[FordDude]

I have 3 carrier housings, and who doesn't? One from a 3.25 equa-loc, 2.75 that came with the axle housing from a '70 Cougar, and the last one is from a 64.5 K coupe Mustang with 3.89 gears. I was going to do a mix and match kinda thing, :: but it turns out that is not going to work. I am using the equa-loc and I put it together this afternoon. The clutches have been sitting in gear oil for the last week. I had already cleaned and painted the carrier housing from the '70 Cougar. I dropped carrier in place and it would not turn. I adjusted it back and forth and it would not turn. The extra thick 3.89 ring gear was hitting the pilot bearing housing. So I pulled the housing that the 3.89 gears were in out of my storage shed and lo and behold there is a difference. Note the arrows pointing to a notch in the pilot bearing housing. Also note that the 3.89 carrier has an "X" stamp on it whereas the 2.75 (and my 3.25) carrier has an "O". http://images.cardomain.com/member_img_a/247000-247999/247994_10_full.jpg
http://images.cardomain.com/member_img_a/247000-247999/247994_11_full.jpg
The reason that I wanted to use the carrier housing from the Cougar was because it has a drain plug in it. So I guess that I will have to drill and tap a drain plug in the old 3.89 housing. There is a place made for it, it just was not drilled and tapped. I just noticed another difference in the pilot bearings, "X" has 11 bearings and the "O" has 13. :: fd

 

[Arto65FB]

Thanks for the issue and pics. Having more than one carrier is what I have thought about. Swapping the pumpkin isn't that hard, having open 2.5 for highway and trak-lok 3.89 for street would be nice. Could be cheaper than T5 conversion.

 

[daveboys]

I have seen this problem fix in 2 ways one is to clearance the carrier. Not suggested by me since it weakens the carrier. The second is to have a machine shop under cut the ring gear. In the bigger ratio gears this is more of a problem, and some of the more expensive gears come undercut.

 

[fast500xl1]

take a die grinder and a carbide bit and make a "relief" area just like the early housing in the late one. I do it ALL the time and as FORD did it to use the thicker ratios(3.70-4.56 and lower) it will NOT weaken the case as long as you remove very little material as the factory does. it really doesn't take much to make it work.