Help needed with pinion angle

[curtis]

Finally installing a 700R4. I have lost track of the correct angle the engine had before I chopped out the tranny crossmember. I believe I need to set the engine angle the exact opposite of the pinion angle. Is that correct? What is the correct pinion angle? Will the driveshaft angle also need to be addressed? I don't even remember if the engine was level in the car. Should it be? How do I measure all this stuff? Really want to get it right the first time. Sure could use some help here!

 

[Jack]

Curtis:
The tool/gage I'd use is an "angle finder" ... mine is from Sears and they call it a "protractor" ... Sears P/N 939840 ... I paid about $10 for mine about 2 years ago. I don't know the correct angles for vette ... but you set gage on valve cover (NOT carb base) to find motor angle ... it'll read angle direct from its scale. Similar for pinion ... set gage against pinion yoke. Mine was hanging where Sears keeps their long levels.

 

[curtis]

Thanks, Jack. I'll look into that tool. Still would like all my other stupid questions answered so I can sleep at night.

 

[Jack]

I'll try & lay the gage on my 71's valve cover tomorrow ... If I can remember ... relax! ... someone else'll probably chime in.
JACK:gap

 

[norvalwilhelm]

There is not fixed angle. Push the rear of the transmission up as high as possible. I put mine against the tunnel and then weld on a mount for the transmission. The rubber mount compresses slightly pulling the transmission away from the tunnel.
I measure this angle. It is down.
You then measure the pinion angle and you can shim the nose of the pinion up to be the same as the down angle on the transmission.
It is not that important what the angle is, just that they are equal and opposite. I too use a magnetic protractor on the output shaft and the pinion yoke.
If you measure the pinion angle, and it points up you could just make the transmission angle the same but opposite/ pointing down.
You also have to cut the driveshaft.

 

[Ludigdrums]

I just recently did the 700R4 sway in my '81...what an awesome difference!

Should I be concerned about this angle stuff too? I didn't check any of it but nothing seemed out of whack and everything went in smoothly.

Thanks!

- Jeremy

 

[Jack]

Curtis:
For a reference point, I first laid angle finder on driver side perimeter frame rail, just forward of my 71 auto trans Xmember. Then I laid angle finder on top of driver side valve cover. The motor is UP in FRONT ... ONE Degree more than reading from frame rail. If you're working under car, and if you can get in there, you might take a motor reading from oil pan rail ... just like the VC, op rail is parallel to crank centerline. G'luck.
JACK:gap

 

[JohnZ]

The installed design engine angle (centerline of crankshaft and output shaft) on '63-'82 Corvettes is three degrees down. Here's the inclinometer I've used for the last 25 years or so:

 

[Ludigdrums]

What are the possible problems of not achieving this desired angle?

- Jeremy

 

[curtis]

You guys are great. Thanks a million for all your input. Now at least I have some answeres instead of worries and questions.

 

[JohnZ]

What are the possible problems of not achieving this desired angle?

- Jeremy

It's not too critical on a '63-'82 Corvette, as the diff is solid-mounted and doesn't move or change angle like it does on a solid-axle car; any movement resulting from bushing compression will generally be well within the U-joint operating angle design limitations. Ideally, the trans output shaft should be at 3* down, and the pinion should be at 3* up so their centerlines are parallel and at equal angles.

 

[curtis]

Now I have to drive to the city to SEars and get the guage. Hopefully work on the thing tomorrow. Had the driveshaft shortened and balanced for $45.thanks again for your help.

 

[curtis]

Boy I wish I never started this project. Drove 60 miles and back to get the Sears thing. Put it on the differential yoke and it read 1 down. Put it on tranny yoke and it read 5 down. Installed driveshaft and it reads 0. Took off shaft and jacked up tranny till it read up 1. Now the driveshaft knuckles won't clear the inside of the tunnel and can't hook up the driveshaft. The engine looks like the back of it is way up in the air and front is way down. Also the transmission output shaft is about 3/4 inch closer to passenger side of tunnel than it is on driver side. Is that right? What a headache! somebody come over here and fix this for me please. Is it correct that the angle between the tranny and the driveshaft should be the exact opposite of the angle between the differential and the driveshaft?

