Corvair DiagramCorvair Photo
Corvair Center
home forum corvairs calendar links Corvair Podcast
California Corvairs
Clarks Corvair
Clarks Corvair
“CORSA"



Chevy Corvair License Plate
Chevy Corvair Chrome Wheel
Corvair Center Forum :  Corvair Center Phorum The fastest message board... ever.
Corvair Center 
Diff and trans mating
Posted by: kaminski45 ()
Date: November 25, 2018 10:29AM

When putting the trans on to the diff should they mate up flush or will I have to draw them up with the bolts? Getting about a 1/8 inch gap between the 2.

Options: ReplyQuote
Re: Diff and trans mating
Posted by: BobV66Vair ()
Date: November 25, 2018 10:42AM

Should slide together. Don't force it. Make 100% sure that they are in line and there is no force on the input shaft. It can be bent if any weight hangs on it. There are several input shafts. if you did not build the same unit you took apart, make sure you have the correct shaft. Also, make sure the input on the trans is flat. The bearing can protrude and that's a problem.

Bob Vinnacombe
Sandy, Oregon
1965 Corsa 140 stock
1966 Monza Soon to be race car
1968 Monza Parts for now

Options: ReplyQuote
Re: Diff and trans mating
Posted by: RexJohnson ()
Date: November 25, 2018 07:43PM

If you have a '65 or earlier pinion shaft in the diff that you are mating to a '66-'9 trans they wont slide all of the way together. You should be able to search and find a thread about the problem. The '65 and earlier pinion shafts are a little to long for the '66 and later trans, but they are easy to shorten.

RJ tools
Salem,Oregon

Options: ReplyQuote
Re: Diff and trans mating
Posted by: jetcat ()
Date: November 25, 2018 07:59PM

I don't know if this is your problem but.....
As Rex stated, don't mix a 65 pinion shaft with a 66-69 trans. I got the fun chore of a redo in my coupe because of this recently. If the pinion shaft is proud of the diff input bearing, and you mate a 66-69 trans, NOT GOOD. The end of the pinion should be flush with the bearing. Data is available on the internet on how to modify the shaft.

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe

Options: ReplyQuote
Re: Diff and trans mating
Posted by: JimBrandberg ()
Date: November 26, 2018 04:21AM

I've never tried it but was under the impression that you could mate a 66 transmission to a 65 differential if you had the proper input shaft and only used 4 of the 6 mounting bolts. Is that not true?

Jim Brandberg
Isanti, MN
CorvairRepair.com

Options: ReplyQuote
Re: Diff and trans mating
Posted by: texas yenko dude ()
Date: November 26, 2018 05:01AM

JimBrandberg Wrote:
-------------------------------------------------------
> I've never tried it but was under the impression
> that you could mate a 66 transmission to a 65
> differential if you had the proper input shaft and
> only used 4 of the 6 mounting bolts. Is that not
> true?


Not true Jim. But you can mate a 65 trans to a 66 diff if you desired.

Options: ReplyQuote
Re: Diff and trans mating
Posted by: kaminski45 ()
Date: November 26, 2018 05:23AM

It's a 64 diff and trans. The trans is the original to the car but the diff is not.

Options: ReplyQuote
Re: Diff and trans mating
Posted by: Wagon Master ()
Date: November 26, 2018 05:27AM

I would suspect a problem with the fit of the trans. output shaft to the pinion shaft internal splines, which are known to wear.

Options: ReplyQuote
Re: Diff and trans mating
Posted by: Wagon Master ()
Date: November 26, 2018 07:45AM

MattNall Wrote:
-------------------------------------------------------
> Please make some 6" x 3/8" guide pins! [ cut the
> head off of long cheap bolts ].

FWIW, I could not find any 3/8"-16 trans. to diff. mounting holes. Mine are all 7/16"-14. Maybe you meant diff. to bellhousing?grinning smiley

'29 Ford Model A Tudor
'61 700 Lakewood 110 4 speed
'69 Monza Convert. 140 Auto.
'70 Dodge Challenger R/T 440 4 speed

Been aircooled since 1973
Northwest Ohio

Options: ReplyQuote
Re: Diff and trans mating
Posted by: MattNall ()
Date: November 26, 2018 07:58AM

Wagon Master Wrote:
-------------------------------------------------------

> FWIW, I could not find any 3/8"-16 trans. to
> diff. mounting holes. Mine are all 7/16"-14. Maybe
> you meant diff. to bellhousing?grinning smiley
=============================================

Of Course you couldn't! long day... cornfuzzled! moody smiley





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: Diff and trans mating
Posted by: vairmech ()
Date: November 27, 2018 07:00AM

There are to many differences to interchange any 65-66 combination of trans/diff.

