Not a limited slip expert as my other 2 65s were both open 9" rears, so I have a question on my current 65 project. The truck sat for 9yrs before I bought it and I just got it moving a few months ago. It has a 9" with a posi rearend in it, not factory, but occasionaly makes a loud popping sound when turning slowly (pulling out of driveay, etc). It's fine when driving down the road. I thought it might be the clutches going out, but had someone tell me that Detroit Lockers do that normally. So, can someone with more experience with posi's tell me what does it do when the clutches are going out in the limited slip? I did top off the gear oil but did not replace it. I have a Dana 44 limited slip that needs brakes and a seal that I can replace it with, but don't have any experience replacing posi units. Not sure how hard this is or if that's the problem. I appreiciate any insite you can give me on this.

Steve

 

In my 89 I have to use a friction modifier or it gets goofy. Will have to wait for some one with more knowledge to chime in.

 

1959/67, and thru mid year 1968 F100's: When Limited Slip (L/S) was ordered, Ford installed Dana 44's. The 9" with L/S was not available until midyear 1968.

If you have L/S, you do not have a Detroit Locker which is a ratchet type rear axle. These rear axles were never installed in F100's, but could be bought at the parts counter.

No Ford had a Posi (or Posi-Traction) rear axle, because these are GM terms.

Dana 44 & Ford 9" with L/S requires 4 ounces of friction modifier to be added to the 90 weight gear lube. Without using the modifier, the lined clutch plates will burn up.

By this stage of the game, even if using the friction modifier since day one, the steel and lined clutch plates are prolly history.

 

Chris, thanks for answering. I'll try some of the friction modifier if no one has a better idea.

Steve

 

Bill, I know it's not factory as you decoded the #s for me earlier and the tag on the rear end matched what you told me (3.50 open). Thanks for that. My first question is as an aftermarket part, if the clutches go bad in a limited slip (sorry reverted to 30 yrs ago when I used to play with Chevys) does it make a loud popping sound when turning, or is this a side effect of the Detroit Locker only? Thanks again for all your help-Steve

 

When the clutch plates fail, the L/S no longer works, all sorts of grinding/popping noises will come from the rear axle.

Detroit Lockers were designed for the drag strip. In other words for straight-ahead performance....only.

Unknowing people used to install them in everyday passenger cars...then when they drove around corners and punched it...the Detroit Lockers self distructed!

 

Thanks Bill. It seems unlikely that the PO would put a Detroit locker in it as it is just the 352 3sp.