I've been working on the 69 GS400 today, and thought I'd try to find some kind of stamping on the rear differential tube, since there is no tag. Couldn't find anything so I counted wheel revolution to drive shaft. I got 1.5 turns of the drive shaft to 1 run of the wheel (with no tire on it). That doesn't seem right. I was wondering if this is even the original 8.2 that came with it factory. Here are some pictures if anyone can help ID it. I have to fix a rear seal leak and want to make sure of what I'm up against here... Thanks!
When you rotated it did both wheels turn in the same direction. If they did you have a posi, if not it's a one legger. Based on your numbers I would bet on a one legger. The stampongs will be on the bottom side of the tube on the drivers side. Steel wool should clean it up so you can read it.
Fred - its definitely a 1 legger. Thanks for the tip on where to look. Looks like it says LD... or maybe LB, as the L is taller than the D. Or LP?
Looks like a buick 8.2.....with it being a non posi you have a a close to 3:1 ratio.....the spider gears effect you this way
Thanks guys.... that would make sense given what Ben stated. I was secretly hoping someone had replaced the 8.2 with an 8.5.
LB for sure That is a 1968 - 1970 8.25 Buick only rear big 1.875 pinion bearing Big driver side carrier bearing rear 28 spline bolt in axles
That is the rear that has special parts for everything. We do make a 2.73 and 2.93 posi for that rear. we also have a 3.23 3.42 posi also BUT we are all waiting for Fab craft 3.42 3.64 gears that fit this carrier.
Thank you Jim! Can you use the 2.73/2.93 posi for the 3.42 gear with a spacer or is it the other way around? So far, I'm OK with the 2.93 gear, but wouldn't mind future planning for the 3.42 gear if I upgrade to the posi.
Jim is correct. You need a real thin spacer. The inner diameter and bolt pattern of the ring gear is the same as the 71-up 8.5” 10-bolt. You can use one of those spacers IF you can find someone to mill it. I wanted a few of them a few years back. The 8.5” spacers are .200” thick,and I wanted them .100” thick. I then began searching for a machine shop that had a magnetic table that could hold it properly. I ended up sending two of them to a shop in Indiana. They did one perfectly. The other one moved,and it’s not flat,but they told me before they sent it back. I was able to use the one,and it worked perfect. It moved the ring gear enough to keep the carrier centered in the housing,and by being thin,it also left plenty of ring gear journal exposed on the carrier for the ring gear to press onto and keep everything deflecting under load. This exact situation is why the 12-bolt Chevy fails with the spacer. The spacer takes up the whole journal on the carrier,which leaves the ring gear floating out in space. It has nothing to keep it true,so it deflects and actually tries to spin on the carrier until the bolts fail and it all comes unwound. IF the ring gear journal was wider on those carriers,you would not have that problem. Sorry for the side rant. On another note,I called FabCraft earlier in the week to check on gears. I guess there has been thought about just making one ratio,a 3:55,but who knows if that will come to fruition. That would require all new design and tooling,starting from scratch,especially since there never was a 3:55 for the 68-70 Buick 8.2”. No cheap date. I looked into this very thing about 5 years ago,and it would have cost a minimum of $10k to get that project off the ground. Everything is already there to continue to produce the 3:42 and 3:64. Hopefully they make something again.
Wow Brian, thanks for all of the info on that spacer. I think I'll probably just stick with the 2.93s and get the correct posi for those, for a while. For now, I'm just gonna fix the pinion seal and reseal the cover.
