1986 Blazer 8.5 Gov Lock Posi options
 

Hello All,

My son Tyler is driving my restored 1986 K5 Blazer and was complaining about some rear wheel chatter when turning left. Since he is in school for auto mechanics, I told him could be posi binding and to pull the rear to drain the fluid take a look. Might just need more limited slip additive.

The rear is a GM 10 bolt 8.5 3.08 Posi. I guess this means it is a Gov Lock type. No surprise after 275,000 on it that it finally grenaded. Lots of little shinny metal pieces on the magnet and the bottom of the housing.

The truck is stock 305 (over 30) with a mild tow cam. He Does not do much towing. One time he did tow a buddy's car 300 miles home last year. It is his daily driver. Gas mileage means more that anything right now.

What are the best options for replacement?

A. Rebuild the posi clutch pack? (heard GM disc the parts in 2010)
B. Replace is with a Reman unit?
C. Get a unit from a junk yard?
D. Replace with aftermarket?
E. Clean out the debris and keep driving it?
F. Other

Remember he is in school with only a part time job at AutoZone, so he needs to make every penny count.

Thanks,
Greg

Re: 1986 Blazer 8.5 Gov Lock Posi options
 

He can go to a opean rear. I think a opean new carriers from GM is about $90.00,or weld it up, a poor man's POSI. *Paul

Re: 1986 Blazer 8.5 Gov Lock Posi options
 

We had an 87 3/4 ton suburban that would chatter the same way especially after driving straight on the highway for extended periods. Despite what additives we used, the chatter never went away. Other than the annoying grumble when making a sharp turn, no harm resulted in 15 years of use. It chattered since day one.

Re: 1986 Blazer 8.5 Gov Lock Posi options
 

DO NOT put another GOV lock in it. They are the worst units on the planet. Just use a standard 3 series 8.5" posi unit from any 1971-1987 passenger car. They usually run around $125 for a used unit plus it would be maintenance free if it was just used as a daily driver.

Or, as suggested above, put an open carrier in it. This would be the cheapest and easiest fix for the least amount of money.

-Matt

Re: 1986 Blazer 8.5 Gov Lock Posi options
 

check Craig's list or pull a part, he should be able to find a whole rear end for 50 bucks to get by on.

Re: 1986 Blazer 8.5 Gov Lock Posi options
 

Try some lock to lock figure eights in reverse to free it up after checking fluid.


*that's right out of the GM service manual [img]<<GRAEMLIN_URL>>/scholar.gif[/img]

Re: 1986 Blazer 8.5 Gov Lock Posi options
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: x Baldwin Motion</div><div class="ubbcode-body">Try some lock to lock figure eights in reverse to free it up after checking fluid.
*that's right out of the GM service manual [img]<<GRAEMLIN_URL>>/scholar.gif[/img] </div></div>

LOL, Do not think that with help. I did say <span style="font-weight: bold"><span style="text-decoration: underline">'LOTS of little shinny metal pieces'</span></span>

The posi has just enough left to make it bind. But most is in the bottom of the housing.

Greg