Chevy & GMC Vans

Just wondering if anyone knows the spline counts on the 10 bolt rear ends on the astros and safaris. I am sure the early ones are low like 16 or something but I need to know if any year has a read end with a 28 spline axle.
Thanks,
Jim

If you are asking about the splines on the axles I believe the vans used two sizes over the years. The early models had 26 and the later had 28. Don't ask when the 28 spline started though. I know the 90 and up I have owned had 28. Can't remember if it had anything to do with the carrier. There were two ring sizes. 7.5 and 7.625 and carriers for low ratios and higher ratios.

Cool, that answers my question. Is there anywhere online I could find specs on the rearends? What I really need is one with a posi but I don't know if they made them in astros with one. It would make sense with the awd models but I am not sure.

Yeah-the G80 code is a posi in a Astro.AWD's have to have matched ratios front and back.Didn't see if your's is a AWD.

GEJ wrote:Yeah-the G80 code is a posi in a Astro.AWD's have to have matched ratios front and back.Didn't see if your's is a AWD.

No, mine is just a 2wd. I have some gears and a posi out of a 4th gen f-body which is why I was asking about the axle spline count. But if I could find a rearend with a posi, that would be fine for now too. With the new engine, I am really tired of spinning one tire.

The G80 code I speak of is the build code sometimes found in the glove box.Sorry I don't know the yr range and where the codes are located given the yr of the van.On my 1985-it's on the drivers door and on my 1994 LT it's in the glove box.

With my 89, the build codes are also in the glove box. It does have 3.23 gears in it (gu5) but not the posi.

The G80 is a Eaton gov lock posi and the camaro would most likely be the Auburn limited slip. I would use the Auburn if for a toy V8 van. The G80 is meant for low speed lockup. Like pulling a trailer out of the water, snow, etc.

1985 to 1989 Astro and Safari vans had a 26 spline 7.5" 10 bolt. 1990 on are 28 spline 7.625" 10 bolts. The carriers and gears are interchangeable as long as the carrier breaks are recognized. The break is 3.08/3.23. The posi unit you are looking at must be the 7.5/7.625" 10 bolt and not the 8.5" 10 bolt.

LiftedAWDAstro wrote:1985 to 1989 Astro and Safari vans had a 26 spline 7.5" 10 bolt. 1990 on are 28 spline 7.625" 10 bolts. The carriers and gears are interchangeable as long as the carrier breaks are recognized. The break is 3.08/3.23. The posi unit you are looking at must be the 7.5/7.625" 10 bolt and not the 8.5" 10 bolt.

Yes, that would be correct. Not the 8.5".