Can anyone tell me what year is the cutoff between the 26 and 28 spline axles?Also, are the bearing diameters the same on the carriers, so that an older 26 spline axle can be upgraded to a 28 spline? what kind of problems am I going to encounter to accomplish this swap?
Thanks.....................................................................................
OLDRED88

 

!. Very few 89 f cars have 28 splines. 90-92 have 28 splines
2. 28 spline axel can bet used in a 26 spline houseing as long as you have a 28 spline carier.
3. I just did a swap on my 86 saturday. I swap in 3.23 gears, an Slp take out posi, And 28 spline axel. I didn't encounter any problems. Make sure you cangte your axel seals while you have the axels out!!!

 

9bolt rear ends came with 28 spline axles in 89 for the F-Bodies. Im not sure if that is the same for the 88 and older.

 

i HAVE A 10 BOLT 28 SLINE IN MY 86 Transam, It originally came with 3:42, non-posi, 305 with a 5-speed manual.

My gears started to hum so I had a 2000 rear end off of a wrecked Ram-Air, I couldn't use the axles since the rear end is 1 1/2 iches to 2 inches wider than my original axle, so I tried to keep the posi off of the Ram-Air (or limited slip) and put it in my original rear end and the unit bolted up with no problem but when I put my original axles from my 3rd gen into the 4th gen carrier it just turned in the carrier. Now I could be wrong, but I think that the splines on that 4th gen carrier were either 31 splines or i had a 26spline and the carrier was a 28spline. Anyways, any of the 3rd gen'rs out there want to know, I succesfully used just the Ring and Pinion gear off of a 4th gen to a 3rd gen carrier and it worked perfect. After shimming my rear end it works perfect, I still get to run my mid 12's without a problem.
just one more thing.....
The ring gear and the Traction control ring are one unit so I dont think this would work for a 9 bolt rear.

thanks,
Eric....

 

hmm, i was under the impression that from 82-89, 26 Spline shafts were used, and from 90-92, 28 Splines were used...am i wrong? This is a common question that comes up and its still elusive to me.

 

That is correct, 89 is the transition year to 28 spline axles, kinda like the swap to a 30 spline input shaft on the 700r4's in 84 and the aux valve bodies and 10 vane pumps in 87. With these mid-late year production changes, it's a grey area as to whether or not your car came with the new components. GM liked to toss an extra wrench into things for that "wow" affect, changing components mid year run.

Only way to indentify your parts is to either read up, or get dirty...

 

Here are the hollinder part numbers for third gen axles

447-1301 82-87 F-body w/disc brakes 10 bold cover GM22515440 26 spline 30 5/16" long
447-1302 82-89 F-body w/drum brakes 10 bolt cover GM22515441 26 spline 30 5/16" long
447-1407R 87-90 Camaro, 85-91 Firebird w/disc brakes 9 bolt cover 28 spline
447-1605L 87-90 Camaro, 85-91 Firebird w/disc brakes 9 bolt cover 28 spline
447-1776 90-92 F-body w/disc brakes 10 bolt cover GM26034018 28 spline 30 5/16" long
447-1777 90-92 F-body w/drum brakes 10 bolt cover GM26031251 28 spline 30 5/16" long

The spicer numbers for the Dana 44 - bill of material number 605218-1, -2, & -3 (listed in the Spicer book as a 1984-85 F-Car)
72384-1X 29.54" long 1.31" x 30 spline
72384-2X 30.50" long 1.31" x 30 spline

 

my 88 came with 28 spline

 

yeah i got 28 spline axles in my 84 t/a

but i put them there

 

My 89 came with 26's, but I put in 28's when I went to 3.23's with a torsen diffy.

 

I know this thread is old, but the search doesn't pull up exactly what I'm wondering; hopefully someone can help me understand. I'm helping my son build his car, its a 90 RS with 305 TBI. We're wanting to switch it to dics in the rear, so I looked at the 4th gen rear end route and then went to Hawks and saw that they sell basically every rear end setup there, 3rd and 4th gen. I see that the 89 would be $550 and a 90 would be $1000, what am I missing? When I searched part numbers for u-joints an 89 and a 90 are the same part number, couldn't I just buy the $550 with disc brakes change out the u-joint and go back together with the 26 spline from an 89? Or is it easier/cheaper to do it different? Or am I just completely thinking about this wrong?

 

The reason is the 89 disc rear they list is a 9 bolt. Completely different rear than the 10 bolt 90 disc rear.The 10 bolt from 90-92 had the 28 spline and the good PBR calipers. The 9 bolt is harder to find parts for and the axles and carriers are different. Unless you want to run factory 15" wheels or factory offset without them sticking out just get a 98-02 4th gen rear.

 

What year Camaro axels did you use or did you have to order new ones? If so can you help me out with the link ?

I have a 87 and came across a torsen zexel