Bum Posi unit?

[71chally416]

I haven't had a chance to check it, but I am going to pull it and I'll post later what I find. I am curious about the pinion snubber. The low (non-adjustable) snubber and the adjustable are a world of difference in regards to height, even with the adjustable at the lowest setting. I have an adjustable installed and it has about 1 1/2 inches of clearance to the body. I'm not sure what is proper and know it's a lot of trial & error to get the car to hook up right. Any input??


                                                         Matt B.

The only purpose of the snibber is to keep the springs from winding up. Same thing as the bolt on traction bars with the rubber snubbers that hit the bottom of the springs, but alot less weight and you don't have those things hanging under the car to hit stuff in the road. When I put my snubber on I had to wack a good portion of it off with a hacksaw to get the right height. It seems like it was made for a car with air shocks with 120lbs of air  And the gap is supposed to be measured with the driver sitting in the car and the car on the ground on jackstands on the rear housing (NOT the frame!). Here's mine installed and the stance of the car. I'm wondering if the noise you hear is the snubber wacking the floorboard. If you went to a lower (numerically higher) gear ratio it will attempt to wind up your rear much quicker and easier because of the added gear reduction. I've seen the floor actually buckle and dent with big block stickshift cars. You need some airgap with the car on the ground and you sitting in the car.

[moparmaniac59]

Well,
I pulled the axle shafts and took a look which I shoulda done when I was installing it. There are no pins in the thrust block. So it was a post 1970 sure grip. No problem there. It made me even more puzzled. I managed to get in touch with Cass, the Doctor Diff man (great guy). He said the symptoms are indicative of stuck clutches. This unit sat for 5 years prior to me installing it. So there we have it. The sure-grip needs rebuilding. I loose again. I think that one cost me about $300 bucks.  :pullinghair:I went yesterday to look at a complete rear end drum to drum with a 742 case 3:91 posi center section installed. It sounded like a really good set up and low miles. I made an appointment to look at it. I talked to the guy twice that day to make sure everything was set up. It was about an hour drive and i had cash in hand. I arrived 5 minutes EARLY. He met me at the vehicle (I guess he didn't want me  get out!!) He said he "Tried" to call me although the cell phone never rang. He told me he had just sold it to a friend who came by with cash. I told him politely that he was a jerk (I really was peeved). That we had an agreement, I arrived on time with cash & now have an hour drive home for nothing!! Once again I took it up the wazoo!!!  :villagers:Now I am putting the old center section back in so I can make it to Mopar Madness at Virginia Motorsports Park this weekend. Should be a great show & drag races! Hopefully Moparal will hook me up with his 3:91 unit!! Thanks for all the input you guys have provided. It's all part of loving the hobby!!

                                                                     Matt B.

[Moparal]

I sent you a reply in email