like that. There's one on 8 Mile and Wyoming too, but I can't recall the name of it.

Don't know of any on the west side over there though, sorry.

I'm wondering if a powder coating place would do it.

[Soup DeVille]

I'm wondering if a powder coating place would do it.

Probably. Its worth asking them anyways.

[hotrodalex]

Depends on the place. Some only do sandblasting. But worth it to ask.

[280Z Turbo]

Well, I just need the shit cleaned out of the inside of that piece of frame. I don't think a sandblaster will do that.

[hotrodalex]

Nope.

[280Z Turbo]

Looks like this place may do it:

http://www.isstrm.com/chemical.php

[280Z Turbo]

I wanted to replace the pinion seal, but apparently there's a crush sleeve in there that has to be replaced when you untorque the pinion yoke.

http://www.digitalcorvettes.com/forums/showthread.php?t=77377

Bummer. I think I'll just let 'er leak.

[Soup DeVille]

Yeah, there almost always is.

[280Z Turbo]

Why are RWD differentials built like this? When you put a differential inside a FWD transmission, it's easy. When it has it's own box, it's got all this preload and shim bullshit going on.

[Soup DeVille]

Idunno boss.

[280Z Turbo]

I suppose I'm going to have to pay however many hundreds of dollars to have this thing rebuilt when the time comes.

Transmission and engine are no problem, but the differential, of all things, scares me.

[280Z Turbo]

I ordered a bearing retainer for the transmission. Old one is on the left, new one is on the right. Looks like a textbook example of a bad casting. Why did they ship me this junk?


Differential is ready for paint. These were originally unpainted, so I think I'll use a cast iron gray paint.


Painted the diff bracket, clutch fork and strut rods. Nobody sees these part, but at least I know they look nice!


Strut rod crossmember looks pretty bent. I can get a refurbished one for a 68-79 Vette for $50. Worth it?


Rubber bushing removal the quick and stinky way:

[Soup DeVille]

Yeah, replace the crossmember.

[280Z Turbo]

Here's the 3rd gen Corvette strut rod bracket:

http://www.ebay.com/itm/Chevy-Corvette-Rear-Strut-Rod-Mounting-Bracket-1968-1969-1970-1971-1972-1973-74-/111422595640?pt=Motors_Car_Truck_Parts_Accessories&hash=item19f14de238&vxp=mtr

It puts the mounting points lower to the ground for less camber gain, which is good.