My 1989 V6 firebird with the stock non locking (3:45 I think ?) rear end has a bent right rear axle . I want to buy two , one for the left and right , I would me most appreciative if one of the forum's in the know members could steer me to to right parts ? Are there different axles for each side or are they both the same ? And does the V6 have 26 or 28 splines ?

I really appreciate any help the forum can give me

 

'89 seems to be the transitional year for 26/28 spline axles. You would be best off pulling one and checking before you order.

 

Hi Wildcard , I was just informed the rearend is out of a 1986 , so if I'm lucky they are 26 splines . I see different lengths available , 30 5/16 or a shorter one 29 3/16 , do you know why different lengths are available and are they both the same or is there a specific left and right ?

Sorry for all the questions but I want to get this right

 

If the rear is out of a 86 car, and still all stock, the correct axles are the 30.3125" 26 spline. The 2 sides are the same. The other length is for some other vehicle; A / G body, or possibly S trucks, would be my guess. But might have been B body.

All 7½" 10-bolts had 26 spline axles, up until some point in the 89 production run, when they started to switch over to 28. In ALL vehicle product lines. Some 90 production still got 26 but not many. I suspect it was one of those deals where they had built up the subassemblies (rear ends) in some plant, with the expiring design, and continued to draw down stock until exhausted. Probably some combinations of options - disc brakes, posi, etc. - changed over sooner as they were depleted, and others later; but I lack the data to confirm this. Just my familiarity with mass production techniques.

DO NOT buy 26 spline axles!!! If you simply MUST have axles, now is the time to upgrade the carrier to 28 spline, and buy those instead.

If your rear is a 10-bolt you don't have 3.45 gears. That's a 9-bolt ratio. The corresponding 10-bolt ratio is 3.42. But of course when you're changing the fluid, you'll identify that part for sure.

 

Thank You Sofa for the response !

I really appreciate the info you gave me , I have ordered the axles , axle bearings , and seals . While I understand the 26 VS 28 splines thing , I want you to know that this is a 6 cylinder daily driver that will never (in my ownership) receive any power upgrades , so since I don't think the 6 banger is strong enough to break the splines with an old guy (me) daily driving it , and since I don't want to mess with replacing the carrier , the 26 spline will be fine for me . It's kinda funny , I've owned this car for years and it always wobbled in the back at highway speeds , and I just now finally figured out why .