Broken Diff Pin Bolt is out!

Topic: Broken Diff Pin Bolt is out! (Read 2070 times) previous topic - next topic

Broken Diff Pin Bolt is out!

March 16, 2007, 10:23:42 PM

I dident want to hijack Thunder Chickens thread any more than I already have so I'm posting my resolution here. Thanks for all your help and the use of your thread Thunder Chicken.

I wanted to start with the least aggressive options first. So called my parts man try to track down a “special tool” for the job and he was able to find a place that had heard of such a thing but didn't know where to get one. While he was doing that I called the local Ford Service center and asked and they never heard of a special tool but had seen this often and suggested the small pick and if that didn't work then the BFH.

While Mark (my parts guy for 20 years) was doing his thing I went out and stood the rear on its side with the pin hole pointing down. I figured gravity on my side couldn't hurt, plus I was being optimistic hoping there were no threads on what was left and it would just FALL out (no such luck) I spent an hour and a half twisting this small screw driver in there and using my thumb nail on the screw driver as a Gage I could see it was coming out, slowly.
About halfway out it seemed to stop, No progress for quite some time.. I tapped the “Large Pin” back and forth a few times being careful not to gouge the small pin and then stopping it in the middle of it’s travel.. I seemed to make a LOT of headway after that.. so the last half I would tap back and forth then twist the screwdriver.. Tap, twist, tap, twist was out the last HALF in 10-15 min

The next person with this problem I would suggest trying tapping the large pin back and forth from the start.

Below is
the Good Pin out of the 7.5 rear
The small screwdriver used to turn it out
The broken pin showing it did indeed have one thread left.

Thanks again Everybody

Broken Diff Pin Bolt is out!

Reply #1 – March 16, 2007, 11:22:20 PM

I tried everything you mentioned (including standing the rear on end) and that would NOT move. I even tried magnetizing a screwdriver with an electromagnetic coil I've got (I usually use it for degaussing CRT's). Bitch would NOT come out. Beating the SOB out was my last, and thankfully successful, resort. Glad yours was easier :D

So, how are your axles?

Broken Diff Pin Bolt is out!

Reply #2 – March 17, 2007, 12:21:49 AM

Yea if none of the above works BFH would be the only option. this little piss ant pin is the keystone of one of these rear's. without it NOTHING comes apart. Axels, Backing Plates, Gears, NONE of it can move with this stupid little pin still in the hole.
And it would seem IT is the weakest link in these rears (breaks quite often). I frequent another site where these rears are used alot.. this is by no means a NEW problem as several there have enjoyed our same experiance. Some got lucky like me... others had to BFH it like you.

Luckly it seems from your experiance and others I have read about that the carrier is stong enough to handel the BFH without hurting it anyway... so thats good.

Also if you notice on that pin from the 7.5 rear.. these pins take at least a little bit of a beating in there. The 7.5 was 100% origional thats what the pin looked like when it came out of the hole.

Broken Diff Pin Bolt is out!

Reply #3 – March 17, 2007, 09:26:39 AM

Quote from: Jim_Miller;134974

Also if you notice on that pin from the 7.5 rear.. these pins take at least a little bit of a beating in there. The 7.5 was 100% origional thats what the pin looked like when it came out of the hole.

I think that's likely more of a problem with a pegleg rear. Any time one wheel is spinning it puts a hell of a load on that pin (and bolt) as the spider gears spin on it. Traction lock won't have that problem because you don't spin only one wheel, so the spider gears stay relatively still (they rotate when turning around corners, of course). I had one in a Cougar 7.5 that was so bad the spider gears welded themselves to the pin and I had to cut it out with a torch...

Broken Diff Pin Bolt is out!

Reply #4 – March 17, 2007, 03:10:26 PM

New question.. or observation as one may see it..
Had Mark make sure he had a new pin in for me when I picked up the new calipers, outer bearings, and seals, and he knew off the top of his head he had a pin in for a GM rear but not sure about ford… as it turns out it’s the same pin. Both list the same Part Number, GM and Ford.

Is this a Dana rear or something?