My '67 Bird was originally a OHC-6 (not Sprint), but now packs a strong 400/4-speed. How can I map my differential, aside from rotating the wheel and couting the drive shaft turns? I haven't seen any numbers on the housing; it's not posi.

Does it look like an original 67 8.2? Count the teeth.

Count the teeth? I guess you mean open it up to see the gears. Haven't done that yet.
Shouldn't there be a number somewhere?

Still can't tell. With all that swapping around. I'm surprised it's non posi.

I'm not surprised. It's usually the last thing on the list. I bet it's still the original. If you have a tachometer, you could use the speed calculator to determine the gear.

(speed*rearend*trans gear (usually 1:1, unless overdrive)*336) / (tire height inches) = rpm

so (rpm*tire height) / (speed*trans gear*336)=rearend ratio if I did my math correctly.

Also, go ahead and get your PHS document and verify against it.

P.S. For you auto guys, a non-lockup type converter may lose about 150-200rpm in slippage.

It's not all that hard to jack up one wheel and spin the tire twice while counting drive shaft revolutions ... is it?

Easier than getting gear oil all over.

If it's a factory 8.2 inch, there should be a 2 letter axle code on the back side of the LH (driver's side) axle tube near where the factory welded on a clip for the LH brake line.

Years of rust and dirt can hide the code which was stamped. Starting at the brake line clip, start sanding down the axle tube around the clip in a widening circle until you see the stamped letters.

PS. Sandblasting will all but obliterate the letters. I restamped mine afterwards.

Sounds good in Arizona! That salt air in Houston probably ate the letters.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> Sounds good in Arizona! That salt air in Houston probably ate the letters.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">???? Jim!?

How`s your geography?
there`s no salt in Houston...not on streets , not in air....in Galveston, Yes...but were 60 mi from the coast!
LOL

60 miles is a short drive. Had a Houston truck when I lived in SA. It was a little rusty on top from the salt air. I was thinking about untreated axle tubes on a 40 year old car. I have had terrible luck finding axle codes on 1st gen rear ends. I imagine my luck would be better with Arizona cars.

Probably that truck went to Galveston a lot....
you can see the difference between Galveston cars and Houston cars...yes its a short drive, 45-50 minutes , but not everyone in Houston goes there....
my axle code, on a Wisconsin car (road salt) is visible ,even though barely...
of course the car was sold in Wis., not sure how long it was i DFW where I bought it...4.5 yrs ago, former owner had it 7

and Houston is pretty well spread out ,your truck could be from the southern part....? its another 60-90 mi from S to N here too...on whats 'considered' Houston.

guess we should start a new topic for this...LOL

Hey Bjorn...Didn't Dean Martin have a tune by the name of "Houston"?..."Goin' back to Houston...Houston...Houston"

Yes he did, I have it on a 33 LP vinyl

Hey - this IS important. It may sound weird, but one of the potential show stoppers for my move to Amarillo (still pending) was whether they used salt on the roads or not (they don't).

NONE of my cars have any undercoating on them (anymore)

And in MY house, we are singing "Amarillo by March" (instead of morning) :p

Mark, if you would ponder Houston, theres no salt on the roads here, unless someone drops a grocery bag....

Speaking of Dean Martin didn't he do a song with Jerry Lewis ?
Baby blow me a kiss when I'm leaving,

he probably did , as much stuff as they did together ,but I dont recall that one..

Best way to get the ratio is pull the cover. If it's an original it probably could use a lube change anyway. On the edge of the ring gear there should be some numbers stamped. 42/19, 42-19 or the like. Just divide and that'll give you the ratio. Axle codes are fine but after that long you don't want to assume a past owner didn't swap gears. Easiest way is Q's method. It'll get you pretty close.

Robert

When we used to scour junk yards, we had a habit of checking every A body and F body for the gears. If it was less than 3 turns, we walked. If it was less than 3-1/4 (but more than 3) we knew it was 3.23. If it was over 3-1/4 but less than 3-1/2, it was 3.36. If it was 3-1/2 we knew th gears were 3.55 and we would pull the cover to see if it was a 2- or 4- pinion. If it was a 4, we'd pull the rear end. If it was 3-3/4 (or more), we'd pull the rear and worry about the type later.

Twice we found 10-bolt posi 3.55 rear ends in A-body cars in the junk yard that had been skipped over. The two-turns-count-the-drive-shaft-rev's method never failed.

When I lived in Dallas, I went through Houston a bezillion times on the way to Galvaston. As a group, Huston cars are rust buckets compared to Dallas cars. I was floored by the rust buckets I saw in Houston. Heck! I thought I was back up in the rust belt when I saw the rust level on the cars.

The reason Houston has a higher tendancy for rust than lots of the other parts of the south is that it has lot of salt in the air from the endless flow of humid Gulf air that crosses Houston. After all, it's only 30 or so miles from the coast.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> The reason Houston has a higher tendancy for rust than lots of the other parts of the south is that it has lot of salt in the air from the endless flow of humid Gulf air that crosses Houston. After all, it's only 30 or so miles from the coast. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">60 miles from Houston to Galveston...70+ from my house , then theres`` a LARGE area of "houston" north , you forget Houston is fairly large....

of course I`ve only been here since 68 so what do I know..LOL

I dont see many rustbuckets here , BUT I do in and around Galveston...yes, its humid , but not salty... there`s a BIG difference , go to Galveston one day and come back, you can see the salt layer on the car...

ENOUGH OF THIS MUMBO-JUMBO ALREADY!...WHO THE HELL CARES HOW SALTY IT IS IN HOUSTON!...I THOUGHT THIS THREAD WAS ABOUT SCHWEES REAR END! :p

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> ENOUGH OF THIS MUMBO-JUMBO ALREADY!...WHO THE HELL CARES HOW SALTY IT IS IN HOUSTON!...I THOUGHT THIS THREAD WAS ABOUT SCHWEES REAR END! </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Agreed,you`re very right!
even though it sounds like a "personal problem"
Stay on topic...no more 'salty/no salty' Houston Air!

I have to side with Quenton on how to check for ratio. It involves little time and you stay relatively clean. But to see if it's a posi, pull the rear cover if there is no tag.

Tom

OT
"'Cause Texas is a world all of it's own."
A line from 'Those Feat'll Steer Ya Wrong Sometimes' on Representing The Mombo by Little Feat.
A little hijack fun :p

Tom