From what I have read on Pirate it seems like the 4.88 has a different housing and gearing. Are they talking about the 3rd member housing or the axle housing?

Basically I would like to eventually have higher gears (so I can use 33" or better with the auto trans) in the rear housing as well as an e-locker but I'd like to know if I have to replace the entire axle to do this...

I found the quote from pirate:
"Note: The above does not apply to the somewhat rare "3rd type" of R&P, the factory 4.88's. These can only be used in the factory 4.88 housing. This housing is different than all the others, and won't accept ANY aftermarket R&P or factory gears of any other ratio. If you have one of these 3rds, it will be that way forever. Please don't sell this 3rd (or god-forbid an empty housing) to anyone without fully explaining what they are getting, think of the potential frustration."

link is here, about 9/10's of the way down:
http://www.pirate4x4.com/forum/showt...hreadid=228681

 

Wow, what an incredibly confusing explanation for something that's not that complicated! The factory 4.88's have an offset pinion, so the only thing that will work in that THIRDMEMBER is factory 4.88's. The axle housing itself is the same, and any other "pretaco" third will fit in there, or an elocker will fit with minor modifications:
http://www.4x4wire.com/toyota/tech/electric_locker/

For all your diff questions:
http://home.4x4wire.com/erik/diffs/

Note for 33's with an auto, you're looking at 5.29 at least, I would go with 5.71's actually. (Molly's 4Runner tachs 2500 RPM at 70 MPH with 35's and 5.71, and it's a DOG)

 

Thanks, TC. 5.71 does seem to be the smarter choice because I would like to do this gear swap once in the rear and be done with it, even if I ended up with a SAS and therefore bigger tires (35's like Molly).

Why does Marlin not recommend 5.71?
http://www.marlincrawler.com/htm/sus...n/sas_inst.htm

Inchworm and trailgear also don't carry 5.71 gears. Do you have to install them yourself then?

 

Yes you can. Zuk has done it.

James

 

The lower you go, the more critical the install, and therefore the more problems people have. Interestingly, 5.29's will be sold and even warrantied, but 5.71 won't despite the fact they both have 7 teeth on the pinion...

 

In a nutshell. The axle housing for a factory 4.88 geared truck is no different than any other ratio. The difference lies in the third member.

Factory 4.88 gears will only fit a factory 4.88 third member. If they made a factory 4.88 e-locker third, you can modify any axle housing to make it fit or put it in any factory e-locker axle housing. Otherwise, you can install aftermarket 4.88 gears on any non-4.88 factory e-locker third and modify the housing to fit or once again put it in any factory e-locker axle housing.