pinion nut overtightened???
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
18-25 inch pounds of turning torque of the assembly, not the nut. you need a beam type torque wrench and you turn the diff with the wrench while watching the gauge on the wrench. should be between 18-25 inch pounds of force to spin everything. i dont remember if thats pinion only or pinion and ring gear.
Melting Slicks
Joined: Jun 2006
Posts: 2,071
Likes: 147
From: S Nevada
To change the crush sleeve you have to disassemble the differential. Get a 4 ft bar with a socket for the pinion nut, and a tool to hold the pinion yoke. Torque the nut so that the pinion requires 18-25 in. Lbs of force to turn. This pre loads the pinion bearing by crushing the sleeve just enough. This step you kind of sneak up on. Torque and check. Go too far and put a new crush sleeve on. Are you sure you went too far?
Last edited by Sunstroked; May 22, 2014 at 10:45 PM.
Melting Slicks
Joined: Jun 2006
Posts: 2,071
Likes: 147
From: S Nevada
Also if you do happen to decide to install a new crush sleeve, beg borrow or rent a dial indicator type inch pound torque wrench. Snap-on makes a really nice one. Too expensive to buy for a one time use.
Last edited by Sunstroked; May 22, 2014 at 10:56 PM.
Thread Starter
Advanced
Joined: Sep 2009
Posts: 75
Likes: 0
From: Fairfax Virginia
Didn't find a inch lbs torque wrench for sale near me, and my boss had a digital Snap On one but it's minimum inch lbs reading is 60.
I ordered a new crush sleeve and seal. And will tackle next week when items arrive. Might just buy one of those wrenches too, they go for around $50. Just don't see any possible use for it in the future.
I ordered a new crush sleeve and seal. And will tackle next week when items arrive. Might just buy one of those wrenches too, they go for around $50. Just don't see any possible use for it in the future.
Melting Slicks
Joined: Jun 2006
Posts: 2,071
Likes: 147
From: S Nevada
That's the problem. Unless you are planning on doing a lot of differential rebuilds, or you do a lot of repairs which require the use of a small inch lb torque wrench, the need for one hardly justifies the expense. I can tell you this from personal experience. About the maximum torque you can apply to a screw with a common screw driver is 25-30 in lbs. now that's not grunting with 2 hands, but 1 hand tightening to a point where it's real snug. In my trade we use the small click style 0-150 in lb torque wrenches frequently.. When I rebuilt my differential I had access to the dial in lb torque wrench. Also a 3/4" drive 4ft torque wrench. I just took my diff into work and did it there. Had the press to press on the pinion bearing, I built a tool to hold the pinion yoke, and the torque wrenches. Talking with a local differential shop where I bought my bearing kit from I'd say I was a lot more **** with attention to detail than they commonly use.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Advanced
Joined: Sep 2009
Posts: 75
Likes: 0
From: Fairfax Virginia
I can have an experienced mechanic that I trust install the new crush sleeve and seal for just about nothing at my work. Would it make sense to have him do it instead of me getting tools?
Melting Slicks
Joined: Jun 2006
Posts: 2,071
Likes: 147
From: S Nevada
Yes, unless you feel like you want to learn how. You really do have to disassemble the differential to change the sleeve. You'll need to pull the side yokes, the posi unit, making sure you record the shims on each side. That's why I asked if you are sure that you over torqued the crush sleeve.
If you do decide to change it out, this is a great time to disassemble the posi unit and examine the clutches. I did a complete overhaul, changing ring and pinion, new posi clutches, and all new bearings and seals. I did a lot of reading, and research. Rear end works great.
If you do decide to change it out, this is a great time to disassemble the posi unit and examine the clutches. I did a complete overhaul, changing ring and pinion, new posi clutches, and all new bearings and seals. I did a lot of reading, and research. Rear end works great.
Thread Starter
Advanced
Joined: Sep 2009
Posts: 75
Likes: 0
From: Fairfax Virginia
Yes, unless you feel like you want to learn how. You really do have to disassemble the differential to change the sleeve. You'll need to pull the side yokes, the posi unit, making sure you record the shims on each side. That's why I asked if you are sure that you over torqued the crush sleeve.
If you do decide to change it out, this is a great time to disassemble the posi unit and examine the clutches. I did a complete overhaul, changing ring and pinion, new posi clutches, and all new bearings and seals. I did a lot of reading, and research. Rear end works great.
If you do decide to change it out, this is a great time to disassemble the posi unit and examine the clutches. I did a complete overhaul, changing ring and pinion, new posi clutches, and all new bearings and seals. I did a lot of reading, and research. Rear end works great.
I will post some photos of the diff before and after a bit later. Huge difference after it was all painted. I also tapped a drain hole in the bottom.
Melting Slicks
Joined: Aug 2012
Posts: 3,487
Likes: 83
From: Titusville Florida
I do not want to disassemble the diff and later find out I messed something up after I have the entire car assembled. I am going to trust the mechanic to do it for me.
I will post some photos of the diff before and after a bit later. Huge difference after it was all painted. I also tapped a drain hole in the bottom.
I will post some photos of the diff before and after a bit later. Huge difference after it was all painted. I also tapped a drain hole in the bottom.
5th Gear
Joined: Feb 2013
Posts: 5
Likes: 0
From: norwood ma
Me, too, on over-tightening...
3/4 turn is alot unless the bearings were very worn, I usually go 1/8 to 1/4 past depending on what feels right. You cant go backwards and if you did go too far a new crush sleeve is the only alternative but truthfully, if you can turn the pinion by hand w/o too much effort you should be OK.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
The reference to the 18-25 in/lb is for the rotating torque of the pinion gear alone. This value is tested without the case assembly bolted to the housing. It's purpose is to test the drag on the pinion bearings. The low value is for used bearings. The high for new bearings. And it's done with a torque meter or, as a last resort, a beam wrench and without the front seal in the housing. It would be very difficult to impossible to accurately set bearing clearance with such a low setting on a clicker wrench. He probably did hit and go well beyond the value but couldn't hear the click. You're probably closer to 150 in/lb when turning the pinion in a fully assembled carrier.
Melting Slicks
Joined: May 2009
Posts: 3,079
Likes: 315
2024 C3 of the Year Finalist - Unmodified
When I had my diff rebuilt I took it to a mechanic and let them do the whole job, first I haven't a clue what I'm doing setting up gears and second this car was at the time 37 years old and I just didn't want to deal with rusted bolts stripping the head and all the other possible headaches. It cost me a good chunk of change but I slept better
Me too, plus mine needed more parts than just bearings and seals. I would not want to remove and replace the pumpkin a second time, laying on my back on the garage floor. That is one heck of a lot of work. The same guy (Machine Shop Bob) rebuilt my M-21 and centered my bell housing after the engine was rebuilt, flywheel re-surfaced and new clutch installed. Sometimes discretion is the better part of valor.