Rear Differential Gear Swap
 

I'm planning to swap out my stock 3.45 gears for a 3.91 and have a question. Does the stock differential carrier work with any gear set? I'm hoping to avoid replacing my stock posi carrier.

Thanks.

Re: Rear Differential Gear Swap
 

From when I researched this some time back, I believe once you go past 3.73, a larger carrier is required.


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Re: Rear Differential Gear Swap
 

Next clutch change, I will move to Viper 4.10 set.


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Re: Rear Differential Gear Swap
 

Yes, you are good to go to change to lower gear ratios with our Dana 44 HD rear. You can do more research, but here is an example
of gear ratios available. It is the Dana 36 in base model autos that have limitations.

https://www.corvettepartsonline.net/...-ring-pinions/

Re: Rear Differential Gear Swap
 

You should be fine. I went from 3.45 to 3.90. Yukon brand pinion and gear and there was no issue.

Re: Rear Differential Gear Swap
 

Has anyone ever produced a step by step guide or, even better, video on how to swap gears on a Dana?

Re: Rear Differential Gear Swap
 

Factory Service Manual is what I use. It shows pinion preload using shims. Most modern replacement gears sets now use crush sleeves for pinion preload. Plenty of videos on YouTube showing crush sleeve pinion preload setups.


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Re: Rear Differential Gear Swap
 

Hey Prof Phil,
I remember you helped me out with the list of parts to rebuilt and do 4.10s in my 90Z many many moons ago. I took the assembly out to a machine shop back then to have a pro do the work. I am almost tempted to try this myself, but aren?t some special tool needed? I?ll see if I can find a shop here in Japan and did check out some YouTube videos. Thanks.

Re: Rear Differential Gear Swap
 

Yes, several special tools are required. Case spreader, set bearings, inch pound torque wrench, 300 lb torque wrench, dial indicator, precision calipers, heavy duty snap ring pliers, pry bars, drifts, pinion bearing removal tool, differential case bearing removal tool, pinion depth setup tool, pinion bearing outer race install tool, side shaft bearing install tool, pinion and side shaft seal installation tools.
All are mentioned in the FSM write up. Most of these were made by Kent-Moore back in the day. FSM lists the KM part numbers. I picked up most by scouring eBay over a couple of years and made the rest in my shop.


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Re: Rear Differential Gear Swap
 

I was lucky back then due GM shutting down a lot of the weaker Chevrolet dealerships. Tool liquidators came in and bought up up a lot of dealerships special tool inventory and many of them ended up on eBay.


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