I shortened a 1960 Mercury M100 pickup 9" axle. It was in storage for over 60 years with about 6000 miles on it because it was supposed to be "special" . Anyway, it had an open 3.55 WAC 4210-A-"C" FORD GEAR SET. It came out of a WAR case. It all went back together with a 1973 Trac-loc carrier and now hard hits the case on the ring gear bolts. How is this possible?
Different series carrier. Meaning the flange for the ring gear on the carrier isn’t like before. Did you stand the two carriers side by side and compare flange heights? Here’s and example
A buddy of mine brought over posi type carrier to put in his 9 inch. I started ***embling the pieces but the posi unit wouldn't quite fit the case. I had never run into that. I didn't want to grind on the case and gave it back to him. He took it somewhere that evidently installs a lot of posi units and they said they grind the case for clearance all the time. I've put a few together with posi units, but they were all stock Ford Trac-Loc and there was no grinding required.
I am not aware that the Ford 9-inch rear has carrier breaks. I have been told that the 2.49:1 ring and pinion had a different carrier, but I have never seen one in the wild.
I realize the ring gear is too thick to move right toward the pinion. But what gets me is that the open center carrier fits like it's supposed to. It's the trac-loc that seems to be the problem. Is it possible that the 1960 WAR case was never cast for trac-loc clearance?
Its amazing the pattern is right on the money. But then, the whole issue is to the outside of the ring gear bolts to the case interference. Got to be that case was not cast for trac-loc clearance. Didn't have them in 1960. Equa-loc may be different. Been a long tome since I worked one of those. Don't even know if THEY were around in 1960. Looked at a lot of pics, even with the fat ring gear. All were either single bar trac-loc, or 4 bar WAR with open diffs.
If you’re sure the pattern and backlash are correct,just grind the case for clearance.I do it all the time. Not big deal.
Open differential, Detroit Locker, and solid spool take the same ring gear bolts. Traction-Loc differential takes a different bolt, ....bolt head is smaller diameter and thinner head along with different length. Note what is said at bottom of listing: Ford 9 Inch Ring Gear Bolts Set Of 10-Broncograveyard.com Ford 8" & 9" TracLoc Ring Gear bolt-Broncograveyard.com Grinding the case is common, especially with aftermarket Trac-Locs since they often have a slightly thicker end cap......the thinner stock ford Trac-Loc end cap is where the stock units typically fail.....they break inboard of the ring gear bolt circle and blow the end cap off the differential.
I don't know about "shrinkage". What I DO know is that the thick ring gear isn't hitting. The thicker ring gear is shifting the ring gear and ring gear flange to the left as seen from the rear to mate properly with the pinion. When this was ***embled with the open diff, there is no clutch pack buldge, or bolt heads located on that buldge to interfere with the case. All good. When I put the same gear that came out of the WAR case back in, but on the trac-loc housing, the interference developed. Looked at dozens of 9" cases, several of which had 3.55 thick ring gears. Many were WAR cases. None showed me the view I needed to see. FINALLY, I found a thick 3.50 ring gear in a WAR housing with the view I needed. 69/70 Ford F100. The inner bracing on that case joggled twice to the left where mine was smooth and much thicker. This provided both clearance for the ring gear mounting flange and the farther left ring gear bolts spotfaced into the clutchpack bulge on the Trac- Loc. Well, so much for thinking that a WAR case is just like any other WAR case. Or any 9" case thinking the differences are just in the rib configuration, other than some N cases having beefier pinion bearng support. Learn something new every day. Thanks for you inputs.
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