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1985 rear end lash

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Old Mar 21, 2009 | 11:12 AM
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Default 1985 rear end lash

I get a big "clunk" when I am going over 35 mph and then take my foot off the gas. I checked the universals and they are ok, I have a new transmission mount in. I was told that it is the "lash" in the rear end and that it is easier to replace the whole rear end with one from the boneyard than to fix this. Does this sound right? or is there any other suggestions?


Thanks
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Old Mar 21, 2009 | 01:34 PM
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If you can find a low miler, then yes, super cheap and super quick to change.
First I would really bust the pumpkin cover open and inspect for the real lash. You can't hold the rear wheel and U-J collar, twist opposites and now know your lash? No way!

Say, you have a lot of gray at the bottom of the pumpkin? Then, I would say you have more than a knock. That gray stuff was mix and is still whirling like windmill in there and all that junk is eating your bearing surfaces.

Pick up about 5-6 sheets of pad paper or copy paper. That is your backlash for heat expansion. Like I said, it is going to be hard to find that kind of knock. Double the paper sheets and maybe there is you knock with the bearings wearing out and the X to Y is moving away from the Z is you do not have the 3 dimensions within spec.
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Old Mar 21, 2009 | 07:58 PM
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Originally Posted by galaxie289
I get a big "clunk" when I am going over 35 mph and then take my foot off the gas. I checked the universals and they are ok, I have a new transmission mount in. I was told that it is the "lash" in the rear end and that it is easier to replace the whole rear end with one from the boneyard than to fix this. Does this sound right? or is there any other suggestions?


Thanks
Rear ends are tough to repair or rebuild if you don't know what you are doing. I think it would be best to get a junkyard one and replace the whole thing. They give warrantees so if you're not satisfied with the one they give you then swap it out.
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Old Mar 21, 2009 | 08:13 PM
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To check ring gear backlash you need a dial indicator and marking compound. Shimming and checking backlash isn't too hard but it will drive you nuts if you don't do it correctly.
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Old Mar 22, 2009 | 08:55 AM
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Default back lash

Thanks for the info. I think I will just replace the whole thing. I can get a low mile rear from a 91 150 w/ 3.08 for $75
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