Do some gears lower than 3.50 need a factory case clearanced ??

[winr1]

A Friend who used to build/sell 9" 3rd members allowed, some gears lower than 3.50 may need a factory case clearanced

Any had a problem such as the above ??


Also, for my F100 am lookin to get some type of carrier that will power both rear wheels under power

I was readin up on a helical type, was is yalls opinion on something street driven please



Ricky.

[chris401]

I hope this answers your traction question instead of derailing it. Ford used Dana 60 in the Camper Special F-100's. Mine is a 3.54 limited slip(Traction Lock). In the nine inch I have had success finding a 9" limited slip (Equalock) under trucks with a straight 6 and manual transmission. Some say they did't exist till the 70's and others say they personally had them as early as 64. Both of mine were tight enough to break the left tire loose from pavement while the right was off the road. PM or call me if your interested in my 5 lug Dana 60.

[BattlestarGalactic]

I have 3.89 in a stock case, with a traction lok without any issue(that gearset came originally in my wagon).  They offered deeper then that, though mostly in a nodular case, but I don't think there is any difference in the design of the case itself.

That 3.89 is in my black car(blown 390) and works just fine.  I installed a new Motorsport t/l in my 8.8 in my 95 f150 and on damp surfaces, going around a corner, I can feel a tire skip/drag occasionally so I know it still works.

[Falcon67]

I have 4.56s in stock C7 cases.  No issues or clearance problems.  Same with 4.11s, 3.73 and such.  I only buy brand name gears, typically stick with Richmond.  I do not buy "house" gears (Summit, Jegs, etc).  I deburr the cases, use ARP studs everywhere, solid pinion spacers and Timkin bearing sets.  Zero issues over the last 20 years on street or track. 

[jayb]

I've had to deal with interference on a couple of gear sets, 4.29s and 4.71s if I recall correctly.  But the weak point is not the gear, it is the case, so you SHOULD NOT grind on the case.  Grind on the gears for clearance, you won't hurt the strength of the gear and the case maintains full integrity that way.

[winr1]

Thanks much guys :-)



Ricky.

[pbf777]

     In the original applications from the O.E. the cases had an additional "clearance" machine operation for the numerically higher gear set (perhaps starting at 3.89/3.91 : 1 (?) and up) intentions, executed on the loop cast to retain the pinion pilot bearing (R1535TAV), as the inside "toe" of the ring gear intruded.

     The later aftermarket gear sets had a reduction in this area of the ring gears' profile to permit their installation with a reduction of difficulty.         

     Scott.

     

[Falcon67]

Probably why I never saw any issues over the years - never used factory gear sets.

[6667fan]

This summer I had a Ford r & p 4.57 set put into an Eaton carrier. Mike Wzorek elected to relieve the area around the pilot bearing. I thought he said .030 had to go away. He knows the intended use of my car. His brother Carl and him have been setting up diffs for me since circa '75.

JB

[pbf777]

     Unfortunately, this clearance relief weakens this casting area supporting the pilot bearing, although under the vehicle acceleration load the force is greatest in the direction of the support web, this area is particularly vulnerable to failure if the pinion bearing preload is not maintained, thereby allowing excessive movement of the pinion head and transfers excessive responsibility to the pinion pilot bearing, and I have witnessed failures.       

     Therefore, back when all we had were O.E.M. gear sets and cases available, to reduce this intrusion and otherwise sum of material removal from the casting required, I would chuck the ring gear in the lathe, spun at a good speed, and applied an air powered disc sander, with the 60-grit, 5-inch flex-disc, at a high speed, and remove the required sum of material from the gear profile.  This execution, with reasonable technique was surprisingly quick an presented a good appearance. And for the naysayer, this reduction in the profile was practiced later by the aftermarket gear producers, this being a surface of little consequence in the gear set relationship anyway.       

     Scott.   

[Falcon67]

>Unfortunately, this clearance relief weakens this casting area supporting the pilot bearing,

My thoughts exactly.  I deburr that area but don't remove any material.  I've seen that fail, then if the load is high enough (drag racing on slicks under sufficient power) the nose of the casting fails with the pinion, yoke, casting nose piece, bearings and all coming out in a convenient sub-assembly.  Another fail mode is cap spread allowing the pinion to put leverage on the upper part of the ring gear teeth and breaking some of those off. 

[pbf777]

   .............I would chuck the ring gear in the lathe, spun at a good speed, and applied an air powered disc sander, with the 60-grit, 5-inch flex-disc, at a high speed, and remove the required sum of material from the gear profile. 
     Scott.   

       Oops, I forgot the "DISCLAIMER"!     

       Note that I have only expressed practices done in the past, (you know,............. when men were men, but one generally noted that machinist before retiring often were missing a finger or two!) and not advised any one to execute a process that probably would send our favorite O.S.H.A. representative into fits; once witnessing the proximity and potential injury of an operators' hands and arms to a spiraling saw toothed ring gear at speed while the individual is attempting to form a smooth progressive radius with hand tools upon the gears toothed inside diameter, and no guards or other protection.       

      Note: I only have a couple of crooked fingers,............so far!       


      Scott.

     

[TomP]

Actually the Dana 60 in an F100 isn't a matter or being a Camper Special but of it being over a certain GVW and having limited slip. Ford didn't use the EquaLok or TractionLok in pickups until the 70's. So any "posi" got a Dana 44 below the GVW break (probably 5500lbs?) and a Dana 60 above that. I think the 4x4's only had the 44 rear if it wasn't an open 9".
Seems like it didn't matter what engine, I had a Dana 60 five lug from a six banger. They all seem to be 3.54 or 4.10's.