In the new Feb 2000 issue on page 42, there is a good article about 10bolt rears. Any tidbit of info that can be absorbed is always good. If nothing else, there is a good comparison of a regular and an axle saver bearing.
Just a quick, long note on axle saver bearings:
Had an F150 in the shop the other day that someone had attempted installing an axle saver bearing into. He said some guy that worked out of his garage did the work. He was not a mechanic by trade. Anyway, apparently when he pounded the saver bearing in, he knocked the snap ring loose inside that holds the rollers in place. (I've had that happen to me on occasion, but always re-install the snap ring. Those can be a pain to get into the tube sometimes.) Anyway, this one wasn't fixed and the owner drove it for about 300 miles before he had it towed to my shop. Needless to say, the axle and bearing were trashed as the rollers all went down the axle tube since nothing held them in place. The axle wore the tube out also, there was no way to put another bearing or seal in. It cost this guy about $1000 for another used housing, installation, etc.
Now, believe me, I am all for using axle saver bearings, but this post is a caution to all to be sure of what you are doing when installing these, or be certain that whoever is installing them knows what they are doing.
Please don't read this post and come to the conclusion that axle saver bearings are no good. They are excellent if installed properly.
This article was good. It even basically said my rear was junk. Not MY rear, but the car's rear. I have the 8.2 10 bolt posi with 3.07 gears. I was looking at getting a 12 bolt posi or 8.5 10 bolt posi. What's the next smallest size under 3.73 for 12 bolt posi? I need some freeway friendly gears, but want that "Kick my butt!" action when it hooks up.
Just got in the mail yesterday.
I like the poster. 64 Pro touring with a 502.
That is what I'm taking about.
It is a similar set up I want to do with a 70 Wagon. ZZ502, 700r4 with lock up convertor and a FAB 9 with 3.73s.
70 396SS El Camino #'s Matching.
69 396SS Chevelle, project "Street Bruiser"
H-D Ultra Classic E-Glide
72 Chevy C20 Flatbed, $500 DRMO sale. Thanks Uncle Sam
I live to own toyz...
Now might be a good time to come out and admit that I paid someone to install the axel saver bearings in my Chevelle just before I put it away this fall. A friend of mine said he had heard of guys "screwing them up" on installation. I called around town and got all different responses from service shops about putting them in. Some guys I talked to didn't even know what I was talking about!?!?! I am not originally from Green Bay where I live now, so I don't really know all the "right" places to take stuff since I usually do everything myself, or know guys that can help me through a job. On the advice of another friend I tried a small Shell service station fairly close to home. The owner owns several old Chevys and is partial to Vettes. Most of his guys at the shop are into old cars. They said they had installed axel saver bearings thousands of times, since they do a lot of work on older cars that people fix up. This is the first time I had ever taken any of my old cars in and paid to have mechanical repairs done. My 72 is about the nicest old car I've owned, and with the new motor and all, I was nervous, but these guys were great. Even had them throw on a new set of brake shoes while they had it all apart (gear oil on the old ones). Very happy with the job they did, and would take my car back there anytime. I guess I share this because anyone that knows me knows that I will bite off more do-it-yourself jobs than most people, but even I realize that sometimes you are better off having a pro do some jobs.
I don't know what tranny you have but I posted a similar question about 3 months ago. Based upon those replies, talks with Richmond Gear and pro's in the car field I've decided to keep my 12 bolt posi 3:07's and am going with the Richmond 4+1 5 speed manual.
While 5th gear is 1:1 (not overdrive) the first gear gives you a seat of the pants feel of a Muncie Rock-Crusher with 4:22's. Go to the tech archives and you'l find some formulas on computing RPM's and MPH with different rear end and tranny combinations, as well as a way to compare different "launch" combinations.
I'm still in the building phase but others here have done this and reported this to be correct.
If your rear is basically good, go through it as a maintenance precaution and invest in the 5 speed tranny. (Unless of course you have a strict factory resto going on. Hope this helps
1970 Chevelle SS Convertible
1937 Master Business Coupe
1996 S-10 Blazer
After removing the old bearing and seal, thoroughly clean the area. I like to VERY lightly oil the area where the bearing goes. Some people like to use sealer, I see no need. To drive it in, be sure it is in the hole straight. I like to use a hard piece of wood and a heavy hammer to drive it in. When it is in all the way, it will stick out a little (1/8-1/4in).
Remember that the scoring on the old axle will act as a beautiful stress riser, and will lead to cracking if you run enough power through it. A wounded axle is still a wounded axle, even if you are using axle saver bearings.
The only tip for installation I know of is to be sure the rubber lip of the seal does not fold over when you slide the axle in.
Did anyone notice in that article that there were a couple of mistakes?
They state the ring gear dia. of a 12 bolt is 8.375......NOT!
Also they state that ALL 8.5 ten bolts use 28 spline axles.......NOT!
If you find an 8.5 posi out of an 88, or 89+ chevy full size pickup, you'd better count the axle splines B4 shelling out $$$ because it most likely will be a 30 spline unit. Also, I've determined that the worst thing Chevy did was go to the 30 spline axles in the full size pickups & Suburbans. I had 4 of these this last week with the left (ring gear side) carrier bearing spun on the carrier. One was completely snapped off the carrier. These were all open diffs, and we stock the open carriers just for this reason. If going to a posi in a 30 spline vehicle, get the Eaton posi with the larger carrier journals and special carrier bearings, it's worth the extra money.
The reason these factory 30 spline units are weak, is this:
To allow for the larger axle diameter, chevy made the internal part of the journal wider, but left the outer diameter the same, resulting in a thinner bearing journal. This thinner journal allows the inner race of the bearing to spin on the journal after many miles of use. This bearing should be a press fit. When this happens, the only cure is a new carrier, and if it's a posi it means more $$. I have only seen this on the 30 spline units, not the older 28 spline ones.
Sorry for the windy message, but thought people sould know.
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