So I blew up my 8.8 and swapped in a 9 inch from a 74 f100

The gawr on the 91 was something like 3778 the 74 axle I thought would be 3750 like my now sold 76 f150

Its 2900 but from what I can tell the low numbers are from the tapered bearings and swapping the axleshaft and bearing to the other kind wouldgive me a 3300 pound rear axle

So my thought is the same process could be used to give me a 3750 pound rear axle the question is what all parts do I need

 

It seems to be the only difference between the axles are the shafts and bearings

the shafts are thicker at the bearing and the id changes on the bearing

So now just to find the right parts

 

Make sure the axle housing tube ends don't taper down at all.

 

What do you mean taper down

 

Sometimes they can be smaller at the end, where the truck stuff won't fit - but I don't know - definitely something worth checking.

 

The outside diameter of the bearings are all the same as far as i can tell so I assume it hasn't been tapered

 

So how did you "blow up" that 8.8?
Did the axle housing fold up from a heavy load in the bed?
Or was it a broken R&P or axle shaft doing burn outs?
I also did not know they installed 8.8's in them year trucks?
Dave ----

 

It's a 91 and the 8.8 blew up after towing a vehicle across country

by blew up I mean it got parked I drove the towed vehicle for a couple weeks and then i went back and I backed up then forward again and the pinion got sucked down into the pumpkin and seized the axle due to a very bad bearing

 

I use it for truck stuff so i need the stronger axle

 

You'll likely end up with less money spent buying the correct axle for your truck. Common Aftermarket 9" Axles are setup for the 1 9/16" ID tapered bearings. To go to the ball bearing style you would need to find the correct stock axles which have a bearing ID around 1 1/2"

 

I put in a crush sleeve eliminator and the new yoke and it has a whine under load it's probably low on oil and I think one of the wheel bearings is bad anyway both seals definitely are