 

[AUSSIEVETTEMAN]

Will this cause a vibration issue?

I am chasing a vibration in the driveline of our Vette. Replaced all drive and half shaft uni's (greasable), balanced all three shafts. Have new tranny mount (rubber), new diff mount (poly). The vibration is hard on & off power. I felt the yoke on the rear of the tranny again and there is play there. Would the angle you are talking about cause premature uni wear?
I have replaced a torque converter and eliminated half the vibe.

Cheers

Tony

 

[curtis]

aussievetteman, some say yes others say it don't matter. Man I am so frustrated with this thing right now I don't know up from down or in from out. I'm about $1500 into this tranny swap with another $300 to go and I don't even think it 's goin to work and there is no going back to the 4 speed as most of the old stuff is gone now.

 

[curtis]

aussievetteman, try this link for vibration questions.http://www.streetrodderweb.com/tech/0205sr_vibrations/

 

[AUSSIEVETTEMAN]

aussievetteman, try this link for vibration questions.http://www.streetrodderweb.com/tech/0205sr_vibrations/

Thanks for the link Curtis.
I will eventually find the cause of the problem. Could even be an off centred steel rallye rim. The nuts centre these and one tyre guy used spacers on mine to try and centre the rim on the hub, not the stud. Problem is he wrecked a new set of steel rallye rims and now I have to cut the spacers off as they are welded on. W#$kers.

Cheers

Tony

 

[Evolution1980]

...Also the transmission output shaft is about 3/4 inch closer to passenger side of tunnel than it is on driver side. Is that right?

Sorry about this, but :LOL :LOL You are experiencing the exact same things I ran across when I did this "drop in" transmission. "You only need a modified crossmember and shortend driveshaft." Yeeeeah, right! A weekend job that ran into 6 weekends...
If I recall on my car, the shaft did favor itself to one side of the car by just a hair. Also, my transmission doesn't sit parallel to the ground for reasons I can't recall.
Another strange anomoly I ran into is when I had the driveshaft shortened. We measured the damn thing at least 3 times from every concievable point of reference before marking it. After it was cut and installed back in the car, it seemed like more than 3" was taken off, but that wasn't the case. An unexplained mystery.

I feel for ya, bro! FYI? You haven't gotten to the hardest part yet! Just wait until you get to adjusting the shift linkage and TV cable! *shivers* I'm glad I don't have to go through it again...

Something to consider here: C4C5Specialist here told me that the following should work as a self-adjusting TV setup. Pretty much if Paul (C4C5) says so, it's gospel.
The TV cable part number is 25515598.
The bracket is discontinued from GM, but your application would be a 84-88 Caprice Classic, with a 5.0 engine with a 700r4 transmission, carbed.
This should let you get a used bracket from a junkyard.

 

[curtis]

OOOOOOHH, God. Just to the verge of puttin and new blade in the sawzall and hack this %^$^**%&^& car into little &^%*()($%#@&)* pieces and forget the 17 grand already in it. Thank you for all the encouragement. I do have a new bracket for the TV cable and throttle that somehow bolts onto the carb base. JUst need the little piece to correct the geometry of the Performer carb.

 

[Evolution1980]

...Just need the little piece to correct the geometry of the Performer carb.

OK, forget what I said about the self-adjusting TV cable. I don't know that it pertains to Performer carbs. It was mentioned with the thought it was mating to a Q-Jet... You could always PM C4C5Specialist and ask...

I took quite a few pics of the transmission installation at various stages. If you want, maybe I can throw some your way to let you know what to expect. Don't know if it will help or not, but...
Trust me though...take the time to make sure it's done correctly. Once it is, the end result IS worth it. (1800 RPM @ 70MPH... just keep repeating that to yourself! )