I ordered a 28 spline posi unit for my 1989 iroc by mistake instead of the 26 spline unit. The axles do need replacing also, so I was wondering if I can use 28 spline axles instead of the 26 spline? Is the number of splines the only difference? I would hate to have to try to return the posi unit, as it was purchased online. I would rather just buy the 28 spline axles if I can. I have tried to contact the company I purchased the posi unit from to find out about this numerous times, but they do not respond to my messages. Thanks in advance for any help you can provide.

American Muscle Rules,
Nick Peters

 

As long as you have a 28 spline posi then yes you can install 28 spline axles.

Factory 28 spline axles can be found in 1990-1992 third gens only. Aftermarket axles from places like www.tomsdifferentials.com are around $125 each and will be much better than factory axles. Fourth gen axles are also 28 spline but they're also longer and won't fit into a third gen diff.

28 spline axles are a slightly larger diameter than 26 spline so they're stronger.

 

Thanks, that's what I was hoping.

 

http://store.summitracing.com/partde...SAG%2DEV10%2D4

Best ones I know of; plus, they come with bearings, seals, & lugs (no extra $50 of incidentals required)