Welded Spiders. Rats!

Update:

The numbers on the ring gear are 47/11 what does this translate to?

 

47 divided by 11 is 4.27

 

Karl,
How many bolts in your ring gear?

 

Sorry, I didn't count before I buttoned it back up and added oil. I decided to go with an open diff so I didn't bother.

 

Remember with 4x4 is common for the front diff to have slightly higher gear ratio. It's viewed to be better for the front axle to slightly drag the rear axle, rather than the rear axle pushing the front, especially on snow and ice.

 

They claim those were being used for 5:38's.......

 

What???? They have to be within a couple points like 4.09 and 4.11 will work but
generally speaking you have to have the same ratio front and rear.

 

Yes, this is my understanding. You may see slightly different ratios front and rear, but that's due to the integer division involved in tooth counts. You can only have so many different practical combinations of tooth counts, and say a front 4.11 and rear 4.09 is the result of the accessible tooth counts and nothing more. AFAIK. I think you'll see the same thing if you evaluate other axle combinations ... the precise ratio will be different front and rear if the ring gear diameters are different.

 

The PowerLoks on eBay should drop into the Dana 27 with the welded spider gears. I'll bet Karl has an 8 bolt ring gear, and this would be a nice upgrade. If this fits a 5:38, it will also fit with 4:88 and 4.27 gears.
-Donny

 

Re ratios: This is one reason 4x should never be used on dry hard roads, where the vehicle would technically be trying to pull itself in half.
Here's an example from Renegade II build info:
20-01....941052............Axle front assy ( 4.88 to 1 ) ( Model 27AF ) ( LHD )
21-01....994211............Axle, rear assy ( 4.89 to 1 ) ( Flanged ) ( Model 44) ( Trac-Lok )
4.88 being slightly higher ratio than 4.89

 

The 4.88 27 is probably 39 ring gear teeth and 8 pinion teeth. 39/8 = 4.875, rounded to 4.88.
The 4.89 44 is probably 44 and 9, so 44/9 = 4.888... rounded to 4.89.

 

The main reason to not use a 4wd on hard surface is the distance traveled by the wheel, even if the ratio's are exactly the same, as soon as you turn the steering wheel you have screwed the distance traveled as the rear will always track a different arc (or distance) than the front will and put stuff in a bind, its the reason AWD vehicles have a viscous drive or similar between the front and rear driveline.

 

^That's why the NP 203 tcase had a differential built into it, so the full time Chevy trucks could have full time 4wd. Took the front driveline out and the truck wouldn't move until I put it in 4wd hi.

 

Ditto on the original Quadratracs. The BW 1339 has a differential between the front and rear driveshaft outputs, plus a means to lock it solid if desired.
-Donny

 

back in the early 70's I worked in gas stations and sold and mounted many tires (on a manual changer) often times people could afford only 2 tires on their 4x vehicles, we would only sell them two if they were the same size as the retained pair and the new always went on the front axle. Sizing up or down, you had to buy 4.
Timgr I think you're right. I have a pending fluid change and will check when I have the covers off.