For one the 66 diff adjuster sleeve will not mate to a 65 trans bearing adapter. If you change the adjuster sleeve to an earlier style then it will work.

The 65 diff pinion shaft is about 1/8" longer than the 66 pinion shaft and if bolted up tight the trans and/or the diff will suffer consequences later.

If you are trying to put the diff/trans up to the engine and you encounter resistance DO NOT just pull it up tight with bolts.
What I have seen many people do on a manual is when they put the clutch together they use a pilot shaft but they fail to center the clutch disc causing a binding. When I put a clutch together I use a pilot but I only just touch the disc to the plate with the bolts enough to hold the disc in place. I then try to remove the pilot, if it doesn't come out easily slightly tap up on the pilot, then slide it out and change one spline and slide it back in. do this 10 times, one for each different spline. If you encounter any resistance tap up again and repeat the pilot sliding 10 times. Why 10? There are 10 splines on the pilot shaft. Once you have the pilot sliding easily on all 10 splines tighten the PP down and repeat the pilot sliding, 10 TIMES.
Once the pilot will slide in easily on all 10 splines of your pilot then you will not have any issue mating the trans/diff to the engine.

I know I morphed into something a little different but they are related.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

Options: ReplyQuote
Re: Diff and trans mating
Posted by: 66vairman ()
Date: November 27, 2018 08:44AM

Good points Ken and it's nice to see folks are now aware of the 65 vs 66 differences.

"Dan the Gear Man" Drommerhausen wrote the original article and it came about because folks were using good used pinion shafts to replace pinion shafts that had worn out inner splines. If you use a 65 (one year only design) pinion shaft in a 66 or later differential (and install a 66 or later transmission) it results in a lack of clearance and eventual transaxle failure. Note the installing a 66 and later pinion shaft in a 65 deferential works.

I always test fit a transmission to a differential WITHOUT the gasket and it should slide up to the differential housing with NO gap. If there is a gap - time to find the problem before final assembly with a gasket.

Options: ReplyQuote
Re: Diff and trans mating
Posted by: Wagon Master ()
Date: November 27, 2018 12:51PM

kaminski45 Wrote:
-------------------------------------------------------
> It's a 64 diff and trans. The trans is the
> original to the car but the diff is not.

Options: ReplyQuote
Re: Diff and trans mating
Posted by: viewmaster ()
Date: November 28, 2018 06:41AM

kaminski45 Wrote:
-------------------------------------------------------
> It's a 64 diff and trans. The trans is the
> original to the car but the diff is not.


Put diffs side by side and compare/measure everything. There seems an issue with the not original diff you are trying to mate. Could be old, hardened grease, or something more...like the wrong pinion shaft. My $ .02

-m



Mike
'65 '500' Sedan 110 PG
'65 Monza Sedan turbo'd 110 SU conversion
Fresno, CA

Options: ReplyQuote
Re: Diff and trans mating
Posted by: Jonathan Knapp ()
Date: December 03, 2018 08:58PM

I had a similar problem with my '66 differential with my '66 transmission. The differential also has a new CIDCO pinion shaft. The problem wasn't the overall length of the pinion shaft (Anderson made them all the short '66 length). The problem was with the length of the internal splines inside the pinion shaft. They were a little long to the front (transmission side) and the transmission mainshaft splines, which are beveled where they come up to the unsplined part of the mainshaft, would bind on the blunt end of the internal pinion splines.

Solution? Extending the mainshaft splines ever so slightly with a tiny die grinder wheel. Then it slipped right together.

Jonathan Knapp
Now in Martins Ferry, OH
'66 Corsa Autocrosser

Options: ReplyQuote
Re: Diff and trans mating
Posted by: Two2brew ()
Date: December 04, 2018 06:16AM

The problem is the rear pinion bearing adjuster. The one for a manual is flush and the one for a power glide protrudes about... 1/8 inch.

Ask me how I know.

Lyle Whitsett
San Diego, CA
64 Monza convertible

Options: ReplyQuote


Sorry, only registered users may post in this forum.
This forum powered by Phorum.