I'm working on beefing up my own diff right now....


Diff reinforcement build

 

That is what puddy dad does. it is all machined to perfect clearanes. That helps protect against bearing cap failure ut will not help the pinion gear failure for that he machines a steel sleeve to replace the crush washer. after a lot of pounding from hard launches the crushes more and creates slop between the gears. it takes time but he does a nice job. for that extra protection he cryoes everything.

 

Edited previous post.....

Nothing BUT positive things to say.

Sorry guys.

 

You are exactly right! If you don't boost up your can or do clutch drops your stock rearend should be fine. I have seen probably 30 blown rearends and the two culprits are the LSD caps and the pinion gear.

I would only reinforce or strengthen if I wanted to change gears or broke a rearend and needed to replace it.

The reinforced caps similar to the comptech help with the bearing caps breaking but I have still seen several with the caps broken off flush with the housing and the bolt still holding it together. I took a rearend to a group of metallurgist I work with in Safety Harbor and they were not please with the quality of metallurgy. Like it was mentioned Proper cryogenic processing can help by restructuring the crystalline structure of the metal, increasing the tensile strength, and redistributing the fine carbide particles.

Puddy Dad spends a long time measuring the gear lash and building custom solid sleeves to help prevent eventual slop between the ring and pinion gear which helps tear up the teeth on the pinion gear.

Here is a list of what I would do to the rearend in order.

1. For only 350 hp, keep it stock and don't drop the clutch or hit the gears hard.
2. Cryo the gears and housing.
3. Add Comptech style reinforcements to 00-03 rearends.
4. Get solid sleeve installed.
5. Puddy Custom rearend or and In-line Pro setup, but you still should rebuild the 300zx rear since most have over 100 k on them.

i hope this helps.

 

i went to a near by dragstrip not to long ago with my neovas on like 20 lb's lol it was fun, my third time i launched at about 7500 spun then wheel hop, then stuck really hard!!!

it was fun and fast but i wont be doing that again any time soon. i cant believe it didnt break.

 

A Stage 2 for N/A and low boosted cars,
Total rebuild from the housing in starting with every part being cryogenically thermo cycled, then all new bearings and seals used to assemble. A one piece PuddyMod solid steel sleeve used instead of an OEM crush collar. The solid sleeve is made of 10/20 mandrel steel, it is seamless and will not compress under heavy stress like the OEM can. Solid sleeves are used in high performance drag racing rear ends because they work. Set the stock bearing caps with new 10.9 flange head screws to hold the caps in place. Polish the gears for less friction and smooth operation. Set the Backlash for a tighter gear to gear fit. Balance the assembly to run a thousands or better true. The OEM LSD is fine to use but, if you wheel bounce the car it can break.
This is my Stage 2 rear diff I run in my car, it has a 4.3 gear ratio
The PM solid steel sleeve is on the right the OEM crush sleeve is on the left. The PM sleeve allows for better oil flow as well


Balanced assembly with 3 to 3.5 thousands backlash 10.9 x 60 mm flange head screws


AP2 Stage 2 with 4.77 none polished gears


Stage 2 4.57 R after polishing


Hope this helps

 

You can probably expect to hear from me this summer sometime per building another diff for me when I get my turbo setup.

 

Can you Cryo treat the half shafts? I have broken 5 half shafts and only 1 diff. Now that i have an upgraded Diff im still worried about the half shafts.