Rear End Issues?
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Tuned
Joined: May 2003
Posts: 454
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From: College Station TX
Rear End Issues?
I have had this thud on take off for a while and it just gets more noticeable all the time. I had my driveshaft rebuilt so I'm pretty sure its not the slip joint spline. I lifted up the rear end this weekend and the pinion gear seems tight when I turned the driveshaft by hand. I turned the wheel by hand and it moves about 3/4" at the edge of the tire before I see the driveshaft move at the differential. Does this sound like a differential problem or is this typical? The thud is going to make me crazy.
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Joined: Jan 2006
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From: Malvern, Ohio
Well if you say your u-joints are good don't have those as a possibility in the brain. As for clearance of backlash you might be outta spec. The way you can check is get a Dial indicator kit from borrowing or buying. Set it up and measure what the actual backlash is. If you have an 8.8 axle I believe is .008 - .013 backlash open diff and .008 - .015 for limited slip.
Adjusting this measurement is done by shims so math is going to take place at some point to get you into the specification and the thub will go away.
Another possibility is your *Drive Pinion bearing* or crush sleeve can be worn n loose enough to let the freeplay happen that way also.
Is this an older vehicle or newer? what year and model exactly too so I can get the right backlash clearance for you.
Adjusting this measurement is done by shims so math is going to take place at some point to get you into the specification and the thub will go away.
Another possibility is your *Drive Pinion bearing* or crush sleeve can be worn n loose enough to let the freeplay happen that way also.
Is this an older vehicle or newer? what year and model exactly too so I can get the right backlash clearance for you.
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Tuned
Joined: May 2003
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From: College Station TX
I just noticed by signature didn't show up on my post but when I refreshed it reappeared. It has my truck information in it. Its a 95 F350 with the 10.25" open differential. 149K miles
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Tuned
Joined: May 2003
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From: College Station TX
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Joined: Jan 2006
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From: Malvern, Ohio
One thing I forgot to mention is there might be a complete overhaul kit for your differential out there. I think SKF has them but you can have the local parts guy look the parts up one by one also if you need to rebuild the diffy.
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Tuned
Joined: May 2003
Posts: 454
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From: College Station TX
Hey, Hemi, I totally forgot this whole time that I have the Ford factory service manual for this truck. I looked at the total backlash check procedure last night and according to it I'm still within tolerance. It says to put one wheel up while the other is on the ground, lock the driveshaft with a clamp and rotate the free wheel in one direction until it stops. I made a mark 12" from the center of the tire, rotated the tire the other way until it stopped and made another mark. The manual says if the marks are within 1" then the tolerance is acceptable. I am at 3/4". Have you checked using this procedure before? I also rotated the driveline easily by hand. It seems like the place there is a clunking is in the transmission. I don't know if that is to be expected when it's in neutral.
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Joined: Jan 2006
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From: Malvern, Ohio
I have never been told/tought that procedure, so its new to me and probably to more than a few people. As for the clunking in the transmission, I couldnt tell ya, this will be a fun one. I will see if I have a exploded view of the E4OD transmission and see whats what inside near the rear portion that could be the cause of this. Thanks for posting that procedure though.
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Tuned
Joined: May 2003
Posts: 454
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From: College Station TX
I am going to check the truck over a little better this weekend and look for anything else this could be. The manual has a lot of diagnostic procedures in it. I hope it's not the transmission, but if it is, mine is still under warranty. Every time I drive now, I'm trying to find the source of the thud. I wish I could hang underneath the truck while someone drives it. Maybe I should mount a video camera underneath.