9" rear end question
Thread Starter
|
New User
Joined: Sep 2013
Posts: 15
Likes: 0
From: San Diego County, CA
9" rear end question
Hey guys,
So I've heard the trick where you can determine if it's limited slip or not by jacking up the rear where both tires are off the ground (in neutral, no parking brake) and turning one tire; if the other tire spins in the opposite direction, it's not a limited slip, and if they spin in the same direction, it is limited slip. I've got a 9" rear in my '56 with the metal ID tag long gone. I pulled the plug on the 3rd member side to check fluid and along with a ton of metal shavings (my hand looked like I slapped a stripper with the resulting "glitter"), I didn't see/feel any fluid so I figured I'd add some. Well, before I buy the kind with/without additive, I figured I'd confirm its not posi. When I tried the method above and turn one wheel forward, the other does nothing. Same result when I turn the opposite wheel...they both rotate the driveshaft, but not the other wheel. Is this common? Thanks!
So I've heard the trick where you can determine if it's limited slip or not by jacking up the rear where both tires are off the ground (in neutral, no parking brake) and turning one tire; if the other tire spins in the opposite direction, it's not a limited slip, and if they spin in the same direction, it is limited slip. I've got a 9" rear in my '56 with the metal ID tag long gone. I pulled the plug on the 3rd member side to check fluid and along with a ton of metal shavings (my hand looked like I slapped a stripper with the resulting "glitter"), I didn't see/feel any fluid so I figured I'd add some. Well, before I buy the kind with/without additive, I figured I'd confirm its not posi. When I tried the method above and turn one wheel forward, the other does nothing. Same result when I turn the opposite wheel...they both rotate the driveshaft, but not the other wheel. Is this common? Thanks!
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
1968 was the first year that Ford offered the 9" with Limited Slip in F100's.
1957/67 F100's with Limited Slip came with Dana rear axles.
All 1957/80 Passenger Cars with 9's were available with Limited Slip.
1957/67 F100's with Limited Slip came with Dana rear axles.
All 1957/80 Passenger Cars with 9's were available with Limited Slip.
Thread Starter
|
New User
Joined: Sep 2013
Posts: 15
Likes: 0
From: San Diego County, CA
-Brent
Fleet Owner
Joined: Jul 2004
Posts: 27,303
Likes: 1,062
From: NM
Thanks for the info. I know it's not stock, not sure what it came from. After some minor web-searching I know it's a 9" based on the presence of a vertical rib on the 3rd member and the fact I can't get a socket straight on the bottom two bolts. It's also got the signature "hump" in the rear of the case with 2 dimples and a large fill plug, so that's where it's confusing. I've read the 66 and earlier cases had smooth backs, so that would put it 67 and later, but the same source (Kevinstang's Ford Nine Inch Differential Page +) says they lose the fill plug after 67. It may not be a stock fill plug. Anyway, it's working as is, so I'm not inclined to pull it apart to check numbers until needed. Thanks for the responses.
-Brent
-Brent
Exactly. I think you'll find the axle tubes full of crap, and the wheel bearings on their last leg (if they are the type that gets lubed by gear oil).
Trending Topics
Senior User
Joined: Jul 2003
Posts: 322
Likes: 1
From: FL
I don't have my history books with me, but i recall the Equa-Loc being available prior to the '67 date listed above. The Traction-lok was definitely not available until 67/68 timeframe, but I'm fairly certain the Equa-loc was available several years earlier, possibly '64.
It's a completely different animal than the traction-lok, using belleville springs to apply an equal load to the side gears as opposed to a spring block. They're not common and almost impossible to get parts for. I had one a long time ago and it's the only reason I know about them...
As for the "right" lube, early traction-loks used grooved/serrated steels instead of clutches, so it doesn't matter if you use the friction modifier or not. And most folks who run any power through a traction-lok don't put the modifer in anyway because all it does is make it easier to slip, which wears them out quicker. They can be nearly as noisy and somewhat harsh as a detroit locker when freshly rebuilt and used without friction modifier...but that's when they work best!
For the OP: pull the pumpkin - it won't cost you anything but a couple hours. Find out where your "glitter" is coming from...could be a worn out T-lok...although I've never seen one so worn out the other tire did nothing when "tested" in the manner in which you did.
It's a completely different animal than the traction-lok, using belleville springs to apply an equal load to the side gears as opposed to a spring block. They're not common and almost impossible to get parts for. I had one a long time ago and it's the only reason I know about them...
As for the "right" lube, early traction-loks used grooved/serrated steels instead of clutches, so it doesn't matter if you use the friction modifier or not. And most folks who run any power through a traction-lok don't put the modifer in anyway because all it does is make it easier to slip, which wears them out quicker. They can be nearly as noisy and somewhat harsh as a detroit locker when freshly rebuilt and used without friction modifier...but that's when they work best!
For the OP: pull the pumpkin - it won't cost you anything but a couple hours. Find out where your "glitter" is coming from...could be a worn out T-lok...although I've never seen one so worn out the other tire did nothing when "tested" in the manner in which you did.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
Equa-Lok, Limited Slip, whatever you want to call it, was not available in F100's with 9" until 1968.
