1987 axle ratio

[Straatmann]

Needing a little help identifying my axle and ratio, I’m assuming it’s a 35. Any help is appreciated.

[Straatmann]

It’s a 4.0 5speed if that helps at all

[jeeptec1]

Model 35. (Dana 35) should have 3.07 with a 5 speed. The tag is unreadable in the picture.

Automatic trucks normally came with 3.55/3.54

 

 

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[Straatmann]

The only numbers I could make out it:

4770

324-1

[89 MJ]

Post the VIN in the registry, they’ll get you the factory gears and a build sheet. 

[Pete M]

ratio can be determined by spinning 1 tire around twice and counting the times the driveshaft spins.    about 3 times is a 3.07

[JustEmptyEveryPocket]

Jack up one tire, make a mark on the tire and fender (chalk works well), make another marker on the driveshaft and pinion snout. Then rotate the tire through two full revolutions counting how many times the driveshaft spins around. This will give you a rough ratio. The only options (unless aftermarket work has been done) are 3.07, 3.55, and 4.10. Maybe 3.73 was an option but I personally have not come across that one.

 

Or pull the cover and count teeth. This will give you the exact answer.

[JustEmptyEveryPocket]

2 minutes ago, Pete M said:

driveshaft spins.

dang, beat me to it Pete

[Straatmann]

I’ll have to jack it up and check it, I added the vin to the registry, but their was no info on the gear ratio

[89 MJ]

1 hour ago, Straatmann said:

I’ll have to jack it up and check it, I added the vin to the registry, but their was no info on the gear ratio

Once it is decoded, they will get your info. 

[Pete M]

the ratio won't always come up since a lot of AMC info was lost before it could be inserted into Chrysler's computers.    But I can say with confidence that it came with the 3.08s from the factory.   that doesn't mean it still has 'em though.  anything can happen in 3 decades. 

[omega_rugal]

3 hours ago, Straatmann said:

It’s a 4.0 5speed if that helps at all

 

4.0 + manual is 3.07

[JustEmptyEveryPocket]

1 hour ago, omega_rugal said:

4.0 + manual was 3.07

My 4.0L manual transmission had 4.10s in it when I got it. So you can't know for sure unless you jack up a tire and count driveshaft spins or remove the cover and count teeth.

[omega_rugal]

obviosuly it doesnt apply if someone messed with the truck

[Straatmann]

Everyone was right, almost 3 turns exactly.

[cruiser54]

You can also remove the rear cover and read the numbers on the ring gear. Probably needs a lube change anyway......