8 3/4 Rearend Question

[GreenGo Danno]

I may be overthinking this and hopefully I am missing something but at this point I am confused. I decided to check the gear ratio on my 8 3/4 rearend. On jacks with 904 trans in neutral, I spin the left rear tire. The right tire spins the opposite direction and I start to count the number of rotations on the driveshaft. It does not spin during the entire time I am spinning the wheel? By the time I get to a full revolution on the wheel, the driveshaft has not even made a full revolution due to it intermittently turning. Everything turns freely with no noise. What am I missing or is there a serious problem with the rearend? 1971 Dodge Dart Swinger 318 2 bbl, 8 3/4 rearend. I am restoring this car and it has not run since 1989. I have zero knowledge of its history other than it was mentioned that they quit driving it for possible transmission issues not shifting properly. I found the kickdown linkage laying unattached on the manifold and was hoping maybe this was their transmission problem that they thought they were having. Engine and trans are coming out for a full rebuild anyway but now I am concerned about the health of the rearend. Also, does anyone know an easy way to get the main crank bolt off and the harmonic balancer? I have had zero success getting the bolt loose. All I have been able to do is bend pulley bolts while trying to loosen the main bolt.

 

[Professor Fate]

You're doing it backwards- put the transmission in neutral and spin the driveshaft/input pinion and count the number of driveshaft revolutions it takes to turn the rear wheels one revolution.
And btw, the wheels spinning in opposite directions only means you have an open rear end and not a SureGrip. It's not an issue.

 

[junkyardhero]

Also, does anyone know an easy way to get the main crank bolt off and the harmonic balancer? I have had zero success getting the bolt loose. All I have been able to do is bend pulley bolts while trying to loosen the main bolt.

rattle gun and big socket? harmonic balancer puller (or a steering wheel puller)

get the crank pulley off first-- you'll need to anyway to use the puller.

 

[GreenGo Danno]

rattle gun and big socket? harmonic balancer puller (or a steering wheel puller)

get the crank pulley off first-- you'll need to anyway to use the puller.

Thanks, yea, pulley is off. Just can't get the crank bolt loose. I have no room to get my impact in there unless I remove lower valence and AC, even with the radiator out.

 

[el5dart]

i saw a video where a guy put socket with long bar on the bolt. rested long bar on the left inner fender. and bumped the starter to loosen his pully bolt. it worked

 

[66Valiant528]

i saw a video where a guy put socket with long bar on the bolt. rested long bar on the left inner fender. and bumped the starter to loosen his pully bolt. it worked

I've always rested a breaker bar on the k frame and bumped the starter.

 

[Righty Tighty]

i saw a video where a guy put socket with long bar on the bolt. rested long bar on the left inner fender. and bumped the starter to loosen his pully bolt. it worked

Can confirm - that method does work.

 

[Infiniti Dave]

Remember , you somehow have to put it back on at some point !!

 

[Charrlie_S]

i saw a video where a guy put socket with long bar on the bolt. rested long bar on the left inner fender. and bumped the starter to loosen his pully bolt. it worked

I've always rested a breaker bar on the k frame and bumped the starter.

I have done that and it works. Just make sure you have the engine in a condition it can't start. (disable the ign).

 

[GreenGo Danno]

With the intake, distributor, and heads off, I am pretty sure it won't start... lol

 

[GreenGo Danno]

Bumping the starter worked like a champ

 

[GreenGo Danno]

Also, I always thought small bolt pattern Dodge always had 5x4.25. Mine are measuring 5x4.0. When googling Dodge, I do not see this as a size. Am I losing my mind?

 

[33IMP]

Also, I always thought small bolt pattern Dodge always had 5x4.25. Mine are measuring 5x4.0. When googling Dodge, I do not see this as a size. Am I losing my mind?

Nope. Early A-body were 5 on 4 inch pattern. 1960 thru early seventies (some slant six cars were still 5 on 4 while V8s were5 on 4.5) Remember, unless changed, left hand threads on the driver side!
There IS an oddball rare 4.25 pattern, but it was on mid-eighties T-birds and Lincolns. Oh, and volvo's
(I'm kinda surprised you've got an 8 3/4 in a 318 car.)

 

[GreenGo Danno]

And I guess with further research I found that Darts came with 5x4 when they have disc brakes on front which I have. Learn something new everyday

 

[33IMP]

And I guess with further research I found that Darts came with 5x4 when they have disc brakes on front which I have. Learn something new everyday

Disc or drum, didn't matter. For at least ten years they were ALL 5 on 4. (Well, except for 60-62 darts, they were 5 on 4 1/2)

 

[340six]

I've always rested a breaker bar on the k frame and bumped the starter.

Same here.
1st did it when I was 16 all my friends thought it was so great.