If customers wanted Limited Slip, the only way to get it, was with one of these optional Spicer/Dana axles: 1959/67: Dana 44 / 1963/66: Dana 60.2 / 1963/67: Dana 60.3
The only "history books" that apply are the 1957/63 & 1964/72 Ford Truck Parts Catalogs. Take a look-see, you won't find a 9" with Limited Slip until 1968.
If customers wanted Limited Slip, the only way to get it, was with one of these optional Spicer/Dana axles: 1959/67: Dana 44 / 1963/66: Dana 60.2 / 1963/67: Dana 60.3
The only "history books" that apply are the 1957/63 & 1964/72 Ford Truck Parts Catalogs. Take a look-see, you won't find a 9" with Limited Slip until 1968.
Cargo Master
Joined: Apr 2005
Posts: 3,338
Likes: 167
From: Harpswell Maine
Equa-Lok, Limited Slip, whatever you want to call it, was not available in F100's with 9" until 1968.
If customers wanted Limited Slip, the only way to get it, was with one of these optional Spicer/Dana axles: 1959/67: Dana 44 / 1963/66: Dana 60.2 / 1963/67: Dana 60.3
The only "history books" that apply are the 1957/63 & 1964/72 Ford Truck Parts Catalogs. Take a look-see, you won't find a 9" with Limited Slip until 1968.
If customers wanted Limited Slip, the only way to get it, was with one of these optional Spicer/Dana axles: 1959/67: Dana 44 / 1963/66: Dana 60.2 / 1963/67: Dana 60.3
The only "history books" that apply are the 1957/63 & 1964/72 Ford Truck Parts Catalogs. Take a look-see, you won't find a 9" with Limited Slip until 1968.
Bill what is the part # for a ring and pinion for a 3.70 ratio 9 inch (28 spline) to fit a 1971 F100?
Senior User
Joined: Jul 2003
Posts: 322
Likes: 1
From: FL
Equa-Lok, Limited Slip, whatever you want to call it, was not available in F100's with 9" until 1968.
If customers wanted Limited Slip, the only way to get it, was with one of these optional Spicer/Dana axles: 1959/67: Dana 44 / 1963/66: Dana 60.2 / 1963/67: Dana 60.3
The only "history books" that apply are the 1957/63 & 1964/72 Ford Truck Parts Catalogs. Take a look-see, you won't find a 9" with Limited Slip until 1968.
If customers wanted Limited Slip, the only way to get it, was with one of these optional Spicer/Dana axles: 1959/67: Dana 44 / 1963/66: Dana 60.2 / 1963/67: Dana 60.3
The only "history books" that apply are the 1957/63 & 1964/72 Ford Truck Parts Catalogs. Take a look-see, you won't find a 9" with Limited Slip until 1968.
So if someone wanted a limited slip prior to 68, they could find one in the junkyards, or perhaps over the counter, as early as 64. Factory? I never claimed that. Available to the DIY-er? Absolutely.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
I've decoded 100's of 1959/67 F100 Warranty Plate codes for FTE members, have the Ford truck parts catalogs.
So I know that 1959/67 F100's with Limited Slip only came with Spicer/Dana rear axles.
And, I bought a 1965 F100 brand new 3/1965, sold it 11/2009.
Its AXLE code: A4 = Spicer/Dana 44 Rear Axle / 3.50-1 / Limited Slip / 3,300 lbs. Rear Axle Capacity.
Senior User
Joined: Jul 2003
Posts: 322
Likes: 1
From: FL
Not in F100's, Passenger Cars only.
I've decoded 100's of 1959/67 F100 Warranty Plate codes for FTE members, have the Ford truck parts catalogs.
So I know that 1959/67 F100's with Limited Slip only came with Spicer/Dana rear axles.
And, I bought a 1965 F100 brand new 3/1965, sold it 11/2009.
Its AXLE code: A4 = Spicer/Dana 44 Rear Axle / 3.50-1 / Limited Slip / 3,300 lbs. Rear Axle Capacity.
I've decoded 100's of 1959/67 F100 Warranty Plate codes for FTE members, have the Ford truck parts catalogs.
So I know that 1959/67 F100's with Limited Slip only came with Spicer/Dana rear axles.
And, I bought a 1965 F100 brand new 3/1965, sold it 11/2009.
Its AXLE code: A4 = Spicer/Dana 44 Rear Axle / 3.50-1 / Limited Slip / 3,300 lbs. Rear Axle Capacity.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
Dealer installed kit: B9AZ-4880-A listed in Ford Passenger Car Parts Catalogs, not listed for F100's with 9" rear axles in Ford Truck Parts Catalogs.
The fact is, if a 1957/67 F100 9" with Limited Slip was found in a junkyard, the axle was swapped, because it was NOT available originally.
And the swapped rear axle would be from a 1968/72 F100, because...
Beginning in 1973, the 9" rear axle is wider, as FoMoCo increased the distance between the inner frame rails behind the cab from 33 1/2" used previously to 37 1/2."
1948/52 F1's and 1953/56 F100's came with Spicer/Dana rear axles. Because the rear frame rail width increased in 1973, people that swap 9's into these truck use them from 1957/72 F100's.
See my signature, I was a Ford parts guy for 35 years (1962/97), so I didn't start doing this jazz yesterday.