My Black Bitza

[bfit]

Hi metal ,
I'm jumping in on Scott's  thread here

Look at the original vette engine to trany setup engine angled down to the rear 3 to 3.5 deg's and angled right to left in the vehicle, ( I never measured the angle )
Diff is mounts horizontal , no drive shaft problems .

The debate on matching diff angle to engine angle  is a long and ongoing.
But look at the history.
C2,C3 and 4 all have the diff  mounted horizontal in the vehicle .

The matching of engine and diff angles is mainly applicable to cars with a solid rear leaf sprung axle set up as the dIf angle changes so much under acceleration bracking  and corning.
Give it some thought .
Just my opinion
I run a tremec magnum in a C3 the main thing is to be make sure the rear of the gearbox is higher than the diff imput.
My engine sits at 3 deg's, diff horizontal
Consider the half shafts  on the diff the yoke is horizontal in both planes.
The wheel normally runs 1 to 2 deg's camber.
How many drive shafts have you seen  fail in a vette due to the variations in angles,
engine to diff , diff to wheel.
Bfit

[Jethro]

Ahhh Bobby your a wealth of knowledge bro 

[Scott]

I didn't settle for a specific angle as such.  I just tried to get the gearbox and diff to run as parallel as I could.  It's not an issue with the driveshaft failing, but more that if the angles differ too greatly, you will get a vibration in the driveline due to the way uni joints work.

When I first bolted everything in using the trans mount supplied in the kit, I had a pretty big slope on the gearbox as you can see below.



I cut the trans mount up and rewelded it 20mm higher so the gearbox was close to the floor, but not touching.  I also has some spacers on the engine mounts to make everything bolt up smoothly.  I removed them and did some clearancing to get the bolts to fit again and dropped the engine around 10mm.

Lastly I took 2-3mm off the front diff mount to lift the nose ever so slightly so things are fairly parallel now.

As mine was an auto swap, I didn't have an original bell housing or clutch to use.  The shifter is a custom one from American Drivetrain to bring it up int eh factory location.  The tailshaft is a different length also.  I believe my new one is shorter than the original.

If you have any Q's, fire away.

[metalhead]

Alright, thanks guys! Yes, I plan to measure the current arrangement before I remove it and align it as closely as possible to original, I'm just collecting information on what others have done before I get started. I was also considering raising the diff, so need to look at my options.

Thanks for all the tips! Hope you don't mind the thread hijack Scott.

[bfit]

I  don't believe you will get a vibration if
The rear of the gearbox is above the imput of the diff at least 25mm
The angle of the engine is less than 3deg's
The angle of the drive shaft is between 1.5 to 2.5 deg's

My drive shaft is going7000rpm flat out in 5th gear  that's about 130 m/h
The only problem I have encounter is stopping the car  Late enought to stay I front of the later modle cars
Bfit

[metalhead]

Yeh, I'm considering raising the diff for suspension geometry reasons rather than driveshaft alignment. Raising the diff will allow me lower ride height without the excessive change in toe with suspension travel that occurs with low ride height and standard diff height.

[Scott]

Booyah!

https://youtu.be/PpL4sfza3pA

Can I embed this somehow?  I can't see the option.

[bfit]

 

[metalhead]

Yeh!!   Congrats, bet that put a smile on your face!

[Jethro]

Nothing like the first start up 

[Scott]

I was pretty happy after that.  It took ages to get the fuel pump to prime, but got there in the end.  There are a few leads sitting on the exhaust, and I haven't added any water yet so only short runs.  I'll stuff in the hei and get some new right angle leads.  That'll fix the issues with exhaust contact.  I have some insulation sleeves too.

[metalhead]

I'll bet! Sounds good. Where'd you buy the insulating sleeves? I need to get some of those myself.

[Scott]

Where'd you buy the insulating sleeves? I need to get some of those myself.

Summit.  I made up a list of a bunch of small parts I needed for 2 different cars.

[metalhead]

Ah ok, thanks. Just received a shipment from summit (and placed one with Jegs). Will have to keep it in mind for the next one...

Measured my engine/box and diff angles tonight. With my hoist lowered onto a lock, the diff angle was 0 degrees and the engine and box was sitting at 2.3 degrees.

Received my package from Hurst on Friday. The gearbox mount looks similar to yours, but there are shims included and the instructions state:

The Hurst TKO crossmember brackets are designed to give you an appropriate driveline angle and at the same time allow your TKO to fit within your tunnel. Your driveline angle with a TKO installed will be slightly different than your stock driveline angle but still within an acceptable tolerance range. If you happen to have enough space between the top of the transmission and the bottom of the floorboard, use the provided transmission mount shims to raise the transmission up further into the tunnel as this will result in an optimal driveshaft angle.

Guessing there wasn't something similar in your kit?

[Scott]

No shims in my kit.

I've hooked up the hydraulics for the clutch and bolted my brake master cylinder on now.  Added some fluid, and it seems one of my front calipers is leaking...  And that's just with gravity.  I pulled the wheel off to have a look.  Pads out and it looks like one piston is leaking.  I've changed from lip seals to o-rings, so I'll have to pull it apart again and see what the go is.  Yay, more brakefluid everywhere...

[metalhead]

D'oh... That's frustrating. Better to find it now though I suppose?

[Scott]

I pulled the caliper apart last night and it was full of grit.  I'd had the same issue previously with the calipers leaking and when I pulled them they were full of grit.  That's when I changed them from lip seals to o-ring seals.  But going through my spare parts and it turns out that was only the rears that I did.  I kind of realised when I split the caliper and the bolts were dry that I hadn't had them apart before, as I put antiseize on everything when I bolt it back together.  Over time I'd forgotten that I needed to do the fronts as well...  At least the fronts are new calipers, or at least where when I got the car 10 years ago.  Nice stainless sleeves etc, but they are still lip seals.  I'll pull the other one tonight as it'll be full too.  I'm not sure where all the grit came from.  It may have been in the lines when I bought it, who knows.  But once I clean out the last caliper, hopefully that's the end of it.

[metalhead]

Fingers crossed. How much left to go before you're driving once you get that done?

[Scott]

Once the brakes work I'll be able to drive it, although:
I'll be sitting on a milk crate as there is no interior at all, bar a steering wheel.
I'll have to hotwire it as there is no wiring whatsoever in the interior.
I can't drive it far as the plug boots are sitting against the headers.
And the fuel supply is currently a gatoraid bottle with the fuel hose stuck into it.
Also there is no exhaust attached to the headers.

So all in all, pretty close 

[metalhead]

Should be on the road by Easter then! Good progress, keep after it and it'll be done soon enough. And do the drive as is, it'll be worthwhile motivation!