10" Drum Upgrade worth it?

[ratdude747]

My BII had a plastic diff cover, FYI, so I don't think that being plastic makes it an 8.8 for sure.

Edit: grabbed the owner's manual, it shows 3.08 gears with 4.0 and standard cab if I'm reading it right.

Can't believe Ford would go to the trouble of making two different drum brake sizes, all that would seem to accomplish would be to make the supply chain more complicated. Who knows......

Mine is definitely RABS, listed on the window sticker

When I changed the fluid awhile back, I bought an 8.8" gasket and the bolts matched up. Leaked terribly (ended up redoing it with The Right Stuff instead), but the bolts matched, confirming it is an 8.8.

My 1995 3.0 I had before had a 7.5 in it... metal cover. So does the 8.8 in my 1984 F150.

 

[MikeG]

My BII had a plastic diff cover, kind of dumb for a 4x4. Got a steel 7.5 diff cover from the JY. My two wheel drive pickup has a steel diff cover, go figure.... sometimes Ford makes no sense at all.

 

[Dirtman]

Plastic does have a very distinct advantage of not rusting. I've seen plenty of steel diff covers with rust holes in them. I still wouldn't use a plastic diff cover, but there is a rationale to it.

 

[franklin2]

Can't believe Ford would go to the trouble of making two different drum brake sizes, all that would seem to accomplish would be to make the supply chain more complicated. Who knows......

After you own and work on Fords for awhile, you get used to this. Don't try to figure out the reasoning behind anything they do.

 

[adsm08]

My BII had a plastic diff cover, FYI, so I don't think that being plastic makes it an 8.8 for sure.

Edit: grabbed the owner's manual, it shows 3.08 gears with 4.0 and standard cab if I'm reading it right.

Can't believe Ford would go to the trouble of making two different drum brake sizes, all that would seem to accomplish would be to make the supply chain more complicated. Who knows......

Mine is definitely RABS, listed on the window sticker

Having the two sets of brakes didn't complicate the supply chain at all. The 7.5 with eh 9" brakes was already a thing, the 8.8. with the 10" brakes was already a thing in other vehicles. The 10" backing plate with the smaller hub pattern for the 28 spline 8.8 was the only "extra" part.

And no, the plastic cover means nothing. The 7.5 in my B2 has it, none of the 8.8s I've ever had did, but I've seen 8.8s with plastic covers, and owned 7.5s with metal ones.

 

[MikeG]

But the factory would have to keep track of which 8.8 went on which 4.0.... I guess they already had a 7.5 axle, eh what's one more part in the chain. You have to wonder if a 4.0 ever went out with a 7.5 axle by mistake, or an 8.8 going out with one of the smaller engines.

I've worked on a Model T, so yeah I've seen some questionable engineering!

 

[ratdude747]

Looked underneath... it's a 3.08. Why I had "2.80" in my memory, I dunno.

 

[19Walt93]

3.08's with an overdrive transmission wouldn't work here, I hope you live in a flat area. Plastic rear end covers, intake manifolds, valve covers, etc. weigh less than steel or aluminum, that's why they use them. Less weight has the same effect as adding power but also increases gas mileage. And they don't rust or corrode. It's easy to tell a 7.5 from an 8.8: 7.5 rear covers are flat top and bottom with curved sides and an 8.8 looks like a square with the corners rounded off.

 

[Dirtman]

 

[adsm08]

But the factory would have to keep track of which 8.8 went on which 4.0.... I guess they already had a 7.5 axle, eh what's one more part in the chain. You have to wonder if a 4.0 ever went out with a 7.5 axle by mistake, or an 8.8 going out with one of the smaller engines.

I've worked on a Model T, so yeah I've seen some questionable engineering!

The 8.8 was an option on the smaller engines, and was quite common on V6 4x4 trucks. I know a guy here in town who has owned at least 1 3.0, 4x4, 8.8 Ranger.

 

[MikeG]

Huh. Did not know that. Guess when you ordered out of the book back then, you got what you wanted (hopefully).

I've known multiple people who ordered vehicles out of a book, but none of them recently.

 

[ratdude747]

3.08's with an overdrive transmission wouldn't work here, I hope you live in a flat area. Plastic rear end covers, intake manifolds, valve covers, etc. weigh less than steel or aluminum, that's why they use them. Less weight has the same effect as adding power but also increases gas mileage. And they don't rust or corrode. It's easy to tell a 7.5 from an 8.8: 7.5 rear covers are flat top and bottom with curved sides and an 8.8 looks like a square with the corners rounded off.View attachment 55501

In the 1995 4.0 Ranger, the 3.08 does fine. No real complaints.

In the 1984 4.9 F150 (AOD trans), its 3.08 is honestly gutless. Highway driving (in anything but purely flat land) is almost impossible to use cruise control without the engine bogging or constant gear shifting (depending on how the TV cable is tuned). I've considered regearing it slightly, but I haven't felt like spending the money and time on it. I know of people with similar stock (or close to stock) carbed I6's who have 3.08's and love them... but AFAIK they're all running C6's (which have no OD, obviously).